A month or two ago there was a thread about CDI indicating north/south
vs. left/right in particular on front course and back course LOC.
I'm studying for the IFR written and not in a single place
does the FAA use north/south. Again I'm banging my head
wondering does a lowly IFR student like me have to scream
learn the wrong way. Further they have questions about MLS approaches?
Has anyone ever flown one or even seen one? I don't
even know what equipment is required for one. A historical
note about this, the founders of the company I work for
were (partial?) inventers of the MLS back in I think the 1940's
or early 50's. One of the brothers (Sig Varian, I think) was a
pilot for a major but ended up biting it while
landing in Mexico at night. He intended to land on
the beach but ended up putting it in the drink.

The same bitching goes to the lack of reference to technology.
I really can't imagine hand flying in the soup, thunderstorms
around, turbulence, at night, etc. and playing around with
an E6B. Umm, how long does a leg take, ummm, give me
2 seconds and the 430 will take care of that. Of course
double check the 430 but an E6B is a bit out dated. It works
and works without batteries but if things are that bad
all around, the last thing I'm doing. If hells breaks loose
and needed to use one, I think I'd declare an emergency over
121.5. :)

sorry to vent.....and no need to remind me how the FAA
is screwed up. Overall though I gotta give them a LOT
of credit as it seems like one of the few big government
agencies that has it reasonably together.

Gerald Sylvester

On Thu, 06 Jan 2005 06:56:33 GMT, "G. Sylvester"
> wrote:

>A month or two ago there was a thread about CDI indicating north/south
>vs. left/right in particular on front course and back course LOC.
>I'm studying for the IFR written and not in a single place
>does the FAA use north/south. Again I'm banging my head
>wondering does a lowly IFR student like me have to scream
>learn the wrong way. Further they have questions about MLS approaches?
>Has anyone ever flown one or even seen one?


OOh you struck a nerve here.

Likewise, you will always get a question on p-t-d entries to holding
patterns, even though you will never have to do one, and questions on
planning x/c's down to the nearest 5 seconds, yet, (amd here's the
criminally negligent part), in spite of the fact that pilots are
killed practically every year because of a lack of understanding of
the rules for obstacle clearance on IFR departures, there is non one
question on the written on this subject (unless things have changed
very recently).

wrote:
> Likewise, you will always get a question on p-t-d entries to holding
> patterns, even though you will never have to do one...

You've gotta know you're wrong by asserting that ATC will never give a pilot
a hold; maybe in your area, but holds are still used by ATC.

Hilton

"G. Sylvester" > wrote in message
...
> A month or two ago there was a thread about CDI indicating north/south
> vs. left/right in particular on front course and back course LOC.
> I'm studying for the IFR written and not in a single place
> does the FAA use north/south. Again I'm banging my head
> wondering does a lowly IFR student like me have to scream
> learn the wrong way. Further they have questions about MLS approaches?
> Has anyone ever flown one or even seen one? I don't
> even know what equipment is required for one. A historical
> note about this, the founders of the company I work for
> were (partial?) inventers of the MLS back in I think the 1940's
> or early 50's. One of the brothers (Sig Varian, I think) was a
> pilot for a major but ended up biting it while
> landing in Mexico at night. He intended to land on
> the beach but ended up putting it in the drink.
>

Give the FAA the FAA answer to the FAA question. If given the FAA question
of "where is the sunrise first seen?" you should answer whatever the FAA
wants to hear, "east, west, left, or magenta." The written test isn't about
testing the thoroughness of your preparation, it's about following
directions. The checkride is the test of your preparations.

Don't confuse real life and FAA written tests. It matters not if you are
right or if telling the FAA the wrong answer they want to hear will corrupt
Western Civilization, it's a fool's errand to argue with them about the
question during or just after test prep. If your score is signicantly
affected by the few bogus questions on the test, you have bigger problems.

Cheer up, at least as much of my FAA mechanic tests concerned WWII radial
engines as turbines or modern recips. Hell, they may have even been a
question about Doppler or Omega on some test I took.

Here's my sure fire method for passing any FAA test. Buy the book with only
the Q&A. Read each Q, highlight each FAA desired answer. After you have
read each question and read only the highlighted answer, go take the test.
Depending on your reading speed, attention span, and the endurance of your
butt, you should be ready for the test in a day or two. You won't know a
damn thing about flying airplanes from doing this but you will get a good
score and not waste anymore time on their silly test. Spend the time you
saved actually learning the subjects and practicing the skills.

The single worst way to pass any FAA test, is to prepare for real-life
flying and then walk in and see the questions for the first time when it
counts. We taxpayers have spent much money collecting all the legally
allowable questions, and many hard-working publishers have spent much time
printing the answers to those out of date questions. Why ignore their
effort?

If you go to one of those expensive ground school courses like my previous
employer produces you will learn a couple of tricks to let you breeze
through the long and tedious questions and the rest of the time will be
essentially "here's the question and this is the answer." The vast majority
of customers promptly pass the test and hardly any of them ever confuse the
written test for real life.

--

Scott

"G. Sylvester" > wrote in message
...
> A month or two ago there was a thread about CDI indicating north/south
> vs. left/right in particular on front course and back course LOC.
> I'm studying for the IFR written and not in a single place
> does the FAA use north/south.

What in heck are you referring to? The CDI refers only to right or left of
the course indicated by the OBS and the TO/FROM window. You have to know how
to use the CDI when it appears to be reverse sensing.

Again I'm banging my head
> wondering does a lowly IFR student like me have to scream
> learn the wrong way. Further they have questions about MLS approaches?
> Has anyone ever flown one or even seen one?

Yes. They are somewhat more common than rumor has it. Since they exist, and
some airplanes are equipped for them, and your instrument rating says you
are allowed to fly them, then they are on the test. And stop banging your
head before you damage something valuable with it. :-)

>
> The same bitching goes to the lack of reference to technology.
> I really can't imagine hand flying in the soup, thunderstorms
> around, turbulence, at night, etc. and playing around with
> an E6B.

I can. Single pilot IFR? Probably not. But as a crew member on an older
airliner, yes. Besides, the questions do not presume that all IFR flying is
in the soup, thunderstorms around, turbulence, at night, etc. Believe it or
not, most IFR flying is in clear weather. You prioritize your tasks and stay
ahead of the airplane -- something that it appears you are still struggling
with. The FAA knows (or at least hopes) that you have enough judgment not to
fool with the E6B when you are too busy with other stuff.

Be glad the FAA has not finished writing questions about modern technology.
Eventually you are going to have to know things like when the GPS switches
from "ARMED" to "APPROACH" modes and what the channel number is for on WAAS
approaches. I still have not been seeing questions on approaches with
vertical guidance. You should know those things now, though, even if they
are not on the test. At least there are no longer any questions about radio
ranges.

On Thu, 6 Jan 2005 08:02:29 -0800, "C J Campbell"
> wrote:

>What in heck are you referring to? The CDI refers only to right or left of
>the course indicated by the OBS and the TO/FROM window. You have to know how
>to use the CDI when it appears to be reverse sensing.


Here we go again.

There ain't no such thing as "reverse sensing".

The receivers sense the same way at all times, regardless of the
position of the receiver.

There is only "reverse thinking".

(A VOR receiver works the same way in a balloon as it does in an
aircrafft. Ask 10 people in a balloon where "left" or "right" is, and
you'll get 10 different answers. Ask them where "north" is, and
they'll all point in tne same direction.)

C J Campbell wrote:

> Be glad the FAA has not finished writing questions about modern technology.
> Eventually you are going to have to know things like when the GPS switches
> from "ARMED" to "APPROACH" modes and what the channel number is for on WAAS
> approaches.

What's the channel number for on WAAS approaches? Thanks.

Dave

> wrote:
> wrote:
> >> Likewise, you will always get a question on p-t-d entries to holding
> >> patterns, even though you will never have to do one...
> >
> >You've gotta know you're wrong by asserting that ATC will never give a
pilot
> >a hold; maybe in your area, but holds are still used by ATC.
> >
> >Hilton

OK, Mr./Mrs./Miss noname at nowhere,


> I didn't say you'll never get a hold.
>
> I said you never have to do a p-t-d entry to one.

I'll bite. What is a p-t-d entry? Parallel, Teardrop, Direct??? So it's
now one entry? Or are you saying you can go fly holds and enter any which
way you want? If so, you'll end up doing one of these (or some version
thereof) anyway.

Hilton

On Thu, 06 Jan 2005 16:38:45 GMT, "Hilton" >
wrote:

>I'll bite. What is a p-t-d entry? Parallel, Teardrop, Direct??? So it's
>now one entry? Or are you saying you can go fly holds and enter any which
>way you want? If so, you'll end up doing one of these (or some version
>thereof) anyway.


I'm saying exactly that. The only requirement is to stay within
holding airspace.

The FAA finally wised up a few years back, and removed the requirement
from the PTS. Nevertheless, it remains a part of the written, while
knowledge of important things like obstaccle departure procedures
remains ignored on both the written and the practical test, and lives
are no doubt lost as a result. It's idiotic.

In a previous article, "Hilton" > said:
>I'll bite. What is a p-t-d entry? Parallel, Teardrop, Direct??? So it's
>now one entry? Or are you saying you can go fly holds and enter any which
>way you want? If so, you'll end up doing one of these (or some version
>thereof) anyway.

Do the "no **** hold entry". Fly to the fix, then turn to the outbound
heading. After a minute, turn 225 degrees towards the protected side.
Intercept the inbound course and you're in the hold. If you sketch it
out, you'll see that if you're coming from the direction where you're
supposed to do a parallel entry, this essentially is a parallel entry.
Otherwise it's sort-of like doing a direct entry, but guarantees that you
won't overshoot your turn and blunder into the non-protected side.


--
Paul Tomblin > http://xcski.com/blogs/pt/
UNIX was half a billion (500000000) seconds old on
Tue Nov 5 00:53:20 1985 GMT (measuring since the time(2) epoch).
-- Andy Tannenbaum

C J Campbell wrote:
> "G. Sylvester" > wrote in message
> ...
>
>>A month or two ago there was a thread about CDI indicating north/south
>>vs. left/right in particular on front course and back course LOC.
>>I'm studying for the IFR written and not in a single place
>>does the FAA use north/south.
>
>
> What in heck are you referring to? The CDI refers only to right or left of
> the course indicated by the OBS and the TO/FROM window. You have to know how
> to use the CDI when it appears to be reverse sensing.

The OBS has no meaning to a CDI when using a localizer.
It's left or right of the localizer beam where "left and right" is defined
as looking inward on the front course. It's only when the pilot's left and
right is reversed (as they are looking inward on the back course) that things
are "reversed."

On Thu, 6 Jan 2005 16:51:08 +0000 (UTC),
(Paul Tomblin) wrote:

>Do the "no **** hold entry". Fly to the fix, then turn to the outbound
>heading. After a minute, turn 225 degrees towards the protected side.
>Intercept the inbound course and you're in the hold. If you sketch it
>out, you'll see that if you're coming from the direction where you're
>supposed to do a parallel entry, this essentially is a parallel entry.
>Otherwise it's sort-of like doing a direct entry, but guarantees that you
>won't overshoot your turn and blunder into the non-protected side.


The only addition I would make to this is that when you turn to the
ooutbound heading, turn to intercept and join the holding course
outbound.

This way, you are alwys beginning your turn back inbound to rejoin
the holding course form a known position, and is less prone to error.

If you simply turn and fly parallel to the course, you risk being
blown out where it's harder to re-intercept the course before the
holding fix when you head back in.

But basically, this is what I have been teaching ever since the p-t-d
requirement was removed from the PTS. It works, it's simple, it's
safe, it's consistent, which you sure can't say for the old p-t-d
stuff.

On Thu, 06 Jan 2005 11:52:39 -0500, Ron Natalie >
wrote:

>The OBS has no meaning to a CDI when using a localizer.
>It's left or right of the localizer beam where "left and right" is defined
>as looking inward on the front course. It's only when the pilot's left and
>right is reversed (as they are looking inward on the back course) that things
>are "reversed."


This is not true. The OBS ring has no effect on the needle, but it
certainly has meaning.

If the OBS ring is set to the inbound (only) localizer course, it can
be interpreted exactly as the equivalent VOR course.

wrote:

> If you simply turn and fly parallel to the course, you risk being
> blown out where it's harder to re-intercept the course before the
> holding fix when you head back in.
>
This is the same thing that happnes on a parallel entry.

wrote:
> On Thu, 06 Jan 2005 11:52:39 -0500, Ron Natalie >
> wrote:
>
>
>>The OBS has no meaning to a CDI when using a localizer.
>>It's left or right of the localizer beam where "left and right" is defined
>>as looking inward on the front course. It's only when the pilot's left and
>>right is reversed (as they are looking inward on the back course) that things
>>are "reversed."
>
>
>
> This is not true. The OBS ring has no effect on the needle, but it
> certainly has meaning.
>
> If the OBS ring is set to the inbound (only) localizer course, it can
> be interpreted exactly as the equivalent VOR course.

You can make the same interpretations no matter what the OBS is set to.
It is necessary and sufficient to know what the inbound course is.

The only time the selector is useful is on a HSI.

GPS indicators can reverse sense also.

"Hilton" > wrote in message news:pQdDd.1923$
> Or are you saying you can go fly holds and enter any which
> way you want?
> Hilton
>

Any way you want. You choose. Just stay on the protected side and inside
the protected airspace.

> wrote in message
...
> On Thu, 6 Jan 2005 08:02:29 -0800, "C J Campbell"
> > wrote:
>
> >What in heck are you referring to? The CDI refers only to right or left
of
> >the course indicated by the OBS and the TO/FROM window. You have to know
how
> >to use the CDI when it appears to be reverse sensing.
>
>
> Here we go again.
>
> There ain't no such thing as "reverse sensing".

I said "appears," or is your hot button really that sensitive?

wrote:

> On Thu, 06 Jan 2005 12:25:01 -0500, Ron Natalie >
> wrote:
>
wrote:
>>
>>> If you simply turn and fly parallel to the course, you risk being
>>> blown out where it's harder to re-intercept the course before the
>>> holding fix when you head back in.
>>>
>>This is the same thing that happnes on a parallel entry.
>
>
> True.
>
> Your point is...?

That it's a lot of extra work if you're in a situation where a direct entry
works better. You seem to think that making the choice of entry method is
a lot of work. Once you're comfortable with these, though, it isn't. At
the start of my training, I had to draw things out. Now, I can just "see"
them.

And I've only been doing this for a few years.

But, having seen the "proper" entry, that entry will give you the least
amount of work. And *that* is the point: keeping the workload down to
permit one to concentrate on other things.

- Andrew

"Dave Butler" > wrote in message
news:1105029137.996075@sj-nntpcache-5...
> C J Campbell wrote:
>
> > Be glad the FAA has not finished writing questions about modern
technology.
> > Eventually you are going to have to know things like when the GPS
switches
> > from "ARMED" to "APPROACH" modes and what the channel number is for on
WAAS
> > approaches.
>
> What's the channel number for on WAAS approaches? Thanks.

From AIM 1-1-20 (d) "Flying Procedures With WAAS"

6. A new method has been added for selecting the final approach segment of
an instrument approach. Along with the current method used by most receivers
using menus where the pilot selects the airport, the runway, the specific
approach procedure and finally the IAF, there is also a channel number
selection method. The pilot enters a unique 5-digit number provided on the
approach chart, and the receiver recalls the matching final approach segment
from the aircraft database. A list of information including the available
IAFs is displayed and the pilot selects the appropriate IAF. The pilot
should confirm that the correct final approach segment was loaded by cross
checking the Approach ID, which is also provided on the approach chart.

"Ron Natalie" > wrote in message
m...
> C J Campbell wrote:
> > "G. Sylvester" > wrote in message
> > ...
> >
> >>A month or two ago there was a thread about CDI indicating north/south
> >>vs. left/right in particular on front course and back course LOC.
> >>I'm studying for the IFR written and not in a single place
> >>does the FAA use north/south.
> >
> >
> > What in heck are you referring to? The CDI refers only to right or left
of
> > the course indicated by the OBS and the TO/FROM window. You have to know
how
> > to use the CDI when it appears to be reverse sensing.
>
> The OBS has no meaning to a CDI when using a localizer.
> It's left or right of the localizer beam where "left and right" is defined
> as looking inward on the front course. It's only when the pilot's left
and
> right is reversed (as they are looking inward on the back course) that
things
> are "reversed."

That is all true.

> wrote in message
...
> On Thu, 06 Jan 2005 16:38:45 GMT, "Hilton" >
> wrote:
>
> >I'll bite. What is a p-t-d entry? Parallel, Teardrop, Direct??? So
it's
> >now one entry? Or are you saying you can go fly holds and enter any
which
> >way you want? If so, you'll end up doing one of these (or some version
> >thereof) anyway.
>
>
> I'm saying exactly that. The only requirement is to stay within
> holding airspace.
>
> The FAA finally wised up a few years back, and removed the requirement
> from the PTS. Nevertheless, it remains a part of the written

It also remains a requirement on most FAA approved part 141 syllabi, so the
entries have to be taught to competency whether they are part of the PTS or
not. The standard entries do guarantee that you will remain in the protected
holding airspace and are recommended in AIM, the FAA Instrument Flying
Handbook, and the FAA Instrument Procedures Handbook, all of which is where
the FAA draws its test questions from. The operations manuals for FAA
approved commercial IFR operators also often specify what holding pattern
entries the operator's pilots will use. Since these are the standard methods
and many students will be required by their employers to use them, there is
little point in teaching anything else.

If you want to do something else, of course, you are perfectly free to do
so.

C J Campbell > wrote:
> The operations manuals for FAA approved commercial IFR operators
> also often specify what holding pattern entries the operator's
> pilots will use. Since these are the standard methods and many
> students will be required by their employers to use them, there is
> little point in teaching anything else.

I don't see anything wrong with teaching or learning them, but I can
also see how it's much more important for a commercial pilot flying
high performance aircraft than for a spam can driver.

If you're holding at 210 kts (and maybe limited to less than standard
rate turns by your FD), you're going to eat up a lot of sky. The
correct entry may be the only thing keeping you from blowing out of
the protected area. This is much less likely to be an issue at 90
kts.

On Thu, 06 Jan 2005 15:40:45 -0500, Andrew Gideon >
wrote:


>
>And I've only been doing this for a few years

Precisely.

On Thu, 6 Jan 2005 12:43:20 -0800, "C J Campbell"
> wrote:

>
>"Ron Natalie" > wrote in message
m...
>> C J Campbell wrote:
>> > "G. Sylvester" > wrote in message
>> > ...
>> >
>> >>A month or two ago there was a thread about CDI indicating north/south
>> >>vs. left/right in particular on front course and back course LOC.
>> >>I'm studying for the IFR written and not in a single place
>> >>does the FAA use north/south.
>> >
>> >
>> > What in heck are you referring to? The CDI refers only to right or left
>of
>> > the course indicated by the OBS and the TO/FROM window. You have to know
>how
>> > to use the CDI when it appears to be reverse sensing.
>>
>> The OBS has no meaning to a CDI when using a localizer.
>> It's left or right of the localizer beam where "left and right" is defined
>> as looking inward on the front course. It's only when the pilot's left
>and
>> right is reversed (as they are looking inward on the back course) that
>things
>> are "reversed."
>
>That is all true.
>


Almost.

The OBS has much meaning to a CDI when using a localizer course, if
you just know how to interpret said meaning.

> wrote in message
...
> >>
> >> The OBS has no meaning to a CDI when using a localizer.
> >> It's left or right of the localizer beam where "left and right" is
defined
> >> as looking inward on the front course. It's only when the pilot's
left
> >and
> >> right is reversed (as they are looking inward on the back course) that
> >things
> >> are "reversed."
> >
> >That is all true.
> >
>
>
> Almost.
>
> The OBS has much meaning to a CDI when using a localizer course, if
> you just know how to interpret said meaning.

It has no meaning to the CDI, which after all is an inanimate object. If you
are properly trained it should have some meaning for you.

wrote:

> If the OBS is set to the course, you can immediately discern whether
> you are north or south of an eastbound course, for example. You can
> do this by looking at a properly set OBS ring, and at which way the
> needle is leaning.

Setting the OBS during a localizer approach is a good mnemonic. I do that.
It's also a good habit.

But it doesn't really impact *interpretation* of the CDI's display (unless
one forgets the course marked by the localizer, in which case the OBS
setting saves having to look down at the plate).

Using your example, the OBS doesn't do anything but remind you that the
course indicated by the localizer is eastbound. Useful, true, but I'd not
consider that a part of the interpretation process. I make this
distinction because, unless I forget the course, I never need to look at
the OBS to discern the meaning of the CDI.

- Andrew

wrote:

> On Thu, 06 Jan 2005 15:40:45 -0500, Andrew Gideon >
> wrote:
>
>
>>
>>And I've only been doing this for a few years
>
> Precisely.

I don't see your point. Are you suggesting that I'll eventually lose the
ease with which I see holds and their entries?

- Andrew

wrote:

> The "one-entry" method makes the initial turn the shortest way to
> outbound.

So if I'm to hold over a VOR on the 270 radial, and I'm flying a track of
080, I should turn left to intercept the 270 outbound after overflying the
VOR?

- Andrew

> wrote in message
...
> >>
> >> The OBS has much meaning to a CDI when using a localizer course, if
> >> you just know how to interpret said meaning.
> >
> >It has no meaning to the CDI, which after all is an inanimate object. If
you
> >are properly trained it should have some meaning for you.
> >
> When I use words, they mean exactly what I mean for them to mean,
> nothing more and nothing less.

Very well, what does the OBS mean to the CDI on a localizer?

There are a whole bunch of useless questions that you just have to get
through. Like the one where you have to pick which aircraft corresponds
to the given CDI indications. Who cares where the aircraft is. You will
no longer be there by the time you blink. What matters most is which
direction you have to turn to. Unfortunately, not only does the FAA
teach this contorted method of CDI interpretation, the majority of CFI's
also teach this way, and many are not even aware that there is a simpler
way. I wrote an article about this and sent it to a few magazines, and
it was turned down because they thought that this method was too
'controversial'. You can see my article at
http://www.geocities.com/asarangan/aviation.html



"G. Sylvester" > wrote in news:Bi5Dd.8613
:

> A month or two ago there was a thread about CDI indicating north/south
> vs. left/right in particular on front course and back course LOC.
> I'm studying for the IFR written and not in a single place
> does the FAA use north/south. Again I'm banging my head
> wondering does a lowly IFR student like me have to scream
> learn the wrong way. Further they have questions about MLS
approaches?
> Has anyone ever flown one or even seen one? I don't
> even know what equipment is required for one. A historical
> note about this, the founders of the company I work for
> were (partial?) inventers of the MLS back in I think the 1940's
> or early 50's. One of the brothers (Sig Varian, I think) was a
> pilot for a major but ended up biting it while
> landing in Mexico at night. He intended to land on
> the beach but ended up putting it in the drink.
>
> The same bitching goes to the lack of reference to technology.
> I really can't imagine hand flying in the soup, thunderstorms
> around, turbulence, at night, etc. and playing around with
> an E6B. Umm, how long does a leg take, ummm, give me
> 2 seconds and the 430 will take care of that. Of course
> double check the 430 but an E6B is a bit out dated. It works
> and works without batteries but if things are that bad
> all around, the last thing I'm doing. If hells breaks loose
> and needed to use one, I think I'd declare an emergency over
> 121.5. :)
>
> sorry to vent.....and no need to remind me how the FAA
> is screwed up. Overall though I gotta give them a LOT
> of credit as it seems like one of the few big government
> agencies that has it reasonably together.
>
> Gerald Sylvester
>
>

wrote in
:

> On Thu, 06 Jan 2005 11:52:39 -0500, Ron Natalie >
> wrote:
>
>>The OBS has no meaning to a CDI when using a localizer.
>>It's left or right of the localizer beam where "left and right" is
>>defined as looking inward on the front course. It's only when the
>>pilot's left and right is reversed (as they are looking inward on the
>>back course) that things are "reversed."
>
>
> This is not true. The OBS ring has no effect on the needle, but it
> certainly has meaning.
>
> If the OBS ring is set to the inbound (only) localizer course, it can
> be interpreted exactly as the equivalent VOR course.
>

Exactly. Glad to see someone else using a more sensible interpretation.

No, it is not just a reminder, it is a tremendous aid in interpretation.
Reverse sensing is all in your head. The aircraft or the CDI does not
know reverse sensing. Read this article:
http://131.238.38.204/~sarangan/aviation/articles/vor-article.pdf





Andrew Gideon > wrote in
online.com:

> wrote:
>
>> If the OBS is set to the course, you can immediately discern whether
>> you are north or south of an eastbound course, for example. You can
>> do this by looking at a properly set OBS ring, and at which way the
>> needle is leaning.
>
> Setting the OBS during a localizer approach is a good mnemonic. I do
> that. It's also a good habit.
>
> But it doesn't really impact *interpretation* of the CDI's display
> (unless one forgets the course marked by the localizer, in which case
> the OBS setting saves having to look down at the plate).
>
> Using your example, the OBS doesn't do anything but remind you that
> the course indicated by the localizer is eastbound. Useful, true, but
> I'd not consider that a part of the interpretation process. I make
> this distinction because, unless I forget the course, I never need to
> look at the OBS to discern the meaning of the CDI.
>
> - Andrew
>

The CDI tells you which heading to turn to if you dial in the correct OBS.
Which do you think is more useful command: turn left, or turn to a heading
of xxx?




"C J Campbell" > wrote in
:

>
> > wrote in message
> ...
>> >>
>> >> The OBS has much meaning to a CDI when using a localizer course,
>> >> if you just know how to interpret said meaning.
>> >
>> >It has no meaning to the CDI, which after all is an inanimate
>> >object. If
> you
>> >are properly trained it should have some meaning for you.
>> >
>> When I use words, they mean exactly what I mean for them to mean,
>> nothing more and nothing less.
>
> Very well, what does the OBS mean to the CDI on a localizer?
>
>

> The CDI tells you which heading to turn to if you dial in the correct OBS.
> Which do you think is more useful command: turn left, or turn to a heading
> of xxx?

If I'm already pointing more or less in the right direction, "turn
left" is more useful. If not, the actual heading is.

When on an approach, I'm pointing more or less in the direction I want
to go, and I use the CDI to make small corrections to keep on the
flight path I want. So long as these corrections remain small, and I
remain more or less on the localizer, all I need is "a little more
left". The command "turn to heading xxx" requires me to figure out
how to get to xxx. "turn a little left" does not.

Jose
--
Money: What you need when you run out of brains.
for Email, make the obvious change in the address.

What you are saying is true. The problem is when you are not aligned
with the correct direction, either because you are being vectored, lost
or some other reason. When you are being vectored (or intercepting from
a PT), how do you tell whether you have blasted through the course, or
still heading towards it?? By the time you figure it out using the
left/right interpretation, you will have gone several miles out. It is
trivial with the heading interpretation. Another example is cross
radials. Some fixes on approaches are defined by a VOR cross radial. How
do you know whether you have passed that fix or still heading towards
it? Again, this is trivial with the heading interpretation, but
significantly more difficult with the left/right interpretation. I can
give you many more examples. However, I do agree with you that
left/right works when you are more or less aligned with the course. But
the important point is that it work ONLY in that situation. The other
technique works in ANY situation.





Jose > wrote in
m:

>> The CDI tells you which heading to turn to if you dial in the correct
>> OBS. Which do you think is more useful command: turn left, or turn
>> to a heading of xxx?
>
> If I'm already pointing more or less in the right direction, "turn
> left" is more useful. If not, the actual heading is.
>
> When on an approach, I'm pointing more or less in the direction I want
> to go, and I use the CDI to make small corrections to keep on the
> flight path I want. So long as these corrections remain small, and I
> remain more or less on the localizer, all I need is "a little more
> left". The command "turn to heading xxx" requires me to figure out
> how to get to xxx. "turn a little left" does not.
>
> Jose

On 6 Jan 2005 22:40:48 -0600, Andrew Sarangan
> wrote:

>Unfortunately, not only does the FAA
>teach this contorted method of CDI interpretation, the majority of CFI's
>also teach this way, and many are not even aware that there is a simpler
>way. I wrote an article about this and sent it to a few magazines, and
>it was turned down because they thought that this method was too
>'controversial'.


It is this kind of stoneage thinking in aviation that is the reason,
for example, that we can log 20 hours of instrument time on totally
ancient, obsolete, and archaic potentiometer-driven simulators, but
only can get 10 hours on a modern, state-of-the-art computer-driven
simulator with many times the capabilities and function.

There is much about aviation stuck in a time warp. Personally, I'm
surprised that we have moved as fast as we have with GPS, (which is
about half as fast as we could and should have.)

> wrote in message
...
> On Thu, 6 Jan 2005 16:07:08 -0800, "C J Campbell"
> > wrote:
>
> >
> > wrote in message
> ...
> >> >>
> >> >> The OBS has much meaning to a CDI when using a localizer course, if
> >> >> you just know how to interpret said meaning.
> >> >
> >> >It has no meaning to the CDI, which after all is an inanimate object.
If
> >you
> >> >are properly trained it should have some meaning for you.
> >> >
> >> When I use words, they mean exactly what I mean for them to mean,
> >> nothing more and nothing less.
> >
> >Very well, what does the OBS mean to the CDI on a localizer?
> >
>
> The information on the OBS, combined with the information from the
> CDI, augmented by information from the DG, tells you, at a single
> glance:
>

Yes, it tells me something, but what does it mean to the CDI? You said your
wording was deliberate and specific.

"Andrew Sarangan" > wrote in message
1...
> The CDI tells you which heading to turn to if you dial in the correct OBS.
> Which do you think is more useful command: turn left, or turn to a
heading
> of xxx?

Yes, it tells me something, but what does the OBS tell the CDI on a
localizer?

"Andrew Sarangan" > wrote in message
1...
> There are a whole bunch of useless questions that you just have to get
> through. Like the one where you have to pick which aircraft corresponds
> to the given CDI indications. Who cares where the aircraft is. You will
> no longer be there by the time you blink.

Are you saying that the aircraft moves from one quadrant to the other in the
blink of an eye?

On Fri, 7 Jan 2005 07:51:51 -0800, "C J Campbell"
> wrote:

>> The information on the OBS, combined with the information from the
>> CDI, augmented by information from the DG, tells you, at a single
>> glance:
>>
>
>Yes, it tells me something, but what does it mean to the CDI? You said your
>wording was deliberate and specific.


Quite the contrary, I said that when I use words, they mean just what
I want them to mean, nothing more and nothing less.

That way I don't get involved in bull**** semantic wordgames.

Adios.

Great article. I read it a while back and ....... *poof*.... it all made
sense.
Thanks!

"Andrew Sarangan" > wrote in message
1...
> No, it is not just a reminder, it is a tremendous aid in interpretation.
> Reverse sensing is all in your head. The aircraft or the CDI does not
> know reverse sensing. Read this article:
> http://131.238.38.204/~sarangan/aviation/articles/vor-article.pdf
>
>
>
>
>
> Andrew Gideon > wrote in
> online.com:
>
>> wrote:
>>
>>> If the OBS is set to the course, you can immediately discern whether
>>> you are north or south of an eastbound course, for example. You can
>>> do this by looking at a properly set OBS ring, and at which way the
>>> needle is leaning.
>>
>> Setting the OBS during a localizer approach is a good mnemonic. I do
>> that. It's also a good habit.
>>
>> But it doesn't really impact *interpretation* of the CDI's display
>> (unless one forgets the course marked by the localizer, in which case
>> the OBS setting saves having to look down at the plate).
>>
>> Using your example, the OBS doesn't do anything but remind you that
>> the course indicated by the localizer is eastbound. Useful, true, but
>> I'd not consider that a part of the interpretation process. I make
>> this distinction because, unless I forget the course, I never need to
>> look at the OBS to discern the meaning of the CDI.
>>
>> - Andrew
>>
>

> wrote in message
...
> On Fri, 7 Jan 2005 07:51:51 -0800, "C J Campbell"
> > wrote:
>
> >> The information on the OBS, combined with the information from the
> >> CDI, augmented by information from the DG, tells you, at a single
> >> glance:
> >>
> >
> >Yes, it tells me something, but what does it mean to the CDI? You said
your
> >wording was deliberate and specific.
>
>
> Quite the contrary, I said that when I use words, they mean just what
> I want them to mean, nothing more and nothing less.

Well, if I misunderstood what you said, I am indeed sorry. OTOH, it is not
just semantic word games. Students tend to take what their instructors say
quite literally.

> When you are being vectored (or intercepting from
> a PT), how do you tell whether you have blasted through the course, or
> still heading towards it?

Do to this, I do have to use more interpretation and I extract enough
heading information to tell me. (All I need to know is "yes/no"). My
mental process is to mentally rotate the airplane to point towards the
runway; this tells me which side I'm on, and then when I mentally
unrotate the airplane, this tells me whether it's the side I want or
not. This does not take me several miles, and is acutally quite
natural when intercepting from a PT, where I'm primarily using the
compass to accomplish the turn anyway (I use the 80-260 method).

> Some fixes on approaches are defined by a VOR cross radial. How
> do you know whether you have passed that fix or still heading towards
> it?

When the OBS is set to the radial, the needle points towards the radio
station until passage, then it points away. On my chart (which I hold
or can orient track up) I can see where the station is. Drop dead
simple. This is easily visualized by mentally flying away from the
station.

Jose
--
Money: What you need when you run out of brains.
for Email, make the obvious change in the address.

"Jose" > wrote in message
m...
>> When you are being vectored (or intercepting from a PT), how do you tell
>> whether you have blasted through the course, or still heading towards it?
>
> Do to this, I do have to use more interpretation and I extract enough
> heading information to tell me. (All I need to know is "yes/no"). My
> mental process is to mentally rotate the airplane to point towards the
> runway; this tells me which side I'm on, and then when I mentally unrotate
> the airplane, this tells me whether it's the side I want or not. This
> does not take me several miles, and is acutally quite natural when
> intercepting from a PT, where I'm primarily using the compass to
> accomplish the turn anyway (I use the 80-260 method).
>
>> Some fixes on approaches are defined by a VOR cross radial. How do you
>> know whether you have passed that fix or still heading towards it?
>
> When the OBS is set to the radial, the needle points towards the radio
> station until passage, then it points away. On my chart (which I hold or
> can orient track up) I can see where the station is. Drop dead simple.
> This is easily visualized by mentally flying away from the station.
>

All this mental rotation of the aircraft and figuring out position is
completely unnecessary. All you have to do is glance at the CDI and see if
your heading is on the same side as the needle. If it is, you are still
headed toward the radial, you have not passed it. If not, you have passed
through it. Doesn't matter whether the radial number is set at the top or
bottom of the dial, it still works exactly the same way.

For a localizer, set the OBS to the inbound course at the top and you
interpret it exactly the same way, whether on the front course or the back
course. For GPS, set the OBS to DTK and it is exactly the same.

"C J Campbell" > wrote in
:

>
> "Andrew Sarangan" > wrote in message
> 1...
>> There are a whole bunch of useless questions that you just have to
>> get through. Like the one where you have to pick which aircraft
>> corresponds to the given CDI indications. Who cares where the
>> aircraft is. You will no longer be there by the time you blink.
>
> Are you saying that the aircraft moves from one quadrant to the other
> in the blink of an eye?
>
>
>

No, what I am saying is, it is more important to turn to the correct
heading than to figure out where you are right now, because by the time you
figure out where you are, you will not be there anymore. The FAA exams
would lead one to think that it is more important to know where you are
now. None of the questions ask 'which heading should the aircraft turn to'.
Instead they dwell on 'where is the aircraft now'.

> All this mental rotation of the aircraft and figuring out position is
> completely unnecessary.

I don't need to do it, I just used it for illustration. Needle points
to the station, you're not there yet.

> All you have to do is glance at the CDI and see if
> your heading is on the same side as the needle. If it is, you are still
> headed toward the radial, you have not passed it. If not, you have passed
> through it. Doesn't matter whether the radial number is set at the top or
> bottom of the dial, it still works exactly the same way.

Also nice.

> For a localizer, set the OBS to the inbound course at the top and you
> interpret it exactly the same way, whether on the front course or the back
> course.

Nice for symmetry, but "a little left" is quicker than finding the
course on the dial for comparison, though it does make the back course
"not special".

Jose
--
Money: What you need when you run out of brains.
for Email, make the obvious change in the address.

If you have to fly to an intersection with both CDI at full scale
deflection, how would you get there? The left/right method will not help
you here, but it is trivial with the heading technique.




Jose > wrote in
:

>> All this mental rotation of the aircraft and figuring out position is
>> completely unnecessary.
>
> I don't need to do it, I just used it for illustration. Needle points
> to the station, you're not there yet.
>
>> All you have to do is glance at the CDI and see if
>> your heading is on the same side as the needle. If it is, you are
>> still headed toward the radial, you have not passed it. If not, you
>> have passed through it. Doesn't matter whether the radial number is
>> set at the top or bottom of the dial, it still works exactly the same
>> way.
>
> Also nice.
>
>> For a localizer, set the OBS to the inbound course at the top and you
>> interpret it exactly the same way, whether on the front course or the
>> back course.
>
> Nice for symmetry, but "a little left" is quicker than finding the
> course on the dial for comparison, though it does make the back course
> "not special".
>
> Jose

> If you have to fly to an intersection with both CDI at full scale
> deflection, how would you get there? The left/right method will not help
> you here, but it is trivial with the heading technique.

That is correct. If I ever need to do this, I would not use the
left/right technique. I'd do the extra steps needed to figure out
which way I needed to go, and I'd expect that I'd intersect one of the
radials before the other (i.e. I'd not end up flying direct to the
intersection)

I don't think one can guarantee a direct ground track if both CDIs are
at full deflection and you need to head directly towards an
intersection. (at least not without fiddling with the OBS to see
where you really are).

How would you fly directly towards an intersection, with both CDIs
pegged, and no fiddling with the OBS? (fiddle with the OBS and you've
unpegged the CDI and now know what radial you're on)

Jose
--
Money: What you need when you run out of brains.
for Email, make the obvious change in the address.

You are correct that it is impossible to fly direct to the intersection.
But you can take a heading that will intercept one of the two radials, and
then you fly along that radial to intersection. I realize this can be done
with the left/right technique also, but it requires a lot of mind numbming
visualizations. It is really trivial the other way.


Jose > wrote in
om:

>> If you have to fly to an intersection with both CDI at full scale
>> deflection, how would you get there? The left/right method will not
>> help you here, but it is trivial with the heading technique.
>
> That is correct. If I ever need to do this, I would not use the
> left/right technique. I'd do the extra steps needed to figure out
> which way I needed to go, and I'd expect that I'd intersect one of the
> radials before the other (i.e. I'd not end up flying direct to the
> intersection)
>
> I don't think one can guarantee a direct ground track if both CDIs are
> at full deflection and you need to head directly towards an
> intersection. (at least not without fiddling with the OBS to see
> where you really are).
>
> How would you fly directly towards an intersection, with both CDIs
> pegged, and no fiddling with the OBS? (fiddle with the OBS and you've
> unpegged the CDI and now know what radial you're on)
>
> Jose

> You are correct that it is impossible to fly direct to the intersection.
> But you can take a heading that will intercept one of the two radials, and
> then you fly along that radial to intersection. I realize this can be done
> with the left/right technique also, but it requires a lot of mind numbming
> visualizations. It is really trivial the other way.

What is mind-numbing to one is trivial for another, with no
denegration intended.

It's important to understand the instrument. Once you do, pick the
technique that works for you, while not forgetting the fundamentals of
the instrument.

Jose
--
Money: What you need when you run out of brains.
for Email, make the obvious change in the address.

>> The CDI tells you which heading to turn to if you dial
>> in the correct OBS. Which do you think is more useful
>> command: turn left, or turn to a heading of xxx?
>
> If I'm already pointing more or less in the right direction,
> "turn left" is more useful. If not, the actual heading is.

I guess it really comes down to... the needle can be read as saying
"turn left... of the course in the OBS". Which if you're pretty much
facing the course in the OBS, is "left". And if not, you get your
heading by looking left of the OBS.

Jose
--
Money: What you need when you run out of brains.
for Email, make the obvious change in the address.

wrote:

> On Thu, 06 Jan 2005 17:52:20 -0500, Andrew Gideon >
> wrote:
>
wrote:
>>
>>> The "one-entry" method makes the initial turn the shortest way to
>>> outbound.
>>
>>So if I'm to hold over a VOR on the 270 radial, and I'm flying a track of
>>080, I should turn left to intercept the 270 outbound after overflying the
>>VOR?
>>
>> - Andrew
>
>
> Yes,

You can do that while staying on the protected side?

- Andrew

Andrew Sarangan wrote:

> No, it is not just a reminder, it is a tremendous aid in interpretation.
> Reverse sensing is all in your head.

Amusing combination of text, as the OBS only helps in this context if the
heading isn't [still] in your head. Yes, the information provided is
important. But - at least in my experience - it's already in memory.

What I don't understand is why nobody has yet mentioned wind correction in
this thread. When flying a localizer, I'll typically have some amount of
crab in place. Thus, my DG should read something different from the track
of the approach (and the OBS). If the needle starts to drift (and assuming
I've maintained my intended heading {8^), I'll correct that intended
heading one way or the other.

So while the plate may tell me to fly 223, I may flying 230. Tempting it is
to put 230 in the OBS, as that's not written anywhere. But that's too much
futzing (esp. as it is a dynamic value), so I just live with the need to
remember.

- Andrew

Think of it as a slide rule. Why bother using a slide rule when you can
do it in your head? Come to think of it, why bother using an E6B? Just
do it in your head. It is all simple math anyway. I am not saying it is
impossible to do all this in your head. One does not need a PhD to
figure out which way to turn when the CDI deflects one way. The goal,
however, is to reduce the number of brain CPU cycles. It frees up more
time for more important things. Everyone has their own favorite way of
using the CDI, but I have never encountered anyone who did not think
that the heading interpretation was significantly simpler than the
left/right interpretation after I finish explaining it to them.
Regarding wind, the wind correction naturally falls out of the CDI
deflection. I have elaborated this elsewhere, and I am getting tired of
sounding like a broken record, so I will leave that up to you to look it
up.




Andrew Gideon > wrote in
online.com:

> Andrew Sarangan wrote:
>
>> No, it is not just a reminder, it is a tremendous aid in
>> interpretation. Reverse sensing is all in your head.
>
> Amusing combination of text, as the OBS only helps in this context if
> the heading isn't [still] in your head. Yes, the information provided
> is important. But - at least in my experience - it's already in
> memory.
>
> What I don't understand is why nobody has yet mentioned wind
> correction in this thread. When flying a localizer, I'll typically
> have some amount of crab in place. Thus, my DG should read something
> different from the track of the approach (and the OBS). If the needle
> starts to drift (and assuming I've maintained my intended heading
> {8^), I'll correct that intended heading one way or the other.
>
> So while the plate may tell me to fly 223, I may flying 230. Tempting
> it is to put 230 in the OBS, as that's not written anywhere. But
> that's too much futzing (esp. as it is a dynamic value), so I just
> live with the need to remember.
>
> - Andrew
>
>

On Mon, 10 Jan 2005 17:33:11 -0500, Andrew Gideon >
wrote:

>Andrew Sarangan wrote:
>
>> No, it is not just a reminder, it is a tremendous aid in interpretation.
>> Reverse sensing is all in your head.
>
>Amusing combination of text, as the OBS only helps in this context if the
>heading isn't [still] in your head. Yes, the information provided is
>important. But - at least in my experience - it's already in memory.
>
>What I don't understand is why nobody has yet mentioned wind correction in
>this thread. When flying a localizer, I'll typically have some amount of
>crab in place. Thus, my DG should read something different from the track
>of the approach (and the OBS). If the needle starts to drift (and assuming
>I've maintained my intended heading {8^), I'll correct that intended
>heading one way or the other.
>
>So while the plate may tell me to fly 223, I may flying 230. Tempting it is
>to put 230 in the OBS, as that's not written anywhere. But that's too much
>futzing (esp. as it is a dynamic value), so I just live with the need to

The OBS is not dynamic unless you are flying an NDB.. It is the course
on the VOR. Your heading changes, not the course, or it shouldn't.
Radial outbound and reciprical inbound, although you don't actually
fly on the radial outbound, but rather parallel to in (usually more at
an angle to get an egg shaped race track) A map display on GPS is
really nice for this once you learn it with out the GPS.
If this was an NDB I always set the *heading* (inbound and outbound)
in the OBS. It makes flying NDBs a breeze.

Whether inbound or outbound I always put the course in the OBS. It's
easy, it's quick, and it's the way I was taught.

I keep the OBS centered inbound. I can read the wind correction as
the difference between heading and course. If I have to hold 300 to
keep the OBS centered on a course of 270 I know the wind correction
angle is 30 degrees. What every the wind correction inbound I double
it outbound. Yes I have flown wind correction angles of 60 degrees
outbound ... twice and one of those was on my check ride.
Here the OBS only serves as a reminder and it lets me know if I'm
drifting off more than expected.

I do a "Kentucky windage" inbound on the first circuit to see if it's
short or long and adjust the outbound leg time accordingly. Normally
the second inbound will be within a few seconds.

I was taught to use heading bugs and the OBS as both remindders and
short cuts.

If you write like I do they are not only easier to remember but you
can read them.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com
>remember.
>
> - Andrew

On Mon, 10 Jan 2005 17:16:00 -0500, Andrew Gideon >
wrote:

wrote:
>
>> On Thu, 06 Jan 2005 17:52:20 -0500, Andrew Gideon >
>> wrote:
>>
wrote:
>>>
>>>> The "one-entry" method makes the initial turn the shortest way to
>>>> outbound.
>>>
>>>So if I'm to hold over a VOR on the 270 radial, and I'm flying a track of
>>>080, I should turn left to intercept the 270 outbound after overflying the
>>>VOR?
>>>
>>> - Andrew
>>
>>
>> Yes,
>
>You can do that while staying on the protected side?

It does for me flying into 3BS at HARPY, but we have left hand turns.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com
>
> - Andrew

On Mon, 10 Jan 2005 17:16:00 -0500, Andrew Gideon >
wrote:

wrote:
>
>> On Thu, 06 Jan 2005 17:52:20 -0500, Andrew Gideon >
>> wrote:
>>
wrote:
>>>
>>>> The "one-entry" method makes the initial turn the shortest way to
>>>> outbound.
>>>
>>>So if I'm to hold over a VOR on the 270 radial, and I'm flying a track of
>>>080, I should turn left to intercept the 270 outbound after overflying the
>>>VOR?
>>>
>>> - Andrew
>>
>>
>> Yes,
>
>You can do that while staying on the protected side?
>> - Andrew

A parallel entry does not keep you on the protected SIDE.

If you can make a 110 degree turn to the left and stay within
protected airspace, do you not think that you can make a 170 degree
turn and stay within protected airspace?

> wrote in message ...
> On Mon, 10 Jan 2005 17:16:00 -0500, Andrew Gideon >
> wrote:
>
wrote:
>>
>>> On Thu, 06 Jan 2005 17:52:20 -0500, Andrew Gideon >
>>> wrote:
>>>
wrote:
>>>>
>>>>> The "one-entry" method makes the initial turn the shortest way to
>>>>> outbound.
>>>>
>>>>So if I'm to hold over a VOR on the 270 radial, and I'm flying a track of
>>>>080, I should turn left to intercept the 270 outbound after overflying the
>>>>VOR?
>>>>
>>>> - Andrew
>>>
>>>
>>> Yes,
>>
>>You can do that while staying on the protected side?
>>> - Andrew
>
> A parallel entry does not keep you on the protected SIDE.
>
> If you can make a 110 degree turn to the left and stay within
> protected airspace, do you not think that you can make a 170 degree
> turn and stay within protected airspace?
>
>

Maybe yes, maybe no, depending on the speed-- but the 170 degree turn certainly uses almost twice as room as
the 110...

Cheers,
John Clonts
Temple, Texas