Missed approach (?) when glideslope fails

"Steven P. McNicoll" wrote
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.

Well Steven, why don't you just come right out and tell them
about the Middle Marker?

Bob Moore

Bob Moore wrote:
"Steven P. McNicoll" wrote

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.


Well Steven, why don't you just come right out and tell them
about the Middle Marker?

Bob Moore
Most MMs have been decommissioned.

Steven P. McNicoll wrote:

Hilton wrote:

[Obvious replies inserted] And that is? How would you identify it?


Since I'm on the GS when my GS receiver fails my distance from the MAP is
directly proportional to my altitude above DH. A 3 degree GS drops 318'
in
each nautical mile. If I'm about 1000' above DH I'm about 3 miles from
the
MAP. Simple.

OK, since we're never going to agree on this, please help me out here. I'm
a CFI-I. If I were to have a lesson with a student who is pretty much ready
for his IR checkride tomorrow morning, please write out the math that he/she
would need to do in IMC on the ILS when his/her glideslope failed. I would
need to convince this student that doing this math in IMC (while doing all
the other stuff) is easy/safer/better than starting the timer.

Let's assume that the GS fails at 2700' (MSL), the DH is at 357' (MSL), a 3
degree glideslope, an 'ILS' airspeed of 100 knots, a climb airspeed of 80
knots. For simplicity, let's assume no wind conditions.

Thanks.

Hilton

Hilton wrote:
OK, since we're never going to agree on this, please help me out
here. I'm
a CFI-I. If I were to have a lesson with a student who is pretty much ready
for his IR checkride tomorrow morning, please write out the math that he/she
would need to do in IMC on the ILS when his/her glideslope failed. I would
need to convince this student that doing this math in IMC (while doing all
the other stuff) is easy/safer/better than starting the timer.

Let's assume that the GS fails at 2700' (MSL), the DH is at 357' (MSL), a 3
degree glideslope, an 'ILS' airspeed of 100 knots, a climb airspeed of 80
knots. For simplicity, let's assume no wind conditions.

Thanks.

Hilton


I don't think I'd want to teach students that when your original idea of
starting the timing at the FAF is much better. At least with the
numbers you used in the example, you'd still be on the other side of the
non-precision FAF at most airports, since you're over 7 miles out at
2700'. They try to keep FAFs within 6 miles so they don't have to add an
"excessive length of final" penalty to the LOC MDA.
What would be bad is if after successfully making the calculations, the
student realized that they forgot to start the timer when they went
missed approach, so now they have to add the guesswork of how far they
flew between MA initiation and completing the calculations.

John

John,
Hilton wrote:
OK, since we're never going to agree on this, please help me out
here. I'm
a CFI-I. If I were to have a lesson with a student who is pretty much
ready
for his IR checkride tomorrow morning, please write out the math that
he/she
would need to do in IMC on the ILS when his/her glideslope failed. I
would
need to convince this student that doing this math in IMC (while doing
all
the other stuff) is easy/safer/better than starting the timer.

Let's assume that the GS fails at 2700' (MSL), the DH is at 357' (MSL),
a 3
degree glideslope, an 'ILS' airspeed of 100 knots, a climb airspeed of
80
knots. For simplicity, let's assume no wind conditions.

Thanks.

Hilton


I don't think I'd want to teach students that when your original idea of
starting the timing at the FAF is much better.

Yeah, me neither. I just want to see what Steven thinks all instrument
rated pilots are capable of while doing other important things when going
missed such as applying full power, adjusting RPM, raising the gear, opening
the cowl flaps, reading a checklist, GPS/VOR changes, talking to ATC, and
all the other things that come with a missed approach. (FYI: these tasks
and others are all aircraft-dependant, so adjust accordingly). I *really*
don't want to be doing any math at that point and betting the only quarter
I'm playing with that I will get it correct 100% of the time. Push the
button!


At least with the
numbers you used in the example, you'd still be on the other side of the
non-precision FAF at most airports, since you're over 7 miles out at
2700'. They try to keep FAFs within 6 miles so they don't have to add an
"excessive length of final" penalty to the LOC MDA.
What would be bad is if after successfully making the calculations, the
student realized that they forgot to start the timer when they went
missed approach, so now they have to add the guesswork of how far they
flew between MA initiation and completing the calculations.

Agreed. BTW: The worst case I've seen of a long ILS is the ACV ILS 32 -
there probably are longer ones, but this one has you descending from 5200'
down to 418' (MSL).

Hilton

Steven P. McNicoll wrote:
"Bob Moore" wrote in message
. 122...

Well Steven, why don't you just come right out and tell them
about the Middle Marker?



Because they're disappearing.


There should be a co-located (and associated) DME if
there are no markers, and in can be used instead of the markers.

--

Tauno Voipio
tauno voipio (at) iki fi

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

Yeah, me neither. I just want to see what Steven thinks all instrument
rated pilots are capable of while doing other important things when going
missed such as applying full power, adjusting RPM, raising the gear,
opening the cowl flaps, reading a checklist, GPS/VOR changes, talking to
ATC, and
all the other things that come with a missed approach. (FYI: these tasks
and others are all aircraft-dependant, so adjust accordingly). I *really*
don't want to be doing any math at that point and betting the only quarter
I'm playing with that I will get it correct 100% of the time. Push the
button!


If you're so overwhelmed by IFR flight don't fly IFR.

"Tauno Voipio" wrote in message
...

There should be a co-located (and associated) DME if
there are no markers, and in can be used instead of the markers.


Only if you're equipped with DME or GPS.

Steven P. McNicoll wrote:
"Tauno Voipio" wrote in message
...

There should be a co-located (and associated) DME if
there are no markers, and in can be used instead of the markers.



Only if you're equipped with DME or GPS.

At least here (Finland), an airplane needs a DME
(among other avionics) to be IFR airworthy.

--

Tauno Voipio
tauno voipio (at) iki fi

"Tauno Voipio" wrote in message
...

At least here (Finland), an airplane needs a DME
(among other avionics) to be IFR airworthy.


Not here in the US.