Pilot Error Likely Played Major Role in Air France 447 Accident

When the French found the black boxes from Air France flight 447 nearly two years after the A330 airplane crashed in the Atlantic off Brazil, it was an incredible feat. But now, the French probably are wishing those black boxes remained on the floor of the ocean, because its national airline is about to face some tough questions regarding the actions of its pilots on that flight. No airplane accident happens because of just one problem, and this is no exception, but so far pilot error is really sticking out as the single largest contributor here.

Un Airbus A330 d'Air France
Photo of Sister Ship to Crashed Airplane via Flickr user Tab59|CC 2.0

The French accident investigation group, the BEA, has put out an update on its investigation around what caused Air France 447 to crash (pdf) in the Atlantic back in 2009. Flightglobal has a good minute-by-minute breakdown of what all of the technical verbiage means, but let’s focus here on a few key points.

Pilots Were Not Inexperienced
One thing that has been picked up on elsewhere is that the Captain was not in the cockpit when this all started happening. That’s true, and it’s not a surprise. That’s why there are three pilots on longer flights like these. They rotate taking rest and this was the Captain’s turn. Does that mean that there were two inexperienced fools manning the controls? No. The co-pilots were highly trained and should have been able to handle this situation without needing the Captain. As Flight notes, one of the co-pilots had more time on the A330 than the Captain himself (just not in command). Experience shouldn’t have been the issue.

Turbulence Was Not a Factor
The aircraft went down in an area near strong equatorial storms, so many people assumed that the storms and the likely associated turbulence played a role. That no longer appears to be the case. The pilots were actively working their way around the storms, and while there was turbulence around, it doesn’t appear to have been anything severe. The storm likely did play a role in that it caused the pitot tubes to freeze over. Let’s talk about that . . .

Frozen Pitot Tubes Are the Likely Trigger
I don’t believe this has been officially confirmed, but the belief remains that the pitot tubes froze and that kicked off the problems on the airplane. Pitot tubes are little pokey-looking things that stick off the side of the airplane and measure airspeed. If the pitot tubes froze as expected, then speed readings would have been erratic and incorrect. That would have caused the airplane to shut off the autopilot as happened here. While it is a serious issue, it shouldn’t have cause and accident on its own.

Ultimately, the Pilots Screwed Up
Regardless of what happened with the pitot tubes, what happened next seems just unbelievable and certainly casts a great deal of blame on the pilots even though we won’t have the final report until next year. About 10 minutes before the autopilot shut off, the pilots noted that they couldn’t climb any higher than the 35,000 feet they were at because of their weight and the relatively warm air outside. In other words, if they climbed higher, they wouldn’t be able to generate enough lift. That makes what happens next even more strange.

When the autopilot shut off, the pilots should have worked to keep the plane flying as it was. After all, there wasn’t an actual speed problem but just a speed measurement issue. The engines worked just fine, so it should have been quite possible to keep the airplane on its path. That’s not what happened. Over the next four minutes, the pilots pulled the airplane into a climb and right into a stall and that led to the crash into the ocean. This goes against one of the most basic rules of flight.

If Your Airplane Stalls

When an airplane stalls, that means its angle of attack (the angle of the wing as compared to the direction of the air) is too great. Fixing it is pretty straightforward and it’s something that gets trained at very basic levels. As the FAA says in its Airplane Flying Handbook:

Reducing the angle of attack is the only way of recovering from a stall regardless of the amount of power used.

That means pushing the airplane’s nose down until the air once again runs smoothly over the wings. If you’re at 35,000 feet, don’t worry about losing altitude. Just get the airplane back into normal flight. How do you know if you’re in a stall? This is where the Boeing vs Airbus people will start their “mine is better than yours” fight.

On Boeing airplanes, the control column actually shakes to warn the pilot. (It’s known, unsurprisingly, as a stick shaker.) But most Airbus types, including the A330 that crashed here, operate with little joysticks on the side and these don’t have stick shakers. Instead, there is a very loud verbal warning repeated multiple times. Either way, it shouldn’t be missed. But don’t Airbus airplanes have greater automation to prevent these things anyway? Not in this case.

Airbus normally has automation protection that prevents pilots from doing something stupid like going into a steep climb in a situation like this, but those protections weren’t in effect because of the inaccurate airspeed readings. That pushed the airplane into Alternate Law which shuts down many of the protections that are in place during Normal Law.

When the Captain got back into the cockpit, the airplane had an angle of attack at an incredibly high 40 degrees and it was losing 10,000 feet per minute in altitude. Despite his best efforts to recover, it was a failed effort. The airplane hit the water with its nose up 16 degrees but still losing more than 10,000 feet per minute in altitude. I can’t imagine how awful those few minutes were for the passengers.

But the Pilots Aren’t To Be Blamed Completely
The final report hasn’t been issued and won’t be until next year, but it’s easy to see from this that the pilots and the pitot tubes were the two biggest contributors. Why did the pilots continue to apply nose-up pressure when that was the exact opposite of what would have happened? We’ll never know what was running through their heads, but it’s easy to see that they could have been distracted.

Remember, the pilots were already working to pick their way through the worst of the storms. Add to that the loss of the autopilot, dozens of failure messages, and inconsistent speed readings and it seems like the answer might be simple. The pilots may have been so distracted that they forgot to do the one thing they needed to do to survive: fly the airplane. Once the final report is issued, look for training changes to come out of this and possibly even some changes in the way Airbus puts its airplane logic together.

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68 Comments on "Pilot Error Likely Played Major Role in Air France 447 Accident"

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Donald
Guest
Brett, I respect your knowledge of the airline industry, but I think your are operating outside of your envelope. I am not going to defend the pilots, I have a few questions about their performance but “The final report hasn’t been issued”. Its not just about the STALL, but also Mach buffet. You can lose control from going too fast at altitude. Funny thing is when a pitot tube ices over, the airspeed indicator acts like a barometer, ie; you go up the airspeed increases, go down it decreases. This may explain the nose up attitude. Perhaps they were trying… Read more »
cstclair
Guest

Agreed with Donald .. speculation and media drama will really abound when those who don’t actually fly the 330 begin assuming what errors led to this tragedy (and let’s also stay away from trashing this airline too – their record and that of the Airbus is pretty impressive).

conzolanzo
Guest
the pilots were at litle fault in this crash. you mention that they incorectly responded to a stall however the stall warning ocured shortly after the airspeed dropped to 60kts which may have confused the pilots and assumed that the stall warning was due to unreliable airspeed, this he was aware of. however he wasnt trained in high altitude recovery situations or even flying high altitude without autopilot which is and was common. as the flight was at night over water he had litle spacial awarenes and therefore may not have realised untill it was too late that he was… Read more »
David SF eastbay
Member

Is it time for computers to start giving advice? Should there now be an audio voice saying point the nose down if the computer see they are about to stall or whatever the the problem may be?

Turbulence Forecast
Guest

Why isn’t GPS used as a backup speed indicator (or indeed, primary speed indicator) in these systems? Seems that relying on a simple tube, while efficient, can go wrong (and did).

SirWired
Guest

When flying a plane, what is important is your speed in relation to the air around the plane (i.e. accounting for the effects of a headwind/tailwind), not the speed in relation to the ground. The pitot-static system will tell you this, a GPS cannot.

Nick Barnard
Member

Although GPS can help if a pitot-static system is grossly wrong.

Andrew
Guest

I have to believe that this incident is more complicated than the pilots forgetting to fly the plane. It seems absolutely inconceivable to me that the pilots could be unaware of the nose-up angle of the plane for the entire duration of the incident…I just can’t believe they could allow the plane to drop to the ocean with a nose-up angle of 40 degrees for three or four minutes without either knowing about it, or trying to correct it.

Donald
Guest
“Is it time for computers to start giving advice?” As Brett mentioned the computers (There are more than one commercial aircraft) did give advice, ie; audio alert of impending stall. There are many other warnings too. I would add that many of the electrons fled to the tail and hid. What I mean is that when the airspeed indicators failed to provide accurate data, the autopilot and auto throttles clicked off and reverted to a lower level of operation that required pilot input. Airliners give many warning of the stall, as airspeed approaches stall speed a red warning indication occurs,… Read more »
Roger
Guest
@Turbulence Forecast: GPS will tell you the ground speed which isn’t relevant. What is needed is the air speed – how fast the plane is moving through the air. The air itself is moving (often fairly quickly) which is why the plane’s air speed and the ground speed diverge. It is unlikely that all 3 pilots had no basic airmanship skills which is why waiting for the final report is better than armchair quarterbacking. Airbus and Boeing have already adjusted training for dealing with stalls and similar situations involving dodgy airspeed information. As with the vast majority of plane accidents,… Read more »
Donald
Guest

GPS tells your ground speed, not airspeed and have no bearing on the stall. When the flight attendant would forward the question from a passenger “How fast are we going”? My reply was, do they want our indicated airspeed, true airspeed, mach number or ground speed? This thread is going to consume me

Endre
Guest
Have you flown in bed weather IFR and have you had all instruments go out on you or show inconsistent readings? One speed shows below stall speed, other speed indicator shows above allowed speed. No horizon ahead of you, you are in a cloud. No stars above you, no city below you. Up, down, left or right, upside down or right side up. Your body has no idea. When Kennedy flew his plane into the ocean at night due to his disorientation, he could turn his autopilot on and possible save himself because all instrument were reading correctly and feeding… Read more »
DesertGhost
Guest

Maybe flying has become too computerized? Please note the question mark. I’m simply throwing the thought out there.

Robertol
Guest
Avid reader that hates to pile on but the analysis presented does seem rather simplistic: Vet pilots that forget the basic rules of flight. A couple of variables for you / others to react to: – It seems like the pilots did give stick down input at least once but were rewarded with a stall warning. I’ve read that under 60 knots the stall warning turns off (in some sort of alternate state). Could it be that the pilots didn’t realize they were in a stall / reacted to inconsistent feedback from the plane given the above (stick down =… Read more »
jimmbbo
Member
As in the movie “Apollo 13” (on steroids), the crew was faced with a cascading number of messages at or near the time the pitot tubes clogged, the autopilot disengaged and the air data computers (ADC) became “confused” and the airplane transferred into “Alternate Law”, likely providing mixed and/or erroneous signals to the primary flight instruments (all of which are driven by one or more of the redundant ADCs)… With the benefit of 20/20 hindsight, the only reliable instruments were the mechanical standby attitude indicator (peanut gyro) which has a separate 30 minute power supply, and the mechanical altimeter and… Read more »
MathFox
Guest
I am certainly with Endre where he describes the situation in the cockpit (dark, in a cloud and inconsistent instrument readings.) Alarm lights go on, alert horns blare… Most of your time flying the A330 has been on auto-pilot and you hand-fly in “normal law” for a few hours per year, mostly at low altitude during take off and approach. Now you’re pushed back into flying the plane in “alternate law”, probably the first time outside of the simulator and some of the control inputs you put into the plane act differently… you can stall the plane now. More hand-flying… Read more »
Armondm
Guest
Actually it is completely false to say turbulence did not play a role in this matter. Turbulence causes disorientation. When in turbulent weather, it becomes extremely difficult to disassociate turbulence with what the plane is actually doing…..particularly in zero visibility conditions. When the aircraft is severely bumped around and you have no visual reference and instruments begin to fail, you may not even know or realize that your aircraft is in an usual attitude or perhaps even stalled. There are occasions where turbulence got so bad while flying a Cessna 152 that the stall warning was chiming on and off… Read more »
Armondm
Guest

And to say the pilots screwed up is ridiculous….you have no idea what those pilots were going through and cannot possibly comprehend the severity of the situation sitting in your office writing this article.

Sounds like you’ve just got a beef with the airline/aircraft/and these pilots. RIP.

Jim M
Guest

Hmmm. . . .a lot of defending pilots today. Some justified, some perhaps not so.

Keep in mind that pilot error is often the cause of fatal air craft accidents. So if I was a betting man it looks like pilot error (or training error) isn’t too far off as a root cause.

http://www.planecrashinfo.com/cause.htm

A
Guest

The one thing we know for sure is that there will be changes to pilot training because of this, probably across all aircraft and all airlines. In the end we will all be safer on future flights because the black boxes were found and the questions about what happened were answered. While this fact is likely little solace for the relatives of the 228 people lost, I contend that their deaths are not in vain.

KB
Guest
Sorry but flying an a330 at FL350 is not the same as tooling around in a C172 at 5000 feet. You may only have a +/-5kt margin to keep the plane inside, and one really does rely upon the a/c to give an indication of the true speed. Do you really think any pilot can give you the airspeed to within 5 knots even in smooth air if blindfolded? In the low/slow regime such as approach and landing, your stall graphic is true. At cruise in a highly turbulent regime, not so much. Stall does not necessarily mean that your… Read more »
Armondm
Guest

I’m not trying to say that the aircraft fly the same…you are missing my point completely.

What I’m saying is at the moment when things are occurring, it’s extremely difficult to assess what’s happening.

A high AoA is relative to the flightpath…..and a stall occurs when separation occurs….which is always due to the angle of attack exceeding what is allowed for the design of that wing.

KB
Guest

Sorry, I was commenting on the original image of the Stall check and cross image. Yes, it’s highly confusing, which is precisely why its so easy for the a/c to move outside the flight envelope.

Separation can be caused by more than just a high AoA, it’s just the most common reason. You can effectively stall a wing at 0 AoA by setting up an area of high pressure behind the wing, entirely possible in a weather event. If you sketch out the vectors this is effectively an increase in AoA without *actually* increasing it.

Armondm
Guest
I fully understand that pilot error can be a contributor to an accident. I doubt anyone is denying that….but to assume that this was a case of these pilots not knowing what they were doing every step of the way is arrogant and facetious. Until someone is put in that particular position where their lives are truly at risk of ending and you are faced with your mortality, it’s pointless to lay blame…particularly in such a peculiar situation as this. I do believe there was an element of disorientation that occurred in the cockpit. It was a perfect storm of… Read more »
Freddy
Guest

“The cheapness and greed of the airlines to not install even more redundant systems in order to prevent such things leads many times to such occurrences happening. ”

Seriously?? Do you really think it’s the airlines saying ‘no, it’s alright, we don’t need a safe aircraft’? Several of the issues were bad luck, which you can’t do anything about. And the airlines have essentially no input in aircraft design other than general range/capacity/comfort/efficiency concerns, so such redundant systems are designed and included by the manufacturer, who knows what they are doing.
What would you propose? A windsock behind the tail?

Armondm
Guest

Yes I do…it’s in the best interests of the airlines to push the safety envelope for profit…what makes you think they operate on a higher level than any other corporation trying to milk profits?

There are PLENTY of examples of how airlines resist change and do not want to spend money to improve safety….HELLO SOUTHWEST.

Nick Barnard
Member

Freddy, my recommendation from experience is not to get into an argument like this with Armond. I’ve done it once before and it wasn’t pleasant.

Armondm
Guest

Likewise for you too…oh yes…I forgot…you’re the guy who needs to get the last word all the time right

Anyway, I’m not going to waste my time on rebutting your nonsense this time around. Unless you have something factual to say, keep to yourself please.

Nick Barnard
Member

Armond, the same goes for you my friend.

Freddy
Guest

o_O
I see what you mean

Endre
Guest
Of course airlines have saying what to install not to install. American decided no to install Right side stick shakers in their DC-10s to reduce cost. When the engine fell off on AA-191…Investigators found that as the jet was beginning its takeoff rotation, engine number one on the left (port) wing separated and flipped over the top of the wing. As the engine separated from the aircraft, it severed hydraulic fluid lines and damaged the left wing, resulting in a retraction of the slats. As the jet attempted to climb, the left wing aerodynamically stalled while the right wing, with… Read more »
Nick Barnard
Member

I’m curious how relevant a 30 year old crash really is. Airliner safety has gotten much better, so isn’t it possible that airlines son have these options?

From what I’ve seen on the sidelines airliners seem to be much less customizable right off the line.

martin
Member

I had been eagerly waiting your commentary and the readers’ comments! Thank you for a helpful and thought provoking post. I have even linked to you from my commentary on this.
http://mjtravlife.blogspot.com/2011/06/what-happened-to-airbus-a330-that-went.html

dan powers
Guest
there is a lot of confusion on this thread…angle of attack is not the same as pitch angle…the A330 does not have an angle of attack indicator…AoA is a percentage of actual lift vs total lift on a wing. AF447 was at an AoA of 40 degrees BUT the angle nose up was only 16 degrees (if you carefully read the BEA report on the FDR). so this story is not simply the pilots stalled the plane…besides transport category swept-back winged jets usually are un-recoverable from deep stalls, and if the pilots saw a pitch angle of 16 nose-up, full… Read more »
tharanga
Guest

Along with others, I think the complete story will be rather more complicated than the presentation here.

mch58
Guest

There is a published procedure in the Airbus manual…3 degrees nose up and 83% N1 engine speed maintains altitude and airspeed until the pitot tube heats enough to dislodge the ice…this has happened on other Thales tube equipped 330s….this is not to blame the AF447 pilots who no doubt had many other issues including reports of severe turbulence in their area.

David Z
Guest

Pardon my ignorance as I try to understand this, but it seems like the pilots essentially…what, overcompensated?

Steve
Guest

WHAT the heck are they stalking about: not enough training? I am only airplane single engine land, but during training about 60% of it was practicing how to recognize and recover from a stall. When air speed falls, WHO in their right mind would RAISE the nose of the airplane? Even if airspeed in increasing, that would not make sense unless something indicated the plane was in a dive. WEIRD.

walldobird
Guest

All the indications are that a severe up draft pushed the plane up to 38,000 and into a high pitched up attitude and a stall which the pilots did not have enough flight control to deal with.
Every operation manual I’ve dealt with for 40 years states “Avoid thunderstorms”.
You can guarantee the pilots were unable to deal with this, not unwilling.

Tocquevil
Guest

“But now, the French probably are wishing those black boxes remained on the floor of the ocean because its national airline is about to face some tough questions”.

Or probably not. Either Air France or French co-owned Airbus – main factory in Toulouse – and probably both, will have to face tough questions anyway. “The French”, who lost many coutrymen in the crash, would rather try to understand what went wrong.

Oliver
Guest
Noz
Guest

Excellent link….some people should actually read that article and stop making such ridiculous “factual” assumptions about what they think happened.

JetAviator7
Guest

Those of us who fly live by one cardinal rule: “Fly the airplane first, worry about anything else second.”

No doubt pilot error will be found in this case, even if it was unavoidable because of the loss of proper inputs into the computer.

On a different note, it makes you wonder if pilotless aircraft will really catch on – after all, can we really trust computers who have been programmed by human beings who may not think of a problem that might arise?

Noz
Guest

It’s a scary thought but consider adaptive algorithms that are now being used in advanced robotics and such have come a long long way.

Of course…any error made on the human side will translate to what the computer does…unless the adaptive skills of the computer can “recognize” something wrong and correct it.

walldobird
Guest

No evidence of turbulence??? They flew dead on into a thunderstorm. Why did everything start to fail? What caused the icing and the failures of the most necessary instruments? What caused the plane to zoom up? Why did every other plane in the area deviate around the CBs? If there was no flight into the heart of the storms, then none of this would have happened.
Thunderstorms can be very dangerous!
Every operations manual warns: Avoid Avoid Avoid!

Randy
Guest

The weather was too much for the plane, not the pilots. Simple truth.

trackback

[…] was plenty of backlash when I wrote about the causes of the 2009 crash of Air France flight 447 into the Atlantic Ocean back in May. Many of you wanted to wait until the final report came out, […]

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[…] Snyder (Cranky Flier) has a very useful commentary on the situation in which he expresses concern about the pilot errors that caused the plane to […]

commercial airplane injuries
Guest

Well, if a human error is involved in the crash (or at least partially involved) I’d really like to know if the relatives of the victims of the crash filed a lawsuit against the company. It’s the right thing to do in these cases, in my opinion. I know the company is a respectable one, but the relatives of the victims should get some comfort and air companies usually get by just fine after such accidents.

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