Why The Hell... (random rant)

[EridanMan]

Are VOR's all MH based?

I was flightplanning the other day (I must be one of the few poor
souls left who flight-plans by hand... I guess I just haven't been
flying long enough to get sick of it yet, I consider my flight
planning to be 'part of the experience') And I got to thinking-

Why in gods name are VOR's Mag heading based?

I know, ideally, that means that you can sync your DG and your VOR
indicator to fly to a waypoint... except that most VOR's around here
have long since fallen behind Magnetic drift... so - now, not only do
you have to flightplan in True Heading, convert to Mag Heading to get
your vectors, THEN you have to get the corrective factor for each of
the VOR's your using for navigation and note that as well? huh?

I'm sorry... call me lazy, but if your not going to keep them all
updated with Magnetic north, then at least stick them on a standard
baseline... True North, for example?

/rantoff.

[Mxsmanic]

EridanMan writes:

> I'm sorry... call me lazy, but if your not going to keep them all
> updated with Magnetic north, then at least stick them on a standard
> baseline... True North, for example?

I think aviation should have started moving towards true north for everything
long ago, but that's just me. The constant shifting of the magnetic poles
(which is accelerating) means perpetual updates for anything that depends on
magnetic north (and you can't use magnetic south, because it isn't even
exactly opposite magnetic north).

--
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[[email protected]]

In rec.aviation.piloting EridanMan > wrote:
> Are VOR's all MH based?

> I was flightplanning the other day (I must be one of the few poor
> souls left who flight-plans by hand... I guess I just haven't been
> flying long enough to get sick of it yet, I consider my flight
> planning to be 'part of the experience') And I got to thinking-

> Why in gods name are VOR's Mag heading based?

You got a true north compass in your airplane?

> I know, ideally, that means that you can sync your DG and your VOR
> indicator to fly to a waypoint... except that most VOR's around here
> have long since fallen behind Magnetic drift... so - now, not only do
> you have to flightplan in True Heading, convert to Mag Heading to get
> your vectors, THEN you have to get the corrective factor for each of
> the VOR's your using for navigation and note that as well? huh?

Center the needle and keep it centered?

> I'm sorry... call me lazy, but if your not going to keep them all
> updated with Magnetic north, then at least stick them on a standard
> baseline... True North, for example?

If the drift is sufficient ( 2 or 3 degrees, I forget the number; it's
in the AIM ) they are supposed to be recalibrated.

The uncertainty in the wind drift angle is usually a lot more than
that.

There are lots of free flight planners that do all that for you.

Golden Eagle for DUATS corrects for everything but your compass
error and is free.

--
Jim Pennino

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[TheSmokingGnu]

EridanMan wrote:
> Are VOR's all MH based?

Because all of the pilot's navigational faculties are magnetic, too.

> most VOR's around here
> have long since fallen behind Magnetic drift...

By how much, and where is "here", if you don't mind my asking?

> you have to flightplan in True Heading, convert to Mag Heading to get
> your vectors, THEN you have to get the corrective factor for each of
> the VOR's your using for navigation and note that as well? huh?

But why do that if the winds you get in a preflight are already in MH?
Wouldn't it be simpler to calc your MH's, and then use the corrective
factors you need to find the "real" radial you should follow?

TheSmokingGnu

PS: Don't worry, I still do things by hand, too.

[TheSmokingGnu]

wrote:
> If the drift is sufficient ( 2 or 3 degrees, I forget the number; it's
> in the AIM ) they are supposed to be recalibrated.

FAR 91.171, VOR Equipment checks.

4 degree variation if using a VOT or other ground-based testing
sites/equipment.

6 degrees if using a designated airborne test point, or using a dead
reckoning technique.

No more than 4 degrees variation between the radios of a dual VOR setup.

Nothing about the accuracy of the VOR station itself, though. If they're
really bad, I would file a report with the nearest FSDO.

TheSmokingGnu

[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> EridanMan writes:

> > I'm sorry... call me lazy, but if your not going to keep them all
> > updated with Magnetic north, then at least stick them on a standard
> > baseline... True North, for example?

> I think aviation should have started moving towards true north for everything
> long ago, but that's just me. The constant shifting of the magnetic poles
> (which is accelerating) means perpetual updates for anything that depends on
> magnetic north (and you can't use magnetic south, because it isn't even
> exactly opposite magnetic north).

Where do you get a true north compass?

Your comment about magnetic south being unusable is just asinine.

--
Jim Pennino

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[[email protected]]

In rec.aviation.piloting TheSmokingGnu > wrote:
> EridanMan wrote:
> > Are VOR's all MH based?

> Because all of the pilot's navigational faculties are magnetic, too.

> > most VOR's around here
> > have long since fallen behind Magnetic drift...

> By how much, and where is "here", if you don't mind my asking?

> > you have to flightplan in True Heading, convert to Mag Heading to get
> > your vectors, THEN you have to get the corrective factor for each of
> > the VOR's your using for navigation and note that as well? huh?

> But why do that if the winds you get in a preflight are already in MH?
> Wouldn't it be simpler to calc your MH's, and then use the corrective
> factors you need to find the "real" radial you should follow?

> TheSmokingGnu

> PS: Don't worry, I still do things by hand, too.

The radial to follow doesn't change with the wind, only your heading.

If you are following a VOR radial, you can ignore wind altogether
and just point the nose in whatever direction keeps the needle
centered.

--
Jim Pennino

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[Robert M. Gary]

On Apr 3, 8:33 pm, "EridanMan" > wrote:
> Are VOR's all MH based?
>
> I was flightplanning the other day (I must be one of the few poor
> souls left who flight-plans by hand... I guess I just haven't been
> flying long enough to get sick of it yet, I consider my flight
> planning to be 'part of the experience') And I got to thinking-
>
> Why in gods name are VOR's Mag heading based?
>
> I know, ideally, that means that you can sync your DG and your VOR
> indicator to fly to a waypoint... except that most VOR's around here
> have long since fallen behind Magnetic drift... so - now, not only do
> you have to flightplan in True Heading, convert to Mag Heading to get
> your vectors, THEN you have to get the corrective factor for each of
> the VOR's your using for navigation and note that as well? huh?
>
> I'm sorry... call me lazy, but if your not going to keep them all
> updated with Magnetic north, then at least stick them on a standard
> baseline... True North, for example?
>
> /rantoff.

My compass is MH.

-Robert

[[email protected]]

In rec.aviation.piloting TheSmokingGnu > wrote:
> wrote:
> > If the drift is sufficient ( 2 or 3 degrees, I forget the number; it's
> > in the AIM ) they are supposed to be recalibrated.

> FAR 91.171, VOR Equipment checks.

> 4 degree variation if using a VOT or other ground-based testing
> sites/equipment.

> 6 degrees if using a designated airborne test point, or using a dead
> reckoning technique.

> No more than 4 degrees variation between the radios of a dual VOR setup.

> Nothing about the accuracy of the VOR station itself, though. If they're
> really bad, I would file a report with the nearest FSDO.

> TheSmokingGnu

I thought I saw somewhere in there a spec for the VOR station drift.

Maybe it was somewhere else; so many regs, circulars, advisory letters,
so little time...

I know there are limits somewhere.

--
Jim Pennino

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[TheSmokingGnu]

wrote:
> In rec.aviation.piloting TheSmokingGnu > wrote:
>> But why do that if the winds you get in a preflight are already in MH?
>> Wouldn't it be simpler to calc your MH's, and then use the corrective
>> factors you need to find the "real" radial you should follow?
> The radial to follow doesn't change with the wind, only your heading.

I know.

1. Find your MH (where you'll be pointing said nose initially)
2. Find the radials you want to use (charted, +/- the correction factor)
3. Tune radials, point nose.
4. Salt and pepper to taste.

TheSmokingGnu

[Tauno Voipio]

EridanMan wrote:
> Are VOR's all MH based?
>
> I was flightplanning the other day (I must be one of the few poor
> souls left who flight-plans by hand... I guess I just haven't been
> flying long enough to get sick of it yet, I consider my flight
> planning to be 'part of the experience') And I got to thinking-
>
> Why in gods name are VOR's Mag heading based?

It's a nuisance for maintenance, but it frees
the pilot from calculating the variation at
the operative time. Just to off-load the pilot.

> I know, ideally, that means that you can sync your DG and your VOR
> indicator to fly to a waypoint... except that most VOR's around here
> have long since fallen behind Magnetic drift... so - now, not only do
> you have to flightplan in True Heading, convert to Mag Heading to get
> your vectors, THEN you have to get the corrective factor for each of
> the VOR's your using for navigation and note that as well? huh?

If they are off the mag variation, it is
mis-maintenance, and the VOR should be
marked defective or taken off-line.

--

Tauno Voipio, avionics engineer, CPL(A)
tauno voipio (at) iki fi

[Mxsmanic]

writes:

> Where do you get a true north compass?

Aviation uses magnetic compasses less and less, and every other navigation
method works best with true north.

> Your comment about magnetic south being unusable is just asinine.

Magnetic south isn't exactly the opposite of magnetic north on the Earth's
surface, so if one entity uses it, all must use it, or make constant
corrections to convert between the two. In fact, the failure of the line
between the poles to pass through the center of the planet introduces
additional complications into precise use of a compass. Not to mention the
many other factors that get in the way.

Early navigators used it because they had nothing better. Today there are
lots of things that are better.

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[Mxsmanic]

writes:

> You got a true north compass in your airplane?

Both GPS and inertial navigation platforms can easily determine true north.
In fact, they work with true north, and must apply an unpredictable conversion
factor to true north to get current and local magnetic north.

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[Mxsmanic]

TheSmokingGnu writes:

> Nothing about the accuracy of the VOR station itself, though.

1-1-3 (1): Accuracy of better than 1 degree.

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[Mxsmanic]

Tauno Voipio writes:

> If they are off the mag variation, it is
> mis-maintenance, and the VOR should be
> marked defective or taken off-line.

Be careful what you wish for.

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[Ron Natalie]

EridanMan wrote:
> Are VOR's all MH based?
>
So that they line up with the compass. All in-flight
navigation is magnetic based.

[Ron Natalie]

Mxsmanic wrote:
> EridanMan writes:
>
>> I'm sorry... call me lazy, but if your not going to keep them all
>> updated with Magnetic north, then at least stick them on a standard
>> baseline... True North, for example?
>
> I think aviation should have started moving towards true north for everything
> long ago, but that's just me. The constant shifting of the magnetic poles
> (which is accelerating) means perpetual updates for anything that depends on
> magnetic north (and you can't use magnetic south, because it isn't even
> exactly opposite magnetic north).
>

Because we don't have a TRUE NORTH indicator in the cockit. Just
a magnetic compass and instruments derived from it. Real flying
ain't a stupid-assed computer simulation.

[Ron Natalie]

Mxsmanic wrote:

> Magnetic south isn't exactly the opposite of magnetic north on the Earth's
> surface,

No you are confused. Magnetic SOUTH is the exact opposite of magentic
north you fool. The fact that the MAGNETIC SOUTH POLE is not exactly
opposite the MAGNETIC NORTH POLE is a different issue. The fact that
the poles aren't aligned with the arbitrary "true" datum just means that
the variation equations aren't as simple as they might be. This is why
we just resort to looking it up on a chart.
>
> Early navigators used it because they had nothing better. Today there are
> lots of things that are better.
>
Really, like what? Compasses are still damned reliable compared to
anything else. Cheap too. The only thing that presumes to do better
perhaps is GPS. And it's easier to program that to deal with the
magnetic measurements than to try to force everybody else the other
way.

[Steven P. McNicoll]

"EridanMan" > wrote in message
oups.com...
>
> Why in gods name are VOR's Mag heading based?
>

Tradition.

[Ron Natalie]

wrote:

>
> If the drift is sufficient ( 2 or 3 degrees, I forget the number; it's
> in the AIM ) they are supposed to be recalibrated.
>
> The uncertainty in the wind drift angle is usually a lot more than
> that.
>
Huh? What does the wind have to do with VOR's. If the needle is
centered, you're within the tolerance of the VOR. The tolerance
is primarily 4-6 degrees. This keeps you inside the airway at
moderate distances from the VORs.

[Kev]

On Apr 4, 2:32 am, Tauno Voipio > wrote:
> EridanMan wrote:
> > Why in gods name are VOR's Mag heading based?
>
> It's a nuisance for maintenance, but it frees
> the pilot from calculating the variation at
> the operative time. Just to off-load the pilot.

A good answer. Same for winds in flight, etc. Everything is based on
the magnetic to make it easier for the pilot. At least, the pilot of
old. If we had 100% reliable aids in the plane, then I suppose you
could argue for just following the red line on the electronic map, and
never even know what course you're taking ;-)

> > I know, ideally, that means that you can sync your DG and your VOR
> > indicator to fly to a waypoint... except that most VOR's around here
> > have long since fallen behind Magnetic drift... so - now, not only do
> > you have to flightplan in True Heading, convert to Mag Heading to get
> > your vectors, THEN you have to get the corrective factor for each of
> > the VOR's your using for navigation and note that as well? huh?
>
> If they are off the mag variation, it is
> mis-maintenance, and the VOR should be
> marked defective or taken off-line.

VORs are allowed to get +/- 6 degrees off. Seems a lot, but it's
only a handful of miles off-course over most VORs' ranges. Anyway,
see:

http://www.naco.faa.gov/index.asp?xml=naco/faq#q2h

Kev

[[email protected]]

Acturally, it's a fairly good question. The answer is tradition.
When the only real navaid one had was a mag compass, it made sense to
reference everything to mag north and accept the need for correcting
for variation. But there was an exception - when navigating in the
polar regions, mag headings are useless, so grid was invented - which
overlaid an arbitrary grid on the map and navigation was done by
setting the DG to the arbitrary grid "north". Works just fine. Now
with GPS and INS, the only reason for converting all headings to mag
is tradition. It really would make more sense to use true headings,
and save the variation drill for emergencies (which navigation purely
via whiskey compass is, usually!).

I personally trust my two independent GPS's as much as my mag
compass. If GPS goes down, or my electrics and batteries all fail,
then it really wouldn't be a huge problem to take up an initial
approximate heading on a mag compass, look up the local variation, and
apply it.

Would be simple to have DGs slaved to true north automatically, given
a GPS or Inertial platform. And if you are flying "retro", then you
could always do the math in reverse!

Maybe in the future...(yeah, along with FM hi-fi comm radios, too)

Kirk

[Steven P. McNicoll]

"Tauno Voipio" > wrote in message
...
>
> It's a nuisance for maintenance, but it frees
> the pilot from calculating the variation at
> the operative time. Just to off-load the pilot.
>

That would be true if VORs were set to local magnetic variation. They
rarely are.


>
> If they are off the mag variation, it is
> mis-maintenance, and the VOR should be
> marked defective or taken off-line.
>

That doesn't happen until they differ by 6 degrees with local variation.

[Steven P. McNicoll]

"Kev" > wrote in message
ups.com...
>
> VORs are allowed to get +/- 6 degrees off. Seems a lot, but it's
> only a handful of miles off-course over most VORs' ranges. Anyway,
> see:
>
> http://www.naco.faa.gov/index.asp?xml=naco/faq#q2h
>

"The magnetic variation of the earth changes at a rate of 50.27 seconds of
arc per year." That seems a bit low to me. At that rate six degrees of
change would take 430 years.

[Steven P. McNicoll]

"Ron Natalie" > wrote in message
m...
>
> So that they line up with the compass. All in-flight
> navigation is magnetic based.
>

But VOR radials rarely line up with the compass. Most haven't been adjusted
for changes in local magnetic variation in decades.

[Steven P. McNicoll]

"Ron Natalie" > wrote in message
m...
>
> Huh? What does the wind have to do with VOR's. If the needle is
> centered, you're within the tolerance of the VOR. The tolerance
> is primarily 4-6 degrees. This keeps you inside the airway at
> moderate distances from the VORs.
>

What about at more than moderate distances from the VOR? At 40 miles from
the VOR 6 degrees is 4 miles.

[Peter Dohm]

>
> I personally trust my two independent GPS's as much as my mag
> compass. If GPS goes down, or my electrics and batteries all fail,
> then it really wouldn't be a huge problem to take up an initial
> approximate heading on a mag compass, look up the local variation, and
> apply it.
>
> Would be simple to have DGs slaved to true north automatically, given
> a GPS or Inertial platform. And if you are flying "retro", then you
> could always do the math in reverse!
>
> Maybe in the future...(yeah, along with FM hi-fi comm radios, too)
>
> Kirk
>
Some of you guys are a *lot* more trusting than I am. I was really hoping
for some of the current airmen to say this, but most have only nibbled
around the edges--so here goes:

The magnetic compass has exactly one thing in its favor, and that is just
plain old Brute Reliability.

It requires no power from the aircraft's systems, it is not subject to
happenstance or whim concerning any transmitting stations, and wide spread
interference with (the) signal is unimaginable.

Learn to love it, because it is here to stay!

Peter

[EridanMan]

On Apr 4, 5:23 am, "Steven P. McNicoll" >
wrote:
> "EridanMan" > wrote in message
>
> oups.com...
>
>
>
> > Why in gods name are VOR's Mag heading based?
>
> Tradition.

Best answer I've heard yet;)

[EridanMan]

What I'm not 100% convinced of is the necessity of keeping the VOR's
aligned with your compass. A compass is a perfectly valid
navigational tool with or without VOR alignment, and all of our
aircraft have compass cards in them anyways for coverting between
Magnetic and True headings.

Seems to me using the same conversion factor for Magnetic Heading to
VOR Radial as we do for Magnetic Heading to True is no more
complicated (and in fact less so) then worrying about particular
magnetic offsets for each station?

Either way its pretty much a moot point - because yes - we fly to keep
the needle centered, period. Again then - why go to the expense and
trouble of re-aligning all the VOR's and re-numbering the Victor
airways every few years? Just align everything true-north and don't
touch it again?

Note - this was a semi-inebriated, pedantic rant, I just thought it
might stimulate some good discussion;)

[EridanMan]

> If you are following a VOR radial, you can ignore wind altogether
> and just point the nose in whatever direction keeps the needle
> centered.

Of course:), this would work regardless of what the VOR was centered
on, why not just center it on true north and not worry about having to
update it (and all the Victor numbering) every few years?

[Mxsmanic]

Ron Natalie writes:

> No you are confused. Magnetic SOUTH is the exact opposite of magentic
> north you fool. The fact that the MAGNETIC SOUTH POLE is not exactly
> opposite the MAGNETIC NORTH POLE is a different issue.

I assumed that others would understand this, but I often get into trouble when
I assume others will understand things.

> The fact that
> the poles aren't aligned with the arbitrary "true" datum just means that
> the variation equations aren't as simple as they might be.

They are more than just misaligned: they are not at opposite points in terms
of longitude and latitude, either. A line drawn between them does not
intersect the center of the Earth.

> Really, like what?

GPS and inertial reference platforms, VORs, NDBs, you name it.

> Compasses are still damned reliable compared to
> anything else. Cheap too. The only thing that presumes to do better
> perhaps is GPS. And it's easier to program that to deal with the
> magnetic measurements than to try to force everybody else the other
> way.

So how often do you fly using just your magnetic compass alone?

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[Mxsmanic]

Ron Natalie writes:

> Because we don't have a TRUE NORTH indicator in the cockit.

You do if you have systems like GPS or INS.

> Just a magnetic compass and instruments derived from it. Real flying
> ain't a stupid-assed computer simulation.

Maybe you should take a tranquilizer; you seem very upset.

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[Kev]

On Apr 4, 9:06 am, "Kev" > wrote:
> On Apr 4, 2:32 am, Tauno Voipio > wrote:
> > It's a nuisance for maintenance, but it frees
> > the pilot from calculating the variation at
> > the operative time. Just to off-load the pilot.
>
> A good answer. Same for winds in flight, etc. Everything is based on
> the magnetic to make it easier for the pilot. [..]

Oops! I can't believe I wrote that about winds in flight. Of course
they're true, so they can be used over a wider area. Winds at the
_airport_ are magnetic, is what I meant to say... so the pilot doesn't
have to convert while landing.

Hmm. So if we switched to true North navigation, then runways would
all need repainting... but at least they and the VORs wouldn't have to
be changed ever again ;-) Seems like something the government would
come up with to save money!

Kev

[Mxsmanic]

writes:

> Would be simple to have DGs slaved to true north automatically, given
> a GPS or Inertial platform.

This is switch-selectable in some aircraft, I think because true north is much
easier to deal with when flying over long routes without navaid coverage
during which latitudes and longitudes must be dealt with directly (e.g.,
transatlantic flights).

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[Don Tuite]

On Wed, 04 Apr 2007 16:28:41 GMT, "Steven P. McNicoll"
> wrote:

>
>"Ron Natalie" > wrote in message
m...
>>
>> Huh? What does the wind have to do with VOR's. If the needle is
>> centered, you're within the tolerance of the VOR. The tolerance
>> is primarily 4-6 degrees. This keeps you inside the airway at
>> moderate distances from the VORs.
>>
>
>What about at more than moderate distances from the VOR? At 40 miles from
>the VOR 6 degrees is 4 miles.

Under the heading of "Enquiring Minds Want to Know:

In defining an intersection, what's the maximum distance from a VOR
that's allowed?

Does an intersection in a GPS database represent the actual
intersection of VOR radials, or is it defined in LAT/LON terms?
(I.e., can there be two locations for an intersection, depending on
whether you're using VORs or GPS?

Apart from shifting declination, what is the mechanism by which VORs
drift out of calibration? Isn't the phase shift for each antenna in
the array set by the length of coax between it and the transmitter?
Does Velocity Factor change significantly as the coax ages? If it is a
matter of aging cable, does that mean the error is uniform and the
pattern is shifted consistently around the compass rose, or are the
longer cables affected more? And in the latter case, how would that
affect the error? (I would think that the higher the radial, the
greater the error, if this were the case.)

(Or do I not understand how a VOR array is phased?)

Don

[Mxsmanic]

Steven P. McNicoll writes:

> "The magnetic variation of the earth changes at a rate of 50.27 seconds of
> arc per year." That seems a bit low to me. At that rate six degrees of
> change would take 430 years.

It changes at a variable rate, and once it approaches a degree, charts and
navaids have to change. It's a tremendous amount of extra work, an additional
source of error, and an imprecise and fickle basis for navigation.

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[Mxsmanic]

Steven P. McNicoll writes:

> That would be true if VORs were set to local magnetic variation. They
> rarely are.

Which variation are they set to, and how useful can they be if their
orientation doesn't match the local magnetic variation?

> That doesn't happen until they differ by 6 degrees with local variation.

Where did you get this figure?

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[Mxsmanic]

Ron Natalie writes:

> So that they line up with the compass. All in-flight
> navigation is magnetic based.

Some transoceanic flights might disagree.

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[[email protected]]

> Some of you guys are a *lot* more trusting than I am. I was really hoping
> for some of the current airmen to say this, but most have only nibbled
> around the edges--so here goes:
>
> The magnetic compass has exactly one thing in its favor, and that is just
> plain old Brute Reliability.
>
> It requires no power from the aircraft's systems, it is not subject to
> happenstance or whim concerning any transmitting stations, and wide spread
> interference with (the) signal is unimaginable.
>
> Learn to love it, because it is here to stay!
>
> Peter

Well, Peter, in 40 some years and 5000 some hours in everything from
no-electric system gliders to modern jet fighters, I've never had to
resort to only a whiskey compass to navigate. Sure I cross check it,
but I view it as an emergency system. And I've actually seen more
inoperative whiskey compasses than other bits of more complicated
navigation equipment.

If you are worried about system failure, then carry a handheld backup
GPS and radio. About the same cost as a good mag compass, by the way
- but will tell you where you are, or let you ask someone where you
are if the GPS gods take a nap. All that mag compass will tell you is
which way you are kinda going.

Anyone out there who (honestly) uses only his mag compass as his
primary navigation equipment, let's hear from you. And using the
whiskey compass to set the DG doesn't count - we're talking navigation
by charted heading and mag compass. Tried rolling out on and holding
an accurate heading using only your whiskey compass lately? Fun,
isn't it...That's why they invented the DG.

Don't have a fancy nav system that figures out true north? Gee, apply
local variation to your mag heading and presto, true north! Easy to
set a DG to true that way.

Bottom line, if the mag compass was demoted to emergency heading
reference, we could accept the mag var problem and use true heading
for day to day use. Heck, most whiskey compasses swing as much as the
local variation inflight, anyway!

But as has been stated; inertia, old habits, and existing equipment
all work against moving to the use of True instead of Magnetic.

Kirk

[Mxsmanic]

Peter Dohm writes:

> Some of you guys are a *lot* more trusting than I am. I was really hoping
> for some of the current airmen to say this, but most have only nibbled
> around the edges--so here goes:
>
> The magnetic compass has exactly one thing in its favor, and that is just
> plain old Brute Reliability.
>
> It requires no power from the aircraft's systems, it is not subject to
> happenstance or whim concerning any transmitting stations, and wide spread
> interference with (the) signal is unimaginable.

It's already so inaccurate without interference that that's bad enough. There
are plenty of spots on charts where the compass will be 6-8 degrees off even
from the already irrgular declination over larger areas.

Anyway, if you push this concept to its limit, you should be able to complete
a trip without an engine, since engines are not 100% reliable. Obviously,
that's not a practical reality, and at some point you have to recognize that a
compass alone, no matter how reliable in the sense of always working to some
extent, may simply not be enough to get you home.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mark Hansen]

On 04/04/07 10:40, EridanMan wrote:
> What I'm not 100% convinced of is the necessity of keeping the VOR's
> aligned with your compass. A compass is a perfectly valid
> navigational tool with or without VOR alignment, and all of our
> aircraft have compass cards in them anyways for coverting between
> Magnetic and True headings.

It's true that all the airplanes in which I've flown have had
compass cards, but that's not what they do. They provide the
deviation for the compass at various headings, which are due to
magnetic fields within the aircraft.

>
> Seems to me using the same conversion factor for Magnetic Heading to
> VOR Radial as we do for Magnetic Heading to True is no more
> complicated (and in fact less so) then worrying about particular
> magnetic offsets for each station?
>
> Either way its pretty much a moot point - because yes - we fly to keep
> the needle centered, period. Again then - why go to the expense and
> trouble of re-aligning all the VOR's and re-numbering the Victor
> airways every few years? Just align everything true-north and don't
> touch it again?
>
> Note - this was a semi-inebriated, pedantic rant, I just thought it
> might stimulate some good discussion;)
>
>



--
Mark Hansen, PP-ASEL, Instrument Airplane, USUA Ultralight Pilot
Cal Aggie Flying Farmers
Sacramento, CA

[Steven P. McNicoll]

> wrote in message
oups.com...
>
> Anyone out there who (honestly) uses only his mag compass as his
> primary navigation equipment, let's hear from you. And using the
> whiskey compass to set the DG doesn't count - we're talking navigation
> by charted heading and mag compass. Tried rolling out on and holding
> an accurate heading using only your whiskey compass lately? Fun,
> isn't it...That's why they invented the DG.
>

I use my magnetic compass as my primary navigation equipment. But only
because it's my only navigation equipment.

[Maxwell]

"Mxsmanic" > wrote in message
...
> Peter Dohm writes:
>
>> Some of you guys are a *lot* more trusting than I am. I was really
>> hoping
>> for some of the current airmen to say this, but most have only nibbled
>> around the edges--so here goes:
>>
>> The magnetic compass has exactly one thing in its favor, and that is just
>> plain old Brute Reliability.
>>
>> It requires no power from the aircraft's systems, it is not subject to
>> happenstance or whim concerning any transmitting stations, and wide
>> spread
>> interference with (the) signal is unimaginable.
>
> It's already so inaccurate without interference that that's bad enough.
> There
> are plenty of spots on charts where the compass will be 6-8 degrees off
> even
> from the already irrgular declination over larger areas.
>
> Anyway, if you push this concept to its limit, you should be able to
> complete
> a trip without an engine, since engines are not 100% reliable. Obviously,
> that's not a practical reality, and at some point you have to recognize
> that a
> compass alone, no matter how reliable in the sense of always working to
> some
> extent, may simply not be enough to get you home.
>

What did you have for dinner last night, Welsh Rarebit????

[Mxsmanic]

Maxwell writes:

> What did you have for dinner last night, Welsh Rarebit????

My point is that you have to strike a balance between assuming all equipment
will work perfectly and depending on that, and assuming that all equipment
will fail and trying to plan for that. In reality, chances are that all
equipment will work; and the chances of equipment failing diminish rapidly as
the number of simultaneous failures increases.

It's true that a compass always works--more or less, since compasses are so
finicky even when they are "working"--but I'm not sure that this is really
much of a practical help if nothing else works. All a compass can do is tell
you your direction of flight in a very approximate way. That isn't much use
for getting where you want to go. Charts help a lot, but you need more than a
compass to find out where you are on the chart, and if you don't know where
you are on a chart, a compass won't help.

Early ships navigated using a compass as one important instrument, but a
compass along was never good enough. It wasn't enough four hundred years ago,
and it's not enough now. If all you have is a compass, you're in deep
trouble.

You're actually better off with an accurate watch and a way to shoot the
stars. But even that is more of a theoretical method than a practical method
these days.

When people talk about how this old method or that old method is reliable,
they tend to forget how many people died in the days when these "reliable"
methods were the only ones available.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Steven P. McNicoll]

"Don Tuite" > wrote in message
...
>
> Under the heading of "Enquiring Minds Want to Know:
>
> In defining an intersection, what's the maximum distance from a VOR
> that's allowed?
>

I guess the simple answer is 135 miles.

The limiting factor is the minimum divergence angle. The minimum divergence
angle (smaller angle of the two crossing radials) is one degree per NM up to
45 miles, beyond 45 miles it's 1/2 degree per NM. Since the mimimum
divergence can't exceed 90 degrees, the furthest you can get is 135 miles.


>
> Does an intersection in a GPS database represent the actual
> intersection of VOR radials, or is it defined in LAT/LON terms?
> (I.e., can there be two locations for an intersection, depending on
> whether you're using VORs or GPS?
>

There can be many locations for a given fix. For example, a fix identified
by intersecting radials as well as radial/DME from either navaid. The exact
position varies with altitude and which navaid you choose to determinr
position.

[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> writes:

> > Where do you get a true north compass?

> Aviation uses magnetic compasses less and less, and every other navigation
> method works best with true north.

Total, utter, nonsense.

The use of magnetic north versus true north hasn't changed.

A sensor to find true north in an airplane in flight doesn't exist.

> > Your comment about magnetic south being unusable is just asinine.

> Magnetic south isn't exactly the opposite of magnetic north on the Earth's
> surface, so if one entity uses it, all must use it, or make constant
> corrections to convert between the two. In fact, the failure of the line
> between the poles to pass through the center of the planet introduces
> additional complications into precise use of a compass. Not to mention the
> many other factors that get in the way.

More babbling nonsense.

The isogonic lines on a chart take care of all the problems of where
the actual north/south magnetic poles are.

As for constant corrections, the time period for corrections is measured
in years.

> Early navigators used it because they had nothing better. Today there are
> lots of things that are better.

Wrong again, bucko, there is nothing better for finding north in an
airplane in flight.

The only way to find magnetic north is a magnetic compass.

The only ways to find true north are celestial navigation and a true
gyro compass.

You can't use celestial navigation unless you have a clear sky, an
almanac, a precise clock, and the necessary instruments to measure
celestial angles and the training to be able to use it all.

You can't use a true gyro compass because they can take hours to
settle to a usefull reading, are enormous and heavy, and don't
work unless you are moving very slowly, i.e. at the speed of a
ship. They do not work if moving at airplane speeds and they
don't work without power.

GPS could be used to indirectly find either type of north, but it
doesn't work without power, which is an important concideration
when flying a real airplane without a pause button.

Inertial navigation requires an initial set up against something
else, constant updating measured in minutes, and again, power.


--
Jim Pennino

Remove .spam.sux to reply.

[[email protected]]

In rec.aviation.piloting EridanMan > wrote:
> What I'm not 100% convinced of is the necessity of keeping the VOR's
> aligned with your compass. A compass is a perfectly valid
> navigational tool with or without VOR alignment, and all of our
> aircraft have compass cards in them anyways for coverting between
> Magnetic and True headings.

Umm, no, the compass card corrects for installation error in the
compass reading.

Isogonic lines on charts gives you the local difference between
true and magnetic north.

> Seems to me using the same conversion factor for Magnetic Heading to
> VOR Radial as we do for Magnetic Heading to True is no more
> complicated (and in fact less so) then worrying about particular
> magnetic offsets for each station?

Any inacurracy in VOR radial alignment with magnetic north will
be more than swamped out by the ambiguity in the winds aloft
forcast.

> Either way its pretty much a moot point - because yes - we fly to keep
> the needle centered, period. Again then - why go to the expense and
> trouble of re-aligning all the VOR's and re-numbering the Victor
> airways every few years? Just align everything true-north and don't
> touch it again?

Exactly.

> Note - this was a semi-inebriated, pedantic rant, I just thought it
> might stimulate some good discussion;)



--
Jim Pennino

Remove .spam.sux to reply.

[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> Ron Natalie writes:

> > No you are confused. Magnetic SOUTH is the exact opposite of magentic
> > north you fool. The fact that the MAGNETIC SOUTH POLE is not exactly
> > opposite the MAGNETIC NORTH POLE is a different issue.

> I assumed that others would understand this, but I often get into trouble when
> I assume others will understand things.

> > The fact that
> > the poles aren't aligned with the arbitrary "true" datum just means that
> > the variation equations aren't as simple as they might be.

> They are more than just misaligned: they are not at opposite points in terms
> of longitude and latitude, either. A line drawn between them does not
> intersect the center of the Earth.

And it doesn't matter.

> > Really, like what?

> GPS and inertial reference platforms, VORs, NDBs, you name it.

> > Compasses are still damned reliable compared to
> > anything else. Cheap too. The only thing that presumes to do better
> > perhaps is GPS. And it's easier to program that to deal with the
> > magnetic measurements than to try to force everybody else the other
> > way.

> So how often do you fly using just your magnetic compass alone?

For some people, quite often, and for some others, all the time.

You do understand there are real, flying, airplanes with no electrical
system, don't you?

--
Jim Pennino

Remove .spam.sux to reply.

[Jose]

> and all of our
> aircraft have compass cards in them anyways for coverting between
> Magnetic and True headings.

That's not what a compass card is for. The compass card corrects for
errors due to installation (such as the local field of the airplane).
Aeronautical charts have the information needed to convert between
magnetic and true.

Jose
--
Get high on gasoline: fly an airplane.
for Email, make the obvious change in the address.

[[email protected]]

On Apr 4, 2:08 pm, wrote:
> Anyone out there who (honestly) uses only his mag compass as his
> primary navigation equipment, let's hear from you. And using the
> whiskey compass to set the DG doesn't count - we're talking navigation
> by charted heading and mag compass. Tried rolling out on and holding
> an accurate heading using only your whiskey compass lately? Fun,
> isn't it...That's why they invented the DG.

Yes, but we're talking about using magnetic course as the main
navigation theme. Setting the DG from the whiskey is just a part of
that overall theme.

> Bottom line, if the mag compass was demoted to emergency heading
> reference, we could accept the mag var problem and use true heading
> for day to day use. Heck, most whiskey compasses swing as much as the
> local variation inflight, anyway!

The arguments presented in this thread for using True North are
actually starting to override my own sense of historical inertia.
Your comment above is icing on the cake. Very interesting
discussion. Especially since, as you pointed out, it's just a math
problem, not a radical change.

Kev

[Jim Logajan]

"EridanMan" > wrote:
> Note - this was a semi-inebriated, pedantic rant, I just thought it
> might stimulate some good discussion;)

Isn't there a Usenet regulation of 8 hours between drinking and posting?
Or is it 8 hours of drinking before posting?

And frankly I'm shocked, shocked I tell you, to see pedantry on Usenet!

[[email protected]]

On Apr 4, 2:52 pm, Mxsmanic > wrote:
> Early ships navigated using a compass as one important instrument, but a
> compass along was never good enough. It wasn't enough four hundred years ago,
> and it's not enough now. If all you have is a compass, you're in deep
> trouble.

Sorry, I have to mildly disagree as far as flying goes, that you'd
automatically be in "deep trouble". Many pilots use just the
compass / DG for cross-country flying.

For cross-water... an airplane, at a sufficient area altitude, does
not have to worry about running aground. Therefore a simple compass
was "good enough" for winged flight across the Atlantic starting in
1919. which is not "four hundred years" ago.

True, when crossing longer distances towards smaller targets (such as
islands in the Pacific), star sightings were important, or even on
shorter distances with unknown wind, but the compass was still the
main direction finder.

Kev

[Mxsmanic]

writes:

> For some people, quite often, and for some others, all the time.

And for still others, never.

> You do understand there are real, flying, airplanes with no electrical
> system, don't you?

Yes, but none that I'd want to fly, any more than I'd want to cross the
Pacific in a log raft.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[flynrider via AviationKB.com]

Peter Dohm wrote:
>
>The magnetic compass has exactly one thing in its favor, and that is just
>plain old Brute Reliability.
>
I like the mag compass too. While they don't rely on any aircraft systems
to work, there are things that can cause them to be innacurate. The earths
magnetic field varies in strength and isn't all that constant in all
locations (and it's getting worse).

I was reading Lindbergh's book about his transatlantic flight and at one
point, both his whiskey compass and Earth Inductor Compass were just wobbling
around uselessly. Eventually, they both started working again on their own,
but he was guessing at his heading for nearly an hour.

I can relate. I have a video that I took on a cross country flight, of my
mag compass doing rapid 360s. It lasted about 5 min. and there were no
magnetic anomolies listed on the chart in that area. There were also no UFO
sightings reported that day :-))

John Galban=====>N4BQ (PA28-180)

--
Message posted via AviationKB.com
http://www.aviationkb.com/Uwe/Forums.aspx/aviation/200704/1

[Mxsmanic]

writes:

> A sensor to find true north in an airplane in flight doesn't exist.

GPS finds true north. And, just incidentally, you can find true north by
looking at the sky. ANS will do that, and people can do it, too.

> The isogonic lines on a chart take care of all the problems of where
> the actual north/south magnetic poles are.

Documenting them doesn't really eliminate them.

> Wrong again, bucko, there is nothing better for finding north in an
> airplane in flight.

GPS is better, and more accurate, to name just one.

> The only ways to find true north are celestial navigation and a true
> gyro compass.

You can find true north by looking at the sky, or with GPS, or with ANS
(automated looking at the sky), or with an INS. The latter usually has to be
on the ground, although some systems support align-in-motion with a longer
setup time.

> You can't use celestial navigation unless you have a clear sky, an
> almanac, a precise clock, and the necessary instruments to measure
> celestial angles and the training to be able to use it all.

You need a precise clock to do just about any navigation. The need for the
rest is debatable, depending on how resourceful you are.

> GPS could be used to indirectly find either type of north, but it
> doesn't work without power, which is an important concideration
> when flying a real airplane without a pause button.

Unless the airplane is a glider, you have power.

> Inertial navigation requires an initial set up against something
> else, constant updating measured in minutes, and again, power.

One third correct: it requires power, but engines provide power. It doesn't
have to be set up against anything else to find true north. It doesn't need
to be constantly updated; the whole idea is to be fairly autonomous.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

writes:

> Sorry, I have to mildly disagree as far as flying goes, that you'd
> automatically be in "deep trouble". Many pilots use just the
> compass / DG for cross-country flying.

A compass / DG is not just a compass.

You can't do much with just a compass alone. You need a clock, some charts,
other things ... not _just_ a compass.

> Therefore a simple compass
> was "good enough" for winged flight across the Atlantic starting in
> 1919. which is not "four hundred years" ago.

They had more than a simple compass. In particular, they had accurate clocks,
and charts.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Peter Dohm]

> > > It's a nuisance for maintenance, but it frees
> > > the pilot from calculating the variation at
> > > the operative time. Just to off-load the pilot.
> >
> > A good answer. Same for winds in flight, etc. Everything is based on
> > the magnetic to make it easier for the pilot. [..]
>
> Oops! I can't believe I wrote that about winds in flight. Of course
> they're true, so they can be used over a wider area. Winds at the
> _airport_ are magnetic, is what I meant to say... so the pilot doesn't
> have to convert while landing.
>
> Hmm. So if we switched to true North navigation, then runways would
> all need repainting... but at least they and the VORs wouldn't have to
> be changed ever again ;-) Seems like something the government would
> come up with to save money!
>
> Kev
>
I was wondering whether to mention something about the probable long term
causes of drift in variation--and then I finally noticed the smiley.

Thanks :-)))
Peter

[Capt. Geoffrey Thorpe]

"EridanMan" > wrote in message
oups.com...
<...>
> Why in gods name are VOR's Mag heading based?

Because that's how God intended it.

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

[Maxwell]

"Mxsmanic" > wrote in message
...
> Maxwell writes:
>
>> What did you have for dinner last night, Welsh Rarebit????
>
> My point is that you have to strike a balance between assuming all
> equipment
> will work perfectly and depending on that, and assuming that all equipment
> will fail and trying to plan for that. In reality, chances are that all
> equipment will work; and the chances of equipment failing diminish rapidly
> as
> the number of simultaneous failures increases.
>
> It's true that a compass always works--more or less, since compasses are
> so
> finicky even when they are "working"--but I'm not sure that this is really
> much of a practical help if nothing else works. All a compass can do is
> tell
> you your direction of flight in a very approximate way. That isn't much
> use
> for getting where you want to go. Charts help a lot, but you need more
> than a
> compass to find out where you are on the chart, and if you don't know
> where
> you are on a chart, a compass won't help.
>
> Early ships navigated using a compass as one important instrument, but a
> compass along was never good enough. It wasn't enough four hundred years
> ago,
> and it's not enough now. If all you have is a compass, you're in deep
> trouble.
>
> You're actually better off with an accurate watch and a way to shoot the
> stars. But even that is more of a theoretical method than a practical
> method
> these days.
>
> When people talk about how this old method or that old method is reliable,
> they tend to forget how many people died in the days when these "reliable"
> methods were the only ones available.
>

So....ya say ya went back for more.

[Maxwell]

"Mxsmanic" > wrote in message
...
> writes:
>
>> Sorry, I have to mildly disagree as far as flying goes, that you'd
>> automatically be in "deep trouble". Many pilots use just the
>> compass / DG for cross-country flying.
>
> A compass / DG is not just a compass.
>
> You can't do much with just a compass alone. You need a clock, some
> charts,
> other things ... not _just_ a compass.
>
>> Therefore a simple compass
>> was "good enough" for winged flight across the Atlantic starting in
>> 1919. which is not "four hundred years" ago.
>
> They had more than a simple compass. In particular, they had accurate
> clocks,
> and charts.
>

You need to go back to the breast feeding forum, at least you have some
recent and actual experience in the subject......or was it just for
mothers?????

[Tim]

Mxsmanic wrote:
> writes:
>
>
>>A sensor to find true north in an airplane in flight doesn't exist.
>
>
> GPS finds true north. And, just incidentally, you can find true north by
> looking at the sky. ANS will do that, and people can do it, too.
>

Not all planes have GPSes. In fact, most don't. Many of the haldheld
units fail. The failure rate for compasses is quite low. The FAA is
not likely to revise its requorements for a compass any time soon.
Thus, the reliance on magnetic north.

>
>>The isogonic lines on a chart take care of all the problems of where
>>the actual north/south magnetic poles are.
>
>
> Documenting them doesn't really eliminate them.
>
>
>>Wrong again, bucko, there is nothing better for finding north in an
>>airplane in flight.
>
>
> GPS is better, and more accurate, to name just one.

Not really. It is unreliable. Its signals can be disrupted - rendering
them useless. I don;t want my only source of reference taken away at
anyone's whim.

>
>
>>The only ways to find true north are celestial navigation and a true
>>gyro compass.
>
>
> You can find true north by looking at the sky, or with GPS, or with ANS
> (automated looking at the sky), or with an INS. The latter usually has to be
> on the ground, although some systems support align-in-motion with a longer
> setup time.
>

Not likely in most GA planes on most flights. Usually one is busy
flying and has no time for that stuff. Not possible on cloudy days.

>
>>You can't use celestial navigation unless you have a clear sky, an
>>almanac, a precise clock, and the necessary instruments to measure
>>celestial angles and the training to be able to use it all.
>
>
> You need a precise clock to do just about any navigation. The need for the
> rest is debatable, depending on how resourceful you are.
>
>
>>GPS could be used to indirectly find either type of north, but it
>>doesn't work without power, which is an important concideration
>>when flying a real airplane without a pause button.
>
>
> Unless the airplane is a glider, you have power.

Bull****. Can you say piper cub (to name one counter example)
There is no need for electric power in a plane.

>
>
>>Inertial navigation requires an initial set up against something
>>else, constant updating measured in minutes, and again, power.
>
>
> One third correct: it requires power, but engines provide power. It doesn't
> have to be set up against anything else to find true north. It doesn't need
> to be constantly updated; the whole idea is to be fairly autonomous.
>

Not in the real world. On a computer maybe...

compass is still the best, most reliable way to find north. (true or
magnetic)

[Kev]

On Apr 4, 5:57 pm, "flynrider via AviationKB.com" <u32749@uwe> wrote:
> I was reading Lindbergh's book about his transatlantic flight and at one
> point, both his whiskey compass and Earth Inductor Compass were just wobbling
> around uselessly. Eventually, they both started working again on their own,
> but he was guessing at his heading for nearly an hour.
>
> I can relate. I have a video that I took on a cross country flight, of my
> mag compass doing rapid 360s. It lasted about 5 min. and there were no
> magnetic anomolies listed on the chart in that area. There were also no UFO
> sightings reported that day :-))

There are lots of old iron mines around my area, and pilots sometimes
comment about their compasses going screwy for a minute or so
(assuming they noticed at all). The early settlers thought the woods
were haunted at first because of this effect... until they figured out
it meant money ;-)

Kev

[Mxsmanic]

Tim writes:

> Not all planes have GPSes. In fact, most don't.

That depends on what category of aircraft you're looking at.

> Many of the haldheld units fail.

How many? I've never seen one fail, although I'm sure it happens
occasionally. They don't even have any moving parts.

> The failure rate for compasses is quite low.

So is their accuracy, even when they are functioning perfectly.

> Not really. It is unreliable. Its signals can be disrupted - rendering
> them useless.

Magnetic bearings are constantly disrupted, everywhere on Earth.

> I don;t want my only source of reference taken away at
> anyone's whim.

But a compass cannot give you the information that a GPS gives you. It can
hardly tell you anything at all.

> Bull****. Can you say piper cub (to name one counter example)
> There is no need for electric power in a plane.

You have an engine turning. That's power. And it can fail, just like
electrical power.

> Not in the real world. On a computer maybe...

Even in the real world. The purpose of INS is to have a way of navigating
without any external references; it's a very advanced and accurate
implementation of dead reckoning.

> compass is still the best, most reliable way to find north.

It's useless for truth north unless you have a chart _and_ you know where you
are. Even for magnetic north, it can be substantially off. And just knowing
which way is north doesn't help you much, anyway.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Peter Dohm]

> > Anyone out there who (honestly) uses only his mag compass as his
> > primary navigation equipment, let's hear from you. And using the
> > whiskey compass to set the DG doesn't count - we're talking navigation
> > by charted heading and mag compass. Tried rolling out on and holding
> > an accurate heading using only your whiskey compass lately? Fun,
> > isn't it...That's why they invented the DG.
>
> Yes, but we're talking about using magnetic course as the main
> navigation theme. Setting the DG from the whiskey is just a part of
> that overall theme.
>
> > Bottom line, if the mag compass was demoted to emergency heading
> > reference, we could accept the mag var problem and use true heading
> > for day to day use. Heck, most whiskey compasses swing as much as the
> > local variation inflight, anyway!
>
> The arguments presented in this thread for using True North are
> actually starting to override my own sense of historical inertia.
> Your comment above is icing on the cake. Very interesting
> discussion. Especially since, as you pointed out, it's just a math
> problem, not a radical change.
>
> Kev
>
I agree with the first part of your statement, that the whiskey compass is
well suited as the on board reference and cross check for other instruments.
That's actually the point I was trying to make, but I didn't carry the
logical argument far enough.

Hopefully, I will only ever have to use the whiskey compass alone as a
navigation aid for pilotage in VMC. If however, after I resume flying, I am
ever caught in IMC with only a whiskey compass; I hope that I can recall the
advice of one of the instructors here, possibly Mr. Campbell, on an earlier
thread--that the whiskey compass is least unstable when heading or turning
to the south when in the northern hemisphere.

Peter

[Mxsmanic]

Nomen Nescio writes:

> The category that has wings and goes up in the sky.

You mean like a 747-400? It has two GPS receivers, three IRUs, two VORs and
two ADFs. One rarely falls back upon the magnetic compass.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> writes:

> > For some people, quite often, and for some others, all the time.

> And for still others, never.

> > You do understand there are real, flying, airplanes with no electrical
> > system, don't you?

> Yes, but none that I'd want to fly, any more than I'd want to cross the
> Pacific in a log raft.

Since you will never actually fly anything, no one cares what you
want.

--
Jim Pennino

Remove .spam.sux to reply.

[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> writes:

> > A sensor to find true north in an airplane in flight doesn't exist.

> GPS finds true north. And, just incidentally, you can find true north by
> looking at the sky. ANS will do that, and people can do it, too.

Utter nonsense; you have no clue.

> > The isogonic lines on a chart take care of all the problems of where
> > the actual north/south magnetic poles are.

> Documenting them doesn't really eliminate them.

It doesn't matter, you go by the chart.

> > Wrong again, bucko, there is nothing better for finding north in an
> > airplane in flight.

> GPS is better, and more accurate, to name just one.

Utter nonsense; you have no clue.

> > The only ways to find true north are celestial navigation and a true
> > gyro compass.

> You can find true north by looking at the sky, or with GPS, or with ANS
> (automated looking at the sky), or with an INS. The latter usually has to be
> on the ground, although some systems support align-in-motion with a longer
> setup time.

Utter nonsense; you have no clue.

> > You can't use celestial navigation unless you have a clear sky, an
> > almanac, a precise clock, and the necessary instruments to measure
> > celestial angles and the training to be able to use it all.

> You need a precise clock to do just about any navigation. The need for the
> rest is debatable, depending on how resourceful you are.

Utter nonsense; you have no clue.

> > GPS could be used to indirectly find either type of north, but it
> > doesn't work without power, which is an important concideration
> > when flying a real airplane without a pause button.

> Unless the airplane is a glider, you have power.

Utter nonsense; you have no clue.

> > Inertial navigation requires an initial set up against something
> > else, constant updating measured in minutes, and again, power.

> One third correct: it requires power, but engines provide power. It doesn't
> have to be set up against anything else to find true north. It doesn't need
> to be constantly updated; the whole idea is to be fairly autonomous.

Utter nonsense; you have no clue.


--
Jim Pennino

Remove .spam.sux to reply.

[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> writes:

> > You got a true north compass in your airplane?

> Both GPS and inertial navigation platforms can easily determine true north.
> In fact, they work with true north, and must apply an unpredictable conversion
> factor to true north to get current and local magnetic north.

No, they can't.

INS has to be initialized from something known and updated because
gyros in the real world precess.

GPS can tell you which direction you are going, but can not tell you
where the nose of the airplane is pointing.

INS is too big and expensive for GA aircraft.

Not all real airplanes have electrical systems.

--
Jim Pennino

Remove .spam.sux to reply.

[Mxsmanic]

writes:

> It doesn't matter, you go by the chart.

So you need a chart, which means that a compass alone isn't much use.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

writes:

> INS has to be initialized from something known and updated because
> gyros in the real world precess.

No, not for true north. An INS determines true north by sensing the rotation
of the Earth. It doesn't require any data input to do this.

> GPS can tell you which direction you are going, but can not tell you
> where the nose of the airplane is pointing.

If you are moving, it can tell you your ground track. If you have more than
one receiver on different parts of the aircraft, you can also determine which
way the nose is pointing.

> INS is too big and expensive for GA aircraft.

That's one reason why I often like to fly big aircraft.

> Not all real airplanes have electrical systems.

True, and some are powered by rubber bands as well, but there's a lower
threshold below which I don't bother.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[[email protected]]

In rec.aviation.piloting Ron Natalie > wrote:
> wrote:

> >
> > If the drift is sufficient ( 2 or 3 degrees, I forget the number; it's
> > in the AIM ) they are supposed to be recalibrated.
> >
> > The uncertainty in the wind drift angle is usually a lot more than
> > that.
> >
> Huh? What does the wind have to do with VOR's. If the needle is
> centered, you're within the tolerance of the VOR. The tolerance
> is primarily 4-6 degrees. This keeps you inside the airway at
> moderate distances from the VORs.

The uncertainty in the wind correction angle is greater than the
total error in a VOR radial.

So you plan the flight given the winds aloft forcast, crank in a
wind correction angle, and come up with a heading.

The heading you wind up flying to keep the needle centered will
seldom be the heading on your planning sheet.

That's all I'm saying.

--
Jim Pennino

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[Tim]

Mxsmanic wrote:
> Peter Dohm writes:
>
>
>>Some of you guys are a *lot* more trusting than I am. I was really hoping
>>for some of the current airmen to say this, but most have only nibbled
>>around the edges--so here goes:
>>
>>The magnetic compass has exactly one thing in its favor, and that is just
>>plain old Brute Reliability.
>>
>>It requires no power from the aircraft's systems, it is not subject to
>>happenstance or whim concerning any transmitting stations, and wide spread
>>interference with (the) signal is unimaginable.
>
>
> It's already so inaccurate without interference that that's bad enough. There
> are plenty of spots on charts where the compass will be 6-8 degrees off even
> from the already irrgular declination over larger areas.
>
> Anyway, if you push this concept to its limit, you should be able to complete
> a trip without an engine, since engines are not 100% reliable. Obviously,
> that's not a practical reality, and at some point you have to recognize that a
> compass alone, no matter how reliable in the sense of always working to some
> extent, may simply not be enough to get you home.
>


Tell that to Charlie Lindbergh.

[Tim]

Mxsmanic wrote:
> Tim writes:
>
>
>>Not all planes have GPSes. In fact, most don't.
>
>
> That depends on what category of aircraft you're looking at.
>
>
>>Many of the haldheld units fail.
>
>
> How many? I've never seen one fail, although I'm sure it happens
> occasionally. They don't even have any moving parts.
>
>
>>The failure rate for compasses is quite low.
>
>
> So is their accuracy, even when they are functioning perfectly.
>
>
>>Not really. It is unreliable. Its signals can be disrupted - rendering
>>them useless.
>
>
> Magnetic bearings are constantly disrupted, everywhere on Earth.
>
>
>>I don;t want my only source of reference taken away at
>>anyone's whim.
>
>
> But a compass cannot give you the information that a GPS gives you. It can
> hardly tell you anything at all.
>
>
>>Bull****. Can you say piper cub (to name one counter example)
>>There is no need for electric power in a plane.
>
>
> You have an engine turning. That's power. And it can fail, just like
> electrical power.
>
>
>>Not in the real world. On a computer maybe...
>
>
> Even in the real world. The purpose of INS is to have a way of navigating
> without any external references; it's a very advanced and accurate
> implementation of dead reckoning.
>
>
>>compass is still the best, most reliable way to find north.
>
>
> It's useless for truth north unless you have a chart _and_ you know where you
> are. Even for magnetic north, it can be substantially off. And just knowing
> which way is north doesn't help you much, anyway.
>


Tell that to Charlie Lindbergh.

[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> writes:

> > It doesn't matter, you go by the chart.

> So you need a chart, which means that a compass alone isn't much use.

If you want to go to and from true and magnetic, you need a chart to
get the local difference.

If you want to go somewhere in particular, you need a chart to find it.

If all you want to do is go in some particular direction until you
can see a recognizable landmark, all you need is a compass.


--
Jim Pennino

Remove .spam.sux to reply.

[EridanMan]

> GPS finds true north. And, just incidentally, you can find true north by
> looking at the sky. ANS will do that, and people can do it, too.

As an expert in Location based services and GPS, let me assure you
that depending solely on GPS for any form of navigation is a fools
errand that is going to get a lot of people killed one of these
days.

The system is a rube goldberg contraption with an instant-on kill
switch. Wait until someone launches a home-made GPS guided cruise
missile into Washington DC, watch them flick the switch, and see what
happens. Just hope it doesn't happen at night, and you're not in the
air at the time.

> Documenting them doesn't really eliminate them.

It does make you aware of them, which is all you need.

> GPS is better, and more accurate, to name just one.

It also requires constant, very expensive maintenance, a complex
receiver in good working order, and as I mentioned, can be turned off
at the push of a button. None of these are traits you want for you
primary navigation system.

> You can find true north by looking at the sky, or with GPS, or with ANS
> (automated looking at the sky), or with an INS. The latter usually has to be
> on the ground, although some systems support align-in-motion with a longer
> setup time.

The simplest, fastest and most dependable (in VMC) way of finding true
north (or any form of navigation) is simple spatial awareness and
pilotage. A good chart, and a good eye.

> You need a precise clock to do just about any navigation. The need for the
> rest is debatable, depending on how resourceful you are.

Not at all... about the only modern navigation that requires a precise
clock is night over uninhabited terrain or over water.

> Unless the airplane is a glider, you have power.

GPS have batteries, power isn't the issue. The problem (in my
experience) with GPS is that they're _SO_ good that people very
quickly delegate all of their navigational requirements to them,
letting their pilotage, dead reaconing, and other navigational skills
atrophy (in my humble experience at least). This is fine, until the
tremendously complex system finally fails (either intentionally or
otherwise). Either way, its not something I want to bet my life on.

> One third correct: it requires power, but engines provide power. It doesn't
> have to be set up against anything else to find true north. It doesn't need
> to be constantly updated; the whole idea is to be fairly autonomous.

The whole idea of navigation is to know where you are in space at any
given time. Autonomy is irrelevant.

[[email protected]]

On Apr 4, 12:22 pm, "Steven P. McNicoll" >
wrote:
> "Kev" > wrote in message
>
> ups.com...
> > VORs are allowed to get +/- 6 degrees off. [..]
> >http://www.naco.faa.gov/index.asp?xml=naco/faq#q2h
>
> "The magnetic variation of the earth changes at a rate of 50.27secondsof
> arc peryear." That seems a bit low to me. At that rate six degrees of
> change would take 430 years.

Yeah, weird, eh? So I ran across this section of a site explaining
that it's often really a lot faster than that (2-25 years per degree).

http://www.geocities.com/magnetic_declination/#FACTORS

The "Local magnetic anomalies" section mentions the Ramapo area by me.

The "Where were/are/will be the magnetic poles? " talks about the
movement.

And the section about the "reversing Earth" theory is just plain
terrifying :-) (Not just reversal of the poles... but the entire
crust rotating upside down in a matter of days... ouch!!)

Kev

[Jose]

> And the section about the "reversing Earth" theory is just plain
> terrifying :-) (Not just reversal of the poles... but the entire
> crust rotating upside down in a matter of days... ouch!!)

"It must be true - I found it on the internet"

Jose
--
Get high on gasoline: fly an airplane.
for Email, make the obvious change in the address.

[Newps]

EridanMan wrote:


>
> GPS have batteries, power isn't the issue. The problem (in my
> experience) with GPS is that they're _SO_ good that people very
> quickly delegate all of their navigational requirements to them,
> letting their pilotage, dead reaconing, and other navigational skills
> atrophy (in my humble experience at least). This is fine, until the
> tremendously complex system finally fails (either intentionally or
> otherwise). Either way, its not something I want to bet my life on.

The exact, word for word, arguments against VOR, NDB, four course
ranges, colored lights, etc. It goes on and on.

[EridanMan]

On Apr 4, 8:01 pm, Newps > wrote:
> EridanMan wrote:
>
> > GPS have batteries, power isn't the issue. The problem (in my
> > experience) with GPS is that they're _SO_ good that people very
> > quickly delegate all of their navigational requirements to them,
> > letting their pilotage, dead reaconing, and other navigational skills
> > atrophy (in my humble experience at least). This is fine, until the
> > tremendously complex system finally fails (either intentionally or
> > otherwise). Either way, its not something I want to bet my life on.
>
> The exact, word for word, arguments against VOR, NDB, four course
> ranges, colored lights, etc. It goes on and on.

I think I have to give you that point, set and match.

[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> writes:

> > INS has to be initialized from something known and updated because
> > gyros in the real world precess.

> No, not for true north. An INS determines true north by sensing the rotation
> of the Earth. It doesn't require any data input to do this.

You are talking about a gyro compass.

A gyro compass is huge, expensive and heavy.

They can take hours to settle on a usable reading.

They don't work if they are moving much faster than a slow ship, and not
at all at aircraft speeds.

An INS system has to be initialized with it's current position and just
tells you where you have moved relative to the starting position.

Wrap some smarts around it with a built in map and it shows you where
you are.

Since real gyros in the real world precess, you have to update the
calculated position to the true position on a regular basis.

You have no idea what you are talking about.


> > GPS can tell you which direction you are going, but can not tell you
> > where the nose of the airplane is pointing.

> If you are moving, it can tell you your ground track. If you have more than
> one receiver on different parts of the aircraft, you can also determine which
> way the nose is pointing.

Theoretically you could do that, but no such thing is available for GA
aircraft.

> > INS is too big and expensive for GA aircraft.

> That's one reason why I often like to fly big aircraft.

You don't fly anything, ever.

> > Not all real airplanes have electrical systems.

> True, and some are powered by rubber bands as well, but there's a lower
> threshold below which I don't bother.

You don't fly anything. You sit on your ass and watch a computer monitor.

Lots of real airplanes don't have electrical systems.


--
Jim Pennino

Remove .spam.sux to reply.

[Gary[_2_]]

On Apr 4, 10:23 pm, Mxsmanic > wrote:

> That's one reason why I often like to fly big aircraft.

You don't fly big aircraft. You don't flyany aircraft. The closest
you come is playing with an entry-level simulator game.

>there's a lower
> threshold below which I don't bother.

Lower threshold? Playing with MSFS is a first baby step into
aviation--there is nothing lower. And your upper threshold excludes
anything actually capable of flight.

[DR]

Mxsmanic wrote:

>
> There
> are plenty of spots on charts where the compass will be 6-8 degrees off even
> from the already irrgular declination over larger areas.
>

LOL! My BS meter just went off scale! Declination? Lines of magnetic
_variation_ are plotted on VP charts and better than 0.5 degree accuracy
(except at local anomalies which are only noted in nautical charts as
far as I've seen so far). Declination in navigation is actually
something else but I'll let you googgle for it.


Cheers MC

[DR]

wrote:

>
> You do understand there are real, flying, airplanes with no electrical
> system, don't you?
>

Err, no I don't think he does. He plugs his airplane(s) into the wall
and waits for it to boot up.

Cheers

[DR]

Mxsmanic wrote:

>
> GPS finds true north. And, just incidentally, you can find true north by
> looking at the sky.
>

LOL! How do _you_ do that exactly?

Cheers

[[email protected]]

In rec.aviation.piloting Newps > wrote:


> EridanMan wrote:


> >
> > GPS have batteries, power isn't the issue. The problem (in my
> > experience) with GPS is that they're _SO_ good that people very
> > quickly delegate all of their navigational requirements to them,
> > letting their pilotage, dead reaconing, and other navigational skills
> > atrophy (in my humble experience at least). This is fine, until the
> > tremendously complex system finally fails (either intentionally or
> > otherwise). Either way, its not something I want to bet my life on.

> The exact, word for word, arguments against VOR, NDB, four course
> ranges, colored lights, etc. It goes on and on.

But, it is a good arguement for not doing away with all the other
backup systems since GPS can totally go away for a number of reasons.

I don't see much real use for NDB's these days (ignoring for a moment
not everywhere has a GPS approach, but that's just a paper work
problem) with VOR's and GPS available.

If some new, independant, system becomes available, then VOR's become
obsolete and can be turned off like the four course ranges were.

--
Jim Pennino

Remove .spam.sux to reply.

[[email protected]]

In rec.aviation.piloting DR > wrote:
> Mxsmanic wrote:

> >
> > There
> > are plenty of spots on charts where the compass will be 6-8 degrees off even
> > from the already irrgular declination over larger areas.
> >

> LOL! My BS meter just went off scale! Declination? Lines of magnetic
> _variation_ are plotted on VP charts and better than 0.5 degree accuracy
> (except at local anomalies which are only noted in nautical charts as
> far as I've seen so far). Declination in navigation is actually
> something else but I'll let you googgle for it.

I can't think of any local anomaly that is both strong enough and large
enough to be anything other than a transitory "burble" at most to the
compass of an airplane in flight.

--
Jim Pennino

Remove .spam.sux to reply.

[Mxsmanic]

Tim writes:

> Tell that to Charlie Lindbergh.

Charles Lindbergh had not only multiple compasses but charts and a timekeeping
device. He never would have gotten anywhere with just a compass alone.

--
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[Mxsmanic]

writes:

> If you want to go to and from true and magnetic, you need a chart to
> get the local difference.

If you want to do anything, you need more than a compass.

> If all you want to do is go in some particular direction until you
> can see a recognizable landmark, all you need is a compass.

In order to recognize the landmark, you need something more than a compass.

--
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[Mxsmanic]

EridanMan writes:

> The system is a rube goldberg contraption with an instant-on kill
> switch.

There is no instant-on kill switch. It takes quite a bit of time to send
commands to all the satellites.

> Wait until someone launches a home-made GPS guided cruise
> missile into Washington DC, watch them flick the switch, and see what
> happens. Just hope it doesn't happen at night, and you're not in the
> air at the time.

They can't do that any more. It would be a worse disaster to turn it off than
it would be to just let it run, for both military and civilian use.

> It also requires constant, very expensive maintenance, a complex
> receiver in good working order, and as I mentioned, can be turned off
> at the push of a button. None of these are traits you want for you
> primary navigation system.

It cannot be turned off at the push of a button. I'm not aware of any
constant maintenance requirement. Databases have to be updated by a
monopolistic price-gouging private enterprise, but that's a separate issue.

> The simplest, fastest and most dependable (in VMC) way of finding true
> north (or any form of navigation) is simple spatial awareness and
> pilotage. A good chart, and a good eye.

I wouldn't trust those.

--
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[Mxsmanic]

Newps writes:

> The exact, word for word, arguments against VOR, NDB, four course
> ranges, colored lights, etc. It goes on and on.

And correct each time.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

DR writes:

> LOL! How do _you_ do that exactly?

I don't. I know the direction of true north at my location, and I don't go
anywhere else.

--
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[CJ]

"Tim" > wrote in message
...

> Not all planes have GPSes. In fact, most don't. Many of the haldheld
> units fail. \
A bit OT, but I was delivering a sailboat from Ventura to Richmond one
November, and the handheld GPS died in heavy fog under the Golden Gate
Bridge. We replaced batteries, figured out it was not the unit, and
navigated by fog horns to the east bay. Sometimes, you just have to know
how to drive (boat, plane, car). And, you can't _simulate_ the real feeling
when a Golden Gate ferry blows across your port bow assuming (and hoping)
his radar saw you.

-CJ

[Mxsmanic]

writes:

> You are talking about a gyro compass.

No, I'm not.

> A gyro compass is huge, expensive and heavy.

But there is none inside an inertial reference platform. An IRS uses laser
gyros.

> They can take hours to settle on a usable reading.

An IRS can find true north in a few minutes, depending on latitude.

> An INS system has to be initialized with it's current position and just
> tells you where you have moved relative to the starting position.

But it also finds true north on its own, without any need for external data.
It simply detects the rotation of the Earth, and that gives it an east-west
reference, to which true north is perpendicular.

> You have no idea what you are talking about.

Google for it. You'll be surprised.

--
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[Mxsmanic]

writes:

> I can't think of any local anomaly that is both strong enough and large
> enough to be anything other than a transitory "burble" at most to the
> compass of an airplane in flight.

Try flying just outside Reno.

--
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[TheSmokingGnu]

DR wrote:
> LOL! My BS meter just went off scale!

Be careful! Exposure to anything over 3 MX posts/m^2/kg/hr (equivalent
to 4,500 Dumbass/kg/hr) is toxic to brain matter.

> Declination?

Next I suppose he'll start in on rhumb lines. :P

TheSmokingnu

[Mxsmanic]

Jose writes:

> "It must be true - I found it on the internet"

I think you'll find that the more you research about the geomagnetic field,
the less reliable you find it to be for navigation.

--
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[RomeoMike]

DR wrote:
Declination in navigation is actually
> something else but I'll let you googgle for it.
>

I'm not sure that's really true. In aviation we talk about variation,
but when I'm using 7.5' topo maps on the ground, declination is the term
used for the difference
between magnetic and true north. (See the bottom left of a US DOI
Geologic Survey 7.5' topo.)
Variation and declination are defined the same
If there's a more sophisticated use of the word declination in
navigation, I'm willing to be enlightened.

[Morgans[_2_]]

"flynrider via AviationKB. wrote>

> I can relate. I have a video that I took on a cross country flight, of
> my
> mag compass doing rapid 360s. It lasted about 5 min. and there were no
> magnetic anomolies listed on the chart in that area. There were also no
> UFO
> sightings reported that day :-))

Well, nobody else has asked, but I'm sure others (besides me) are thinking
it! ;-)

Well, were you in the "Bermuda Triangle" or not? <g>

Where (about) were you?
--
Jim in NC

[Sylvain]

Mxsmanic wrote:

> In order to recognize the landmark, you need something more than a
> compass.

It is called a chart. If you have a chart and a compass, you are
all set.

--Sylvain

[Bertie the Bunyip]

On Apr 4, 6:05 am, Mxsmanic > wrote:
> EridanMan writes:
> > I'm sorry... call me lazy, but if your not going to keep them all
> > updated with Magnetic north, then at least stick them on a standard
> > baseline... True North, for example?
>
> I think aviation should have started moving towards true north for everything
> long ago, but that's just me.

Bwahahwhawhawhawhawhawhawhawhawhahwawhawhawh

OH BTW doooofus, I'm getting closer and closer. Oh wait, you're not
birght enough to even know what a header eeez.

bertie

[Bertie the Bunyip]

On Apr 4, 7:47 pm, Mxsmanic > wrote:
> Ron Natalie writes:
> > No you are confused. Magnetic SOUTH is the exact opposite of magentic
> > north you fool. The fact that the MAGNETIC SOUTH POLE is not exactly
> > opposite the MAGNETIC NORTH POLE is a different issue.
>
> I assumed that others would understand this, but I often get into trouble when
> I assume others will understand things.
>
> > The fact that
> > the poles aren't aligned with the arbitrary "true" datum just means that
> > the variation equations aren't as simple as they might be.
>
> They are more than just misaligned: they are not at opposite points in terms
> of longitude and latitude, either. A line drawn between them does not
> intersect the center of the Earth.

I do very few flights to the center of the earth: I know that's the
first place you'd head for if someone was dumb enough to trust yuo
with a real airplane; though:: >
> So how often do you fly using just your magnetic compass alone?

Every week, fjukkktard.



Bertie

[Bertie the Bunyip]

On Apr 5, 3:11 am, Mxsmanic > wrote:
> Nomen Nescio writes:
> > The category that has wings and goes up in the sky.
>
> You mean like a 747-400? It has two GPS receivers, three IRUs, two VORs and
> two ADFs. One rarely falls back upon the magnetic compass.


You're obviously not fa,iliar with the limitations of an inertial
system, fjukkwit:

Hell, you're not even familiar with the limitations of the doorknob on
your bedroom door,

Bertei

[Bertie the Bunyip]

On Apr 4, 7:55 pm, Mxsmanic > wrote:
> Ron Natalie writes:
> > So that they line up with the compass. All in-flight
> > navigation is magnetic based.
>
> Some transoceanic flights might disagree.
>

No they wouldn't fjukktyard: We use true only when necessary.

Bertie

[Bertie the Bunyip]

On Apr 5, 7:31 am, Mxsmanic > wrote:
> Jose writes:
> > "It must be true - I found it on the internet"
>
> I think you'll find that the more you research about the geomagnetic field,
> the less reliable you find it to be for navigation.

I think you'd find that if you flew, you'd find that you don't know
**** from shinola:

I've crossed oceans, preGPS and with no inertial systems,; and ended
yup withina few miles, which is the same accuracy as an INS BTW, of my
landfall target:

You; OTOH; sit in your room and jerkooff



Bertie

[Bertie the Bunyip]

On Apr 5, 12:02 am, Mxsmanic > wrote:
> writes:
> > Sorry, I have to mildly disagree as far as flying goes, that you'd
> > automatically be in "deep trouble". Many pilots use just the
> > compass / DG for cross-country flying.
>
> A compass / DG is not just a compass.
>
> You can't do much with just a compass alone. You need a clock, some charts,
> other things ... not _just_ a compass.
>
> > Therefore a simple compass
> > was "good enough" for winged flight across the Atlantic starting in
> > 1919. which is not "four hundred years" ago.
>
> They had more than a simple compass. In particular, they had accurate clocks,
> and charts.

Yeah, nice to have charts of course 'yo look, Alcock, there's a Whale.
I'll just check it against position'


Fjukkkwit:


Bertei

[[email protected]]

On Apr 5, 5:33 pm, RomeoMike > wrote:
> DR wrote:
>
> Declination in navigation is actually
>
> > something else but I'll let you googgle for it.
>
> I'm not sure that's really true. In aviation we talk about variation,
> but when I'm using 7.5' topo maps on the ground, declination is the term
> used for the difference
> between magnetic and true north. (See the bottom left of a US DOI
> Geologic Survey 7.5' topo.)
> Variation and declination are defined the same
> If there's a more sophisticated use of the word declination in
> navigation, I'm willing to be enlightened.

OK, it's celestial Nav. Stars are located by declination (angle from
the celestial equator) and RA. The geographical use of declination to
describe variation is the result of bad education propagating a
specilaized technical term into incorrect use IMHO. As I think about
it, how could a word derived from "decline" be related to horizontal
angle...?

Cheers MC

[[email protected]]

On Apr 5, 5:37 am, "EridanMan" > wrote:
> On Apr 4, 5:23 am, "Steven P. McNicoll" >
> wrote:
>
> > "EridanMan" > wrote in message
>
> oups.com...
>
> > > Why in gods name are VOR's Mag heading based?
>
> > Tradition.
>
> Best answer I've heard yet;)

Isn't the difference between your compass heading and the radial you
are flying the drift? Knowing drift is pretty useful...

Cheers MC

[[email protected]]

On Apr 5, 4:35 pm, wrote:
> In rec.aviation.piloting DR > wrote:
>
> > Mxsmanic wrote:
>
> > > There
> > > are plenty of spots on charts where the compass will be 6-8 degrees off even
> > > from the already irrgular declination over larger areas.
>
> > LOL! My BS meter just went off scale! Declination? Lines of magnetic
> > _variation_ are plotted on VP charts and better than 0.5 degree accuracy
> > (except at local anomalies which are only noted in nautical charts as
> > far as I've seen so far). Declination in navigation is actually
> > something else but I'll let you googgle for it.
>
> I can't think of any local anomaly that is both strong enough and large
> enough to be anything other than a transitory "burble" at most to the
> compass of an airplane in flight.
>

Yes, I agree, that is true of most but some are very big, the biggest
is in Kursk, Russia. If your autopilot is flying a magnetic heading
how fast would it respond if it flew over a common 6 degree anomaly?


Cheers MC

[Ron Natalie]

Mxsmanic wrote:
> Steven P. McNicoll writes:
>
>> That would be true if VORs were set to local magnetic variation. They
>> rarely are.
>
> Which variation are they set to, and how useful can they be if their
> orientation doesn't match the local magnetic variation?

Because some were never right. Some where set right but the local
variation has changed and the VOR's were never realigned. It's
not necessary for them to set exact, just that they are known with
a reasonable precision. The fact that they are close to magnetic
north is again as we've been saying, convenience because all courses
and headings IN FLIGHT are done magnetic.

[Ron Natalie]

Steven P. McNicoll wrote:
> "Ron Natalie" > wrote in message
> m...
>> Huh? What does the wind have to do with VOR's. If the needle is
>> centered, you're within the tolerance of the VOR. The tolerance
>> is primarily 4-6 degrees. This keeps you inside the airway at
>> moderate distances from the VORs.
>>
>
> What about at more than moderate distances from the VOR? At 40 miles from
> the VOR 6 degrees is 4 miles.
>
>
At 51 miles, 4.5 degrees gives you 4 miles. 6 degrees gives you about
6. Theres' 2 miles of protected area outside the airway.
Statistically you're within it, but even in the worst case you're
safe.

[Ron Natalie]

wrote:
> On Apr 5, 5:37 am, "EridanMan" > wrote:
>> On Apr 4, 5:23 am, "Steven P. McNicoll" >
>> wrote:
>>
>>> "EridanMan" > wrote in message
>>> oups.com...
>>>> Why in gods name are VOR's Mag heading based?
>>> Tradition.
>> Best answer I've heard yet;)
>
> Isn't the difference between your compass heading and the radial you
> are flying the drift? Knowing drift is pretty useful...
>
The correction angle maybe. You aren't drifting at all if you are
on the radial.

[Ron Natalie]

Mxsmanic wrote:
> Ron Natalie writes:
>
>> No you are confused. Magnetic SOUTH is the exact opposite of magentic
>> north you fool. The fact that the MAGNETIC SOUTH POLE is not exactly
>> opposite the MAGNETIC NORTH POLE is a different issue.
>
> I assumed that others would understand this, but I often get into trouble when
> I assume others will understand things.

You expect others to understand things when you blither incorrect
concepts.

>> The fact that
>> the poles aren't aligned with the arbitrary "true" datum just means that
>> the variation equations aren't as simple as they might be.
>
> They are more than just misaligned: they are not at opposite points in terms
> of longitude and latitude, either. A line drawn between them does not
> intersect the center of the Earth.

Correct, that was my point. It doesn't change anything. Magnetic
south and magnetic north are still opposite directions at any given
point on the earth.
>
>> Really, like what?
>
> GPS and inertial reference platforms, VORs, NDBs, you name it.

GPS and INS use elaborate internal computation to determine it, yes.
Haven't ever seen an INS in anything smaller than a transport category.

NDB's chortle..you haven't a clue.
VORs not on your life, unless you're sitting on station.
You should learn something about navigation and geodessy before
you make these bogus statements.

>
>> Compasses are still damned reliable compared to
>> anything else. Cheap too. The only thing that presumes to do better
>> perhaps is GPS. And it's easier to program that to deal with the
>> magnetic measurements than to try to force everybody else the other
>> way.
>
> So how often do you fly using just your magnetic compass alone?
>
Give me a chart and a compass and I'll do just fine VFR. Managed
to fly the Navion around just fine that way when I had all the
avionics and the gyros pulled out while I was redoing the panl.

[Mxsmanic]

Ron Natalie writes:

> Correct, that was my point. It doesn't change anything. Magnetic
> south and magnetic north are still opposite directions at any given
> point on the earth.

They are close to opposite, but not exactly so.

> Give me a chart and a compass and I'll do just fine VFR.

If you have a chart, you're not using your magnetic compass _alone_.

And even if you have a chart and a compass, how do you determine where you
are?

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Ron Natalie]

Mxsmanic wrote:
> writes:
>
>> A sensor to find true north in an airplane in flight doesn't exist.
>
> GPS finds true north.

Nope, GPS finds a 3-d position based on the relative distances between
sets of satellites in geosynchronous orbit. It knows no more about
true north than magnetic without elaborate conversion between where
the satellites are at any given instant and where the earth is.

> And, just incidentally, you can find true north by
> looking at the sky. ANS will do that, and people can do it, too.

Funny, I'm looking at the sky today and all I see are clouds.
My compass still works.

>
>> The isogonic lines on a chart take care of all the problems of where
>> the actual north/south magnetic poles are.
>
> Documenting them doesn't really eliminate them.

It gives you the tool, just like your beloved GPS knows how to find
the real north pole between the combination of the downloaded data
on where the satellites are and a substantial amount of information
on the shape of the earth inside it's internal database.

>
> Unless the airplane is a glider, you have power.

You are clueless aren't you. The engine in just about every airplane
out there runs just freaking fine without any electrical power consumed
nor delivered to the rest of the aircraft.

> One third correct: it requires power, but engines provide power. It doesn't
> have to be set up against anything else to find true north. It doesn't need
> to be constantly updated; the whole idea is to be fairly autonomous.
>

You are clueless. Your GPS is constantly updated or it won't work.
You put the thing in a box for a week or so or power it up in an
undisclosed location and it will DO NOTHING for you until it downloads
enough information to continue.

[Ron Natalie]

Mxsmanic wrote:
> Tim writes:
>
>> Not all planes have GPSes. In fact, most don't.
>
> That depends on what category of aircraft you're looking at.

Doesn't matter what category you are looking at. We've still
got transport aircraft with just steam gauges.

>
>> Many of the haldheld units fail.
>
> How many? I've never seen one fail, although I'm sure it happens
> occasionally. They don't even have any moving parts.

I've had them fail lots of times. All it takes is the battery to go doead.

>
>> The failure rate for compasses is quite low.
>
> So is their accuracy, even when they are functioning perfectly.

Accurate enough. Reliable...never really have seen one fail.
>
>> Not really. It is unreliable. Its signals can be disrupted - rendering
>> them useless.
>
> Magnetic bearings are constantly disrupted, everywhere on Earth.

Between your ears primarily.

> You have an engine turning. That's power. And it can fail, just like
> electrical power.

That power only propells the aircraft. There's no guarantee that it
provides electricity for avionics. I can tell you that I've been
in a number of aircraft where it did not, either by malfunction or
DESIGN.

>
>> Not in the real world. On a computer maybe...
>
> Even in the real world. The purpose of INS is to have a way of navigating
> without any external references; it's a very advanced and accurate
> implementation of dead reckoning.

CHORTLE. Have you any experience with a real INS. A real INS can't
find squat without being told where it is starting from. This has
to be boostrapped from other navigational devices. It's long term
stability isn't any better than a compass. It needs additional
input.

> It's useless for truth north unless you have a chart _and_ you know where you
> are. Even for magnetic north, it can be substantially off. And just knowing
> which way is north doesn't help you much, anyway.
>

Your GPS and INS are useless without a chart or their internal
electronic equivelent.

[Ron Natalie]

Mxsmanic wrote:
> Nomen Nescio writes:
>
>> The category that has wings and goes up in the sky.
>
> You mean like a 747-400? It has two GPS receivers, three IRUs, two VORs and
> two ADFs. One rarely falls back upon the magnetic compass.
>
Once again you decide to generalize the entire realm of aviation
by your simplistic study of the simulation of one aircraft.

There are a great number of transport category aircraft with
neither INS nor GPS.

[Ron Natalie]

Mxsmanic wrote:
> DR writes:
>
>> LOL! How do _you_ do that exactly?
>
> I don't. I know the direction of true north at my location, and I don't go
> anywhere else.
>
This is perhaps not only the truth, but the telling story of your
problem.

You don't go anywhere else.

[Ron Natalie]

Mxsmanic wrote:

>
> That's one reason why I often like to fly big aircraft.

No you like to fly simulations of big aircraft.
>
>> Not all real airplanes have electrical systems.
>
> True, and some are powered by rubber bands as well, but there's a lower
> threshold below which I don't bother.
>
Yes, but you come here arguing that any outside your willingness
to simulate don't exist. This is makes you look pathetically
stupid and is the main reason that most people on this forum
are hostile to you.

[Peter Dohm]

> wrote in message
oups.com...
> On Apr 5, 5:33 pm, RomeoMike > wrote:
> > DR wrote:
> >
> > Declination in navigation is actually
> >
> > > something else but I'll let you googgle for it.
> >
> > I'm not sure that's really true. In aviation we talk about variation,
> > but when I'm using 7.5' topo maps on the ground, declination is the term
> > used for the difference
> > between magnetic and true north. (See the bottom left of a US DOI
> > Geologic Survey 7.5' topo.)
> > Variation and declination are defined the same
> > If there's a more sophisticated use of the word declination in
> > navigation, I'm willing to be enlightened.
>
> OK, it's celestial Nav. Stars are located by declination (angle from
> the celestial equator) and RA. The geographical use of declination to
> describe variation is the result of bad education propagating a
> specilaized technical term into incorrect use IMHO. As I think about
> it, how could a word derived from "decline" be related to horizontal
> angle...?
>
> Cheers MC
>
Declination also applies to the earth's magnetic field, and can be measured
and charted. However, its use generally involves an earth inductor compass.
(BTW, Lindberg apparently had one installed on the Spirit of St Louis; but I
don't know whether he ever commented on the ease of use in what obviously
qualified as a light aircraft.)

Peter

[Mxsmanic]

Ron Natalie writes:

> CHORTLE. Have you any experience with a real INS. A real INS can't
> find squat without being told where it is starting from. This has
> to be boostrapped from other navigational devices. It's long term
> stability isn't any better than a compass. It needs additional
> input.

Not to find true north. It can find true north all on its own.

> Your GPS and INS are useless without a chart or their internal
> electronic equivelent.

I have a GPS with no chart and it's extremely useful.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

Ron Natalie writes:

> Nope, GPS finds a 3-d position based on the relative distances between
> sets of satellites in geosynchronous orbit.

Roughly, yes.

> It knows no more about
> true north than magnetic without elaborate conversion between where
> the satellites are at any given instant and where the earth is.

With two fixes, it has true north. If it's moving, it has at least two fixes.

> Funny, I'm looking at the sky today and all I see are clouds.
> My compass still works.

There are lots of places on Earth where your compass won't work, but an ANS
will.

> You are clueless aren't you. The engine in just about every airplane
> out there runs just freaking fine without any electrical power consumed
> nor delivered to the rest of the aircraft.

Are they all Diesels?

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

Ron Natalie writes:

> This is makes you look pathetically
> stupid and is the main reason that most people on this forum
> are hostile to you.

I think that's a bit backwards. People who are stupid are likely to be
hostile.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Steven P. McNicoll]

"Ron Natalie" > wrote in message
m...
>
> Because some were never right. Some where set right but the local
> variation has changed and the VOR's were never realigned. It's
> not necessary for them to set exact, just that they are known with
> a reasonable precision. The fact that they are close to magnetic
> north is again as we've been saying, convenience because all courses
> and headings IN FLIGHT are done magnetic.
>

If they were set to true north they would still be known with a reasonable
precision. They'd be no less useful and they wouldn't have to ever be reset
due to magnetic drift.

[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> Ron Natalie writes:

> > Correct, that was my point. It doesn't change anything. Magnetic
> > south and magnetic north are still opposite directions at any given
> > point on the earth.

> They are close to opposite, but not exactly so.

And that doesn't matter in the slightest.

> > Give me a chart and a compass and I'll do just fine VFR.

> If you have a chart, you're not using your magnetic compass _alone_.

> And even if you have a chart and a compass, how do you determine where you
> are?

By looking out the windows.

In my real airplane, I can fly all around the local area for about
50 miles by doing nothing other than looking out the window and
occasionally at the compass.

In your toy flight simulator, I can't get from one local airport to
another by looking at terrain. I have to use the simulator instruments.

That's yet another difference between real and simulated flight.

--
Jim Pennino

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In rec.aviation.piloting Mxsmanic > wrote:
> Tim writes:

> > Tell that to Charlie Lindbergh.

> Charles Lindbergh had not only multiple compasses but charts and a timekeeping
> device. He never would have gotten anywhere with just a compass alone.

A true enough statement, but one that shows how very little you know
about navigation.

--
Jim Pennino

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[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> Ron Natalie writes:

> > CHORTLE. Have you any experience with a real INS. A real INS can't
> > find squat without being told where it is starting from. This has
> > to be boostrapped from other navigational devices. It's long term
> > stability isn't any better than a compass. It needs additional
> > input.

> Not to find true north. It can find true north all on its own.

Total, utter, nonsense.

You haven't the slightest clue how either a INS or a gyro compass
work.

<snip rest>

--
Jim Pennino

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[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> writes:

> > If you want to go to and from true and magnetic, you need a chart to
> > get the local difference.

> If you want to do anything, you need more than a compass.

You need to know the heading to use to get somewhere. You use the
compass to actually go that direction.

> > If all you want to do is go in some particular direction until you
> > can see a recognizable landmark, all you need is a compass.

> In order to recognize the landmark, you need something more than a compass.

You mean like fly a heading 230 degrees for 47 miles and there will be
a lake. At the lake fly a heading of 273 degrees for 32 miles and
at that airport, fly a heading of 264 degrees for another 44 miles
and you will be at your destination?

You obviously know nothing of real world navigation.

--
Jim Pennino

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[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> EridanMan writes:

> > The system is a rube goldberg contraption with an instant-on kill
> > switch.

> There is no instant-on kill switch. It takes quite a bit of time to send
> commands to all the satellites.

Yeah, a few seconds once the decision is made.

> > Wait until someone launches a home-made GPS guided cruise
> > missile into Washington DC, watch them flick the switch, and see what
> > happens. Just hope it doesn't happen at night, and you're not in the
> > air at the time.

> They can't do that any more. It would be a worse disaster to turn it off than
> it would be to just let it run, for both military and civilian use.

If backup systems like VOR, NDB, LORAN didn't exist, that might be
true, but the backukp systems do exist.

> > It also requires constant, very expensive maintenance, a complex
> > receiver in good working order, and as I mentioned, can be turned off
> > at the push of a button. None of these are traits you want for you
> > primary navigation system.

> It cannot be turned off at the push of a button. I'm not aware of any
> constant maintenance requirement. Databases have to be updated by a
> monopolistic price-gouging private enterprise, but that's a separate issue.

We'll just add that to the long and growing list of things you are
not aware of.

> > The simplest, fastest and most dependable (in VMC) way of finding true
> > north (or any form of navigation) is simple spatial awareness and
> > pilotage. A good chart, and a good eye.

> I wouldn't trust those.

That's because you haven't a clue as to how to use them, especially
the awareness part.

--
Jim Pennino

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[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> Ron Natalie writes:

> > Nope, GPS finds a 3-d position based on the relative distances between
> > sets of satellites in geosynchronous orbit.

> Roughly, yes.

> > It knows no more about
> > true north than magnetic without elaborate conversion between where
> > the satellites are at any given instant and where the earth is.

> With two fixes, it has true north. If it's moving, it has at least two fixes.

And that tells you your course, not which direction the nose is pointed.

There is no GPS instrument available that will tell you which way
your nose is pointed.

> > Funny, I'm looking at the sky today and all I see are clouds.
> > My compass still works.

> There are lots of places on Earth where your compass won't work, but an ANS
> will.

The only two places on Earth a magnetic compass doesn't work in an
airplane are over the north and south magnetic poles.

You really are ignorant, aren't you?

> > You are clueless aren't you. The engine in just about every airplane
> > out there runs just freaking fine without any electrical power consumed
> > nor delivered to the rest of the aircraft.

> Are they all Diesels?

Good lord.

Ignorant doesn't even begin to describe how totally, utterly, and
completely clueless you are.

Piston engines have magnetos which generate the spark plug firing
voltage, and only the spark plug voltage. The engine has no other
need for electrical power and doesn't generate electrical power
to run things like GPS unless it has a generator or an alternator
installed. Many airplanes have neither a generator or an alternator.

Turbine engines only require electrical power to start. Once they
are running, they are self sustaining.

If you are going to be a pretend pilot, at least go learn some
basics so you don't look like a complete fool.

--
Jim Pennino

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[[email protected]]

On Apr 5, 1:33 am, RomeoMike > wrote:
> DR wrote:
> Declination in navigation is actually
> > something else but I'll let you googgle for it.
>
> I'm not sure that's really true. In aviation we talk about variation,
> but when I'm using 7.5' topo maps on the ground, declination is the term
> used for the difference
> between magnetic and true north. (See the bottom left of a US DOI
> Geologic Survey 7.5' topo.)
> Variation and declination are defined the same
> If there's a more sophisticated use of the word declination in
> navigation, I'm willing to be enlightened.

Astro navigation, but it's still an angle away from a standard
vector. So different sciences are using the same word with different
meanings.

However, you're of course correct that for magnetic navigation,
declination and variation are the same thing.

http://www.ngdc.noaa.gov/seg/geomag/faqgeom.shtml

Kev

[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> writes:

> > You are talking about a gyro compass.

> No, I'm not.

Yes, you are.

> > A gyro compass is huge, expensive and heavy.

> But there is none inside an inertial reference platform. An IRS uses laser
> gyros.

They are still big, heavy, and expensive.

> > They can take hours to settle on a usable reading.

> An IRS can find true north in a few minutes, depending on latitude.

An INS system can NOT find true north and requries an external input
to tell it where north is.

You are clueless.

> > An INS system has to be initialized with it's current position and just
> > tells you where you have moved relative to the starting position.

> But it also finds true north on its own, without any need for external data.
> It simply detects the rotation of the Earth, and that gives it an east-west
> reference, to which true north is perpendicular.

No, INS can not find true north, only a gyro compass can find true
north.

A gyrocompass doesn't work at airplane speeds.

> > You have no idea what you are talking about.

> Google for it. You'll be surprised.

Lets sum up reality versus your babbling ignorance:

Only a gyrocompass can find true north.

A gyrocompass won't work at all at airplane speeds and is problematic
at fast, modern ship speeds.

Because a gyrocompass uses the precession caused by the Earth's rotation
to find north and the Earth rotates so slowly, it can take several
hours for a gyrocompass to settle when first turned on.

An INS is a collection of gyros and accelerometers that sense movement.

An INS does not contain a gyrocompass.

An INS requires an external input to tell it where north is.

An INS has to be initialized to tell it it's current position.

Once an INS is initialized, it can tell you how far you have moved.

An INS has to be periodically updated with it's true position because
the gyros, including laser gyros, drift.

No GA aircraft and few transport aircraft have INS installed.

For how gyrocompasses work:

http://en.wikipedia.org/wiki/Gyrocompass

http://www.navis.gr/navaids/gyro.htm

http://tpub.com/content/administration/14221/css/14221_74.htm

For how INS works:

http://en.wikipedia.org/wiki/Inertial_guidance_system

--
Jim Pennino

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In rec.aviation.piloting wrote:
> On Apr 5, 4:35 pm, wrote:
> > In rec.aviation.piloting DR > wrote:
> >
> > > Mxsmanic wrote:
> >
> > > > There
> > > > are plenty of spots on charts where the compass will be 6-8 degrees off even
> > > > from the already irrgular declination over larger areas.
> >
> > > LOL! My BS meter just went off scale! Declination? Lines of magnetic
> > > _variation_ are plotted on VP charts and better than 0.5 degree accuracy
> > > (except at local anomalies which are only noted in nautical charts as
> > > far as I've seen so far). Declination in navigation is actually
> > > something else but I'll let you googgle for it.
> >
> > I can't think of any local anomaly that is both strong enough and large
> > enough to be anything other than a transitory "burble" at most to the
> > compass of an airplane in flight.
> >

> Yes, I agree, that is true of most but some are very big, the biggest
> is in Kursk, Russia. If your autopilot is flying a magnetic heading
> how fast would it respond if it flew over a common 6 degree anomaly?

It wouldn't; autopilots are linked to the heading indicator which
wouldn't care.

--
Jim Pennino

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In rec.aviation.piloting Mxsmanic > wrote:
> writes:

> > I can't think of any local anomaly that is both strong enough and large
> > enough to be anything other than a transitory "burble" at most to the
> > compass of an airplane in flight.

> Try flying just outside Reno.

I have, have you?

Did I miss something?

--
Jim Pennino

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[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> Jose writes:

> > "It must be true - I found it on the internet"

> I think you'll find that the more you research about the geomagnetic field,
> the less reliable you find it to be for navigation.

I think you'll find that if you ever get an education, the less likely
you will be to babble nonsense like that.

--
Jim Pennino

Remove .spam.sux to reply.

[Tauno Voipio]

Kev wrote:
> On Apr 4, 2:32 am, Tauno Voipio > wrote:
>
>>EridanMan wrote:
>>
>>>Why in gods name are VOR's Mag heading based?
>>
>>It's a nuisance for maintenance, but it frees
>>the pilot from calculating the variation at
>>the operative time. Just to off-load the pilot.
>
>
> A good answer. Same for winds in flight, etc. Everything is based on
> the magnetic to make it easier for the pilot. At least, the pilot of
> old. If we had 100% reliable aids in the plane, then I suppose you
> could argue for just following the red line on the electronic map, and
> never even know what course you're taking ;-)
>
>
>> > I know, ideally, that means that you can sync your DG and your VOR
>> > indicator to fly to a waypoint... except that most VOR's around here
>> > have long since fallen behind Magnetic drift... so - now, not only do
>> > you have to flightplan in True Heading, convert to Mag Heading to get
>> > your vectors, THEN you have to get the corrective factor for each of
>> > the VOR's your using for navigation and note that as well? huh?
>>
>>If they are off the mag variation, it is
>>mis-maintenance, and the VOR should be
>>marked defective or taken off-line.
>
>
> VORs are allowed to get +/- 6 degrees off. Seems a lot, but it's
> only a handful of miles off-course over most VORs' ranges. Anyway,
> see:
>
> http://www.naco.faa.gov/index.asp?xml=naco/faq#q2h
>
> Kev
>

This seems too much to match the ICAO specified system accuracy
of +/- 5.2 degrees. The system accuracy includes transmitter
and receiver errors and the operative margin.

The VORs here are adjusted for an error of less than 1 degree
at the station, and a flight test is not passed if the error
exceeds 3 degrees (except on special terrain cases, which have
to be announced by NOTAMs).

--

Tauno Voipio
tauno voipio (at) iki fi

[Maxwell]

"Mxsmanic" > wrote in message
...
> writes:
>
>
>> INS is too big and expensive for GA aircraft.
>
> That's one reason why I often like to fly big aircraft.
>

Just how big is your desk????



>> Not all real airplanes have electrical systems.
>
> True, and some are powered by rubber bands as well, but there's a lower
> threshold below which I don't bother.
>

Then how can you be bothered by playing a sim????

[Maxwell]

"Mxsmanic" > wrote in message
...
> Ron Natalie writes:
>
>> This is makes you look pathetically
>> stupid and is the main reason that most people on this forum
>> are hostile to you.
>
> I think that's a bit backwards. People who are stupid are likely to be
> hostile.
>

Odd..you are clearly the poster child for stupidity, but you don't see
hostile.

[Maxwell]

"Mxsmanic" > wrote in message
...
> Jose writes:
>
>> "It must be true - I found it on the internet"
>
> I think you'll find that the more you research about the geomagnetic
> field,
> the less reliable you find it to be for navigation.
>

That's OK, you can relax anyway. No matter how many hours you sim, you will
still find your desk in your bedroom.

[TheSmokingGnu]

wrote:
> An INS does not contain a gyrocompass.

I thought I read somewhere that certain INS do have a gyrocompass, for
setting the initial positional reference.

The compass (compii??? :P ) in question was erected much faster than a
ship-borne model by being held at magnetic north by a mag compass while
it spun up (so the calibration time was only that to correct for local
variation, and not to find the entire harmonic of the Earth).

In any case, it was useless when actually flying, and the system only
used the accelerometers thereafter.

TheSmokingGnu

[RomeoMike]

wrote:

>
> Astro navigation, but it's still an angle away from a standard
> vector. So different sciences are using the same word with different
> meanings.
>
> However, you're of course correct that for magnetic navigation,
> declination and variation are the same thing.
>
> http://www.ngdc.noaa.gov/seg/geomag/faqgeom.shtml
>
> Kev
>

Thanks to you, farr1220, and Peter. I always wondered in the back of my
mind how the term declination came to mean variation. Now I'm ready to
navigate the outer space :-)

[dgs]

On 4/5/2007 10:08 AM Maxwell fell asleep at the keyboard, and awoke to
find this:

> "Mxsmanic" > wrote in message
> ...
>
> [...] People who are stupid are likely to be
>>hostile.
>
> Odd..you are clearly the poster child for stupidity, but you don't see
> hostile.

Something you should know: Anthony claims to be a proponent and
practitioner of the so-called "Golden Rule," so he treats others as
he feels they should treat him.

So, when he attempts to label people as stupid (even if only by
implication), or treat others as if they're idiots, remember, he's
actually proposing that he be treated as if he's stupid too. At least
it's consistent.
--
dgs

[dgs]

On 4/4/2007 10:47 AM Mxsmanic fell asleep at the keyboard, and awoke to
find this:

> I assumed that others would understand this, but I often get into trouble when
> I assume others will understand things.

Is this another example of how you practice the Golden Rule?
--
dgs

[[email protected]]

In rec.aviation.piloting TheSmokingGnu > wrote:
> wrote:
> > An INS does not contain a gyrocompass.

> I thought I read somewhere that certain INS do have a gyrocompass, for
> setting the initial positional reference.

> The compass (compii??? :P ) in question was erected much faster than a
> ship-borne model by being held at magnetic north by a mag compass while
> it spun up (so the calibration time was only that to correct for local
> variation, and not to find the entire harmonic of the Earth).

> In any case, it was useless when actually flying, and the system only
> used the accelerometers thereafter.

Well, if you forced it to magnetic north on turn on, it would be
statistically faster than some random position, but still takes
a long time to settle; the Earth doesn't rotate that fast.

What a gyrocompass actually seeks is alignment of it's axis with the
axis of the Earth's rotation, so you would also have to throw in
a latitude initializer to do much good.

That's not saying no one ever tried to build such a thing, but the
laws of physics that make it work make it impractical for airplanes.

Plus, the initialization for INS has to set the position AND which
way is north.


--
Jim Pennino

Remove .spam.sux to reply.

[Mxsmanic]

dgs writes:

> Is this another example of how you practice the Golden Rule?

Yes.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

writes:

> A true enough statement, but one that shows how very little you know
> about navigation.

When did truth become evidence of ignorance?

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

writes:

> You need to know the heading to use to get somewhere. You use the
> compass to actually go that direction.

You don't know what that heading is unless you already know where you are.

> You mean like fly a heading 230 degrees for 47 miles and there will be
> a lake.

How do you know about the lake, with only a compass as your guide?

> At the lake fly a heading of 273 degrees for 32 miles and
> at that airport, fly a heading of 264 degrees for another 44 miles
> and you will be at your destination?

How do you get this information from a compass?

> You obviously know nothing of real world navigation.

No, it's just that I know about covert channels.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

writes:

> Yeah, a few seconds once the decision is made.

No, far longer than that. I seem to recall it being minutes or hours,
probably the latter.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

writes:

> And that tells you your course, not which direction the nose is pointed.

For navigation, your ground track is more important.

> There is no GPS instrument available that will tell you which way
> your nose is pointed.

As I've said, you just use two.

> The only two places on Earth a magnetic compass doesn't work in an
> airplane are over the north and south magnetic poles.

No. There are thousands of local magnetic anomalies that can make a compass
useless.

> Piston engines have magnetos which generate the spark plug firing
> voltage, and only the spark plug voltage.

Last time I checked, sparks counted as electricity.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Barney Rubble]

So what do you periodically use to align the DG to? Hint: it's not the true
magnetic north as see out of the window....


"Mxsmanic" > wrote in message
...
> writes:
>
>> Sorry, I have to mildly disagree as far as flying goes, that you'd
>> automatically be in "deep trouble". Many pilots use just the
>> compass / DG for cross-country flying.
>
> A compass / DG is not just a compass.
>
> You can't do much with just a compass alone. You need a clock, some
> charts,
> other things ... not _just_ a compass.
>
>> Therefore a simple compass
>> was "good enough" for winged flight across the Atlantic starting in
>> 1919. which is not "four hundred years" ago.
>
> They had more than a simple compass. In particular, they had accurate
> clocks,
> and charts.
>
> --
> Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

writes:

> They are still big, heavy, and expensive.

Laser gyros are not big or heavy, although they are usually expensive.

I'll skip the rest of your post, as there are more anomalies than I care to
address.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

Maxwell writes:

> Odd..you are clearly the poster child for stupidity, but you don't see
> hostile.

I'm neither stupid nor hostile.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

dgs writes:

> So, when he attempts to label people as stupid (even if only by
> implication), or treat others as if they're idiots, remember, he's
> actually proposing that he be treated as if he's stupid too. At least
> it's consistent.

No. When I give honest assessments of something or someone, I expect others
to do the same.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Maxwell]

"Mxsmanic" > wrote in message
...
> writes:
>
>> And that tells you your course, not which direction the nose is pointed.
>
> For navigation, your ground track is more important.
>
>> There is no GPS instrument available that will tell you which way
>> your nose is pointed.
>
> As I've said, you just use two.
>
>> The only two places on Earth a magnetic compass doesn't work in an
>> airplane are over the north and south magnetic poles.
>
> No. There are thousands of local magnetic anomalies that can make a
> compass
> useless.
>
>> Piston engines have magnetos which generate the spark plug firing
>> voltage, and only the spark plug voltage.
>
> Last time I checked, sparks counted as electricity.
>

Then hook up a spark plug wire to your GPS.

[Maxwell]

"Mxsmanic" > wrote in message
...
> writes:
>
>> They are still big, heavy, and expensive.
>
> Laser gyros are not big or heavy, although they are usually expensive.
>
> I'll skip the rest of your post, as there are more anomalies than I care
> to
> address.

Then why wonder about real flying dip****, it certainly does the same.

[Maxwell]

"Mxsmanic" > wrote in message
...
> dgs writes:
>
>> So, when he attempts to label people as stupid (even if only by
>> implication), or treat others as if they're idiots, remember, he's
>> actually proposing that he be treated as if he's stupid too. At least
>> it's consistent.
>
> No. When I give honest assessments of something or someone, I expect
> others
> to do the same.
>

Dang, when did you do that????????????????????????

[Maxwell]

"Mxsmanic" > wrote in message
...
> Maxwell writes:
>
>> Odd..you are clearly the poster child for stupidity, but you don't see
>> hostile.
>
> I'm neither stupid nor hostile.
>

That's the funny thing about being nuts, you're always the last one to know.

[Maxwell]

"Barney Rubble" > wrote in message
...
> So what do you periodically use to align the DG to? Hint: it's not the
> true magnetic north as see out of the window....
>
>
> "Mxsmanic" > wrote in message
> ...
>> writes:
>>
>>> Sorry, I have to mildly disagree as far as flying goes, that you'd
>>> automatically be in "deep trouble". Many pilots use just the
>>> compass / DG for cross-country flying.
>>
>> A compass / DG is not just a compass.
>>
>> You can't do much with just a compass alone. You need a clock, some
>> charts,
>> other things ... not _just_ a compass.
>>
>>> Therefore a simple compass
>>> was "good enough" for winged flight across the Atlantic starting in
>>> 1919. which is not "four hundred years" ago.
>>
>> They had more than a simple compass. In particular, they had accurate
>> clocks,
>> and charts.
>>

He aligns it with his bedroom picture of Pavlov.

[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> writes:

> > A true enough statement, but one that shows how very little you know
> > about navigation.

> When did truth become evidence of ignorance?

The moment you posted your tripe.

--
Jim Pennino

Remove .spam.sux to reply.

[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> writes:

> > You need to know the heading to use to get somewhere. You use the
> > compass to actually go that direction.

> You don't know what that heading is unless you already know where you are.

If you have a heading to get to where you want to go, the details of
your current position are irrelevant.

If the bathroom is down the hallway to the left, does it matter where
you are in getting to the bathroom?

> > You mean like fly a heading 230 degrees for 47 miles and there will be
> > a lake.

> How do you know about the lake, with only a compass as your guide?

> > At the lake fly a heading of 273 degrees for 32 miles and
> > at that airport, fly a heading of 264 degrees for another 44 miles
> > and you will be at your destination?

> How do you get this information from a compass?

Don't be an even bigger idiot than you already are.

Given the task is to get from point A to point B and you have a compass,
the only information you need is the heading from point A to point B.

No, the compass doesn't tell you what it it supposed to be, you need
something else to tell you that, whether it is another person, a
chart, or you just happen to know it.

So, you need a heading and a compass to follow that heading.


> > You obviously know nothing of real world navigation.

> No, it's just that I know about covert channels.

Do you wrap your head with foil when you don't want to receive those
channels?

--
Jim Pennino

Remove .spam.sux to reply.

[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> writes:

> > Yeah, a few seconds once the decision is made.

> No, far longer than that. I seem to recall it being minutes or hours,
> probably the latter.

Maybe, just maybe, the satellites on the other side of the planet, but
for everything in view, seconds.

--
Jim Pennino

Remove .spam.sux to reply.

[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> writes:

> > And that tells you your course, not which direction the nose is pointed.

> For navigation, your ground track is more important.

> > There is no GPS instrument available that will tell you which way
> > your nose is pointed.

> As I've said, you just use two.

There is are GPS instruments available that can be linked to tell you
that.

> > The only two places on Earth a magnetic compass doesn't work in an
> > airplane are over the north and south magnetic poles.

> No. There are thousands of local magnetic anomalies that can make a compass
> useless.

Not at airplane altitudes and speeds.

If there are thousands, name just 30.

> > Piston engines have magnetos which generate the spark plug firing
> > voltage, and only the spark plug voltage.

> Last time I checked, sparks counted as electricity.

Well, I can see electricity can be added to that ever growing list
of things about which you know nothing.

Magnetos generate pulses measured in the thousand of volts and microamps
of current. Even if they were hooked to something else, which they
aren't, the power generated would be useless for powering something like
a GPS.

My god, everytime you say something, more ignorance just roles out.


--
Jim Pennino

Remove .spam.sux to reply.

[[email protected]]

In rec.aviation.piloting Maxwell > wrote:

> "Mxsmanic" > wrote in message
> ...
> > writes:
> >
> >> And that tells you your course, not which direction the nose is pointed.
> >
> > For navigation, your ground track is more important.
> >
> >> There is no GPS instrument available that will tell you which way
> >> your nose is pointed.
> >
> > As I've said, you just use two.
> >
> >> The only two places on Earth a magnetic compass doesn't work in an
> >> airplane are over the north and south magnetic poles.
> >
> > No. There are thousands of local magnetic anomalies that can make a
> > compass
> > useless.
> >
> >> Piston engines have magnetos which generate the spark plug firing
> >> voltage, and only the spark plug voltage.
> >
> > Last time I checked, sparks counted as electricity.
> >

> Then hook up a spark plug wire to your GPS.

Better to his forehead; electroshock therapy sounds like it is called
for in his case.

--
Jim Pennino

Remove .spam.sux to reply.

[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> writes:

> > They are still big, heavy, and expensive.

> Laser gyros are not big or heavy, although they are usually expensive.

> I'll skip the rest of your post, as there are more anomalies than I care to
> address.

Or in other words, you don't know what the hell you are talking about
and don't want to learn what an ignorant fool you are.

--
Jim Pennino

Remove .spam.sux to reply.

[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> dgs writes:

> > So, when he attempts to label people as stupid (even if only by
> > implication), or treat others as if they're idiots, remember, he's
> > actually proposing that he be treated as if he's stupid too. At least
> > it's consistent.

> No. When I give honest assessments of something or someone, I expect others
> to do the same.

Honest does not equal true.

Honest just means that you aren't lying when you spout your ignorant,
incorrect, nonsense; you really believe your own crap.

--
Jim Pennino

Remove .spam.sux to reply.

[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> Maxwell writes:

> > Odd..you are clearly the poster child for stupidity, but you don't see
> > hostile.

> I'm neither stupid nor hostile.

A smart person wouldn't keep spouting the same ignorant nonsense
after they've been given references to eliminate the ignorance.

--
Jim Pennino

Remove .spam.sux to reply.

[Peter Dohm]

"RomeoMike" > wrote in message
...
>
>
> wrote:
>
> >
> > Astro navigation, but it's still an angle away from a standard
> > vector. So different sciences are using the same word with different
> > meanings.
> >
> > However, you're of course correct that for magnetic navigation,
> > declination and variation are the same thing.
> >
> > http://www.ngdc.noaa.gov/seg/geomag/faqgeom.shtml
> >
> > Kev
> >
>
> Thanks to you, farr1220, and Peter. I always wondered in the back of my
> mind how the term declination came to mean variation. Now I'm ready to
> navigate the outer space :-)

Hmmmm. I see that what I have been calling declination is called
inclination on the NOAA site, so I will correct as appropriate.

In view of my recollections of ground school, I believe that it might be
least confusing to continue using the term deviation for the instrument
error as installed, variation for the difference between true and magnetic
north, and inclination for the angle between the lines of force and the
horizontal--leaving the term declination unused.

Peter
(Planning to think about this at leisure)

[Steven P. McNicoll]

"Peter Dohm" > wrote in message
.. .
>
> In view of my recollections of ground school, I believe that it might be
> least confusing to continue using the term deviation for the instrument
> error as installed, variation for the difference between true and magnetic
> north, and inclination for the angle between the lines of force and the
> horizontal--leaving the term declination unused.
>

You could use declination for the difference between the magnetic variation
a VOR is set to and the actual local magnetic variation.

[[email protected]]

On Apr 6, 12:31 am, Ron Natalie > wrote:
> wrote:
> > On Apr 5, 5:37 am, "EridanMan" > wrote:
> >> On Apr 4, 5:23 am, "Steven P. McNicoll" >
> >> wrote:
>
> >>> "EridanMan" > wrote in message
> oups.com...
> >>>> Why in gods name are VOR's Mag heading based?
> >>> Tradition.
> >> Best answer I've heard yet;)
>
> > Isn't the difference between your compass heading and the radial you
> > are flying the drift? Knowing drift is pretty useful...
>
> The correction angle maybe. You aren't drifting at all if you are
> on the radial.

Yes, that's what I mean, you are holding off "x" degrees of drift.
That fact is very useful and given the choice between a true and
magnetic VOR I think I would prefer magnetic for just that reason.
You?

Cheers MC

[[email protected]]

On Apr 6, 8:56 am, "Peter Dohm" > wrote:
> "RomeoMike" > wrote in message
>
> ...
>
>
>
>
>
> > wrote:
>
> > > Astro navigation, but it's still an angle away from a standard
> > > vector. So different sciences are using the same word with different
> > > meanings.
>
> > > However, you're of course correct that for magnetic navigation,
> > > declination and variation are the same thing.
>
> > >http://www.ngdc.noaa.gov/seg/geomag/faqgeom.shtml
>
> > > Kev
>
> > Thanks to you, farr1220, and Peter. I always wondered in the back of my
> > mind how the term declination came to mean variation. Now I'm ready to
> > navigate the outer space :-)
>
> Hmmmm. I see that what I have been calling declination is called
> inclination on the NOAA site, so I will correct as appropriate.
>
> In view of my recollections of ground school, I believe that it might be
> least confusing to continue using the term deviation for the instrument
> error as installed, variation for the difference between true and magnetic
> north, and inclination for the angle between the lines of force and the
> horizontal--leaving the term declination unused.
>

Yes and then aviators would be in perfect alignment with ocean
naavigators who use variation and deviation. The conversion from true
to compass heading makes a nice nemonic:

timid virgins make dull company

for TRUE (variation) MAGNETIC (deviation) COMPASS

Cheers MC

[Steven P. McNicoll]

> wrote in message
ups.com...
>
> Yes, that's what I mean, you are holding off "x" degrees of drift.
> That fact is very useful and given the choice between a true and
> magnetic VOR I think I would prefer magnetic for just that reason.
>

Most are neither. The GRB VORTAC was aligned to a magnetic variation of 1E
in 1965. It's still there, but local magnetic variation is now 3W The
airways are more closely aligned with true north than magnetic north.

[Bertie the Bunyip]

On Apr 4, 8:52 pm, Mxsmanic > wrote:
> Maxwell writes:
> > What did you have for dinner last night, Welsh Rarebit????
>
> My point is that you have to strike a balance between assuming all equipment
> will work perfectly and depending on that, and assuming that all equipment
> will fail and trying to plan for that. In reality, chances are that all
> equipment will work; and the chances of equipment failing diminish rapidly as
> the number of simultaneous failures increases.
>
> It's true that a compass always works--more or less, since compasses are so
> finicky even when they are "working"--but I'm not sure that this is really
> much of a practical help if nothing else works. All a compass can do is tell
> you your direction of flight in a very approximate way. That isn't much use
> for getting where you want to go. Charts help a lot, but you need more than a
> compass to find out where you are on the chart, and if you don't know where
> you are on a chart, a compass won't help.
>
> Early ships navigated using a compass as one important instrument, but a
> compass along was never good enough. It wasn't enough four hundred years ago,
> and it's not enough now. If all you have is a compass, you're in deep
> trouble.
>
> You're actually better off with an accurate watch and a way to shoot the
> stars.


oh, you know how to do that do you?

I do.


But even that is more of a theoretical method than a practical
method
> these days.

No, it isn't, fjukkktard. it's still used and to good effect in quite
a few military applications.


>
> When people talk about how this old method or that old method is reliable,
> they tend to forget how many people died in the days when these "reliable"
> methods were the only ones available.

You've obvioulsy never tried using a GPS anywhere near the middle est
these days.

Oh wait, you don't even fly... forgot..




Bertie
>

You're an idiot. It wasn't the method that killed, fjukktrd..

[RomeoMike]

Peter Dohm wrote:

> In view of my recollections of ground school, I believe that it might be
> least confusing to continue using the term deviation for the instrument
> error as installed, variation for the difference between true and magnetic
> north, and inclination for the angle between the lines of force and the
> horizontal--leaving the term declination unused.
>
> Peter
> (Planning to think about this at leisure)
>
>

I suppose that the term declination would better be unused in favor of
"variation" in the context of defining the difference between magnetic
and true north, and in my experience it is unused in aviation.
Unfortunately, it is used on government issued topo maps and in some
orienteering books and by some orienteering compass makers, who tell one
to enter the "declination" into the compass card so that the needle
points to true north. Inclination is another term with different meaning
in different contexts.

[RomeoMike]

RomeoMike wrote:

>>
>
> I suppose that the term declination would better be unused in favor of
> "variation" in the context of defining the difference between magnetic
> and true north, and in my experience it is unused in aviation.
> Unfortunately, it is used on government issued topo maps and in some
> orienteering books and by some orienteering compass makers, who tell one
> to enter the "declination" into the compass card so that the needle
> points to true north. Inclination is another term with different meaning
> in different contexts.


OK, before I get flamed, I know that the compass needle always points to
magnetic north, but on an orienteering compass the "declination" is set
in the compass card so that the north indication is under the needle.

[Peter Dohm]

> >
> > > Thanks to you, farr1220, and Peter. I always wondered in the back of
my
> > > mind how the term declination came to mean variation. Now I'm ready to
> > > navigate the outer space :-)
> >
> > Hmmmm. I see that what I have been calling declination is called
> > inclination on the NOAA site, so I will correct as appropriate.
> >
> > In view of my recollections of ground school, I believe that it might be
> > least confusing to continue using the term deviation for the instrument
> > error as installed, variation for the difference between true and
magnetic
> > north, and inclination for the angle between the lines of force and the
> > horizontal--leaving the term declination unused.
> >
>
> Yes and then aviators would be in perfect alignment with ocean
> naavigators who use variation and deviation. The conversion from true
> to compass heading makes a nice nemonic:
>
> timid virgins make dull company
>
> for TRUE (variation) MAGNETIC (deviation) COMPASS
>
> Cheers MC
>
That's the nemonic that I was taught--and then forgot. :-(

Peter

[Peter Dohm]

"RomeoMike" > wrote in message
...
>
>
> Peter Dohm wrote:
>
> > In view of my recollections of ground school, I believe that it might be
> > least confusing to continue using the term deviation for the instrument
> > error as installed, variation for the difference between true and
magnetic
> > north, and inclination for the angle between the lines of force and the
> > horizontal--leaving the term declination unused.
> >
> > Peter
> > (Planning to think about this at leisure)
> >
> >
>
> I suppose that the term declination would better be unused in favor of
> "variation" in the context of defining the difference between magnetic
> and true north, and in my experience it is unused in aviation.
> Unfortunately, it is used on government issued topo maps and in some
> orienteering books and by some orienteering compass makers, who tell one
> to enter the "declination" into the compass card so that the needle
> points to true north. Inclination is another term with different meaning
> in different contexts.

I'm comfortable with "variation" because that's what I learned, but believe
that you are probably right.

BTW, you sent me to the dictionary for "orienteering"

Peter

[Maxwell]

> wrote in message
...
> In rec.aviation.piloting Maxwell > wrote:
>
>> "Mxsmanic" > wrote in message
>> ...
>> > writes:
>> >
>> >> And that tells you your course, not which direction the nose is
>> >> pointed.
>> >
>> > For navigation, your ground track is more important.
>> >
>> >> There is no GPS instrument available that will tell you which way
>> >> your nose is pointed.
>> >
>> > As I've said, you just use two.
>> >
>> >> The only two places on Earth a magnetic compass doesn't work in an
>> >> airplane are over the north and south magnetic poles.
>> >
>> > No. There are thousands of local magnetic anomalies that can make a
>> > compass
>> > useless.
>> >
>> >> Piston engines have magnetos which generate the spark plug firing
>> >> voltage, and only the spark plug voltage.
>> >
>> > Last time I checked, sparks counted as electricity.
>> >
>
>> Then hook up a spark plug wire to your GPS.
>
> Better to his forehead; electroshock therapy sounds like it is called
> for in his case.
>

That's a good idea. I wonder if Jim Weir has a kit for that?

[Mxsmanic]

writes:

> If you have a heading to get to where you want to go, the details of
> your current position are irrelevant.

You cannot calculate a heading for where you want to go unless you already
know where you are. The only places you can go with a compass without already
knowing where you are are the north and south magnetic poles.

> Don't be an even bigger idiot than you already are.

I'm simply pointing out the errors in your argument. You cannot know where
the lake is without a chart; a compass will not tell you about lakes. And if
you have a chart, you are not navigating with a compass alone.

> Given the task is to get from point A to point B and you have a compass,
> the only information you need is the heading from point A to point B.

You can only calculate that heading by knowing the positions of points A and
B, which means you cannot do it with just a compass, unless point B is one of
the magnetic poles.

> No, the compass doesn't tell you what it it supposed to be, you need
> something else to tell you that, whether it is another person, a
> chart, or you just happen to know it.

So a compass alone does not suffice. QED.

--
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[Mxsmanic]

writes:

> Maybe, just maybe, the satellites on the other side of the planet, but
> for everything in view, seconds.

The satellites take twelve hours to orbit the planet, and they don't pass over
the same spots on each orbit. As I recall, it takes several hours to have
them all execute a command, although that may be changing in future blocks.

--
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[Mxsmanic]

Nomen Nescio writes:

> But your altitude is much more important than ground track.

You cannot find your altitude with a compass alone.

> Why not three.

Three adds mostly redundancy rather than any additional functionality in
lateral navigation.

> But it powers NO electronics in the plane.

The assertion was that there was no electricity. I've demonstrated this
assertion to be incorrect if the aircraft is powered by a typical
reciprocating gasoline engine.

--
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[d.g.s.]

On 4/5/2007 11:25 AM Mxsmanic jumped down, turned around, and wrote:

> dgs writes:
>
>> Is this another example of how you practice the Golden Rule?
>
> Yes.

You snipped the part of the post where I quoted the example, thus
destroying the context my question quoted above, a very dishonest
practice (which, by the way, is contrary to your self-proclaimed
adherence to honesty as a guiding principle). Why did you do this?
Is this another example of how you practice the Golden Rule?
--
dgs

[Mxsmanic]

writes:

> Not at airplane altitudes and speeds.

Then why are they marked on the charts?

> Well, I can see electricity can be added to that ever growing list
> of things about which you know nothing.

Are you saying that sparks are something other than electricity? What are
they, then?

> Magnetos generate pulses measured in the thousand of volts and microamps
> of current.

Volts? Microamps? These units are used in electrical engineering, not
plumbing.

> Even if they were hooked to something else, which they
> aren't, the power generated would be useless for powering something like
> a GPS.

But that wasn't the assertion. The assertion was that there was no
electricity in some aircraft. If they have typical powerplants, there is
electricity.

> My god, everytime you say something, more ignorance just roles out.

I'm not the one making the mistakes.

--
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[Mxsmanic]

Nomen Nescio writes:

> Since self audits are always suspect ...

I'll remember this the next time someone here claims to be a qualified pilot.

--
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[Mxsmanic]

writes:

> A smart person wouldn't keep spouting the same ignorant nonsense
> after they've been given references to eliminate the ignorance.

True, but that is hardly relevant here.

I know from experience that stupid people rapidly become hostile, abusive, and
emotional in debates, because they have only their emotions upon which to base
their behavior (not having much of an intellect by definition). The more
stupid they are, the more abusive, hostile, and emotional they become. Smart
people do not have this handicap and so do not show this behavior,
particularly since intellect is much more useful than emotion in debate and
thus rarely leads to frustration.

--
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[Mxsmanic]

RomeoMike writes:

> OK, before I get flamed, I know that the compass needle always points to
> magnetic north ...

Actually it always aligns with the magnetic field in which it is placed, which
often means that it points roughly to magnetic north, but not always, as the
geomagnetic field is quite irregular.

--
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[Mxsmanic]

d.g.s. writes:

> You snipped the part of the post where I quoted the example, thus
> destroying the context my question quoted above, a very dishonest
> practice ...

No, simply an accepted means of saving bandwidth. You snipped everything
except my reply and the sentence that immediately preceded it. Why would it
be dishonest for me, but not for you?

> Why did you do this?

See above.

> Is this another example of how you practice the Golden Rule?

Yes.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> writes:

> > Not at airplane altitudes and speeds.

> Then why are they marked on the charts?

Why are not what marked on the charts?

<snip>

> But that wasn't the assertion. The assertion was that there was no
> electricity in some aircraft. If they have typical powerplants, there is
> electricity.

Spewing idiot, by that interpretation, there is electricity when you
shuffle across the rug.

That is NOT what people are talking about when they are talking about
powering things.

Have you not the slightest bit of common sense?

<snip>

--
Jim Pennino

Remove .spam.sux to reply.

[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> writes:

> > A smart person wouldn't keep spouting the same ignorant nonsense
> > after they've been given references to eliminate the ignorance.

> True, but that is hardly relevant here.

Tell us again how gyroscopes and INS works.

<snip>

--
Jim Pennino

Remove .spam.sux to reply.

[d.g.s.]

On 4/5/2007 6:53 PM Mxsmanic jumped down, turned around, and wrote:

> d.g.s. writes:
>
>> You snipped the part of the post where I quoted the example, thus
>> destroying the context my question quoted above, a very dishonest
>> practice ...
>
> No, simply an accepted means of saving bandwidth. You snipped everything
> except my reply and the sentence that immediately preceded it. Why would it
> be dishonest for me, but not for you?

First, show how I snipped your reply and the sentence that immediately
preceded it.

Also, show where I claimed that I followed this so-called "Golden Rule."
*You're* the one who made this claim, not me.

Also, show where I claimed that it *WASN'T* dishonest for me to do so.
If you're being dishonest, then according to the Golden Rule, you should
be perfectly content with me being dishonest also.

Also, your "accepted means of saving bandwidth" is merely a dishonest
dodge in an attempt to cover up your dishonesty, while bleating on and
on about how honest you really are. Why do you feel this need to be
so dishonest?

>> Why did you do this?
>
> See above.

See what above?

>> Is this another example of how you practice the Golden Rule?
>
> Yes.

It shows. But if this is such an example, then you have no cause to
complain about the treatment you receive here, as it is consistent with
the responses you get in many of the Usenet forums in which you, um,
"participate."
--
dgs

[Maxwell]

"Mxsmanic" > wrote in message
...
> Nomen Nescio writes:
>
>> But your altitude is much more important than ground track.
>
> You cannot find your altitude with a compass alone.
>
>> Why not three.
>
> Three adds mostly redundancy rather than any additional functionality in
> lateral navigation.
>
>> But it powers NO electronics in the plane.
>
> The assertion was that there was no electricity. I've demonstrated this
> assertion to be incorrect if the aircraft is powered by a typical
> reciprocating gasoline engine.
>

You haven't demonstrated anything but your ignorance.

[Maxwell]

"Mxsmanic" > wrote in message
...
> writes:
>
>> Not at airplane altitudes and speeds.
>
> Then why are they marked on the charts?
>
>> Well, I can see electricity can be added to that ever growing list
>> of things about which you know nothing.
>
> Are you saying that sparks are something other than electricity? What are
> they, then?
>
>> Magnetos generate pulses measured in the thousand of volts and microamps
>> of current.
>
> Volts? Microamps? These units are used in electrical engineering, not
> plumbing.
>
>> Even if they were hooked to something else, which they
>> aren't, the power generated would be useless for powering something like
>> a GPS.
>
> But that wasn't the assertion. The assertion was that there was no
> electricity in some aircraft. If they have typical powerplants, there is
> electricity.
>
>> My god, everytime you say something, more ignorance just roles out.
>
> I'm not the one making the mistakes.
>

You can talk more **** than a Jap radio.

[Maxwell]

"Nomen Nescio" > wrote in message
...
> -----BEGIN PGP SIGNED MESSAGE-----
>
> From: Mxsmanic >
>
>>>>I'm neither stupid nor hostile.
>>>
>>>Since self audits are always suspect, please provide a psychological
>>>evaluation from an outside source to support your claim.
>
>>I'll remember this the next time someone here claims to be a qualified
>>pilot.
>
> How about responding to the whole sentence?
>
> My flying ability, physical health, and mental health are evaluated by
> an independent source every 2 years.
>
> How about you?
>

The last time he took a personality test, the results came back negative.

[d.g.s.]

On 4/5/2007 11:43 AM Mxsmanic jumped down, turned around, and wrote:

> dgs writes:
>
>> So, when he attempts to label people as stupid (even if only by
>> implication), or treat others as if they're idiots, remember, he's
>> actually proposing that he be treated as if he's stupid too. At least
>> it's consistent.
>
> No. When I give honest assessments of something or someone, I expect others
> to do the same.

So when you posted this:

> I don't care how you treat me; you're just a name on a screen.

.... you expected that person to do the same? And no matter what that
person's response was, it would be equally valid, whether it was some-
thing you considered useful, or a derogatory comment? You expect others
who post here to treat you not as a human being, but as "just a name on
a screen?"
--
dgs

[Maxwell]

"Mxsmanic" > wrote in message
...
> d.g.s. writes:
>
>> You snipped the part of the post where I quoted the example, thus
>> destroying the context my question quoted above, a very dishonest
>> practice ...
>
> No, simply an accepted means of saving bandwidth.

If you gave a **** about bandwidth you would just shut up, listen and quit
trying to MC an advice column on a subject for which you have no real
experience.

[Mxsmanic]

Maxwell writes:

> If you gave a **** about bandwidth you would just shut up, listen and quit
> trying to MC an advice column on a subject for which you have no real
> experience.

I find this ironic coming from someone who writes post after post attacking me
and ignoring the topic of the thread.

So, why are magnetic headings still used, and do you think they should
continue to be used?

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

d.g.s. writes:

> So when you posted this:
>
> > I don't care how you treat me; you're just a name on a screen.
>
> ... you expected that person to do the same?

Yes.

> And no matter what that person's response was, it would be equally
> valid, whether it was something you considered useful, or a
> derogatory comment?

There is no correlation between validity and utility.

> You expect others who post here to treat you not as a human being,
> but as "just a name on a screen?"

Yes, I'd prefer that. I'm here to discuss aviation, not people (except within
the context of aviation).

--
Transpose mxsmanic and gmail to reach me by e-mail.

[d.g.s.]

On 4/5/2007 10:14 PM Mxsmanic jumped down, turned around, and wrote:

> Maxwell writes:
>
>> If you gave a **** about bandwidth you would just shut up, listen and quit
>> trying to MC an advice column on a subject for which you have no real
>> experience.
>
> I find this ironic coming from someone who writes post after post attacking me
> and ignoring the topic of the thread.

You're just a name on a screen. Why should anyone care how you find
this, or what you think of anything?
--
dgs

[d.g.s.]

On 4/5/2007 10:16 PM Mxsmanic jumped down, turned around, and wrote:

> [...] I'm here to discuss aviation

No, you aren't. If this was so, you would do nothing but discuss
aviation, and you wouldn't respond to anything else. In addition,
you wouldn't conflate flying airplanes with a piddly-ass Microsoft
flight simulation program, and pretend that they are the same thing.
Why are you so dishonest?
--
dgs

[Mxsmanic]

Nomen Nescio writes:

> If you really wanted to save bandwidth. You'd STFU.

If you really wanted to save bandwith, you discuss aviation, and not me.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

d.g.s. writes:

> No, you aren't. If this was so, you would do nothing but discuss
> aviation, and you wouldn't respond to anything else.

It takes two to discuss aviation, and when most of the replies are from people
like yourself who cannot overcome their personal fascination with me, aviation
tends to fall by the wayside. However, I'm happy to discuss aviation, if I
can find anyone willing to do so.

Would you like to discuss the thread topic? Do you know anything about it?

> In addition, you wouldn't conflate flying airplanes with a piddly-ass Microsoft
> flight simulation program, and pretend that they are the same thing.

Both of these are aviation-related, unlike your diatribe.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[d.g.s.]

On 4/5/2007 10:16 PM Mxsmanic jumped down, turned around, and wrote:

> d.g.s. writes:
>
>> You expect others who post here to treat you not as a human being,
>> but as "just a name on a screen?"
>
> Yes, I'd prefer that. I'm here to discuss aviation, not people (except within
> the context of aviation).

Irrelevant. You are just a name on a screen. You are not a human
being, and nobody is to regard you as one, or treat you with any form
of respect. Nobody is obliged to care why you're here, and nobody is
obliged to discuss things on your terms. This is what you just agreed
to, above.
--
dgs

[Mxsmanic]

d.g.s. writes:

> Irrelevant. You are just a name on a screen. You are not a human
> being, and nobody is to regard you as one, or treat you with any form
> of respect. Nobody is obliged to care why you're here, and nobody is
> obliged to discuss things on your terms. This is what you just agreed
> to, above.

I tell you what: Since you are either unwilling or unable to discuss anything
except me, and you seem equally unable to resist replying along those lines,
I'll stop it for you.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

d.g.s. writes:

> You're just a name on a screen. Why should anyone care how you find
> this, or what you think of anything?

Nobody should. They should simply be interested in and willing to discuss
aviation, in accordance with the purpose of the newsgroup.

Are you willing and able to do that, or are you only interested in me? In teh
former case, the current topic is the reason(s) for using magnetic headings in
aviation, and, by extension, the utility and/or advisability of continuing to
do so. (I started a similar thread long ago, but since many people seem to be
more interested in me than in the topic, it degenerated quickly.)

--
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[d.g.s.]

On 4/5/2007 10:24 PM Mxsmanic jumped down, turned around, and wrote:

> d.g.s. writes:
>
>> No, you aren't. If this was so, you would do nothing but discuss
>> aviation, and you wouldn't respond to anything else.
>
> It takes two to discuss aviation, and when most of the replies are from people
> like yourself who cannot overcome their personal fascination with me, aviation
> tends to fall by the wayside.

You are also responding to me and posting nothing about aviation. Thus,
you are incapable of overcoming your fascination with me.

> However, I'm happy to discuss aviation, if I
> can find anyone willing to do so.

You can't. You have repeatedly been unable to find anyone willing to do
so. Are you insane?

> Would you like to discuss the thread topic? Do you know anything about it?

I am uninterested in discussing what I know about aviation with you.

>> In addition, you wouldn't conflate flying airplanes with a piddly-ass Microsoft
>> flight simulation program, and pretend that they are the same thing.
>
> Both of these are aviation-related, unlike your diatribe.

And your response here *is* aviation-related?
--
dgs

[d.g.s.]

On 4/5/2007 10:26 PM Mxsmanic jumped down, turned around, and wrote:

> d.g.s. writes:
>
>> Irrelevant. You are just a name on a screen. You are not a human
>> being, and nobody is to regard you as one, or treat you with any form
>> of respect. Nobody is obliged to care why you're here, and nobody is
>> obliged to discuss things on your terms. This is what you just agreed
>> to, above.
>
> I tell you what: Since you are either unwilling or unable to discuss anything
> except me, and you seem equally unable to resist replying along those lines,
> I'll stop it for you.

Will you? How do you propose to stop me from posting?
--
dgs

[d.g.s.]

On 4/5/2007 10:26 PM Mxsmanic jumped down, turned around, and wrote:

> I tell you what: Since you are either unwilling or unable to discuss anything
> except me, and you seem equally unable to resist replying along those lines,
> I'll stop it for you.

Is this another example of how you follow the Golden Rule?
--
dgs

[d.g.s.]

On 4/5/2007 11:43 AM Mxsmanic jumped down, turned around, and wrote:

> dgs writes:
>
>> So, when he attempts to label people as stupid (even if only by
>> implication), or treat others as if they're idiots, remember, he's
>> actually proposing that he be treated as if he's stupid too. At least
>> it's consistent.
>
> No. When I give honest assessments of something or someone, I expect others
> to do the same.

And others do just that. It has been demonstrated here repeatedly.
--
dgs

[d.g.s.]

On 4/5/2007 10:27 PM Mxsmanic jumped down, turned around, and wrote:

> d.g.s. writes:
>
>> You're just a name on a screen. Why should anyone care how you find
>> this, or what you think of anything?
>
> Nobody should.

And nobody does.

> They should simply be interested in and willing to discuss
> aviation, in accordance with the purpose of the newsgroup.

Irrelevant. What people choose to be interested in doing in this
newsgroup is entirely up to them. Got a problem with that?
--
dgs

[d.g.s.]

On 4/5/2007 10:26 PM Mxsmanic jumped down, turned around, and wrote:

> I'll stop it

If only that were true.

Run away, Anthony, run away and hide! Pretend you're a "real" pilot on
your widdle simulator program on your widdle PC!
--
dgs

[Snowbird]

"Mxsmanic" wrote

> It changes at a variable rate, and once it approaches a degree, charts and
> navaids have to change. It's a tremendous amount of extra work, an
> additional
> source of error, and an imprecise and fickle basis for navigation.
>

I came to aviation from boats. In that field of navigation, in my part of
the world we mostly use true north as reference, but I've seen charts using
magnetic north, e.g. in the Caribbean where the magnetic variation is
considerable (around 15 degrees). Also, all boat GPSes can be set to show
either true or magnetic north, so using magnetic north is obviously a viable
method also at sea. So, let me give some arguments why using magnetic north
on aviation charts is not as stupid as it may sound.

1. A GPS does not show a reliable heading unless the aircraft is moving
(unless the GPS is of a very advanced type with dual antennas, not widely
used in aircraft). Before every takeoff the DG needs to be set, and the
magnetic compass enables this also when the aircraft is stationary.

2. The extra work referred to by Mx above is the same as would otherwise
have to be done in-flight in each aircraft, adding to the crew's workload
and introducing many possibilities for errors. (Mariners actually do this
en-route, but they have much more time to do the calculations than pilots
have.) For aviation, it's safer to do the calculations and corresponding
changes to charts and navaid data at a central source where they can be
quality-controlled much more extensively than what the co-pilot can do in an
aircraft in-flight. Charts need to be updated frequently anyway, regardless
of changes in magnetic variation, so it's not a big deal.

3. Even though electronic or inertial systems would allow navigation without
any reference to magnetic north, making the above mentioned calculations
unnecessary, experience and tradition so far points to the conclusion that a
magnetic compass and the corresponding magnetic designations on charts are
still useful. Note that when the magnetic compass is most critically needed,
i.e. in case of a failure of the electronic navigation systems, that's also
the time when the pilots have least time and opportunity to perform the
extra calculations that would be required if the chart data were given in
true north.

4. The magnetic compass system gives a simple foolproof method to ensure the
aircraft is lined up on the correct runway, anywhere in the world. Last
August, 49 real people died at KLEX in an accident that might have been
prevented by this simple check.

5. Omitting the magnetic compass would make the aircraft totally dependent
on external sources for all navigation other than chart-based VFR (unless it
has an inertial navigation system, which is obviously a much more expensive
solution viable only for large aircaft). This is so far not considered
acceptable.

[Mxsmanic]

Snowbird writes:

> I came to aviation from boats. In that field of navigation, in my part of
> the world we mostly use true north as reference, but I've seen charts using
> magnetic north, e.g. in the Caribbean where the magnetic variation is
> considerable (around 15 degrees). Also, all boat GPSes can be set to show
> either true or magnetic north, so using magnetic north is obviously a viable
> method also at sea.

Just out of curiosity, what are the usual navigation methods for boats and
ships these days? I suppose at sea you don't really have any equivalent of
VORs, so that's not an option, although I seem to recall that Loran and
(formerly) Omega were developed specifically for ships at sea (as well as GPS,
in part). It sounds like you don't navigate much with a magnetic compass.
And how do you find your way around with charts when you have no landmarks?

--
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[Snowbird]

"Mxsmanic" wrote .
>
> Just out of curiosity, what are the usual navigation methods for boats and
> ships these days? I suppose at sea you don't really have any equivalent
> of
> VORs, so that's not an option, although I seem to recall that Loran and
> (formerly) Omega were developed specifically for ships at sea (as well as
> GPS,
> in part). It sounds like you don't navigate much with a magnetic compass.
> And how do you find your way around with charts when you have no
> landmarks?
>
OK, this becomes partly OT but bear with me.

Basics are as always: Chart, compass, floating navaids (navigation buoys)
and fixed navaids (beacons and lighthouses).

Boats nowadays use fancy GPS chartplotters. In addition, ships and big boats
use radar.
There used to be radio beacons (corresponding to NDBs) but they are being
phased out. Before GPS there was Loran-C and Decca, which could provide a
fix with about 300 metres accuracy in coastal areas.

For me, the mag compass is still the primary steering reference at sea. GPS
is a very nice addition as it provides cross-track (i.e. course deviation)
indication as well as the distance to next waypoint. In coastal waters,
there are usually visual landmarks so in those areas only the chart is
needed.

Big ships seem to rely extensively on GPS, more so than in aviation. But
that has to be put in context. They also have excellent radar, which is a)
not relying on external sources and b) shows not only navigational features
(beacons etc) but also other traffic. In addition, unlike aircraft, in case
of a GPS navigation system failure, they always have the backup options of
using the sextant or, as a last resort, to stop and anchor.

Dual antenna GPS systems are quite common on ships, but as far as I
understand, not so much to give a heading reference (the compass is still
excellent for that) but more to aid maneuvering in cramped harbours. A big
ship has a lot of inertia, so once it starts yawing it will keep going for a
minute or so even with full opposite rudder. Therefore modern ships have
smart computers that compute each "wheel-over-point" where a turn has to be
initiated, in order to exit the turn at the right position. With dual GPS,
the yaw rate as well as the position of bow and stern can be precisely
monitored.

GPS on boats is a very nice thing, but it has its drawbacks. For example,
everyone tends to program their routes in exactly the same way from buoy to
buoy, with the result that traffic going both ways concentrates in a narrow
area. A dangerous thing, well known also in VFR aviation. Another danger is
that people venture out in IMC conditions (i.e. fog) much more than
previously. They can navigate OK, but without radar they have no way to see
and avoid other traffic until it's dangerously close. And of course Coast
Guard gets lots of work from boaters who become utterly lost when their
fancy GPS plotter fails.

[Maxwell]

"Mxsmanic" > wrote in message
...
> Nomen Nescio writes:
>
>> If you really wanted to save bandwidth. You'd STFU.
>
> If you really wanted to save bandwith, you discuss aviation, and not me.
>

Can't, you don't understand it.

[Kev]

On Apr 6, 1:22 am, Mxsmanic > wrote:
> Nomen Nescio writes:
> > If you really wanted to save bandwidth. You'd STFU.
>
> If you really wanted to save bandwith, you discuss aviation, and not me.

How about a contest..

The most mature of you, please stop responding with, or to, no-content
posts.

Thanks,
Kev

[Kev]

On Apr 5, 1:12 am, Mxsmanic > wrote:
> writes:
> > If you want to go to and from true and magnetic, you need a chart to
> > get the local difference.
>
> If you want to do anything, you need more than a compass.
>
> > If all you want to do is go in some particular direction until you
> > can see a recognizable landmark, all you need is a compass.
>
> In order to recognize the landmark, you need something more than a compass.

Yeah, eyes. Lots of people flew across the Atlantic with sometimes
just a compass, and they easily recognized the coast of England /
France / whatever with their bare old eyes ;-)

Heck, you don't need a chart with you to recognize the Eiffel Tower,
for example.

Kev

[Kev]

On Apr 4, 9:11 pm, Mxsmanic > wrote:
> Nomen Nescio writes:
> > The category that has wings and goes up in the sky.
>
> You mean like a 747-400? It has two GPS receivers, three IRUs, two VORs and
> two ADFs. One rarely falls back upon the magnetic compass.

But when you have to, you're damned glad it's there. Take for
example, the Gimli Glider or Air Transit glider, more recently. In
both planes, when the engines ran out of fuel, the only standby
instruments left were: a magnetic compass, an artificial horizon, an
airspeed indicator and an altimeter.

Kev

[Steven P. McNicoll]

"Kev" > wrote in message
oups.com...
>
> Heck, you don't need a chart with you to recognize the Eiffel Tower,
> for example.
>

How would I know if I was in France or Virginia?

[Bertie the Bunyip]

On Apr 5, 5:45 pm, wrote:
> In rec.aviation.piloting Mxsmanic > wrote:
>
> > Jose writes:
> > > "It must be true - I found it on the internet"
> > I think you'll find that the more you research about the geomagnetic field,
> > the less reliable you find it to be for navigation.
>
> I think you'll find that if you ever get an education, the less likely
> you will be to babble nonsense like that.
>

Umm, I doubt it. It´s a bit like saying if he lost a few pounds he
could levitate.



Bertie

[John Godwin]

"Steven P. McNicoll" > wrote in
hlink.net:

>
> "Kev" > wrote in message
> oups.com...
>>
>> Heck, you don't need a chart with you to recognize the Eiffel
>> Tower, for example.
>>
>
> How would I know if I was in France or Virginia?
>

.... or LV, Nevada :-)

--

[Rick Branch]

Steven P. McNicoll wrote:
> "Kev" > wrote in message
> oups.com...
>> Heck, you don't need a chart with you to recognize the Eiffel Tower,
>> for example.
>>
>
> How would I know if I was in France or Virginia?
>
>

.... or Mason, Ohio :-)

[Mxsmanic]

Kev writes:

> But when you have to, you're damned glad it's there.

If I had failures serious enough to fall back on a magnetic compass, the
presence of the compass would not be very reassuring overall.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

Kev writes:

> Yeah, eyes.

Not just eyes. You need a source of information. Without that, you won't
recognize anything. People overlook this sort of thing and then get in
trouble when they discover the hardware that an essential source of
information that they had previously taken for granted is no longer available.

> Lots of people flew across the Atlantic with sometimes
> just a compass, and they easily recognized the coast of England /
> France / whatever with their bare old eyes ;-)

Just a compass? No charts or other aids at all?

It's true that if you start at certain latitudes and fly due east, you'll
eventually hit some part of Europe. That's essentially just throwing darts,
however.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Snowbird]

"Mxsmanic" wrote
>
> If I had failures serious enough to fall back on a magnetic compass, the
> presence of the compass would not be very reassuring overall.
>

That's your opinion then. I can speak from my own experience, I've been in
that situation a few times and the magnetic compass has been a great help.

Of course without training and practical experience in using the magnetic
compass, its value is limited. But using it happens to be included in the
pilot's license curriculum, and for a reason.

[Snowbird]

"Mxsmanic" wrote ...
> Kev writes:
>
>> Yeah, eyes.
>
> Not just eyes. You need a source of information. Without that, you won't
> recognize anything. People overlook this sort of thing and then get in
> trouble when they discover the hardware that an essential source of
> information that they had previously taken for granted is no longer
> available.
>
>> Lots of people flew across the Atlantic with sometimes
>> just a compass, and they easily recognized the coast of England /
>> France / whatever with their bare old eyes ;-)
>
> Just a compass? No charts or other aids at all?
>
> It's true that if you start at certain latitudes and fly due east, you'll
> eventually hit some part of Europe. That's essentially just throwing
> darts,
> however.
>

How is this relevant to the topic? Has anyone here questioned the need for
charts (except when flying in familiar areas) ?

[george]

On Apr 7, 8:43 am, "Snowbird" > wrote:
> "Mxsmanic" wrote
>
>
>
> > If I had failures serious enough to fall back on a magnetic compass, the
> > presence of the compass would not be very reassuring overall.
>
> That's your opinion then. I can speak from my own experience, I've been in
> that situation a few times and the magnetic compass has been a great help.
>
> Of course without training and practical experience in using the magnetic
> compass, its value is limited. But using it happens to be included in the
> pilot's license curriculum, and for a reason.


I remember flying 'partial panel' under the hood where the compass was
an essential part of the scan..
and its unbreakable (unless you hang a magnet off it)

[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> Kev writes:

> > But when you have to, you're damned glad it's there.

> If I had failures serious enough to fall back on a magnetic compass, the
> presence of the compass would not be very reassuring overall.

Of course it wouldn't.

It wouldn't be reassuring to anyone that has had no training as a pilot.

--
Jim Pennino

Remove .spam.sux to reply.

[[email protected]]

In rec.aviation.piloting Mxsmanic > wrote:
> Kev writes:

<snip>

> > Lots of people flew across the Atlantic with sometimes
> > just a compass, and they easily recognized the coast of England /
> > France / whatever with their bare old eyes ;-)

> Just a compass? No charts or other aids at all?

> It's true that if you start at certain latitudes and fly due east, you'll
> eventually hit some part of Europe. That's essentially just throwing darts,
> however.

Not to real pilots, sim pilots maybe, but not real pilots.

--
Jim Pennino

Remove .spam.sux to reply.

[Mark Hansen]

On 04/06/07 13:56, george wrote:
>
> I remember flying 'partial panel' under the hood where the compass was
> an essential part of the scan..
> and its unbreakable (unless you hang a magnet off it)
>

I wouldn't say it's unbreakable. It may not suffer from problems due
to electrical or vacuum failure (other than perhaps the light), but
it can certainly leak it's fluid or get knocked out of alignment, etc.

[Maxwell]

"Mxsmanic" > wrote in message
...
> Kev writes:
>
>> But when you have to, you're damned glad it's there.
>
> If I had failures serious enough to fall back on a magnetic compass, the
> presence of the compass would not be very reassuring overall.
>

Don't worry, there has never been a navigation failure reported on a desk or
any of it's related hardware.

[Sylvain]

Maxwell wrote:

> Don't worry, there has never been a navigation failure reported on a desk
> or any of it's related hardware.

....well, I have had occasions when I was no longer quite sure where I was
(nor who was I, nor what was the time, nor why was I there in the first
place) after sitting at my desk for too long... but that's what expresso
machines are for.

--Sylvain

[CJ]

"Mxsmanic" > wrote in message
...
> writes:
>

> But that wasn't the assertion. The assertion was that there was no
> electricity in some aircraft. If they have typical powerplants, there is
> electricity.

Uh, no. What Ron Natalie said was:

"The engine in just about every airplane out there runs just freaking fine
without any electrical power consumed nor delivered to the rest of the
aircraft."

It's an accurate statement - that's probably what confused you.

"..no electricity" is what you mis-stated. Who asserted no electricity?

CJ

[Snowbird]

"Nomen Nescio" wrote ...
>
> You do realize that MX is an emotionally disturbed individual has has
> never flown in a small plane and thinks that Microsoft Flight Sim is
> real, don't you?
>

Well, he's an interesting personality. He was active in the rec.photo groups
around 2003 . Interestingly, over there he was opposed to new technology and
was heavily against the then-new digital cameras, while here he advocates
total reliance on electronic digital systems in aircraft. A surprising
change of attitude.

I won't go any further diagnosing Mx. But I do use MS Flight Sim sometimes
myself, mainly to rehearse the VFR route and approach to airports I haven't
visited before. It's a good tool for that. But for getting the feel of
flying most of the other sims I've tried are better. Too bad none of them
can replicate that feeling when the seat suddenly drops away from you in a
bump ;-)

[Marty Shapiro]

"Snowbird" > wrote in
.fi:

>
> "Nomen Nescio" wrote ...
>>
>> You do realize that MX is an emotionally disturbed individual has has
>> never flown in a small plane and thinks that Microsoft Flight Sim is
>> real, don't you?
>>
>
> Well, he's an interesting personality. He was active in the rec.photo
> groups around 2003 . Interestingly, over there he was opposed to new
> technology and was heavily against the then-new digital cameras, while
> here he advocates total reliance on electronic digital systems in
> aircraft. A surprising change of attitude.
>
> I won't go any further diagnosing Mx. But I do use MS Flight Sim
> sometimes myself, mainly to rehearse the VFR route and approach to
> airports I haven't visited before. It's a good tool for that. But for
> getting the feel of flying most of the other sims I've tried are
> better. Too bad none of them can replicate that feeling when the seat
> suddenly drops away from you in a bump ;-)
>
>
>

Try and get a ride in NASA's VMS (Verticle Motion Simulator). It will
let you feel the bump and even some G's. I saw it in action on a tour (no,
I didn't get to ride on it) and it was awesome. Think of a full motion
simulator which, in addition to pitch, roll, and yaw can also move 60'
vertically, 40' forward/backward and 8' side-to-side. To simulate Gs in a
turn, they slowly lower the "cab" and pull it back to the rear-most
position. Then when they pitched the cab down and rolled it in the
direction of the turn while simultaneously moving it forward and raising it
at a pretty rapid pace. (They were practicing a shuttle arrival at KSC.)

They have one motion base and several cabs. The cabs can be
configured independently of the motion base. NASA has simulated blimps,
helicopters, fighters, transport aircraft, and the space shuttle with the
VMS by simply changing the cab.

If you ever get to the San Francisco area, try and get a tour at NASA
AMES at Moffett Field (KNUQ).

--
Marty Shapiro
Silicon Rallye Inc.

(remove SPAMNOT to email me)

[Kev]

On Apr 6, 4:38 pm, Mxsmanic > wrote:
> Kev writes:
> > Lots of people flew across the Atlantic with sometimes
> > just a compass, and they easily recognized the coast of England /
> > France / whatever with their bare old eyes ;-)
>
> Just a compass? No charts or other aids at all?

A chart over nothing but water is useless :-)

> It's true that if you start at certain latitudes and fly due east, you'll
> eventually hit some part of Europe. That's essentially just throwing darts,
> however.

Yes, but in this case, it worked. The point was, just a compass is
all you need sometimes.

However, the discussion is about compass and magnetic navigation.
Charts are a given part of navigation.

Kev

[Mxsmanic]

Snowbird writes:

> That's your opinion then. I can speak from my own experience, I've been in
> that situation a few times and the magnetic compass has been a great help.

In a jet airliner? (That was the aircraft being discussed.)

I'll grant that it would be okay in a tiny aircraft with just you as
passenger. It would be as bad as nothing at all in the case of a large
airliner with hundreds of people aboard.

> Of course without training and practical experience in using the magnetic
> compass, its value is limited. But using it happens to be included in the
> pilot's license curriculum, and for a reason.

How often do pilots practice flying with just a compass once they've obtained
their licenses?

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

george writes:

> I remember flying 'partial panel' under the hood where the compass was
> an essential part of the scan..
> and its unbreakable (unless you hang a magnet off it)

Or turn on the air conditioning.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

Snowbird writes:

> How is this relevant to the topic? Has anyone here questioned the need for
> charts (except when flying in familiar areas) ?

It has been asserted that a compass alone is sufficient. But it's not. You
need charts or other sources of information in order to make a compass useful.

While one method of using a compass alone has been given here, it would only
be useful in populated areas. If you're truly out in the wilderness, it won't
help.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

Snowbird writes:

> Interestingly, over there he was opposed to new technology and
> was heavily against the then-new digital cameras, while here he advocates
> total reliance on electronic digital systems in aircraft.

No, I do not. If you examine my posts here, you'll find that I'm opposed to
extremes. I'm opposed to relying entirely on systems such as GPS or
computerized glass cockpits, and I'm also opposed to the romantic notion that
somehow a mere compass is going to get you out of trouble if more complex
instrumentation fails.

In other words, moderation is best in all things. You cannot fly safely with
just a compass. You also run a risk of flying unsafely if you rely entirely
on a fancy navigation system that is not proven 100% reliable, such as GPS.

To stay safe, you must recognize that anything can fail--and you must also
recognize that something as crude as a compass is really no more useful than
nothing at all, so you must not assume that having a compass makes you any
safer.

A corollary of this is that you must always verify that everything in your
aircraft is working. If you think you can get by with malfunctioning
equipment, then you don't need that equipment to begin with. If you normally
need it and it is malfunctioning and you choose to fly anyway, you may never
come back.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

writes:

> Not to real pilots, sim pilots maybe, but not real pilots.

A lot of sailors died that way. Airmen are no more immortal than sailors.

--
Transpose mxsmanic and gmail to reach me by e-mail.

[Mxsmanic]

Kev writes:

> A chart over nothing but water is useless :-)

"No charts or other aids."

> Yes, but in this case, it worked. The point was, just a compass is
> all you need sometimes.

That's not a risk I'd want to take.

And Lindbergh did have charts. Ironically, he had bought them at a boat shop,
and they were nautical charts, but they did the job.

--
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[Mxsmanic]

CJ writes:

> Uh, no. What Ron Natalie said was:
>
> "The engine in just about every airplane out there runs just freaking fine
> without any electrical power consumed nor delivered to the rest of the
> aircraft."
>
> It's an accurate statement - that's probably what confused you.

"Without any electrical power consumed." And before you say it, "nor"
excludes the remainder of the sentence (unlike "or").

--
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[Snowbird]

"Mxsmanic" wrote ..
> Snowbird writes:
>
>> That's your opinion then. I can speak from my own experience, I've been
>> in
>> that situation a few times and the magnetic compass has been a great
>> help.
>
> In a jet airliner? (That was the aircraft being discussed.)
>

I see no reference to jet airliners in the OP's post. On the contrary, since
he referred to his own flightplanning, that likely implies he flies a light
aircraft. An airliner pilot would presumably have the airline's planning
department do these chores for him.


> I'll grant that it would be okay in a tiny aircraft with just you as
> passenger. It would be as bad as nothing at all in the case of a large
> airliner with hundreds of people aboard.
>

Your opinion again. That airliner captain would have training and experience
in using a magnetic compass, so it certainly would be better than nothing to
him.


>> Of course without training and practical experience in using the magnetic
>> compass, its value is limited. But using it happens to be included in the
>> pilot's license curriculum, and for a reason.
>
> How often do pilots practice flying with just a compass once they've
> obtained
> their licenses?
>

There are such things as proficiency check flights, where the examiner may
choose to test the pilot's knowledge on that subject. Pilots obviously want
to pass the checkride. Anyway, it's not a particularly difficult skill.

[Mxsmanic]

Snowbird writes:

> I see no reference to jet airliners in the OP's post.

It was in the posts preceding mine.

> Your opinion again. That airliner captain would have training and experience
> in using a magnetic compass, so it certainly would be better than nothing to
> him.

It's better than nothing in the sense that hitting dirt is better than hitting
concrete.

> There are such things as proficiency check flights, where the examiner may
> choose to test the pilot's knowledge on that subject. Pilots obviously want
> to pass the checkride. Anyway, it's not a particularly difficult skill.

Okay, how many private pilots are compelled to demonstrate flying with just a
compass alone for proficiency check flights? And how realistic is such a
demonstration; that is, how often are pilots actually in this type of
situation in real life?

--
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[Snowbird]

"Mxsmanic" wrote
> Snowbird writes:
>
>> Interestingly, over there he was opposed to new technology and
>> was heavily against the then-new digital cameras, while here he advocates
>> total reliance on electronic digital systems in aircraft.
>
> No, I do not. If you examine my posts here, you'll find that I'm opposed
> to
> extremes. I'm opposed to relying entirely on systems such as GPS or
> computerized glass cockpits, and I'm also opposed to the romantic notion
> that
> somehow a mere compass is going to get you out of trouble if more complex
> instrumentation fails.

We obviously disagree on what is "extreme". The proposals regarding autoland
and pure simulator-based training strike me as highly extreme.

>
> In other words, moderation is best in all things. You cannot fly safely
> with
> just a compass. You also run a risk of flying unsafely if you rely
> entirely
> on a fancy navigation system that is not proven 100% reliable, such as
> GPS.
>

Your opinion. Aviation authorities accept compass and chart as sufficient
for VFR navigation. They also require it as mandatory.


> To stay safe, you must recognize that anything can fail--and you must also
> recognize that something as crude as a compass is really no more useful
> than
> nothing at all, so you must not assume that having a compass makes you any
> safer.

The magnetic compass is included in the minimum equipment list of any
aircraft I know, so obviously authorities disagree with that opinion.

>
> A corollary of this is that you must always verify that everything in your
> aircraft is working. If you think you can get by with malfunctioning
> equipment, then you don't need that equipment to begin with. If you
> normally
> need it and it is malfunctioning and you choose to fly anyway, you may
> never
> come back.
>

The first sentence is incorrect, while I agree with the second and third
sentence. What you must do is check if the equipment required for the
mission at hand is in working order, per the minimum equipment list. You may
take off with some malfunctioning equipment, as long as it does not
jeopardize the safety of the mission.


Regarding the magnetic compass, note that its usefulness is not limited to
those "catastrophic blackout" emergency-landing scenarios that some of the
posts here suggest. It may be simpler events such as an in-flight restart of
the FMS, or a handheld GPS falling on the floor in a small aircraft. In such
cases the magnetic compass helps against straying off course until the
problem is fixed.

[Snowbird]

"Mxsmanic" wrote ..
>
>> Your opinion again. That airliner captain would have training and
>> experience
>> in using a magnetic compass, so it certainly would be better than nothing
>> to
>> him.
>
> It's better than nothing

Good, we're making some progress.

> in the sense that hitting dirt is better than hitting
> concrete.
>

I don't find that comparison universally valid, so I have to disregard it.
For example, if you have to make a gear-up landing, you are advised to do it
on concrete rather than grass (or dirt). That's what the literature says
anyway.

[Mxsmanic]

Snowbird writes:

> I don't find that comparison universally valid, so I have to disregard it.
> For example, if you have to make a gear-up landing, you are advised to do it
> on concrete rather than grass (or dirt). That's what the literature says
> anyway.

But both are considered accidents, as opposed to a normal landing with gear,
which is not an accident. Thus, while a landing on one surface may do less
damage than a landing on another surface, that is not a huge consolation to
the pilot who has to land without gear.

--
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[BDS]

"Mxsmanic" > wrote

> Okay, how many private pilots are compelled to demonstrate flying with
just a
> compass alone for proficiency check flights? And how realistic is such a
> demonstration; that is, how often are pilots actually in this type of
> situation in real life?

Just about any decent instrument BFR or IPC is going to involve a loss of
the DG or HSI in IMC.

BDS

[Mxsmanic]

Snowbird writes:

> We obviously disagree on what is "extreme". The proposals regarding autoland
> and pure simulator-based training strike me as highly extreme.

They aren't, though. Most training for airline pilots today takes place in
simulators, so pure simulator-based training is only one small step away from
the current practice. And landing with autoland is much easier than commonly
believed--that's the whole idea. It's certainly easy enough that anyone could
do it by carrying out instructions given by someone else. This is not the
case with hand-flying, which requires a certain amount of practice
irrespective of any instruction provided by others.

> Your opinion. Aviation authorities accept compass and chart as sufficient
> for VFR navigation. They also require it as mandatory.

I don't judge safety on the basis of what others say. I have a much higher
standard.

> The magnetic compass is included in the minimum equipment list of any
> aircraft I know, so obviously authorities disagree with that opinion.

Or they simply haven't bothered to change the regulations, and have little
motivation to do so.

> The first sentence is incorrect, while I agree with the second and third
> sentence. What you must do is check if the equipment required for the
> mission at hand is in working order, per the minimum equipment list. You may
> take off with some malfunctioning equipment, as long as it does not
> jeopardize the safety of the mission.

I suppose if you consider malfunctioning avionics to be acceptable, you can
take off with that. I wouldn't. I know that even airlines are careless in
this way.

--
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[Mxsmanic]

BDS writes:

> Just about any decent instrument BFR or IPC is going to involve a loss of
> the DG or HSI in IMC.

But those are only a few of many instruments.

--
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[Snowbird]

"Mxsmanic" wrote

> I don't judge safety on the basis of what others say. I have a much
> higher
> standard.
>

Please elaborate what that higher standard is and how you claim to achieve
it. As a minimum, I will expect you never to have broken anything on those
simulated planes you fly.

[Mxsmanic]

Snowbird writes:

> Please elaborate what that higher standard is and how you claim to achieve
> it.

I've already explained it. I want all instruments to work, not just those on
the MEL.

> As a minimum, I will expect you never to have broken anything on those
> simulated planes you fly.

That minimum is satisfied.

--
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