4 ms·
Although at least now you're trying to solve a more logical problem. Increasing angle of attack => counter with elevator, if not sufficient reduce thrust
by cjrp 8y ago
Although at least now you're trying to solve a more logical problem. Increasing angle of attack => counter with elevator, if not sufficient reduce thrust
- foldr 8y agoReducing thrust will increase angle of attack. The angle of attack is the angle of the wing relative to the airflow, not the angle of the plane relative to the horizon.
- salawat 8y agoYes conceptually, no because of signage error. If you were in a position MCAS would have to kick in, you were at positive AoA, reduced thrust would impart a negative AoA moment.
- cjrp 8y agoExactly, I'm only talking about in the MCAS-scenario.
- foldr 8y ago> you were at positive AoA, reduced thrust would impart a negative AoA moment I don't think that is correct. I think you're still thinking of the angle of the plane with respect to the horizon, not the AoA. If reducing thrust reduced AoA, then you could recover from a stall by reducing thrust. In reality, the opposite is the case. The only way to recover from a stall by manipulating engine thrust is to increase it (though this won't always be sufficient by itself).
- pas 8y agoAFAIAK the procedure is to not increase thrust, quite the opposite (disable the autothrust thingie), get the nose below the "horizon" (which is of course wind dependent), gain airspeed, and then start to increase thrust (which will automatically start to up the nose a bit), then climb back to whatever altitude you should be at.
- foldr 8y agoI don't mean to say that increasing thrust is the standard stall recovery procedure in most aircraft, or that all stalls could be recovered from merely by increasing thrust. But if one could only manipulate thrust, one would increase thrust to recover from a stall, not decrease it.
- pas 8y agoAh, yes, of course, theoretically if you can just increase thrust arbitrarily, that always solves the issue. (Again, of course, this might mean the whole plane becomes a rocket because the wings already fell off, so you might need some thrust vectoring too.)
- salawat 8y agoOkay, I get what your saying. I just wasn't reading right, and while what I've said may be theoretically correct, under most circumstances, the control surfaces are the primary contributors to the aircraft's orientation. Fiddling with engines in an MCAS activation situation would just offset the flight envelope into a more dangerous zone, that could be even more difficult to recover from. Took me a bit, but I got there.
- foldr 8y agoWe're not talking about the aircraft's orientation, we're talking about the Angle of Attack. The AoA can increase even if the nose of the aircraft is dropping relative to the horizon.