The Smells, Sounds, and Sensations of Air France 447's Final Minutes

Popular Mechanics' recent feature narrating Air France flight 447's final five minutes gives one of the most detailed and sensory-rich accounts of the mysterious crash, and from it we can start to understand what it would have been like as a passenger on the doomed aircraft.

Popular Mechanics' recent feature narrating Air France flight 447's final five minutes gives one of the most detailed and sensory-rich accounts of the mysterious crash, and from it we can start to understand what it would have been like as a passenger on the doomed aircraft. So far, much of the reporting on the crash, the discovery of its black boxes, and the French government's eventual report has focused on what happened in the cockpit, where the pilots lost control of the plane. And rightly so -- that's where the chain of events happened that eventually caused it to crash in the Atlantic, midway between Rio de Janeiro and Paris on June 1, 2009. Writer Jeff Wise also focuses on the goings-on in the cockpit, but with a level of detail about the sights, smells, and attitude of the airplane that allow us to extrapolate (with the help of plenty other reporting that's been done on the disaster) what it would have felt like to be in the passenger cabin of Air France flight 447.

Obviously we can't imagine what the mood was like in the cabin -- what people said, thought, and did -- and we'd be unwise to make any guesses. But we can decipher what people probably smelled, saw, and felt as their aircraft fell 38,000 feet to plunge into the middle of the Atlantic.

The environment:

First, a look at the inside of an Airbus 330 passenger cabin (via Flickr user Jigmi). This isn't an Air France plane, but the setup is about right, with a four-wide row of seats in the middle and two rows of two along each side, per Airbus's website:

A weird light:

The Popular Mechanics account starts with the airplane flying into a storm, and the appearance of St. Elmo's fire around the cockpit.

At 1h51m, the cockpit becomes illuminated by a strange electrical phenomenon. The co-pilot in the right-hand seat, an inexperienced 32-year-old named Pierre-Cédric Bonin, asks, "What's that?" The captain, Marc Dubois, a veteran with more than 11,000 hours of flight time, tells him it is St. Elmo's fire, a phenomenon often found with thunderstorms at these latitudes. 

According meteorologist Keith Heidorn at The Weather Doctor,  "With the age of flight, the Fire has appeared along the wing tips, propellers, and antennae of aircraft, often disrupting radio communications." So it seems reasonable to assume passengers might have seen some of the ghostly bluish luminescence outside their windows.  Flickr user Kent Wien posted this shot of St. Elmo's fire, as seen from inside an airplane cockpit:

A funny smell:

As the pilots realize they're flying into the middle of a storm, they bank the plane to the left. As they're performing this maneuver, the plane's autopilot disconnects and the airspeed gauge stops working when a speed sensor known as a pitot tube ices over. This is the beginning of the pilots eventual loss of control of the airplane. But it brought with it an odd smell, Wise writes:

Bonin wordlessly banks the plane to the left. Suddenly, a strange aroma, like an electrical transformer, floods the cockpit, and the temperature suddenly increases. At first, the younger pilot thinks that something is wrong with the air-conditioning system, but Robert assures him that the effect is from the severe weather in the vicinity.

That smell is ozone, which you sometimes catch during a lightning storm. A lightning Q&A feature at PBS's Nova website explains: "Ozone, or O3 can be created during electrical discharges, which abound during thunderstorms."

Buffeting and falling:

The Popular Mechanics account, and the French government's official reports, point to black box data that shows the plane fell with its nose pointed up, indicating it went into a stall and never recovered. As The Atlantic's James Fallows explained in May, an aerodynamic stall happens when the wings' angle of attack steepens and the plane's thrust decreases, reducing lift and making the plane fall. The inexperienced pilots at the helm reportedly pulled the nose up, apparently as a reflex, which made the plane stall. Author Jean-Pierre Otelli, who published the first unedited transcript of the cabin conversation in his French-language book Pilot Errors, Volume 5, on which Wise bases much of his report, told The New York Times in November that the response to trouble for pilots is to pull up, even though that exacerbates the stall. " 'The first reaction of all of them is to pull back on the control stick' and drive the plane’s nose higher — a move that only exacerbates the problem. 'It’s a reflex that’s almost uncontrollable,' he said."

The plane's upturned nose made it unstable, and it buffeted as it fell, Wise reports. For a passenger in the cabin, with no instruments to keep him or her oriented, the sensation would have been one of falling and buffeting, the plane rolling back and forth. From Popular Mechanics:

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.

Alarms sound:

The Airbus 330 has a built-in alarm that's "designed to be impossible to ignore," to alert the pilots of a stall. It went off twice, but they ignored it both times. That seems like it would be hard to do, as Wise describes the sound: "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.' " Wise suggests the pilots may have believed a stall was impossible:

It's not an entirely unreasonable idea: The Airbus is a fly-by-wire plane; the control inputs are not fed directly to the control surfaces, but to a computer, which then in turn commands actuators that move the ailerons, rudder, elevator, and flaps. The vast majority of the time, the computer operates within what's known as normal law, which means that the computer will not enact any control movements that would cause the plane to leave its flight envelope. "You can't stall the airplane in normal law," says Godfrey Camilleri, a flight instructor who teaches Airbus 330 systems to US Airways pilots. 

But once the computer lost its airspeed data, it disconnected the autopilot and switched from normal law to "alternate law," a regime with far fewer restrictions on what a pilot can do. "Once you're in alternate law, you can stall the airplane," Camilleri says. 

Toward the end of the nose-up fall, a final alarm sounds: "As they near 2000 feet, the aircraft's sensors detect the fast-approaching surface and trigger a new alarm." But it's too late. The plane plunged into the Atlantic, killing all 228 people aboard.