KayPam
What does any A320/330 do when it overspeeds Autopilot engaged?
(usually due to turbulence)
Clearly you have never flown either.
With AP/ATHR on, the ATHR will gradually reduce its power to flight idle (slower than if you put it on idle notch manually)
(In a wholly different context: In final approach, the ATHR gains are lowered in order to avoid a too "lively" ATHR when closer to the ground. So one should pay all the more attention to their speed, and never rely entirely on the ATHR. It can do a better job than a pilot but not always)
However, the ATHR will (in any case) have much trouble managing wind gradients higher than 2kt/s
If the speed increases, the ATHR will reduce but not fast enough.
The pilots can notice the increase in speed and deploy spoilers.
Another possible reaction (but less academic) is to pitch up. I even see some pilots reducing to idle notch (and some others forgetting to put it back to cruise thrust when required)
In any case, if an airbus with AP ON is accelerating, the normal law will start to pull up in order to reduce speed, once just above MMO.
Full forward stick while in overspeed will make the airplane stabilize at MD - Mach Dive (which is 0.07 above MMO on all airbus aircraft if my memory is correct, .82-.89 for the 320, .86-.96 for the 380)
Neutral stick will give you MMO (in stabilized conditions)
The High speed protection starts to really worry and to really pull up more when you're about halfway between MMO and MD or more.
In fact I am not (yet!) a qualified Airbus pilot but I do work in the very building where integration tests are carried out for the A380 and the A350, with integration simulators (Airbus factory at Toulouse Airport)
I am about 80% sure that AP will disconnect if high speed protection engages (well, you don't care about that question because in the high speed prot, wings are levelled so you would lose nav capability and you would obviously lose altitude holding as well)
So I would be very interested in knowing how easy/hard it is to fly the speed with the attitude in a wind gradient. Would there be a risk of oscillations around the target altitude due to overcorrection ?
Are pilots trained to operate manually at higher altitudes ?
A A320-pilot-friend told me it was very difficult to transition from climb to cruise manually at high cruising altitudes.
FCOM will confirm most of this (maybe not the 2kt/s value), mainly in DSC 27-20-10-20, see page 111 here :
http://nicmosis.as.arizona.edu:8000/...tems_part2.pdf )
Originally Posted by
Concours77
When pilot saw he was not over the runway threshold, he reverted to muscle memory, an unfortunate one. "Pull the stick, firewall the throttle." But he was not flying a Corsair, he was flying a Beech twin....
The aircraft made a small hole in the roof, not a long gash. He should have pulled the stick, and firewalled the throttles......arse about.
As to 447, the reason this discussion is eight years on, and twelve threads in, is because we yak about the part of the flight path that is fundamentally irrelevant. What was the status and attitude of the aircraft at the most important moment in the flight? As the A/P quit, and the a/c was four hundred feet low, Nose Down, and the Stall Warn was active? Oh, and rolled right?
It is the interface, Machinbird, as you say. The human is being evolved out of the equation, replaced by ever more "dependable" automation. Emotion and intuition are poison, data and speed are paramount.
Are you implying this corsair pilot pulled too much and stalled his beech ?
About AF447, going from FL370 to FL366 (there is a debate among our team of engineers about whether we can say FL followed by a number not finishing by 0 or even 5) in a short time span (as short as the one between cavalry charge for AP disconnection and the moment you look at your altimeter) would be really feelable through vertical acceleration, and the crew should have realized that.
They should have realized that they were actually in straight and steady flight without the need for touching anything. (CF the post that I wrote the other day about "it does not take exceptionnal flyings skills to do nothing")
As for attitude indication, IRS do not freeze ! (They do, however, suffer from laser lock, ATPL monkey knowledge here)
As for the Airbus stall warning.... AOA is considered invalid under 60kt (CAS invalid under 30kt, the ADR do not even try to compute it), and the stall warning was based on an AOA higher than a treshold. So invalidity of the AOA would make the stall warning stop.
According to one of our teachers in engineering school, that behavior is illegal. I hope that Airbus management decided to solve this ***slight*** problem.