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Air France Crash Blame Game Starts Early
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Though the cause of the Air France 447 crash is not known, the Air France pilots' union has launched a premptive strike against pilot error. They have reportedly blamed governmental agencies for not requiring a fix following several incidents in which faulty probes disabled systems on highly automated Airbus 330s.
Aircraft manufacturers and government agencies have a vested interest in pointing the finger of blame elsewhere. Dead pilots are an easy target, as shown by Air France CEO Pierre-Henri Gourgeon's claim that the pilots may have failed to deal with weather properly. Several flights took the same route Air France 447 did. Some passed through the storm area just ahead of flight 447 and some just behind. None reported any difficulty with the storm. But, none of those flights lacked full instrumentation nor lost automation as flight 447 did. Though an airliner can penetrate virtually any weather, doing so successfully may depend upon full instrumentation and, on a highly automated airliner, properly operating automation.
The blame game is of greater than usual importance. The winner may also win the competition between Boeing and Airbus for the huge Department Of Defense tanker contract. An article in Vanity Fair may be part of the game. When Captain Sullenberger landed an Airbus in the Hudson, aviation writer William Langewiesche praised the highly automated Airbus fly-by-wire computerized flight control system as the key factor in the successful landing. Langewiesche wrote, that before contacting the water, the Airbus automated system "raised the nose to the perfect landing attitude."
Normally, an airliner descends on a 2.5 to 3.5 degree glide angle with a descent rate of about seven-hundred feet-per-minute. Then, a few feet above the runway, the pilot "flares" the glide angle by raising the nose and reducing the descent rate, so the plane can touch down gently, at a descent rate of one-hundred feet-per-minute, or less.
According to investigation testimony, and as can be seen on video of the landing, the perfect landing Mr. Langewiesche described in eloquent detail did not happen. The plane did not "flare" prior to contact with the water. The so-called miracle in the Hudson was very nearly a disaster. When the engines of the Airbus shut down, the electrical system switched to emergency back-up power. Some of the computer logic used in the fly-by-wire was lost causing the plane to contact the water with several times the force the Airbus fuselage was designed to withstand.
During the certification process, an airliner must show it can ditch without catastrophic damage. But upon impact with the water, the rear fuselage of the Airbus broke open and rapidly began to flood. Fortunately, perhaps miraculously, passengers in the flooding area were able to keep their heads above water long enough to escape.
Though the Airbus could land in the water gently with normal electrical power and full automation working, when on emergency power, the full fly-by-wire logic needed for a gentle landing was impaired. Noting that the plane did not perform according to certification criteria for ditching, during investigative hearings Airbus disingenuously asserted the landing in the Hudson was not a ditiching. Airbus claimed a ditching is a prepared water landing with at least one engine operating, and since no engines were operating, this was not a prepared water landing, thus not a ditching.
Clearly, the aft fuselage failed due to failure of the plane to flare prior to entry into the water. The automation Langewiesche praised for saving the day, apparently almost doomed the plane.
Meanwhile, the search for signals from flight 447's black boxes is being called off. Major fuselage pieces will continue to be sought which may contain the black boxes. Without the black boxes, both speculation about the cause and the blame game continue.
