Why The Hell... (random rant)

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..

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 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.

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

"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

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?

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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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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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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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