Posted on 07/31/2011 9:31:55 AM PDT by lbryce
"What do you think? What do you think? What should we do?"
The 37-year-old Air France co-pilot with over 6,000 flying hours was running out of ideas as a stall alarm bellowed through the Airbus cockpit for the sixth time in exactly two minutes.
His junior colleague with two years on the job was already in despair as he battled to control the jet's speed and prevent it rocking left to right in pitch darkness over the Atlantic, on only his second Rio de Janeiro-Paris trip as an A330 pilot.
"I don't have control of the plane. I don't have control of the plane at all," the younger pilot, 32, said.
The captain was not present and it was proving hard to get him back to the cockpit, where his more than 11,000 hours of flying experience were badly needed.
"So is he coming?" the senior co-pilot muttered, according to a transcript released on Friday. Light expletives were edited out of the text here and elsewhere, according to people familiar with the probe into the mid-Atlantic crash on June 1, 2009.
The 58-year-old captain and former demonstration pilot had left 10 minutes earlier for a routine rest. In his absence the plane had begun falling at more than 200 km (125 miles) an hour.
"Hey what are you --," he said on entering the cockpit.
"What's happening? I don't know, I don't know what's happening," replied the senior co-pilot, sitting on the left.
With the benefit of black boxes hauled up 4,000 metres (13,000 feet) from the ocean floor just two months ago, investigators now say the aircraft had stopped flying properly and entered a hazardous stall, as its 3,900 square feet (362 sq metres) of wings gasped for air.
(Excerpt) Read more at in.reuters.com ...
I don't know the redundancy logic for the AH, but looking at the A-330 cockpit it looks like a separate instrument, even if it is a mini-screen instead of mechanical.
http://www.flickr.com/photos/jpavao/4644756009/
I would have also thought that the Pilots Handbook would give details on which instruments are powered by what for use in emergency situations.
I would also hope that the certification authorities would demand some sort of back-up for the triple redundant computer...:^)
IMO, AF447 is the logical consequence of the prevaling “gear up, autopilot on” operating procedures on the line. IOW pilots get very little time “hand flying” - that is in direct control of the aircraft - in the simulator or on the line. Primarily this is because the autopilot systems can fly the aircraft more efficiently than the pilots.
In today’s ultra-competitive passenger business that means a smoother ride and fuel money saved. But it also means, IMO, the pilot flying is “out of the loop”, watching “George do it” when his brain ought to actively making corrective inputs so if/when “George” decides to pack it in seconds/minutes aren’t wasted trying to “get back in”. Based upon the flight data, these pilots never did.
There are a host of other technical aspects to this accident dealing with systems failures and the hard/software operations of the Airbus I’ll leave to many others far more qualified than I to opine upon. >PS
It is my understanding that there is no backup to the triply-redundant FCS on the Airbus, other than a back-up software system, but that requires good air-data to work.
I know Boeing has looked at quad-redundant systems but I'm not sure what aircraft they use them on, if any. It is my understanding that Boeing does have a back-up system outside the FC computers, but I'm not sure of that.
Years ago, there were a series of articles in IEEE journals on flight management engineering of both Airbus and Boeing.
The prevailing take-away I got from reading the articles written by the Airbus engineers was that they thought pilots were incompetent cowboys who waste fuel. They made design choice upon design choice to cut off pilot judgement and replace it with technocratic assumptions of efficiency.
When I fly, I am paying for the judgement of the guys up front, who I believe have the highest level of enlightened self-interest there could be: those pilots will usually be the first to arrive at the crash site if they make a big mistake. If they think it is prudent to burn some additional fuel, then burn away.
There is a cute story about future aircraft, re automation.
There will be only two occupants in the cockpits of the future, a dog and a pilot. The pilot is there to feed the dog. The dog is there to bite the pilot if he touches anything.
Yes, but what can you expect from engineers (Remember the joke about the engineer and the guillotine?). It’s another case of “to a man with a hammer in his hand...”, and was also a big issue in the Apollo program.
In an Airbus, I am no longer as certain as you are in that assessment.
Go back and look at all the losses of Airbus craft where you might equally apply what you just said, and you start to see pattern. The Airbus FMS appears to be a contributing factor to pilot error in situations where making correct assessment and corrective inputs in a short time period in several crashes now.
Being a retired engineer, I know well what to expect from engineers. However, Boeing engineers take a very different attitude towards pilots than EADS engineers, especially the French engineers. My thought process, were I designing a FMS, would be to assist the pilot, not try to replace him. Further, the last thing I would do is inundate him with worse-than-useless information in a tight spot. It is better for an instrument to stop providing information than to provide bad information. When you take away instruments, pilots are trained to fall back on other instruments.
I wish I had kept those IEEE journals from the late 80’s through the 90’s. American engineers aren’t quite in a position to say “we told you so,” but they are very close...
That could be.
In an Airbus, I am no longer as certain as you are in that assessment.
There are other instances of Airbuses losing airspeed indicators in similar situations and they all arrived at their destinations safely. There are plenty of indications in the BEA report that this particular crew was incompetent, not the least of which was they flew directly into bad weather that other aircraft were flying around, including an A330 Air France flight right behind them.
When the computer says land you land ... http://www.youtube.com/watch?v=qYHJLH_ewRY
As early as two days after the crash I realized that this was going to be blamed on pilot error. There was a major malfunction which the investigators almost completely ignored and instead chose to blame the pilots. I lost two immediate family members on that flight, and the BEA did not answer my questions by blaming the pilots.
Some pilot FReepers came on and said SOP is to set angle of attack and throttle and let the plane fly out of the situation.
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with no horizon and no reliable instruments they were toast.. I don’t know what was happening with the power though I would think a stall warning would have the pilots adding power if the computer would allow it. I can see the Air France abnormal/emergency procedure manual update for 2012 ... in case of a total systems failure power up and get a glass of water for an attitude indicator.
Dumb question here. I’ve never been in the cockpit of am airliner and I fly quite infrequently, & then mostly on small planes, so I’m guessing that the pilots experience is a little like sitting back in the living room easy chair but wouldn’t there be some physical signs that might give their true situation away?. It should seem to me that at some angle you would know that you were nose up or down or how fast you were falling by the feeling in the proverbial seat of your pants, or in the case of the captain returning to the cockpit having to climb a steep grade if the nose was up or walking down hill if the nose was down. Does this make any sense?.
Instead of pi$$ing your pants you should carry a glass and make good use of the urine, huh? Of course, that truly wouldn't tell you much unless you were in acceleration-free flight (no turns and level flight), and that is unusual in troubled times. But you knew that, didn't you?
It has been conclusively shown that you can’t tell from just the seat of your pants what attitude your aircraft is in when it is in an unusual attitude. For example, level acceleration feels just like a pitch-up.
LOL. I couldn't describe the flying experience more aptly than this. For the benefit of other passengers, I try to look as cool as a cucumber when I fly.
I was once on a flight from Dallas with a large group of co-workers when one of the ladies became hysterical and started running down the aisle screaming. It was very unsettling, particularly since I had no idea she suffered a flying phobia. She later told someone she had sedated herself with Valium prior to the flight, but it just made her more agitated. I felt terrible for her, particularly since she was so embarrassed about the occurrence. She would probably be arrested if this happened today.
Exactly. That is what I was referring to in #72. In the air-show case, it was the low altitude that forced the landing, but they fixed that problem. I wonder if they don’t use low speed as a signal to switch the computers to landing mode......
“True, the HSI (artificial horizon) would have settled the question if it could be trusted. The gyros can go bad, so you can’t automatically assume the HSI isn’t lying, especially if the VSI is going nuts, as I understand it was. Plus, the FCS was apparently trying to fly the plane out of a stall, and fighting the pilots.”
The HSI is a Horizontal Situation Indicator. It does not give pitch or bank information like an Attitude Indicator or artificial horizon.
Q. What's the definition of a good airplane landing?
A. When the passengers can leave under their own power.
Q. What's the definition of a great airplane landing?
A. When the plane can be flown again.
I feel like you do when I fly.
It's totally irrational, I know.
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