Asiana 777 Crash at SFO
#972
Not my experience at all with the 777 and auto throttles. I almost always turned them off on a visual. I did however turn off the arm switches which will provide you wake up in certain circumstances.
#973
I don't believe it is a poor design because the entire idea of FLCH is to pitch for speed. Had the autopilot been engaged, they never would have stalled. He put the airplane into a pitch for airspeed mode and didn't hold the required pitch. They also failed miserably at basic airmanship and CRM/TEM.
#974
I say this because I shot a VNAV (similar to a V/S) approach the other day when the ILS was OTS for the first time in 6 years on the airplane. It was a non-event. In fact, when we saw the ILS OTS on the atis, the other FO and I said, cool, we get to practice a VNAV for real.
#975
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Joined APC: Nov 2008
Position: A330
Posts: 1,043
#976
Remember we have our quick reference cards in the FAT for everything non-ILS to make all the non-ILS stuff a non-event. Other airlines may not have the same handy items. Additionally, with the VNAV to the feather protocol that we have, we run that stuff even on ILS's a lot more than other carriers may.
#977
I don't believe it is a poor design because the entire idea of FLCH is to pitch for speed. Had the autopilot been engaged, they never would have stalled. He put the airplane into a pitch for airspeed mode and didn't hold the required pitch. They also failed miserably at basic airmanship and CRM/TEM.
It was a combination of poor airmanship, poor systems management/awareness, poor energy management, and the strange no wake-up in FLCH sure didn't help matters.
#978
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Joined APC: Jun 2008
Posts: 3,716
It's strange at the least with the hybrid design of the 777. It poses as a super modern airliner, but yet in more than a few modes than other super modern airliners will just let you go there. "Wake-up" is a stall protection that they are trained is there. 777 pilots in most arenas are trained to never turn the A/T off. The A/T column on the FMA was green and the saturated pilots assumed it was active I'm sure.
It was a combination of poor airmanship, poor systems management/awareness, poor energy management, and the strange no wake-up in FLCH sure didn't help matters.
It was a combination of poor airmanship, poor systems management/awareness, poor energy management, and the strange no wake-up in FLCH sure didn't help matters.
#979
#980
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Joined APC: Jul 2005
Posts: 245
It is not just the 777. The 787 and 747-8 have the exact same logic for A/T wakeup.
The reason is the auto throttle can't wakeup to provide speed protection in FL CH SPD, VNAV SPD, TO/GA because the pitch is controlling the speed.
You can't have the speed controlled by both pitch and auto throttle.
They had V/S selected, set missed approach altitude, and at this point were very high. PF selected FL CH to get down, but the A/C started to climb to the MA altitude.
PF pulled thrust levers to idle, and A/T mode went to hold.
Initially in the descent he was more or less following the F/D.
Once the PF got low and started to shallow out he was no longer respecting the F/D.
As the FCOM states, AFDS speed protection is provided through the elevators in FL CH SPD, VNAV SPD, and TO/GA. But you have to follow the F/D.
The PM had the F/D off.
If the PF wanted to ignore the F/D guidance, he should have turned off the F/D.
If there is no F/D active, than the A/T wake feature is now available.
The design is good, and in fact really the only plausible way.
How any training department can claim that the A/T will wake up in all situations is irresponsible at best.
The reason is the auto throttle can't wakeup to provide speed protection in FL CH SPD, VNAV SPD, TO/GA because the pitch is controlling the speed.
You can't have the speed controlled by both pitch and auto throttle.
They had V/S selected, set missed approach altitude, and at this point were very high. PF selected FL CH to get down, but the A/C started to climb to the MA altitude.
PF pulled thrust levers to idle, and A/T mode went to hold.
Initially in the descent he was more or less following the F/D.
Once the PF got low and started to shallow out he was no longer respecting the F/D.
As the FCOM states, AFDS speed protection is provided through the elevators in FL CH SPD, VNAV SPD, and TO/GA. But you have to follow the F/D.
The PM had the F/D off.
If the PF wanted to ignore the F/D guidance, he should have turned off the F/D.
If there is no F/D active, than the A/T wake feature is now available.
The design is good, and in fact really the only plausible way.
How any training department can claim that the A/T will wake up in all situations is irresponsible at best.
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