Pressing "Start" on the timer when shooting an ILS

Like a mile, or even two, is going to make any difference at all. It's protected.

Sent from my Galaxy Nexus that ate your iPhone.
 
Houston said:
The typical runway with an ILS approach is between one and two nautical miles in length. Combine that with the vagueness of determining where the localizer antenna might be on top of the effort associated with making a missed approach and it seems difficult to justify forgoing the timing.
Click to expand...

I haven't done a CFIT escape maneuver in a while, so I don't know exactly how far the VSI pegs out when we do it, but I'd be willing to bet that I could hit any MSA in under 30 seconds, and very likely before getting to the runway if I was that concerned about running into terrain on a missed, if the GS went, and the LOC went, and I hadn't started time, and the two GPS receivers both bit it, and the RNAV stopped working, and the DME stopped working, and the ADF stopped working, and we were in the soup, and ATC's radar went down (or we were in a no radar environment).
 
jtrain609 said:
I haven't done a CFIT escape maneuver in a while, so I don't know exactly how far the VSI pegs out when we do it, but I'd be willing to bet that I could hit any MSA in under 30 seconds, and very likely before getting to the runway if I was that concerned about running into terrain on a missed, if the GS went, and the LOC went, and I hadn't started time, and the two GPS receivers both bit it, and the RNAV stopped working, and the DME stopped working, and the ADF stopped working, and we were in the soup, and ATC's radar went down (or we were in a no radar environment).
Click to expand...

Are you under the impression that every aircraft has that set of avionics and that climb capability?
 
Houston said:
Just a couple miles. Then, by all means, don't go to the trouble of starting a timer.
Click to expand...

I don't. Missed approaches are designed to accommodate everything from a 172 to an SR-71. They are also designed to accommodate circling approaches that could initiate a missed from anywhere, even a mile PAST the localizer antenna GOING THE WRONG DIRECTION. Being off by a couple miles is not going to make any difference.

Sent from my Galaxy Nexus that ate your iPhone.
 
Ralgha said:
I don't. Missed approaches are designed to accommodate everything from a 172 to an SR-71. They are also designed to accommodate circling approaches that could initiate a missed from anywhere, even a mile PAST the localizer antenna GOING THE WRONG DIRECTION. Being off by a couple miles is not going to make any difference.

Sent from my Galaxy Nexus that ate your iPhone.
Click to expand...

Just a couple miles past, assuming you knew when you passed the antenna. You might want to submit that as a suggested change to the Instrument Flying Handbook. I'm sure your idea would be viewed with great interest.
 
Houston said:
Just a couple miles past, assuming you knew when you passed the antenna. You might want to submit that as a suggested change to the Instrument Flying Handbook. I'm sure your idea would be viewed with great interest.
Click to expand...

You got a cite for where the Instrument Flying Handbook says that you should start time on an ILS approach in case the GS goes out? I cruised through it to the places where I figured such information would be, but I can't quite find it.

EDIT: And while I was looking through the IFH, I found another way you could identify where the MAP is; the marker.
 
Houston said:
Just a couple miles past, assuming you knew when you passed the antenna. You might want to submit that as a suggested change to the Instrument Flying Handbook. I'm sure your idea would be viewed with great interest.
Click to expand...

You don't know when you pass the antenna? You must be the greatest pilot ever to exist if you can fly over a localizer antenna with nary a twitch in the needle.

I'm not advocating flying every missed like this, I'm saying that if you lose the glideslope on an ILS, which is an INCREDIBLY remote possibility, that you have means other than time to fly the missed. If you start the lateral missed procedure when you cross the antenna, you'll be fine. It's not even worth worrying about.

I'm more worried about going missed off a failed circle, because you're NOWHERE NEAR the published approach or missed paths, yet it's still fine. Actually, I don't even worry about that situation either, because it's protected too.

Sent from my Galaxy Nexus that ate your iPhone.
 
.
jtrain609 said:
You got a cite for where the Instrument Flying Handbook says that you should start time on an ILS approach in case the GS goes out? I cruised through it to the places where I figured such information would be, but I can't quite find it.

EDIT: And while I was looking through the IFH, I found another way you could identify where the MAP is; the marker.
Click to expand...

Are you under the impression that every ILS has a middle marker located at the MAP?
 
Ralgha said:
You don't know when you pass the antenna? You must be the greatest pilot ever to exist if you can fly over a localizer antenna with nary a twitch in the needle.
Click to expand...

Can you describe the "twitch" that gives positive indication that the aircraft is passing over a localizer antenna? How would that "twitch" be distinguishable from any other spurious twitch?
 
I don't remember the last time I started time on an ILS. Also helps to have 3 ILS receivers, 3 independent IRUs, and a couple FMCs. :D

Even a hack 121 guy like me knows when you pass the localizer antenna, though.
 
Houston said:
Can you describe the "twitch" that gives positive indication that the aircraft is passing over a localizer antenna? How would that "twitch" be distinguishable from any other spurious twitch?
Click to expand...

This is one of those things where you need (a little) experience. If you seriously can't tell when you cross a navigation antenna, then I have nothing more to say aside from suggesting that you go find a CFI and practice your VOR/LOC skills.

Sent from my Galaxy Nexus that ate your iPhone.
 
34971666.jpg
 
jtrain609 said:
I haven't done a CFIT escape maneuver in a while, so I don't know exactly how far the VSI pegs out when we do it, but I'd be willing to bet that I could hit any MSA in under 30 seconds, and very likely before getting to the runway if I was that concerned about running into terrain on a missed, if the GS went, and the LOC went, and I hadn't started time, and the two GPS receivers both bit it, and the RNAV stopped working, and the DME stopped working, and the ADF stopped working, and we were in the soup, and ATC's radar went down (or we were in a no radar environment).
Click to expand...
If all that happens to you at the same time in any airliner Im pretty sure some one wants you dead.
 
You must log in or register to reply here.
Back
Top