Hello,
I am using Fs9 with my PMDG 747 Queen Of The Skies, my problem is upon entering a landing pattern on a CATIII ILS landing. my altimeter would show 2000ft but I will get a call out of 1000ft. This is only one example. My aircraft May be 1000ft above the ground but I get call outs of 500, 200 or others. when I look at the PFD and see the altimeter would show 1000 ft or more.
What is going on ?, Am I reading this wrong. I have posted the same question to PMDG
Ron from Texas
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#2
Ian P
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Posted 05 February 2012 - 07:42 PM
The altitude callouts are created by the TCAS - Terrain and Collision Avoidance System - and are not references to what it says on the altimeter unless you are over water, or land at "Mean Sea Level" or MSL (all treated as 0' in FS) - they are announced with respect to your distance "Above Ground Level" (AGL) which, of course, changes as you go over hills and thus can cause interesting effects.
If the airport you are approaching is at, say 600', then when flying at 1000'AMSL (1000 on the altimeter), you are actually only 400'AGL and thus as you approached it, you would have heard every call down to 400'. Now say there is a rise in the ground before you reach the airport, with a 200' increase, you'll be down to 200' AGL as you go over the crest of the hill and you will hear the "TWO HUNDRED" call, then possibly a "THREE HUNDRED" and even "FOUR HUNDRED" call as you pass over the hill and back to normal ground level.
Typically, an airliner will intercept an ILS at around 9 Nautical Miles from the threshold at 2000 or so above the airport, depending on local requirements. That should mean that you only hear each call once, but it does sometimes happen that undulations can cause "TWO HUNDRED, TWO HUNDRED" calls and similar. The thing you have to remember is that they are warnings of the vertical distance between you and the solid stuff, not a warning of what altitude you have set to fly at.
Ian P.
If the airport you are approaching is at, say 600', then when flying at 1000'AMSL (1000 on the altimeter), you are actually only 400'AGL and thus as you approached it, you would have heard every call down to 400'. Now say there is a rise in the ground before you reach the airport, with a 200' increase, you'll be down to 200' AGL as you go over the crest of the hill and you will hear the "TWO HUNDRED" call, then possibly a "THREE HUNDRED" and even "FOUR HUNDRED" call as you pass over the hill and back to normal ground level.
Typically, an airliner will intercept an ILS at around 9 Nautical Miles from the threshold at 2000 or so above the airport, depending on local requirements. That should mean that you only hear each call once, but it does sometimes happen that undulations can cause "TWO HUNDRED, TWO HUNDRED" calls and similar. The thing you have to remember is that they are warnings of the vertical distance between you and the solid stuff, not a warning of what altitude you have set to fly at.
Ian P.
#3
buffaloron
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Posted 06 February 2012 - 12:03 AM
Okay I Guess my novice position showed up. for some reason I was reacting to the call outs and would overshoot the runway everytime. I got tired of landing on Wal Mart roofs so I had to check. it all makes sense now, so look out I may actually land at the air port
Thanks Ron
Thanks Ron
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