VOR approach- when to descend from the FAF

[Terence Wilson]

When flying a VOR approach in which the FAF is defined by the VOR, is
it appropriate to start the descent to the MAP, or next stepdown,
immediately after overflying the VOR or should I wait until I have
positive course guidance for the final approach segment?

I ask because it can sometimes take 1-2nm for the CDI to move, which
may require a rushed descent to the MAP on some approaches.

[Sam Spade]

Terence Wilson wrote:
> When flying a VOR approach in which the FAF is defined by the VOR, is
> it appropriate to start the descent to the MAP, or next stepdown,
> immediately after overflying the VOR or should I wait until I have
> positive course guidance for the final approach segment?
>
> I ask because it can sometimes take 1-2nm for the CDI to move, which
> may require a rushed descent to the MAP on some approaches.

Are you a simulator only pilot?

I ask, because that is a question that would be answered during
instrument training.

[[email protected]]

On Sat, 16 Feb 2008 18:56:05 -0800, Terence Wilson >
wrote:

>When flying a VOR approach in which the FAF is defined by the VOR, is
>it appropriate to start the descent to the MAP, or next stepdown,
>immediately after overflying the VOR or should I wait until I have
>positive course guidance for the final approach segment?
>
>I ask because it can sometimes take 1-2nm for the CDI to move, which
>may require a rushed descent to the MAP on some approaches.

Good question. Yes you may. Don't have the aim or far in front of
me, but I've always waited for first positive indication of the FROM
indicator. You do not need pos course guidance to start descent.

[[email protected]]

On Feb 17, 7:00*am, wrote:
> On Sat, 16 Feb 2008 18:56:05 -0800, Terence Wilson >
> wrote:
>
> >When flying a VOR approach in which the FAF is defined by the VOR, is
> >it appropriate to start the descent to the MAP, or next stepdown,
> >immediately after overflying the VOR or should I wait until I have
> >positive course guidance for the final approach segment?
>
> >I ask because it can sometimes take 1-2nm for the CDI to move, which
> >may require a rushed descent to the MAP on some approaches.
>
> Good question. * Yes you may. *Don't have the aim or far in front of
> me,

You do if you're online. :) Just Google "Aeronautical Information
Manual" or "CFRs". (I don't find that information in those documents,
however. But perhaps I didn't look in the right places.)

> but I've always waited for first positive indication of the FROM
> indicator. *You do not need pos course guidance to start descent.

[Terence Wilson]

On Sat, 16 Feb 2008 19:01:14 -0800, Sam Spade >
wrote:

>Terence Wilson wrote:
>> When flying a VOR approach in which the FAF is defined by the VOR, is
>> it appropriate to start the descent to the MAP, or next stepdown,
>> immediately after overflying the VOR or should I wait until I have
>> positive course guidance for the final approach segment?
>>
>> I ask because it can sometimes take 1-2nm for the CDI to move, which
>> may require a rushed descent to the MAP on some approaches.
>
>Are you a simulator only pilot?
>
>I ask, because that is a question that would be answered during
>instrument training.

Sam, I think you asked me that question before and I answered ;).

I'm a RW instrument student.

[Bob F.]

"Terence Wilson" > wrote in message
...
> On Sat, 16 Feb 2008 19:01:14 -0800, Sam Spade >
> wrote:
>
>>Terence Wilson wrote:
>>> When flying a VOR approach in which the FAF is defined by the VOR, is
>>> it appropriate to start the descent to the MAP, or next stepdown,
>>> immediately after overflying the VOR or should I wait until I have
>>> positive course guidance for the final approach segment?
>>>
>>> I ask because it can sometimes take 1-2nm for the CDI to move, which
>>> may require a rushed descent to the MAP on some approaches.
>>
>>Are you a simulator only pilot?
>>
>>I ask, because that is a question that would be answered during
>>instrument training.
>
> Sam, I think you asked me that question before and I answered ;).
>
> I'm a RW instrument student.


The step down altitudes are shown on the IAP. You should try to get down to
that altitude as soon as practical so that you can stop the altitude descent
and start concentrating on looking for the airport. You do realize that
except for this case (VOR at FAF) in the last few seconds as you cross over
the VOR, if you get a full deflected CDI, it's time for missed approach.
Just a final thought. There is no legal requirement to descend at all.
You could stay at the initial altitude until you reach the MAP and then
circle down. You might no see the airport though. The only reason I would
think you might keep this in mind is if you had an emergency situation and
wanted to hold on to altitude as long as possible (very rough engine). You
would just give up altitude as you felt safe.
BobF.

[Sam Spade]

Terence Wilson wrote:
> On Sat, 16 Feb 2008 19:01:14 -0800, Sam Spade >
> wrote:
>
>
>>Terence Wilson wrote:
>>
>>>When flying a VOR approach in which the FAF is defined by the VOR, is
>>>it appropriate to start the descent to the MAP, or next stepdown,
>>>immediately after overflying the VOR or should I wait until I have
>>>positive course guidance for the final approach segment?
>>>
>>>I ask because it can sometimes take 1-2nm for the CDI to move, which
>>>may require a rushed descent to the MAP on some approaches.
>>
>>Are you a simulator only pilot?
>>
>>I ask, because that is a question that would be answered during
>>instrument training.
>
>
> Sam, I think you asked me that question before and I answered ;).
>
> I'm a RW instrument student.

Forgive me my lousy memory. I figured your CFI-I would have covered
this by now.

When the two-from indicator indicated "from," you should turn to the
appropriate heading and begin descent at that time. You are effectively
on-course because you are over the station where the courses are very,
very small. Sort of like lines of longitude at the North Pole.

[Terence Wilson]

On Mon, 18 Feb 2008 07:24:39 -0800, Sam Spade >
wrote:

>Forgive me my lousy memory. I figured your CFI-I would have covered
>this by now.

I'm sure he did, but I'm empty-headed and it's just as easy to check
here rather than wait for my next lesson.

Thanks for the info.

[Les Izmore]

On Mon, 18 Feb 2008 07:24:39 -0800, Sam Spade >
wrote:

>Terence Wilson wrote:
>> On Sat, 16 Feb 2008 19:01:14 -0800, Sam Spade >
>> wrote:
>>
>>
>>>Terence Wilson wrote:
>>>
>>>>When flying a VOR approach in which the FAF is defined by the VOR, is
>>>>it appropriate to start the descent to the MAP, or next stepdown,
>>>>immediately after overflying the VOR or should I wait until I have
>>>>positive course guidance for the final approach segment?
>>>>
>>>>I ask because it can sometimes take 1-2nm for the CDI to move, which
>>>>may require a rushed descent to the MAP on some approaches.
>>>
>>>Are you a simulator only pilot?
>>>
>>>I ask, because that is a question that would be answered during
>>>instrument training.
>>
>>
>> Sam, I think you asked me that question before and I answered ;).
>>
>> I'm a RW instrument student.
>
>Forgive me my lousy memory. I figured your CFI-I would have covered
>this by now.
>
>When the two-from indicator indicated "from," you should turn to the
>appropriate heading and begin descent at that time. You are effectively
>on-course because you are over the station where the courses are very,
>very small. Sort of like lines of longitude at the North Pole.


Now, the question is, when you are 2 miles from the VOR and the needle
still has not moved (because of bad navigation, winds, whatever),and
you have descended xhundred feet, what do you do?


Are you going back up? Probably not.

Starting down without at least some indication that the needle is
moving back towards center can very well be the beginning of the
pernicious and well-known accident chain.

Don't do it.

[Sam Spade]

Les Izmore wrote:
> On Mon, 18 Feb 2008 07:24:39 -0800, Sam Spade >
> wrote:
>
>
>>Terence Wilson wrote:
>>
>>>On Sat, 16 Feb 2008 19:01:14 -0800, Sam Spade >
>>>wrote:
>>>
>>>
>>>
>>>>Terence Wilson wrote:
>>>>
>>>>
>>>>>When flying a VOR approach in which the FAF is defined by the VOR, is
>>>>>it appropriate to start the descent to the MAP, or next stepdown,
>>>>>immediately after overflying the VOR or should I wait until I have
>>>>>positive course guidance for the final approach segment?
>>>>>
>>>>>I ask because it can sometimes take 1-2nm for the CDI to move, which
>>>>>may require a rushed descent to the MAP on some approaches.
>>>>
>>>>Are you a simulator only pilot?
>>>>
>>>>I ask, because that is a question that would be answered during
>>>>instrument training.
>>>
>>>
>>>Sam, I think you asked me that question before and I answered ;).
>>>
>>>I'm a RW instrument student.
>>
>>Forgive me my lousy memory. I figured your CFI-I would have covered
>>this by now.
>>
>>When the two-from indicator indicated "from," you should turn to the
>>appropriate heading and begin descent at that time. You are effectively
>>on-course because you are over the station where the courses are very,
>>very small. Sort of like lines of longitude at the North Pole.
>
>
>
> Now, the question is, when you are 2 miles from the VOR and the needle
> still has not moved (because of bad navigation, winds, whatever),and
> you have descended xhundred feet, what do you do?
>
>
> Are you going back up? Probably not.
>
> Starting down without at least some indication that the needle is
> moving back towards center can very well be the beginning of the
> pernicious and well-known accident chain.
>
> Don't do it.
>
>
>
That would represent issues of lack of competency to be 2 miles from the
station and not have a needle moving back towards center. In fact the
needle should be moving back towards center far sooner than that.

[Les Izmore]

On Tue, 19 Feb 2008 05:22:18 -0800, Sam Spade >
wrote:

>Les Izmore wrote:
>> On Mon, 18 Feb 2008 07:24:39 -0800, Sam Spade >
>> wrote:
>>
>>
>>>Terence Wilson wrote:
>>>
>>>>On Sat, 16 Feb 2008 19:01:14 -0800, Sam Spade >
>>>>wrote:
>>>>
>>>>
>>>>
>>>>>Terence Wilson wrote:
>>>>>
>>>>>
>>>>>>When flying a VOR approach in which the FAF is defined by the VOR, is
>>>>>>it appropriate to start the descent to the MAP, or next stepdown,
>>>>>>immediately after overflying the VOR or should I wait until I have
>>>>>>positive course guidance for the final approach segment?
>>>>>>
>>>>>>I ask because it can sometimes take 1-2nm for the CDI to move, which
>>>>>>may require a rushed descent to the MAP on some approaches.
>>>>>
>>>>>Are you a simulator only pilot?
>>>>>
>>>>>I ask, because that is a question that would be answered during
>>>>>instrument training.
>>>>
>>>>
>>>>Sam, I think you asked me that question before and I answered ;).
>>>>
>>>>I'm a RW instrument student.
>>>
>>>Forgive me my lousy memory. I figured your CFI-I would have covered
>>>this by now.
>>>
>>>When the two-from indicator indicated "from," you should turn to the
>>>appropriate heading and begin descent at that time. You are effectively
>>>on-course because you are over the station where the courses are very,
>>>very small. Sort of like lines of longitude at the North Pole.
>>
>>
>>
>> Now, the question is, when you are 2 miles from the VOR and the needle
>> still has not moved (because of bad navigation, winds, whatever),and
>> you have descended xhundred feet, what do you do?
>>
>>
>> Are you going back up? Probably not.
>>
>> Starting down without at least some indication that the needle is
>> moving back towards center can very well be the beginning of the
>> pernicious and well-known accident chain.
>>
>> Don't do it.
>>
>>
>>
>That would represent issues of lack of competency to be 2 miles from the
>station and not have a needle moving back towards center. In fact the
>needle should be moving back towards center far sooner than that.


Well, that is precisely the reason why it is bad advice to start down
with no indication of movement of the needle.

If it does indeed start moving far sooner than that, then there is
minimal if any penalty for waiting.

If it does not start moving sooner than that, there is good reason
(issues of incompetency being one) not to have already begun the
descent.

So I'll say it again for emphasis. Until there is some indication
that the needle is moving toward the center, indicating a return to
the desired course, don't descend below the FAF altitude.

(The 2 miles, incidentally, was what the poster used as a basis for
his question).

[Greg Esres[_2_]]

Sam Spade wrote:

<<I ask, because that is a question that would be answered during
instrument training. >>

Do you think that every instrument instructor has the knowledge to
provide informed opinions on subjects like these?

[Greg Esres[_2_]]

Les Ismore wrote:

<<Well, that is precisely the reason why it is bad advice to start
down
with no indication of movement of the needle. >>

I think your advice is good and would be more easily defensible if you
were being evaluated by a check airman. Very few of them are TERPS
experts.

[Greg Esres[_2_]]

pstanley wrote:

<<You do not need pos course guidance to start descent. >>

Such a statement needs documentation, IMO.

[Sam Spade]

Greg Esres wrote:
> Sam Spade wrote:
>
> <<I ask, because that is a question that would be answered during
> instrument training. >>
>
> Do you think that every instrument instructor has the knowledge to
> provide informed opinions on subjects like these?

No, but the good ones know.

[Les Izmore]

On Tue, 19 Feb 2008 08:07:11 -0800 (PST), Greg Esres
> wrote:

>pstanley wrote:
>
><<You do not need pos course guidance to start descent. >>
>
>Such a statement needs documentation, IMO.
>
>
>


This is being treated like some kind of academic
angels-on-the-head-of-a-pin question. It is not.

Stuff happens. I have seen enough "competent" pilots screw up a
course intercept to know that it doesn't take all that much for a
pilot to end up well below the FAF altitude with no positive course
guidance, if he starts his descent with none. Distractions can mount
up in a hurry, and one can find himself in a situation with a high
pucker factor in a hurry. Few pilots who find themselves in this
situation then take the proper corrective action, in my experience.
They usually "try harder" to reintercept the course while going still
lower. This practially always ends up in a situation that could be
disastrous in actual conditions.

Advising someone new to instrument flying that it is an OK thing to
start a descent with no positive course guidance is a really bad
thing, in my opinion, and I base that opinion on watching a lot of
pilots, many of them experienced and instrument rated, screw
approaches up pretty badly, for any number of reasons.

I don't care what the "book" says.

[Greg Esres[_2_]]

Les Izmore wrote:

<<This is being treated like some kind of academic angels-on-the-head-
of-a-pin question. It is not. >>

Not to you, maybe. People ask questions here for a variety of
reasons: 1) legality, 2) safety, 3) passing checkrides, 4) curiosity,
etc.

Regarding safety, no doubt you're 100% correct.

We have a local VOR approach with a course change at the FAF and a
high descent gradient on final. Without descending immediately pass
the VOR, the odds of getting in shrink rapidly.

[Greg Esres[_2_]]

Peter wrote:
<<For what this is worth, on the European IR one is not supposed to
descend (from the platform altitude) unless one is established within
5 degrees of the track. I don't know the reference but this is what I
was always taught. To me, it makes sense and the only time I would
deviate from it would be
>>

ICAO standards for "established" are 1/2 scale deflection. The US
doesn't have a similar definition, unfortunately. Sam Spade was
arguing that, over the VOR, that standard doesn't have much meaning.
For a staying-in-protected-airspace point of view, I'm sure he's
correct.

[[email protected]]

On Feb 19, 2:53*pm, Les Izmore > wrote:

> This is being treated like some kind of academic
> angels-on-the-head-of-a-pin question. *It is not.

It is academic.

Two choices, very simple. Either you are on the final approach
course, or not. If not, you go missed, nothing complicated.

> They usually "try harder" *to reintercept the course while going still
> lower. *This practially always ends up in a situation that could be
> disastrous in actual conditions.

Then that pilot is behind the plane. See above for choices of
action. Really very academic. It may not be a training issue, but a
currency issue, thus the IMPORTANCE of staying current.

> and I base that opinion on watching a lot of
> pilots, many of them experienced and *instrument rated, screw
> approaches up pretty badly, for any number of reasons.

At anytime a pilot "screws up" as you alleged, missed is always that
option. Very academic. I personally experience quite the opposite
for IA pilots when I was their safety pilot, they get it right and
never gone full deflection. I am not a CFI by any means for what this
is worth.

> I don't care what the "book" says.

Book is very clear. If you are not on the final approach course
within the established tolerances, you go missed. What part of the
book is hard to understand?

The orignal question is a very elementary question for IA flying.

For what it's worth, in my 600 hours of instrument flying, it takes a
hell of a lot more then 1 or 2 miles for the CDI to start moving. If
that is happening to the original poster, or you experienced that,
then there is something wrong with that station signal or airplane
equipment and a missed approach is in order. KMBO has the VOR alpha
approach and I can pick up the VOR signal strong on both my NAV1 and
NAV2 within 20 miles.

When you are within 1 or 2 miles of a final approach fix (I.E. VOR) it
is normal to get a full deflection from that "zone of confusion" for
the CDI. The needles will recapture within a mile or two of station
passage.

But you do not descend before getting the from flag on your NAV1 or
NAV2 AND being on the final approach course. If you don't get a from
flag you go missed even if you are on the final approach course as
something is radically wrong equipment wise.. Note the word AND, both
being on the approach course AND from flag, BOTH must be present.
VERY SIMPLE!

The original question was so basic, that it sounded like an Mx
question..

Allen

[Sam Spade]

Greg Esres wrote:
> Peter wrote:
> <<For what this is worth, on the European IR one is not supposed to
> descend (from the platform altitude) unless one is established within
> 5 degrees of the track. I don't know the reference but this is what I
> was always taught. To me, it makes sense and the only time I would
> deviate from it would be
>
>
> ICAO standards for "established" are 1/2 scale deflection. The US
> doesn't have a similar definition, unfortunately. Sam Spade was
> arguing that, over the VOR, that standard doesn't have much meaning.
> For a staying-in-protected-airspace point of view, I'm sure he's
> correct.

Correct. The protected airspace for a VOR IAP overhead the VOR when
it's the FAF is 1 mile each side of the station. This width expands as
the aircraft departs the VOR/FAF. The maximum course change permitted
at the VOR/FAF is 30 degrees.

Descent shouldn't be made unless the pilot is tracking on course inbound
to the VOR/FAF. If he is on course as station passage occurs, and a
course change is required, a turn to intercept while commencing descent
is expected in the design of the criteria; i.e., the descent gradient is
calculated from the VOR/FAF, not from some imaginary post-facility point
of intercept, and the maneuver required to reintercept is minimal
assumming reasonable comptetency.

[Sam Spade]

Greg Esres wrote:

> Les Izmore wrote:
>
> <<This is being treated like some kind of academic angels-on-the-head-
> of-a-pin question. It is not. >>
>
> Not to you, maybe. People ask questions here for a variety of
> reasons: 1) legality, 2) safety, 3) passing checkrides, 4) curiosity,
> etc.
>
> Regarding safety, no doubt you're 100% correct.
>
> We have a local VOR approach with a course change at the FAF and a
> high descent gradient on final. Without descending immediately pass
> the VOR, the odds of getting in shrink rapidly.

Not to mention real issues trying to do a slam-dunk low to the ground.

[Les Izmore]

On Wed, 20 Feb 2008 05:41:20 -0800 (PST), "
> wrote:

>On Feb 19, 2:53*pm, Les Izmore > wrote:
>
>> This is being treated like some kind of academic
>> angels-on-the-head-of-a-pin question. *It is not.
>
>It is academic.
>
>Two choices, very simple. Either you are on the final approach
>course, or not. If not, you go missed, nothing complicated.
>

I think you need to go back and re-read the original post.


>> They usually "try harder" *to reintercept the course while going still
>> lower. *This practially always ends up in a situation that could be
>> disastrous in actual conditions.
>
>Then that pilot is behind the plane. See above for choices of
>action. Really very academic. It may not be a training issue, but a
>currency issue, thus the IMPORTANCE of staying current.
>
>> and I base that opinion on watching a lot of
>> pilots, many of them experienced and *instrument rated, screw
>> approaches up pretty badly, for any number of reasons.
>
>At anytime a pilot "screws up" as you alleged, missed is always that
>option. Very academic. I personally experience quite the opposite
>for IA pilots when I was their safety pilot, they get it right and
>never gone full deflection. I am not a CFI by any means for what this
>is worth.
>
>> I don't care what the "book" says.
>
>Book is very clear. If you are not on the final approach course
>within the established tolerances, you go missed. What part of the
>book is hard to understand?
>
>The orignal question is a very elementary question for IA flying.
>
>For what it's worth, in my 600 hours of instrument flying, it takes a
>hell of a lot more then 1 or 2 miles for the CDI to start moving. If
>that is happening to the original poster, or you experienced that,
>then there is something wrong with that station signal or airplane
>equipment and a missed approach is in order. KMBO has the VOR alpha
>approach and I can pick up the VOR signal strong on both my NAV1 and
>NAV2 within 20 miles.
>
>When you are within 1 or 2 miles of a final approach fix (I.E. VOR) it
>is normal to get a full deflection from that "zone of confusion" for
>the CDI. The needles will recapture within a mile or two of station
>passage.
>
>But you do not descend before getting the from flag on your NAV1 or
>NAV2 AND being on the final approach course. If you don't get a from
>flag you go missed even if you are on the final approach course as
>something is radically wrong equipment wise.. Note the word AND, both
>being on the approach course AND from flag, BOTH must be present.
>VERY SIMPLE!
>
>The original question was so basic, that it sounded like an Mx
>question..
>
>Allen

[[email protected]]

On Feb 20, 12:33*pm, Les Izmore > wrote:
> On Wed, 20 Feb 2008 05:41:20 -0800 (PST), "
>
> > wrote:
> >On Feb 19, 2:53*pm, Les Izmore > wrote:
>
> >> This is being treated like some kind of academic
> >> angels-on-the-head-of-a-pin question. *It is not.
>
> >It is academic.
>
> >Two choices, very simple. *Either you are on the final approach
> >course, or not. *If not, you go missed, nothing complicated.
>
> I think you need to go back and re-read the original post.

Why? My response was directed to you.

It was a very academic question and I responses were to what I quoted
on you, not the original poster.

If I wanted to respond to the original post, I would have done so.

Your response at best was very questionable, and see what I quoted on
what I was questioning.

Allen

[Les Izmore]

The original post, and subsequent messages (with the exception of
yours) all related to the advisability of starting a descent on a VOR
approach immediately upon passing a VOR, before aquiring any course
guidance from the VOR needle or HSI.

Your response was not germane.


Read the posts, Grasshopper. Your responses will then more likely be
relevant to the issues.





On Wed, 20 Feb 2008 11:28:54 -0800 (PST), "
> wrote:

>On Feb 20, 12:33*pm, Les Izmore > wrote:
>> On Wed, 20 Feb 2008 05:41:20 -0800 (PST), "
>>
>> > wrote:
>> >On Feb 19, 2:53*pm, Les Izmore > wrote:
>>
>> >> This is being treated like some kind of academic
>> >> angels-on-the-head-of-a-pin question. *It is not.
>>
>> >It is academic.
>>
>> >Two choices, very simple. *Either you are on the final approach
>> >course, or not. *If not, you go missed, nothing complicated.
>>
>> I think you need to go back and re-read the original post.
>
>Why? My response was directed to you.
>
>It was a very academic question and I responses were to what I quoted
>on you, not the original poster.
>
>If I wanted to respond to the original post, I would have done so.
>
>Your response at best was very questionable, and see what I quoted on
>what I was questioning.
>
>Allen

[[email protected]]

On Feb 20, 4:01*pm, Les Izmore > wrote:
> Your response was not germane.

REALLY???????

Where did I misquote you and where did I misappropriately reply to
YOUR responses.

Like I said, if I wanted to respond to the original post, I would
have. I responded to you, and quoted your response.

Better hop to English reading courses grasshopper.

Allen

[Les Izmore]

On Wed, 20 Feb 2008 14:56:13 -0800 (PST), "
> wrote:

>On Feb 20, 4:01*pm, Les Izmore > wrote:
>> Your response was not germane.
>
>REALLY???????
>
>Where did I misquote you and where did I misappropriately reply to
>YOUR responses.



Where did anyone say you misquoted me? "Not germane" does not mean
"misquote".

You were off the thread topic, very simply.

If you wish to discuss that topic (see the Subject line- "re: VOR
approach - when to descend from the FAF"), I will be happy to
accomodate you.

The other stuff you mentioned is of no interest.


>
>Like I said, if I wanted to respond to the original post, I would
>have. I responded to you, and quoted your response.
>
>Better hop to English reading courses grasshopper.
>
>Allen

[[email protected]]

On Feb 20, 9:31*pm, Les Izmore > wrote:

> The other stuff you mentioned is of no interest.

To you maybe of no interest.... because I responded to you,
questioning some things you said?

Clearly what you said regarding pilots messing up approaches didn't
have anything to do with the original posted question.

Clearly the way you don't believe in what the book said had nothing to
do with the original posted question.

Clearly pilots trying to reintercept the localizer had nothing to do
with the original question.

So, who drifted of topic????

Like I said grasshopper, get to a reading course,

ALL I DID was respond to your very strange responsey. Don't believe
me? Reread your own post and my subsequent replies.

Like it or not grasshopper, my replies were relevant to your post
since I replied DIRECTLY to your post.

Allen

[Les Izmore]

On Wed, 20 Feb 2008 20:26:41 -0800 (PST), "
> wrote:

>On Feb 20, 9:31*pm, Les Izmore > wrote:
>
>> The other stuff you mentioned is of no interest.
>
>To you maybe of no interest.... because I responded to you,
>questioning some things you said?
>
>Clearly what you said regarding pilots messing up approaches didn't
>have anything to do with the original posted question.
>

It had everything to do with the original question.

Let me explain:

The original poster asked about starting to descend on a VOR approach
before receiving an on-course indication from his navigation
equipment. A responder or two either implied or said explicitly that
there was no problem in doing that.

I posted a contrary opinion, and said I thought it was not a good
practice.

To support that statement, I said that I had seen (and I have) many
approaches messed up once the pilot loses the approach course below
altitude and then tries to remedy the situation in undesirable ways.


>Clearly the way you don't believe in what the book said had nothing to
>do with the original posted question.


Clearly it does. I was stating that safety issues often override what
might be permitted by "the book", in this case, descending without
positve guidance.

>
>Clearly pilots trying to reintercept the localizer had nothing to do
>with the original question.
>

Au contraire, but it clearly did. It was a part of the scenario I was
using to describe an accident chain that could begin with the case in
point. (It was a VOR approach, incidentally, not a localizer)


>So, who drifted of topic????
>
>Like I said grasshopper, get to a reading course,
>
>ALL I DID was respond to your very strange responsey. Don't believe
>me? Reread your own post and my subsequent replies.
>

In the future, I might suggest that you think twice before responding
to what you describe as "strange response[s])". They may appear
strange to you because, as is obvious in this case, you simply do
not have a firm grasp of the issue under discussion.

I can't help you with that. However, if you wish to try to discuss
the safety issues involved in beginning a descent without course
guidance, I will be happy to oblige, in the interests of aviation
safety.



>Like it or not grasshopper, my replies were relevant to your post
>since I replied DIRECTLY to your post.
>
>Allen

[gatt[_2_]]

"Terence Wilson" > wrote in message
...
> When flying a VOR approach in which the FAF is defined by the VOR, is
> it appropriate to start the descent to the MAP, or next stepdown,
> immediately after overflying the VOR or should I wait until I have
> positive course guidance for the final approach segment?
>
> I ask because it can sometimes take 1-2nm for the CDI to move, which
> may require a rushed descent to the MAP on some approaches.

I spend that minute or so making sure my heading and approach airspeed are
under control, and then simply catch up to the descent afterward when the
needle comes back. It'll be interesting to see how other people do it, but
that's the way I was trained.

-c

[Mark Hansen]

On 02/21/08 09:27, gatt wrote:
> "Terence Wilson" > wrote in message
> ...
>> When flying a VOR approach in which the FAF is defined by the VOR, is
>> it appropriate to start the descent to the MAP, or next stepdown,
>> immediately after overflying the VOR or should I wait until I have
>> positive course guidance for the final approach segment?
>>
>> I ask because it can sometimes take 1-2nm for the CDI to move, which
>> may require a rushed descent to the MAP on some approaches.
>
> I spend that minute or so making sure my heading and approach airspeed are
> under control, and then simply catch up to the descent afterward when the
> needle comes back. It'll be interesting to see how other people do it, but
> that's the way I was trained.
>
> -c
>
>

I was taught to begin the descent at station passage (using the 5 'T's).
It's never taken more than just a very few seconds for the CDI to start
coming back in. A minute seems awfully long.

By the way, if the needle doesn't come back in, I would go missed. The
first thing I do there is begin a climb. I really don't see how it causes
any problems to begin the descent at station passage (assuming that is
what the procedure calls for, of course).


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

[gatt[_2_]]

"Mark Hansen" > wrote in message
...

>> I spend that minute or so making sure my heading and approach airspeed
>> are
>> under control, and then simply catch up to the descent afterward when the
>> needle comes back. It'll be interesting to see how other people do it,
>> but
>> that's the way I was trained.
>>
> I was taught to begin the descent at station passage (using the 5 'T's).
> It's never taken more than just a very few seconds for the CDI to start
> coming back in. A minute seems awfully long.

Yeah, I was just throwing that out as a ballpark figure. It shouldn't take
very long at all, which means it's even less of a problem to catch up to the
descent afterward.

I prefer to have the altitude under me rather than above me throughout the
approach, but, at that point it's not like you're going to fly into anything
if you're 50 feet lower immediately after crossing the station than if you
waited. Or, you have bigger issues.

If I were taking the IFR checkride, though, I'd definately hold the altitude
until I could demonstrate to the examiner that I had recaptured the CDI was
100% established. That's the kind of thing my examiner would have expected
and how I was taught to do it. (caveat: Since they almost always use the
examiner, they teach to his specific expectations, which may be a factor.)

-c
CP-ASEL-IA

[Les Izmore]

On Thu, 21 Feb 2008 09:27:00 -0800, "gatt" >
wrote:

>
>"Terence Wilson" > wrote in message
...
>> When flying a VOR approach in which the FAF is defined by the VOR, is
>> it appropriate to start the descent to the MAP, or next stepdown,
>> immediately after overflying the VOR or should I wait until I have
>> positive course guidance for the final approach segment?
>>
>> I ask because it can sometimes take 1-2nm for the CDI to move, which
>> may require a rushed descent to the MAP on some approaches.
>
>I spend that minute or so making sure my heading and approach airspeed are
>under control, and then simply catch up to the descent afterward when the
>needle comes back. It'll be interesting to see how other people do it, but
>that's the way I was trained.
>
>-c
>

Trained well, in my opinion.

That's exactly the way to do it, IMHO.

[[email protected]]

For you folks voting to go missed if the CDI remains fully deflected
when passing the FAF...

I hope you mean that you will proceed to the missed approach fix and
then go missed. Initiating a missed approach early is not advised
because
obstacle clearance is not guarenteed per the AIM:

"...Reasonable buffers are provided for normal maneuvers. However, no
consideration is given to an abnormally early turn. Therefore, when an
early missed approach is executed, pilots should, unless otherwise
cleared by ATC, fly the IAP as specified on the approach plate to the
missed approach point at or above the MDA or DH before executing a
turning maneuver."
(5.4.21b)


wrote:
> On Feb 19, 2:53�pm, Les Izmore > wrote:
>
> > This is being treated like some kind of academic
> > angels-on-the-head-of-a-pin question. �It is not.
>
> It is academic.
>
> Two choices, very simple. Either you are on the final approach
> course, or not. If not, you go missed, nothing complicated.
>
> > They usually "try harder" �to reintercept the course while going still
> > lower. �This practially always ends up in a situation that could be
> > disastrous in actual conditions.
>
> Then that pilot is behind the plane. See above for choices of
> action. Really very academic. It may not be a training issue, but a
> currency issue, thus the IMPORTANCE of staying current.
>
> > and I base that opinion on watching a lot of
> > pilots, many of them experienced and �instrument rated, screw
> > approaches up pretty badly, for any number of reasons.
>
> At anytime a pilot "screws up" as you alleged, missed is always that
> option. Very academic. I personally experience quite the opposite
> for IA pilots when I was their safety pilot, they get it right and
> never gone full deflection. I am not a CFI by any means for what this
> is worth.
>
> > I don't care what the "book" says.
>
> Book is very clear. If you are not on the final approach course
> within the established tolerances, you go missed. What part of the
> book is hard to understand?
>
> The orignal question is a very elementary question for IA flying.
>
> For what it's worth, in my 600 hours of instrument flying, it takes a
> hell of a lot more then 1 or 2 miles for the CDI to start moving. If
> that is happening to the original poster, or you experienced that,
> then there is something wrong with that station signal or airplane
> equipment and a missed approach is in order. KMBO has the VOR alpha
> approach and I can pick up the VOR signal strong on both my NAV1 and
> NAV2 within 20 miles.
>
> When you are within 1 or 2 miles of a final approach fix (I.E. VOR) it
> is normal to get a full deflection from that "zone of confusion" for
> the CDI. The needles will recapture within a mile or two of station
> passage.
>
> But you do not descend before getting the from flag on your NAV1 or
> NAV2 AND being on the final approach course. If you don't get a from
> flag you go missed even if you are on the final approach course as
> something is radically wrong equipment wise.. Note the word AND, both
> being on the approach course AND from flag, BOTH must be present.
> VERY SIMPLE!
>
> The original question was so basic, that it sounded like an Mx
> question..
>
> Allen

[Les Izmore]

I don't think anyone advocated going missed " if the CDI remains
fully deflected when passing the FAF..."

The debate was whether it was prudent to begin a descent while the
needle was fully deflected.




On Mon, 25 Feb 2008 11:54:58 -0800 (PST), wrote:

>For you folks voting to go missed if the CDI remains fully deflected
>when passing the FAF...
>
>I hope you mean that you will proceed to the missed approach fix and
>then go missed. Initiating a missed approach early is not advised
>because
>obstacle clearance is not guarenteed per the AIM:
>
>"...Reasonable buffers are provided for normal maneuvers. However, no
>consideration is given to an abnormally early turn. Therefore, when an
>early missed approach is executed, pilots should, unless otherwise
>cleared by ATC, fly the IAP as specified on the approach plate to the
>missed approach point at or above the MDA or DH before executing a
>turning maneuver."
>(5.4.21b)
>
>
wrote:
>> On Feb 19, 2:53?pm, Les Izmore > wrote:
>>
>> > This is being treated like some kind of academic
>> > angels-on-the-head-of-a-pin question. ?It is not.
>>
>> It is academic.
>>
>> Two choices, very simple. Either you are on the final approach
>> course, or not. If not, you go missed, nothing complicated.
>>
>> > They usually "try harder" ?to reintercept the course while going still
>> > lower. ?This practially always ends up in a situation that could be
>> > disastrous in actual conditions.
>>
>> Then that pilot is behind the plane. See above for choices of
>> action. Really very academic. It may not be a training issue, but a
>> currency issue, thus the IMPORTANCE of staying current.
>>
>> > and I base that opinion on watching a lot of
>> > pilots, many of them experienced and ?instrument rated, screw
>> > approaches up pretty badly, for any number of reasons.
>>
>> At anytime a pilot "screws up" as you alleged, missed is always that
>> option. Very academic. I personally experience quite the opposite
>> for IA pilots when I was their safety pilot, they get it right and
>> never gone full deflection. I am not a CFI by any means for what this
>> is worth.
>>
>> > I don't care what the "book" says.
>>
>> Book is very clear. If you are not on the final approach course
>> within the established tolerances, you go missed. What part of the
>> book is hard to understand?
>>
>> The orignal question is a very elementary question for IA flying.
>>
>> For what it's worth, in my 600 hours of instrument flying, it takes a
>> hell of a lot more then 1 or 2 miles for the CDI to start moving. If
>> that is happening to the original poster, or you experienced that,
>> then there is something wrong with that station signal or airplane
>> equipment and a missed approach is in order. KMBO has the VOR alpha
>> approach and I can pick up the VOR signal strong on both my NAV1 and
>> NAV2 within 20 miles.
>>
>> When you are within 1 or 2 miles of a final approach fix (I.E. VOR) it
>> is normal to get a full deflection from that "zone of confusion" for
>> the CDI. The needles will recapture within a mile or two of station
>> passage.
>>
>> But you do not descend before getting the from flag on your NAV1 or
>> NAV2 AND being on the final approach course. If you don't get a from
>> flag you go missed even if you are on the final approach course as
>> something is radically wrong equipment wise.. Note the word AND, both
>> being on the approach course AND from flag, BOTH must be present.
>> VERY SIMPLE!
>>
>> The original question was so basic, that it sounded like an Mx
>> question..
>>
>> Allen