Originally Posted by
Turbine D
Dozy
Your posts were at one time informative and interesting to read, but have turned into total protection of Airbus recently. Airbus doesn't need protection, they are experts at "protections".
If that is the case then I suggest you read what I've been posting in isolation from what others (including yourself, it would appear) chose to read into what I was saying.
I have got to go with gums on this. The computer system, e.g., Alternate Law 1, Alternate Law 2 and subsets of Alternate laws are very confusing. Normal Law and Direct Law are very clear: Normal Law - the computers fly the plane and the pilots watch, Direct Law - the pilots fly the plane and the computers watch. That is simple. The in-betweeners are a mish mash of: You have this but not that except when this is this or that is that....
Then you didn't read what I was saying - which is that at the most basic level, all a pilot has to understand about the control laws is that you have hard protections in Normal Law, but do not have them in any of the other laws. What that means in the case of this accident is that as such, pulling up and continuing to pull up in the face of a Stall Warning is just as dangerous as it would be in any other airliner once Normal Law is lost.
The sub-modes are there purely for engineering and systems management purposes - as I said, think of them as the different systems configurations that would have been handled by the Flight Engineer on aircraft of earlier generations in the case of damage or failure. Gums knows his stuff, there's no doubting that - but he has got it into his head that the Normal Law protections are akin to autopilot limitations, when in fact they give the pilot considerably more leeway than that (I sent him along some of the Flight articles that covered the A320's development as evidence).
Think about it, in the case of AF447, they had at most three minutes to determine what was wrong, what was going on and what to do, with the balance of time being on the express elevator to the sea.
They'd have had a lot longer if the PF had not started pulling back on the sidestick and continued to do so for the majority of those three minutes. If this was any other aircraft this would have been an open-and-shut case, but because there are those on here that will continue to insist that the computers must be to blame in any Airbus accident, we're still going over the same stuff months later.
From a technical and engineering point of view, here is what I see wrong on Airbus' part in this saga:
1. Airbus failed to handle the pitot tube problems in a manner that they should have.
They told the operators to fix it and sent out bulletins to pilots explaining workarounds until such time as the fixes were completed - what more could they have done without grounding the entire fleet (which prior to this accident would have looked like overkill)?
2. Airbus failed in their risk assessment/risk abatement to adequately cover the total waterfront, e.g., total flight envelope. They were nearly mute on flight problems at high altitudes and speeds.
Them and the rest of the industry.
Guess they assumed problems couldn't happen there.
That's a little bit of editorialising from you. I think it's fairer to say that - like the rest of the industry - they assumed that pilots would be sufficiently qualified and knowledgable to recover from most high-altitude problems.
3. Airbus failed to provide complete key memorization items in their flight instructions for the A-330, leaving out for the most part, high altitude and high Mach cruise situations.
Could you be more specific?
You can also say and you have on many occasions, the plane did exactly what it was supposed to do, but in reality, it crashed. That was not Airbus' intent I am sure, nor was it the pilots flying or Air France's intent either.
It wasn't Bombardier's or ColganAir/Continental's either, but the sad truth is that if you shave the training budgets to the extent where basic airmanship is deprecated in favour of checking only up to the onset of warnings then you will start to get problems.
As in the role of leader, Airbus must not have/didn't push the issue hard enough with EADS, or so it seems or didn't view correctly the critical nature of pitot icing at high altitude and high Mach.
Not wanting to nitpick, but do you mean EASA (European safety authority) rather than EADS (Airbus's parent company)? I'm sure that Airbus went into consultation with EASA and the airlines and together they determined what the response should be. For better or worse, it seems to have been assumed by the industry in general that problems at high-altitude by their nature should buy the pilots enough time and altitude to remedy the situation. Even the most extreme examples of UAS upset prior to AF447 led to relatively minor level busts rather than significant control difficulties - so even if Airbus came to the discussion with a serious AD in mind, it is likely that the airlines would have pushed back at the prospect of large chunks of their fleets spending weeks in MX.
AF447, three minutes to go (not knowing that at the time), A/P come off, A/T come off, the stall warning sounds, the nose is slightly down and one wing is lower than the other.
OK -so we're not in any danger yet. Let's not touch the controls until we're sure what's happening.
[Actual response : Immediate grip on the PF's sidestick including a significant nose-up command, far in excess of what would be required to bring the nose back up to S&L. ]
We are in Alternate, is it 1 or 2?
Doesn't matter. Anything other than Normal => No hard protections. We need to be more careful with the inputs (though no more careful than in any airliner without protections)
Going too fast? Going too slow? What is the speed?
We don't know, so fly pitch and power until things are stable.
What are the protections?
See above - there aren't any (or to be more precise there aren't any that will counteract pilot demands).
What do we have and what don't we have? What does the memorized list developed by Airbus say? Do we have a memorized list for high altitude/high Mach?
Pitch and power. That's just airmanship - no memory list should be necessary (although admittedly it would likely have helped).
That was the situation. Now Airbus did do a good risk analysis/risk abatement for low speed, low altitude situations, landings, T/O's, thus developed the memory lists. But they stopped short.
As did every other manufacturer.
In fact, if you apply the low altitude low speed do's to high altitude/high Mach, it probably makes the problem worse.
Well yes - the procedure the PF appeared to be closest to following was in fact the low-altitude Wind Shear/Microburst escape - although no procedure was in fact followed to the letter.
What happens to THS flight protection in Alternate law?
Same as the others - it goes away - so we need to be careful.
What's the AOA? Confusion? Help? Panic? 3 minutes to sort things out. Cavalry charges, single chimes after single chimes, single chimes every 5 seconds, lots of crickets? Get the gist?
We're getting Stall Warnings - we've had them for a minute. Why then is our nose at 15 degrees up?
[Answer : Because the PF was holding it there.]
Did Airbus have a strong recommendation?
Yes - replace them as quickly as [the airlines] were able (see above).
Now Airbus knew the AOA was a critical key component to assure safe flight, but where was the indicator to know what it was and where it was going?
Same place it was on every other modern airliner - nowhere.
Is there a key memory list, e.g., level wings fly pitch and power? What should be the correct pitch setting when you have no speed indications?
The assumption was probably that basic airmanship would preclude a 15 degree nose-up pitch at high-altitude - unfortunately relying on that does not appear to have been enough.
And I could go on in more detail and ask more questions, but I won't. I think there is enough to illustrate that Airbus shares much responsibility as do the flight crew, the airline and even EASA if they relaxed on an Airbus' "Strong" recommendation, if there was one.
Which I've never argued with, if you go back over my posts on the subject - my contention has been with those that have argued that there is something fundamentally wrong with the aircraft design and that as such Airbus must carry the whole can.
But Dozy, to continue to protect Airbus is fruitless, it is like pi**ing into the wind, sooner than later you are going to get wet and I think you are getting wet.
OK - let me make this as clear as I can - I'm not "protecting Airbus". I'm simply taking issue with some posters on here that are not discussing the factors of the case honestly, but instead are coming to the table with their pre-conceived notions about why they dislike the Airbus FBW design and are trying to hammer the facts of the case to fit the mould of their prejudice.
At least one poster continues to come up with ever more lurid theories about how it must have been the aircraft's fault. Indeed, insisted until *very* recently that the VS must have broken off in flight, then made excuse after excuse including how there must have been a software bug that popped the spoilers on one side, that the THS control software suffered a glitch and ordered a runaway trim without the pilot's knowledge...
Others are trying to turn this into an argument about a 23-year-old accident in which the pilot thought he was better than he was, crashed the aircraft and killed three people (two of them children) in the process - and consistently refused to take responsibility for his actions since, making up excuse after excuse as every one was disproven by the investigation.
All of this comes from the patently false idea that Airbus and airline management were in cahoots with each other to develop an aircraft that would de-skill the job of airline pilots and reduce them to "systems operators" akin to any other office monkey. Even gums, who clearly deserves to be taken seriously in most respects, harbours this idea in the background of his thinking - which is a shame because it clouds the rest of what he's saying.
I have never said that Airbus should not shoulder some responsibility - in fact I've always been at pains to point out that because of the pitot tube issues there is no way they can avoid it. However, I do take issue with some posters going on the "same old !!!!!" tour when it comes to incidents involving the FBW Airbus family and bringing up factors that have no bearing on the case (sidestick vs. yoke) or could be applied to the whole industry (lack of preparation for high-speed stalls, recurrent training cut to the bone).
So please - if you're going to level this kind of stuff at me, please have a look at what I'm actually saying - in isolation from what others claim I am saying.
[EDIT : I hope IGh won't mind me borrowing this image from his post on the ANA 737 upset thread in R&N, but it sums up more succinctly than I could what I believe to be the crux of the issue regarding the crew response (mitigated in this case by a poor attitude to training on the part of the industry):
]