Last Words Air France 447
Today, I have a chilling ATC transcript for you from Plane Crash Info.com. Plane Crash Info, run by Richard Kebabjian, is an excellent database of aviation incidents, including photographs, statistics and articles on unusual accidents. Last words is a heart-breaking series of cockpit voice recordings and transcripts from fatal crashes, forcing us to remember that plane crashes aren’t just sensationalist headlines but real people in real emergencies.
Mr Kebabjian kindly gave me permission to reprint his annotated transcript from 2009 when Air France 447 disappeared over the Atlantic.
June 1, 2009
Atlantic Ocean, 570 miles northeast of Natal, Brazil
Air France 447
The Airbus went missing over the Atlantic Ocean on a flight from Rio de Janeiro, Brazil to Paris, France.
The last radio contact with the flight was at 01:33 UTC. The aircraft left CINDACTA III radar coverage at 01:48 UTC, flying normally at FL350. The aircraft reportedly went through a thunderstorm with strong turbulence at 02:00 UTC. At 02:14 UTC an automated message was received indicating a failure of the electrical system. The plane carried 12 crew members and 216 passengers. The wreckage was finally discovered on April 3, 2011 using unmanned submarines. Flight447 passed into clouds associated with a large system of thunderstorms, its speed sensors became iced over, and the autopilot disengaged. In the ensuing confusion, the pilots lost control of the airplane because they reacted incorrectly to the loss of instrumentation and then seemed unable to comprehend the nature of the problems they had caused.
Marc Dubois – Captain
Pierre-Cédric Bonin – Copilot
David Robert – Copilot
FA – Flight Attendant
Translated from French
|02:03:44 (Bonin)||The inter-tropical convergence… look, we’re in it, between ‘Salpu’ and ‘Tasil.’ And then, look, we’re right in it…|
|02:05:55 (Robert)||Yes, let’s call them in the back, to let them know…|
|02:05:59 (FA)||Yes? Marilyn.|
|02:06:04 (Bonin)||Yes, Marilyn, it’s Pierre up front… Listen, in 2 minutes, we’re going to be getting into an area where things are going to be moving around a little bit more than now. You’ll want to take care.|
|02:06:13 (FA)||OK, we should sit down then?|
|02:06:15 (Bonin)||Well, I think that’s not a bad idea. Give your friends a heads-up.|
|02:06:18 (FA)||Yeah, OK, I’ll tell the others in the back. Thanks a lot.|
|02:06:19 (Bonin)||I’ll call you back as soon as we’re out of it.|
|02:06:50 (Bonin)||Let’s go for the anti-icing system. It’s better than nothing.|
|Because they are flying through clouds, the pilots turn on the anti-icing system to try to keep ice off the flight surfaces; ice reduces the plane’s aerodynamic efficiency, weighs it down, and in extreme cases, can cause it to crash.|
|02:07:00 (Bonin)||We seem to be at the end of the cloud layer, it might be OK.|
|02:08:03 (Robert)||You can possibly pull it a little to the left.|
|02:08:05 (Bonin)||You can possibly pull it a little to the left. We’re agreed that we’re in manual, yeah?|
|An alarm sounds for 2.2 seconds, indicating that the autopilot is disconnecting. The cause is the fact that the plane’s pitot tubes, externally mounted sensors that determine air speed, have iced over, so the human pilots will now have to fly the plane by hand. Aside from the loss of airspeed indication, everything is working fine. Neither Bonin nor Roberts has ever received training in how to deal with an unreliable airspeed indicator at cruise altitude, or in flying the airplane by hand under such conditions.|
|02:10:06 (Bonin)||I have the controls.|
|Perhaps spooked by everything that has unfolded over the past few minutes—the turbulence, the strange electrical phenomena, his colleague’s failure to route around the potentially dangerous storm—Bonin reacts irrationally. He pulls back on the side stick to put the airplane into a steep climb. Almost as soon as Bonin pulls up into a climb, the plane’s computer reacts. A warning chime alerts the cockpit to the fact that they are leaving their programmed altitude. Then the stall warning sounds. This is a synthesized human voice that repeatedly calls out, "Stall!" in English, followed by a loud and intentionally annoying sound called a "cricket."|
|02:10:07 (Robert)||What’s this?|
|02:10:15 (Bonin)||There’s no good… there’s no good speed indication.|
|02:10:16 (Robert)||We’ve lost the, the, the speeds, then?|
|The plane is soon climbing at a blistering rate of 7000 feet per minute. While it is gaining altitude, it is losing speed, until it is crawling along at only 93 knots, a speed more typical of a small Cessna than an airliner. Robert notices Bonin’s error and tries to correct him.|
|02:10:27 (Robert)||Pay attention to your speed. Pay attention to your speed.|
|02:10:28 (Bonin)||OK, OK, I’m descending.|
|02:10:31 (Robert)||Descend… It says we’re going up… It says we’re going up, so descend.|
|02:10:37 (Bonin)||Here we go, we’re descending.|
|Bonin eases the back pressure on the stick, and the plane gains speed as its climb becomes more shallow. It accelerates to 223 knots. The stall warning falls silent. For a moment, the co-pilots are in control of the airplane.|
|02:10:41(Bonin)||We’re… yeah, we’re in a climb.|
|02:10:49 (Robert)||Damn it, where is he?|
|02:10:55 (Robert)||Damn it!|
|Another of the pitot tubes begins to function once more. The cockpit’s avionics are now all functioning normally. The flight crew has all the information that they need to fly safely, and all the systems are fully functional. The problems that occur from this point forward are entirely due to human error.|
|02:11:03 (Bonin)||I’m in TOGA, huh?|
|Bonin’s statement here offers a crucial window onto his reasoning. TOGA is an acronym for Take Off, Go Around. When a plane is taking off or aborting a landing—"going around"—it must gain both speed and altitude as efficiently as possible. At this critical phase of flight, pilots are trained to increase engine speed to the TOGA level and raise the nose to a certain pitch angle. Clearly, here Bonin is trying to achieve the same effect: He wants to increase speed and to climb away from danger. But he is not at sea level; he is in the far thinner air of 37,500 feet. The engines generate less thrust here, and the wings generate less lift. Raising the nose to a certain angle of pitch does not result in the same angle of climb, but far less. Indeed, it can—and will—result in a descent.|
|02:11:06 (Robert)||Damn it, is he coming or not?|
|The plane now reaches its maximum altitude. With engines at full power, the nose pitched upward at an angle of 18 degrees, it moves horizontally for an instant and then begins to sink back toward the ocean.|
||We still have the engines! What the hell is happening? I don’t understand what’s happening.|
|Robert has no idea that, despite their conversation about descending, Bonin has continued to pull back on the side stick. The men are utterly failing to engage in an important process known as crew resource management, or CRM. They are failing, essentially, to cooperate. It is not clear to either one of them who is responsible for what, and who is doing what. This is a natural result of having two co-pilots flying the plane. "When you have a captain and a first officer in the cockpit, it’s clear who’s in charge. The vertical speed toward the ocean accelerates. If Bonin were to let go of the controls, the nose would fall and the plane would regain forward speed. But because he is holding the stick all the way back, the nose remains high and the plane has barely enough forward speed for the controls to be effective. As turbulence continues to buffet the plane, it is nearly impossible to keep the wings level.|
||Damn it, I don’t have control of the plane, I don’t have control of the plane at all!|
|02:11:37 (Robert)||Left seat taking control!|
|At last, the more senior of the pilots (and the one who seems to have a somewhat better grasp of the situation) now takes control of the airplane. Unfortunately, he, too, seems unaware of the fact that the plane is now stalled, and pulls back on the stick as well. Although the plane’s nose is pitched up, it is descending at a 40-degree angle. The stall warning continues to sound. At any rate, Bonin soon after takes back the controls.
A minute and a half after the crisis began, the captain returns to the cockpit. The stall warning continues to blare.
||What the hell are you doing?|
|02:11:45 (Bonin)||We’ve lost control of the plane!|
|02:11:47 (Robert)||We’ve totally lost control of the plane. We don’t understand at all… We’ve tried everything.|
|By now the plane has returned to its initial altitude but is falling fast. With its nose pitched 15 degrees up, and a forward speed of 100 knots, it is descending at a rate of 10,000 feet per minute, at an angle of 41.5 degrees. It will maintain this attitude with little variation all the way to the sea. Though the pitot tubes are now fully functional, the forward airspeed is so low—below 60 knots—that the angle-of-attack inputs are no longer accepted as valid, and the stall-warning horn temporarily stops. This may give the pilots the impression that their situation is improving, when in fact it signals just the reverse.
The captain of the flight makes no attempt to physically take control of the airplane. Had Dubois done so, he almost certainly would have understood, as a pilot with many hours flying light airplanes, the insanity of pulling back on the controls while stalled. But instead, he takes a seat behind the other two pilots.
|02:12:14 (Robert)||What do you think? What do you think? What should we do?|
|As the stall warning continues to blare, the three pilots discuss the situation with no hint of understanding the nature of their problem. No one mentions the word "stall." As the plane is buffeted by turbulence, the captain urges Bonin to level the wings—advice that does nothing to address their main problem. The men briefly discuss, incredibly, whether they are in fact climbing or descending, before agreeing that they are indeed descending. As the plane approaches 10,000 feet, Robert tries to take back the controls, and pushes forward on the stick, but the plane is in "dual input" mode, and so the system averages his inputs with those of Bonin, who continues to pull back. The nose remains high.|
|02:13:40 (Robert)||Climb… climb… climb… climb…|
||But I’ve had the stick back the whole time!|
|At last, Bonin tells the others the crucial fact whose import he has so grievously failed to understand himself.|
|02:13:42 (Captain)||No, no, no… Don’t climb… no, no.|
|02:13:43 (Robert)||Descend, then… Give me the controls… Give me the controls!|
|Bonin yields the controls, and Robert finally puts the nose down. The plane begins to regain speed. But it is still descending at a precipitous angle. As they near 2000 feet, the aircraft’s sensors detect the fast-approaching surface and trigger a new alarm. There is no time left to build up speed by pushing the plane’s nose forward into a dive. At any rate, without warning his colleagues, Bonin once again takes back the controls and pulls his side stick all the way back|
|02:14:23 (Robert)||Damn it, we’re going to crash… This can’t be happening!|
|02:14:25 (Bonin)||But what’s happening?|
|02:14:27 (Captain)||Ten degrees of pitch…|
|Exactly 1.4 seconds later, the cockpit voice recorder stops.|
Reprinted with permission from Plane Crash Info.com.