The search for clues into the crash of Air France flight 447 was thrown into confusion Thursday, after the Brazilian military said initially that it had recovered the first piece of floating debris from the plane, a structural support piece about eight feet long that might have come from the jet’s cargo hold. But by Thursday evening, the military said that information had been incorrect, and that the debris had probably come from a ship or another source.
Based on the initial reports from the military, experts postulated that the plane had broken up in flight, an idea for which there is now less evidence.
So what DID happen?
As much macabre fun as it may be to envision the plane as having crashed off some island where Ben Linus is running a ragtag band of people, the reality may be even more sobering:
The revelation came as Airbus, the manufacturer of the missing jet, issued a warning on Thursday to all its customers to follow established procedures when pilots suspect airspeed indicators are not functioning properly. The bulletin appeared to be the first hint that malfunctioning instruments indicators might have played an important role in the crash.
The message, approved by French investigators, said that the message had been sent “without prejudging the final outcome of the investigation,” but clearly it pointed to the possibility that mismanaging the plane’s speed could have been one step in a cascade of on-board failures, leading to the crash northeast of Brazil on Monday and the death of all 228 people on board.
The message noted that “there was inconsistency between the different measured airspeeds” in the Airbus 330 that crashed, one of several error messages that were sent by the plane’s automatic systems to an Air France maintenance base.
Airspeed on jets is measured by the combination of a tube that faces forward, called a Pitot tube, and an opening on the side of the plane known as a static port. The plane’s speed is determined by comparing the pressure in the Pitot tube that is created by the oncoming wind with the pressure from the static port.
The model that crashed, an A330, has three pairs of tubes and static ports. But other instruments can also be involved in calculating air speed, and the notice to airlines, called an Accident Information Telex, did not specify the nature of the inconsistency.
The message went to airlines that operate all Airbus models, from narrow-body A318 models to the double-decker jumbo A380.
Failure to manage an inconsistency properly has been cited in several crashes of big jets from various manufacturers. In 1996, a Boeing 757 taking off from the Dominican Republic crashed because the airspeed indicators of the captain and the first officer disagreed, and the crew mismanaged the problem. Mud wasps had nested in one of the Pitot tubes.
I'm no expert on flight. In fact, I'm a nervous nellie about flying. But this sounds like something that could happen more often than we want to think about.
Aucun commentaire:
Enregistrer un commentaire