Missed approach (?) when glideslope fails

"JPH" wrote in message
news:016Ue.2559$P34.221@okepread07...

So, you're reverting to timing anyway. The only difference is you start
your timing at a point other than the non-precision FAF and try to figure
it out as you go. (Let's see, I was passing 2650 when I lost the
glideslope a few seconds ago, the DH is 852, the glideslope is 2.8
degrees, I drop XXX amount of feet from here to there at a rate of XXX ft
per mile, so I'll cover that distance in XX minutes/seconds). Sounds like
it would be a whole lot simpler to start the timing at the non-precision
FAF than try to do those computations on the fly as you're starting to
climb as you're trying to figure if it's your equipment or the glideslope
failure.


I didn't say timing was wrong. I just responded to what Hilton wrote:

"Thirdly, as you point out, what the heck do you do (can you do) if you're
in
IMC on an ILS and your GS fails? You're screwed and only luck will save
your butt (it may be less dramatic when surrounded by flatter terrain)."

That just ain't so. You aren't screwed if you didn't punch the clock at the
FAF. There is another way determine (at least approximately) where the MAP
is.

Steven,

Hilton wrote:

The problem is that you have no missed approach procedure to follow.

Show me an ILS without a missed approach procedure.

If you're gonna quote me out of context, then we're wasting our time here.
To thoroughly beat this dead horse, my point was that if you start your turn
before the MAP, you have no missed approach procedure to follow that will
guarantee you 'safety' since the missed approach procedure starts at the
MAP.


Let's
say, for example, that the missed is a 180 degree turn back to the LOM.
If
you start your turn early (i.e. fly the missed right now), you may hit a
mountain.

i.e. you must have a way to determine (at least approximately) where the
MAP
is; for examples are GS, DME, VOR, timing...


Easily done. A standard 3 degree GS descends 318' per nautical mile,
altitude above DH is directly proportional to distance from the MAP. To
make the arithmetic simpler 300' per mile is a close enough approximation.

And if it is not standard? So they have to do this divide by 300 math and
then figure out the time from their airspeed? Well, you're welcome to teach
your students (if you're a CFI-I) to suddenly do this math real-time in IMC
on an ILS during a good-ol' pucker moment. I will teach my students to push
one little button in exactly the same place every time on every instrument
approach.

Hilton

Steven P. McNicoll wrote:

Hilton wrote:

You work for Microsoft?


Nope. Do you hold an instrument rating?

I really dislike these ****ing contests on the NGs because I think that
everyone's input is perfect valid and should be seriously considered whether
they are a student pilot or a high-time 747 Captain.

But if you're bored enough, Hilton in San Jose, CA will get my details on
landings.com

Hilton

"Peter" wrote in message
...
DME is really important, IMHO, if flying a NP approach using the
autopilot; one sets the MDA as the target altitude on the AP, the VS
to appropriate value for the ground speed, and counts off the DME
miles, checking the altimeter at each point against the approach
plate.

Yes, I agree that DME is essential for NP approaches - though you need to
understand where the sources of radio waves actually are in relation to each
other (the thing you're measuring DME from may, of course be some miles from
the thing your ADF is pointing at). At my local airfield, things are looking
good if you're heading in from the east and the ADF needle swings around
when the DME says 3.2nm.

What would be nice on NP approaches, of course, is technology you can rely
on. When I went out for a "pretend" test before my IMC exam, I was asked to
do an NDB approach into an unfamiliar airfield. By some miracle, everything
happened just as it should, and I soon found myself at the right altitude,
with the needle pointing forward and starting to twitch as if we were
approaching the NDB's overhead.

The instructor turned to me, and pointed out at a grassy mound in our
three-o'clock (we had screens in so I couldn't see forward and cheat). "You
know," he said, "if they hadn't hidden the NDB behind that pile of muck, the
ADF might stand a better chance of pointing at it".

D.

On Fri, 09 Sep 2005 00:14:48 GMT, "Hilton" wrote:

Ron Rosenfeld wrote:

Hilton wrote:
what the heck do you do (can you do) if you're in
IMC on an ILS and your GS fails? You're screwed and only luck will save
your butt

You can't be serious with that claim.

Firstly, please note that after the word "butt", I had "(it may be less
dramatic when surrounded by flatter terrain)." So, we're assuming
mountainous terrain or other nearby obstacles.

When would you start flying the missed?

I would start climbing immediately and turn when close to the MAP

How would you start flying the missed?

See above

Are you guaranteed to be flying the missed approach as published?

Yes

Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

You can go miss anywhere on the approach, not just the MAP. If you get a
false glideslope (not a totally uncommon occurence and the reason they
glideslope intercept altitude is published), then you have to go missed, or
possible downgrade to the localizer. The correct procedure is to climb and
continue the course until you can determine by any means you can that you
are at the MAP and then turn. In the mean time, call ATC.

Paul
"Hilton" wrote in message
nk.net...
Steven,

Hilton wrote:

The problem is that you have no missed approach procedure to follow.

Show me an ILS without a missed approach procedure.

If you're gonna quote me out of context, then we're wasting our time here.
To thoroughly beat this dead horse, my point was that if you start your
turn
before the MAP, you have no missed approach procedure to follow that will
guarantee you 'safety' since the missed approach procedure starts at the
MAP.


Let's
say, for example, that the missed is a 180 degree turn back to the LOM.
If
you start your turn early (i.e. fly the missed right now), you may hit
a
mountain.

i.e. you must have a way to determine (at least approximately) where
the
MAP
is; for examples are GS, DME, VOR, timing...


Easily done. A standard 3 degree GS descends 318' per nautical mile,
altitude above DH is directly proportional to distance from the MAP. To
make the arithmetic simpler 300' per mile is a close enough
approximation.

And if it is not standard? So they have to do this divide by 300 math and
then figure out the time from their airspeed? Well, you're welcome to
teach
your students (if you're a CFI-I) to suddenly do this math real-time in
IMC
on an ILS during a good-ol' pucker moment. I will teach my students to
push
one little button in exactly the same place every time on every instrument
approach.

Hilton

On Fri, 09 Sep 2005 06:07:00 GMT, "Hilton" wrote:

If you're gonna quote me out of context, then we're wasting our time here.
To thoroughly beat this dead horse, my point was that if you start your turn
before the MAP, you have no missed approach procedure to follow that will
guarantee you 'safety' since the missed approach procedure starts at the
MAP.

What you write about an early turn is true. However, nobody who advocates
not timing from the FAF is advocating turning prior to the missed approach
point!

What you don't seem to understand is that there are a number of ways to
determine a MAP in addition to timing from the FAF. And that timing is
probably the least accurate of all of them.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

"Hilton" wrote in message
nk.net...

If you're gonna quote me out of context, then we're wasting our time here.


Nobody quoted you out of context.



To thoroughly beat this dead horse, my point was that if you start your
turn before the MAP, you have no missed approach procedure to follow that
will
guarantee you 'safety' since the missed approach procedure starts at the
MAP.


Nobody suggested starting the turn before the MAP.



And if it is not standard?


Multiplying the GS angle in degrees by 100 provides a close approximation of
the altitude loss in feet for each mile. It's not exact, but the difference
is less than 6%.



So they have to do this divide by 300 math and then figure out the time
from
their airspeed?


It's just simple arithmetic. Many common pilot tasks call for doing simple
arithmetic.



Well, you're welcome to
teach your students (if you're a CFI-I) to suddenly do this math real-time
in
IMC on an ILS during a good-ol' pucker moment. I will teach my students
to
push one little button in exactly the same place every time on every
instrument
approach.


Nobody said timing an ILS was wrong. What we're trying to help you
understand is you're not screwed and must rely on luck to save your butt if
you're in IMC on an ILS and your GS fails and you didn't punch the timer at
the FAF. That there is a way to determine (at least approximately) where
the MAP is without DME or GPS or VOR. Do you understand that now?

"Hilton" wrote in message
ink.net...

I really dislike these ****ing contests on the NGs because I think that
everyone's input is perfect valid and should be seriously considered
whether they are a student pilot or a high-time 747 Captain.


I seriously considered your input, it took just a few nanoseconds for me to
determine it was not valid. You asserted there's no way to ensure you are
at the MAP without timing from the FAF. That's simply not correct.



But if you're bored enough, Hilton in San Jose, CA will get my details on
landings.com


I asked only because you don't seem to have a good knowledge of ILS.

"Peter" wrote in message
...

Are you referring to looking on a GPS?


Nope.