On 31st May 2009 Air France Flight 447 took off at night from Rio de Janeiro, Brazil. The Airbus A330 carrying 228 passengers and crew is scheduled to arrive in Paris, France next morning. Planes flying this route traverse an enormous distance across the Atlantic Ocean.
Air France Flight 447. Photo: collected.
The plane hits moderate turbulence as it passes through an area known as the intertropical convergence zone. About 30 minutes later the flight is expected to show up in Senegalian air space but the crew doesn’t check in with Senegal’s air traffic controllers.
Air France Flight 447 is missing. In the morning, an aerial search team is deployed. They search miles around planes' last known location. But by early afternoon Air France and the French government presumed that the aircraft was lost at sea. If there is any doubt about the fate of flight 447, 5 days later grime discoveries confirm it. Bodies, boarding passes and small pieces of planes were found floating on the surface of the ocean. Next day a major piece of wreckage was found, a vertical stabilizer. The investigators need to locate the flight recorders (commonly known as blackbox).
Small pieces of the plane found floating on the surface. Photo: collected.
After nearly a year searching underwater, the French investigators turned to World Leaders for Ocean Exploration for help, the Massachusetts based Woods Hole Oceanographic Institution, for them this isn’t the first time they searched the bottom of the Atlantic.
According to Dave Gallo, director of special projects, Woods Hole Oceanographic Institution, ‘Finding the Air France 447 would be daunting; the plane is believed to be lost in most mysterious and hard to reach places.’
The team launches three autonomous underwater vehicles to search the ocean floor. 104 bodies were recovered along with the wreckage a few weeks later and nearly two years after the crash French investigators located what they were desperately hoping to find, the flight data and cockpit voice recorders.
Plane wreckage found underwater. Photo: collected.
After downloading the information on the flight data and cockpit voice recorders investigators begin to unravel just what happened onboard the Airbus A330. About three and a half hours into the flight the captain leaves the cockpit to take a break trading places with one of the two co-pilots.
Investigators found that the pitot tubes (device to measure air speed) can be susceptible to icing and as a result they are heated but the icing is overwhelming the heating capabilities and the pitot tubes froze. According to Aviation Expert Greg Feith, ‘In a highly automated airplane if you iced over that tube you no longer have that air pressure which all of these computers are dependent upon.’ With no valid airspeed to work with autopilot and other automated system disconnects. The co-pilot must manually fly the plane without the ability to monitor their airspeed. According to Why Planes Crash Aviation Analyst John Cox, ‘The big thing is not to make any major changes with the airplane. In all likelihood it’s going to recover shortly if you start making large inputs things can get worse.’
The co-pilot in the right seat, the youngest and least experienced of the crew attempts to level the plane that has been jostled by turbulence but he over corrects on the side stick controller pitching the aircraft up at a steep angle. ‘Those inputs were massive both in magnitude and duration’, John Cox added.
As the crew reacted incorrectly to the situation, caused the plane to aerodynamic stall and the plane didn’t recover from there. It’s still unclear whether the pilot didn’t recognize that the plane stalled despite the audible stall warning that at one point sounded for 54 seconds. Prior to the crash of flight 447 Airbus and Air France had recognized potential problems with pitot tubes freezing over and had begun modifications just two days prior to the accident.
The official French investigative report states that a phenomenon called the startle effect may have played a role. The official report maintains that improving pilot training and exercises dedicated to manual aircraft handling is the key lesson of flight 447. None of these pilots had ever been trained to fly the airplane manually at high altitude with these levels of sensitivity.
This accident of flight 447 is the deadliest in the history of Air France and also the deadliest involving Airbus A330.
(For more information watch ‘Air France 447: Vanished’ and read ‘A332, en-route, Atlantic Ocean, 2009’ and ‘Final Report On the accident on 1st June 2009 to the Airbus A330-203 registered F-GZCP operated by Air France flight AF 447 Rio de Janeiro - Paris'.)
