Missed approach (?) when glideslope fails

Hilton wrote:

I can't believe people still discuss this issue. Firstly, timing an
approach takes a fraction of a second - simply push a button. Secondly, if
you time every approach it becomes part of your checklist, your routine etc.
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).

Well, I won't disagree with you about doing the timing. Its cheap, its
easy, and it couldn't hurt.

However, if I'm on the ILS and my only GS fails, I'm going missed RIGHT
NOW. I don't care wether I have a timer or not.

Yes, of course, if I'm down to my last pint of fuel, I'm rather forced to
continue and the timer would be very useful. However, if thats the case,
I've made a whole batch of mistakes.


--
Frank Stutzman
Bonanza N494B "Hula Girl"
Hood River, OR

Frank,

Hilton wrote:

I can't believe people still discuss this issue. Firstly, timing an
approach takes a fraction of a second - simply push a button. Secondly,
if
you time every approach it becomes part of your checklist, your routine
etc.
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).

Well, I won't disagree with you about doing the timing. Its cheap, its
easy, and it couldn't hurt.

However, if I'm on the ILS and my only GS fails, I'm going missed RIGHT
NOW. I don't care wether I have a timer or not.

The problem is that you have no missed approach procedure to follow. 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... You have to fly to the MAP to
be safe on the missed. Of course, you can and should climb if your GS dies.

Hilton

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

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


Show me an ILS without a missed approach procedure.



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.

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

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?