76mike
9th May 2013, 21:40
The following two sentences are from the Boeing 767 Volume 2 AOM: Aircraft Systems (pages 4.20.14 and 4.20.15):
"If the airplane is floating within five feet radio altitude for more than two seconds when the GA switch is pushed, the autopilot pitch mode will remain in FLARE and the autothrottle go–around mode will engage.
If the airplane is on the ground but has been below five feet radio altitude for less than two seconds when the GA switch is pushed, the autopilot GA pitch mode will engage but the A/T mode will remain IDLE."
Any thoughts on the logic behind this? I hope I'm not missing something obvious, but I don't understand the reasoning behind this: in one case the thrust comes up but you have to manually rotate the aircraft; in the other, the aircraft rotates to Go Around pitch but you have to manually add thrust.
The 757 is similarly designed.
Apologies if this has been covered elsewhere...
"If the airplane is floating within five feet radio altitude for more than two seconds when the GA switch is pushed, the autopilot pitch mode will remain in FLARE and the autothrottle go–around mode will engage.
If the airplane is on the ground but has been below five feet radio altitude for less than two seconds when the GA switch is pushed, the autopilot GA pitch mode will engage but the A/T mode will remain IDLE."
Any thoughts on the logic behind this? I hope I'm not missing something obvious, but I don't understand the reasoning behind this: in one case the thrust comes up but you have to manually rotate the aircraft; in the other, the aircraft rotates to Go Around pitch but you have to manually add thrust.
The 757 is similarly designed.
Apologies if this has been covered elsewhere...