Hi Gums! Yes absolutely, everything I said goes out the window for FBW airplanes with C* control law (classic Airbus, F-16) which maintain a blend of attitude rate and G.
But it still stands, in a modified way, for C*U planes (777, 787, A220). It seeks to maintain a speed (like a non-FBW plane) but even better: eliminates the effect of thrust-pitch couple so the trimmed speed doesn’t change, damps oscillations, and maybe other clean-ups I’m not aware of. So while not acting to maintain AOA, it still ends up doing it as a byproduct.
Now I’ve never been trained in a FBW plane of either type and this is just from doing a lot of reading, so I hope I’m not talking out of my APU exhaust on the topic. But I would absolutely love the chance to fly a C*U plane and experience this in person.
Originally Posted by
BluSdUp
I hear what You say about the elegance of the pitch power copeling , on the 737-800 I found it rather excessive and ridicules. Then it becomes second nature.
I do worry about the transition for the P3 Orion crew to the P8 Poseidon.
I have seen some nice low passes filmed from flightdeck inspecting trawlers and the likes at 100 feet with steep turns from the P3.
Dont know about the Electra , but the 738 takes no prisoners with rapid thrust reduction without massive pull and trim.
I am sure someone will mention this to them,,,,,
Regards
Cpt B
You remind me of a point, where in all the discussions of the MCAS crashes you see all these reflexive quips about how they should have pulled the thrust levers back to slow down to unload the stab, as the obvious move that both crews missed, leaving the commenter bewildered. But it’s only “obvious” on the naive premise that thrust controls speed and ignores what we’ve discussed here, that trim determines speed and thrust determines climb/descent angle... as well as its own effect on trim.
So this ubiquitous solution to the problem of being severely mistrimmed nose-down and excessive on speed while too low on height, is an action that...
1, immediately pitches down due to the thrust pitch couple
2, trims to a higher speed due to the same
3, establishes a descent due to reduction of excess thrust
... which seems more than a little misguided. I brought this up in one of the MAX threads in Rumours & News and got accused of being a nonpilot impostor.
Now I don’t know if this consideration went through their minds and they dismissed it as an option upon reasoning, or (I think, the more likelier) that they were brainlocked. But if I was in their scenario I wouldn’t pull back the thrust either.
I acknowledge that some time between 1 and 2 above there would be a speed reduction, but only temporary and, by my intuition, small, before reversing. I’ve never flown any Boeing, but you being a 737 pilot and conversant in this topic, I’m curious for your take on it.