AIR FRANCE 447: New details suggest the Airbus design contributed to the crash.

[mgh 89]

They were actually in "alternate law" after the AP dropped out. So they the crew were flying the a/c not the computer.

 

And look at the FO's pitch commands and resulting AoA while the Stall Warning Was sounding.

 

 

 

Source 3rd interim Report

[japascoe 98]

Okay. Now we're going in circles. Did you understand my post? The point was to convey the short comings of being too reliant on FBW.

 

Being over reliant on the envelope protections (which is only a part of FBW as implemented on Airbuses) is a training / piloting problem, not a failure of the FBW system itself.

 

Add to the fact that the PNF cannot see what the PF is doing (like you can on a Boeing).

 

It's natural reaction to want to pull back when you stall (look at the Colgan Air Q400 crash near KBUF for another recent example) but dammit if I didn't think an AFR A330 crew would fall victim to this. It's easy to second guess a crew sitting here at the comfort of my desk, not in the dark, warnings galore and with everything at stake.....my heart goes out to all those on board.

 

Actually according to some posts on airliners.net it's more than possible to see the side-stick of the other pilot though you probably do need to turn your head. Of course on the Colgan Q400 the plane was equipped with linked controls, and even yokes in fact. That didn't stop the pilots from pulling back while stalled, so I'm not sure why linked controls would have made a difference to AF447, especially since the pilots were capable of completely ignoring STALL STALL STALL being shouted into their ears for about a minute. Yet not once did anyone on the flight deck mention anything about maybe being in a stall.

 

 

 

That Telegraph article has not once mentioned the obvious regarding the pitot tubes which apparently iced up----their heaters, which a BBC or C4 documentary,---- cannot remember precisely which,---- did analyse and theorise that these heaters had failed because of the level of ice in those storm clouds, thus leading to false signals being sent to the flight deck.

I've seen some snippets of that documentary and it seemed to have been well researched. However it is good to keep in mind that it was produced before the black boxes were found, so the conclusions are not based on all the data we now have available.

 

As a final point I'd like to point out that linked vs un-linked controls, side-stick vs. yoke and mechanical links vs FBW are three different questions, and it's important not to mix them up.

[vc10man 732]

Good, fair points, John.

[tf51d 284]

The one thing I don't understand in all this, is why when it was clear they were in trouble, didn't the senior pilot take positive control of the aircraft?

[vololiberista 205]

What I find quite amazing is that the a/c was at max throttle / full nose up and falling out of the sky at 124mph. For some reason this went completely unnoticed. One would think that at least one crew member would have said "What we're doing isn't working. Let's try something different like pushing the nose down perhaps?" or "Oh, is that the stall warning? Let's try a standard stall recovery then." Nobody will ever know why all three pilots and worst of all the Captain forgot simple basic training and airmanship. He made three serious errors that amount to dereliction of duty. First he put the a/c, crew and passengers at risk by electing to fly toward and through a major storm instead of diverting around it. Second, as they approached the storms he chose to leave the cockpit. And third when he was recalled he did not take control.

One can argue until the cows come home about side sticks v control columns. FBw computer systems or not. Iced pitot tubes. The rub is this that it comes down to basic airmanship. None of the crew were thinking "What if..." which is a pilot's duty and mantra on "every" flight. "We have decided to fly through an immense storm. Let's prepare ourselves for what might occur." They were caught napping literally! (the captain "was" having a nap!).

vololiberista

[FLEX1978 373]

The PNF did take control, the PF took it back unannounced hense why the aircraft announced 'dual input'

 

If you are talking about the captain taking his seat, I'm not sure musical chairs would have been a good idea in that situation.

 

Regarding a clear view of sidestick position- When a A3xx is sitting on the ground with at least one engine running you get a cross on the PFD that shows exact sidestick position. The cross disappears shortly after rotation, this cross would have been extremely helpful to the PNF and captain if available in alternate law.

 

Regards

 

 

[vololiberista 205]

The PNF who did "some" control input was not the captain though. Either he (the captain) should have played "musical chairs" as you put it or at the very least should have been scanning the instruments and observing and instructing the junior pilots. For example "We've lost the airspeed indication." - "Well what do you do in that situation?" - "Ummm dunno" - "Fly attitude / thrust". Or "Is that the stall warning Sir?" - "Yes, what are you going to do?" - "Pull the stick hard back Sir" - "That's not the classic stall recovery is it!!!! Try pushing the nose down." - "Oh, give it to me - I have control!"

The instruments clearly showed that they were falling out of the sky faster than a brick. They did nothing about it except ensure that the a/c continued to play the part of said brick.

"Lack of airmanship" will stain the reputation of Air Chance so obviously they will do their best to pass the buck and blame Airbus. Yes, there are some improvements they can make. The stall warning should stay on all the time. The throttles should move. Perhaps also a stick pusher should operate in "alternate law". Having said all that though it comes back full circle to lack of airmanship. The accident was avoidable on numerous counts.

vololiberista

[japascoe 98]

All very valid points, communication on the flight deck was severely lacking. However don't forget that by the time the captain reached the flight deck the IAS had already decayed to less than 60 kts so the stall warning wasn't working properly anymore.

Also until AF447 stall recovery in airliners was focused on minimum loss of altitude and assumed that the pilot would react to the stall warning (i.e. before the plane is actually stalled). Pushing the stick down may be what you learn in basic flight training, but during the airliner type rating the technique taught was merely to release back pressure (rather than go full nose down), firewall the throttles and fly out of the stall. Of course since 'modern airliners don't get into stalls' stall recovery was typically not practiced after the type rating. I believe in the Turkish Airlines crash at Schiphol it had been something like 18 years since the captain had last practiced a stall recovery.

[vololiberista 205]

Two weeks ago I had to "criticise" a trainee PO. During a simulated electrical and engine failure on an MD80 deliberately done to create maximum distraction. During the exercise the stick shaker went off twice and the PO only responded when advised to. Later I asked him to read the accident report for G-ARPI where not only did they ignore the warnings they actually turned it off and subsequently crashed.

In any a/c the stall warning and stick shaker/pusher is likely to be the only warning that can be relied upon 100% in any given sittuation. Whatever else is happening you must react to that immediately regardless of what else is happening.

Of course if you are piloting the a/c correctly in an emergency sittuation then that is an unlikely event. But, however much it takes you by surprise or however much it is unbelievable you must react instinctively and get the a/c out of the stall. By doing so you will have more time to sort out any other problem and less likely to become a statistic.

vololiberista

[Ben Cap 89]

This is so true that many companies are replacing their Boeing fleet with Buses.

Then how do you explain the 451 orders for the 737 Max? :Nerd:

[out 769]

This is so true that many companies are replacing their Boeing fleet with Buses.

Then how do you explain the 451 orders for the 737 Max?

 

Did he write 'all'?

BTW, speaking of orders, A320 Neo has 1256 firm orders (plus 753 options).

 

As this is AF447 thread, I hope there will be no AvsB turn of the discussion.

Especially that some people are really crazy about A or B. See an extreme example of the A fanism:

 

[Airbrakes 0]

Comparing AF447 to the Colgan crash is like comparing apples to oranges. The Colgan crash happened during approach when the aircraft was near 3,000' AGL. Nosing down at this altitude will invite the inevitable CFIT. There is nothing that crew could have done differently to recover from that stall. AF447 stalled at altitude. They had more time to correct. There is nothing wrong with the structural integrity of the A330. Discrepencies between pilot inputs caused the plane to operate outside of it's flight envelope, and break apart. Any plane would have crumbled under what stresses AF447 went through.

[Chock 17,769]

I agree that the two accidents are not really comparable, but it is probaably worth pointing out that a crash following a stall is not a controlled flight into terrain, by definition the aircraft is not controlled if it is stalled. And as far as I'm aware, AF447 did not break apart prior to impact.

 

I'd have slapped that woman on that video by the way for making that irritating wailing racket, what a complete fruitcake.

 

Al

[Airbrakes 0]

I agree that the two accidents are not really comparable, but it is probaably worth pointing out that a crash following a stall is not a controlled flight into terrain, by definition the aircraft is not controlled if it is stalled. And as far as I'm aware, AF447 did not break apart prior to impact.

 

I'd have slapped that woman on that video by the way for making that irritating wailing racket, what a complete fruitcake.

 

Al

 

A stall wouldn't be a CFIT, that much is correct. BUT, pointing the yoke down and smacking the turf would be a CFIT. It's not the stall recovery methods that should be the object of debate by investigators, rather what led to the stall in the first place. There isn't much you can do to recover from a stall in a Dash-8 at 3,000' AGL besides enjoy the ride. I think both instances can be linked to inadequate training in icing conditions. The ASI would have been no good in either case being that the pitot tubes froze.

 

If AF447 didn't brake apart prior to impact, why is the integrity of the A330's fuselage even in question??? Hitting the water at a wrong angle is just as bad as concrete. If you put Sully in AF447, I don't think he would have done any better than the crew did.

[Cessnaflyer 56]

There isn't much you can do to recover from a stall in a Dash-8 at 3,000' AGL besides enjoy the ride.

 

One thing to note is the aircraft wasn't stalled at first. The stall warning activated but it was an improper reaction and made the situation worse. Also stalling a Dash-8 is not like stalling a jet. It has quite a bit of power and nice straight high lift wings so a stall at 3000 AGL should easily be recoverable.