737NG A/T & F/D GA Mode
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Hallo Alberto,
when engaging the A/P after a GA the TMA will revert to climb, irrespective of the fact if level change was selected beforehand or not. To ease the understanding, just imagine what the designer thought: is the aircraft still in the TOGA mode, commanding all the known facts like climb rate, ground track, G/A power, etc,
OR is the aircraft in the climb mode, analog level change.
Hope that helps.
when engaging the A/P after a GA the TMA will revert to climb, irrespective of the fact if level change was selected beforehand or not. To ease the understanding, just imagine what the designer thought: is the aircraft still in the TOGA mode, commanding all the known facts like climb rate, ground track, G/A power, etc,
OR is the aircraft in the climb mode, analog level change.
Hope that helps.
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To set things straight, I just tried it in the sim.
If, during a G/A, you select A/P in command, TMA remains G/A.
Only changes to climb if you manually select "N1", or automatic at acceleration altitude, if you have that option.
If, during a G/A, you select A/P in command, TMA remains G/A.
Only changes to climb if you manually select "N1", or automatic at acceleration altitude, if you have that option.
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Hey latetonite and repulo,
You guys are awesome! Thanks for your answers.
So the system works just as I suspected.... Dammed "wording"!!!! As I said, SELECT, and ENGAGE aren't the same thing! Arrrrrrggggg
Cheers, great help chaps
You guys are awesome! Thanks for your answers.
So the system works just as I suspected.... Dammed "wording"!!!! As I said, SELECT, and ENGAGE aren't the same thing! Arrrrrrggggg
Cheers, great help chaps
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Hey albertofdz, latetonite, repulo, framer and everyone else thanks for all your replies.
However my question only relates to the G/A annunciation on the TMD.
During my last few flights, I was able observe the following.
a) Level Flight at 1900 RA (Flaps UP, TMD: CRZ).
b) Level Flight at 1800 RA (Flaps UP, TMD: G/A).
This answers the following when descending below 2000 feet RA, A/T go–around mode is armed.
However,
a) Level Flight at 2400 RA (Flaps 05, TMD: CRZ)
This fails to answer when above 2000 feet RA with flaps not up . How above are we looking at?
Please note, that I have tried these on 700/800/900ER Series of Aircrafts. The result was same. No approach was being conducted.
Once, again I really appreciate, all of your efforts.
However my question only relates to the G/A annunciation on the TMD.
During my last few flights, I was able observe the following.
a) Level Flight at 1900 RA (Flaps UP, TMD: CRZ).
b) Level Flight at 1800 RA (Flaps UP, TMD: G/A).
This answers the following when descending below 2000 feet RA, A/T go–around mode is armed.
However,
a) Level Flight at 2400 RA (Flaps 05, TMD: CRZ)
This fails to answer when above 2000 feet RA with flaps not up . How above are we looking at?
Please note, that I have tried these on 700/800/900ER Series of Aircrafts. The result was same. No approach was being conducted.
Once, again I really appreciate, all of your efforts.
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Hi again 737NG,
first, I enjoy talking about these subjects since there is always something I haven't thought about, even after being on the NG since it was first delivered to my company in 1999.
As it was mentioned beforehand, there are several customer options, eg we are having 6 fix pages, IAN enabled... So we might fly the same aircraft but observe slightly different annunciation.
In our config, TMA remained in CRZ at 1600' AGL in the clean config. I might have a chance to try the GA AP engaged situation on Sunday, depends on ATC on my way to LPA.
I don't trust the SIM, it does not always represent the company config by 100%. And usually it's exactly these little gimmicks that are concerned.
first, I enjoy talking about these subjects since there is always something I haven't thought about, even after being on the NG since it was first delivered to my company in 1999.
As it was mentioned beforehand, there are several customer options, eg we are having 6 fix pages, IAN enabled... So we might fly the same aircraft but observe slightly different annunciation.
In our config, TMA remained in CRZ at 1600' AGL in the clean config. I might have a chance to try the GA AP engaged situation on Sunday, depends on ATC on my way to LPA.
I don't trust the SIM, it does not always represent the company config by 100%. And usually it's exactly these little gimmicks that are concerned.
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OK Gentlemen,
here is the final answer to your questions: Had a chance to try the scenario yesterday on a visual approach to LPA. (Quite nasty wx with wind gusting to 45 kts..)
Condition: FD on, MCP speed and VS being the active mode. Missed app alt of 4000' set. Pressing TOGA, TMA goes to GA, as said before. Then AP selected, level change and heading select becomes the active mode. And the TMA? It goes to climb as I said before. Now if some of you observe different things in the SIM, probably it's a programming fault, I don't think that the NG's of different companies have substantial software differences.
Somebody mentioned earlier that the thrust reduction alt can be programmed, I don't think that that is an option for the GA, just for the T/O. GA thrust limit is very much the same value as max cont thrust so no need to hurry.
here is the final answer to your questions: Had a chance to try the scenario yesterday on a visual approach to LPA. (Quite nasty wx with wind gusting to 45 kts..)
Condition: FD on, MCP speed and VS being the active mode. Missed app alt of 4000' set. Pressing TOGA, TMA goes to GA, as said before. Then AP selected, level change and heading select becomes the active mode. And the TMA? It goes to climb as I said before. Now if some of you observe different things in the SIM, probably it's a programming fault, I don't think that the NG's of different companies have substantial software differences.
Somebody mentioned earlier that the thrust reduction alt can be programmed, I don't think that that is an option for the GA, just for the T/O. GA thrust limit is very much the same value as max cont thrust so no need to hurry.
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Correct, Repulo. I let it slip so early in the morning. GA mode terminates when a different pitch mode is selected, or Alt Acq.
Last edited by latetonite; 19th Feb 2014 at 07:20.
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Hi B737NG_Pilot,
I think albertofdz pointed you in the right direction: you might be confusing N1 limits (TMD) and A/T modes (FMA).
The conditions you name from the FCOM are related to the A/T mode, e.g. the left indication of the FMA. Your observations in the A/C seem to be of the TMD, which represents the current active N1 limit.
Correct me if I missed the point.
I think albertofdz pointed you in the right direction: you might be confusing N1 limits (TMD) and A/T modes (FMA).
The conditions you name from the FCOM are related to the A/T mode, e.g. the left indication of the FMA. Your observations in the A/C seem to be of the TMD, which represents the current active N1 limit.
Correct me if I missed the point.
