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Air France - Airbus A330-203
Atlantic ocean
1st June, 2009 |
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 The Air France Airbus A330-200 went missing on transatlantic flight from Rio de Janeiro, Brazil, to Paris, France. The airplane carried 12 crew members and 216 passengers. The plane crashed in the Atlantic Ocean, killing all onboard.
Flight AF447 departed Rio de Janeiro heading toward Paris. Three hours later, while the plane was flying over the Atlantic Ocean, the aircraft reportedly went through a thunderstorm with strong turbulence. A few minutes later, Air France received an automatic message from the A330 indicating electrical circuits malfunction. It was the last information received from AF447. Six minutes later, Brazilian Air Force said plane failed to make previously scheduled radio contact with Brazil.
Last radio contact with the flight was at 01:33 UTC. The crew was in contact with the Atlantic Area Control Centre (CINDACTA III) when the flight reported over the INTOL waypoint, estimating TASIL at 02:20 UTC. INTOL is an RNAV waypoint located in the Atlantic Ocean, 565 km from Natal, Brazil. The TASIL waypoint is located 1228 kilometers from Natal.
Over a time span of four minutes, starting at 02:10 UTC, a series of ACARS messages were sent -automatically- from the plane. Indication was that the
autopilot had disengaged and the fly by wire system had changed to alternate law (mode allowing the flight control to work properly while some inputs paramters are not available or detected erroneous). Between 02:11Z and 02:13Z a flurry of messages indicating failure of navigation and air data systems arrived. At 02:13Z flight control system faults were indicated, at 02:14Z the last message received was an advisory regarding cabin vertical speed.
A preliminary analysis of meteorological information shows that AF447 crossed through three key thunderstorm clusters: a small one around 01:51 UTC, a new rapidly growing one at about 01:59 UTC, and finally a large multicell convective system (MCS) around 02:05-02:16 UTC.
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Plane flight path through thunderstorm clusters
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Bottom-to-top deformation of structural components recovered from the water showed the aircraft appears to have struck the ocean surface with a sharp vertical acceleration. The nature of the damage indicates that the jet did not break up in mid-air.
Also, investigators said the aircraft's maintenance complied with requirements, there were no reports of technical problems from the crew, and there was no distress call - either to air traffic control or other aircraft - at the time of the loss on 1 June.
Analysis of the storm the aircraft crossed through suggests that:
- Strong turbulence could have occured around the periphery of the storm
- Recent evidence from spaceborne sensors is pointing to the possibility that this system contained no lightning
- Although it is possible the plane flew through exceptionally high values of precipitable water content, it is more likely that the plane have been mostly in an area of ice crystals with possibly some graupel at flight level.
- The plane, if at FL350, was experiencing flight level temperatures of between -41 and -36 deg C. Supercooled water is considered to be exceptionally rare or insigificant at temperatures below -30 deg C, but if it does occur it does present the possibility of aggravating airframe, engine and probes icing.
- The plane, if at FL350, would have been far above the level where big hail particles would grow.
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