Air France Flight 447

(States Twitter)-Air France Flight 447 was a scheduled airline flight from Rio de Janeiro to Paris that crashed into the Atlantic Ocean on 1 June 2009, killing all 216 passengers and 12 aircrew. Investigators have not yet determined a cause of the accident, but preliminary investigation found that the crash may have involved an icing-over of its air-speed sensors – called pitot tubes – during the flight, which would have led to inaccurate airspeed data, although this claim has been contested.
The airliner, an Air France Airbus A330-203, registered as "F-GZCP", took off on 31 May 2009 at 19:03 local time (22:03 UTC). The last contact from the crew was a routine message to Brazilian air traffic controllers at 01:33 UTC, as the aircraft approached the edge of Brazilian radar coverage over the Atlantic Ocean, en route to Senegalese airspace off the coast of West Africa. Forty minutes later, a four-minute-long series of automatic radio messages was received from the plane, stating numerous problems and warnings. The airliner was believed to have been lost shortly after it sent the automated messages.
On 6 June 2009, a search and rescue operation recovered two bodies and some aircraft debris floating in the ocean about 680 mi (1,090 km) northeast of the Fernando de Noronha Islands off the northeastern coast of Brazil. The debris included a briefcase containing an airline ticket, later confirmed to have been issued for the flight. On 27 June the search for bodies and debris was called off. The bodies of 51 people were recovered from the surface of the ocean.
The investigation into this accident was severely hampered by the lack of any eyewitness evidence and radar tracks, as well as the loss of the airplane's black boxes, which were not located on the ocean floor until 2 years later in May 2011. The search for the black boxes was called off on 20 August 2009, but the Bureau d'Enquêtes et d'Analyses pour la Sécurité de l'Aviation Civile (BEA) later announced that it would resume the search later in 2009. The search continued through May 2010, and on 6 May 2010 it was reported that the location of the black boxes had been pinpointed to within a three to five square kilometer area. The French Navy spokesperson Hugues du Plessis d'Argentre described the task of finding the devices as "trying to find a shoe box in an area the size of Paris, at a depth of 3,000 meters (9,800 feet) and in a terrain as rugged as the Alps," cautioning that there is no guarantee the data recorders would be recovered. On 3 April 2011, the BEA announced that it had located and would recover large pieces of the wreckage. It was also announced that corpses had been seen in the wreckage.
On 1 May 2011 BEA announced that it had located and recovered the airplane's flight data recorder and its accompanying memory unit. Investigators are hopeful that the discovery will allow them to determine what caused the crash. However, BEA raised doubts about the readability of the recorder given the pressure to which the device had been subjected for two years on the ocean floor. On 3 May 2011 it was announced that the airplane's second recorder, the cockpit voice recorder, had been found.
The accident was the deadliest in the history of Air France. Paul-Louis Arslanian, the head of the BEA, described it as the worst accident in French aviation history. This was the deadliest commercial airliner accident to occur since the crash of American Airlines Flight 587 near New York City in 2001. This was the only fatal accident with an Airbus A330 airliner while in passenger service until the Afriqiyah Airways Flight 771 crashed in Tripoli, Libya, in May 2010.


Disappearance
The aircraft departed from Rio de Janeiro-Galeão International Airport on 31 May 2009 at 19:03 local time (22:03 UTC), with a scheduled arrival at Paris-Charles de Gaulle Airport approximately 11 hours later.
The last verbal contact with the aircraft was at 01:33 UTC, when it was near waypoint INTOL (1°21′39″S 32°49′53″W), located 565 km (351 mi) off Natal, on Brazil's north-eastern coast. The crew reported that they expected to use airway UN873 and enter Senegalese-controlled airspace at waypoint TASIL (4°0′18″N 29°59′24″W) within 50 minutes, and that the aircraft was flying normally at flight level 350 (a nominal altitude of 35,000 ft/11,000 m) and at a speed of 467 knots (865 km/h; 537 mph). The aircraft left Brazil Atlantic radar surveillance at 01:48 UTC.

Weather conditions
A meteorological analysis of the area surrounding the flight path showed a mesoscale convective system extending to an altitude of around 50,000 feet (15 km; 9.5 mi) above the Atlantic Ocean before Flight 447 disappeared. From satellite images taken near the time of the incident, it appears that the aircraft encountered a thunderstorm, likely containing significant turbulence.
Detailed analysis of the weather conditions for the flight shows it is possible that the aircraft's final 12 minutes could have been spent "flying through significant turbulence and thunderstorm activity for about 75 mi (121 km)", and may have been subjected to rime icing, and possibly clear ice or graupel. Satellite imagery loops from the CIMSS clarify that the flight was coping with a series of storms, not just one.
Aircraft


The accident aircraft was an Airbus A330-203, with manufacturer serial number 660, registered as "F-GZCP". This airliner first flew on 25 February 2005. The aircraft was powered by two General Electric CF6-80E1 engines with a maximum thrust of 72,000 lb giving it a cruise speed range of Mach 0.82 – 0.86 (871 – 913 km/h, 470 − 493 KTAS, 540 – 566 mph), at 35,000 ft (10.7 km altitude) and a range of 12,500 km (6750 NM). The aircraft underwent a major overhaul on 16 April 2009, and at the time of the accident had accumulated 18,870 flying hours. On 17 August 2006, the A330 was involved in a ground collision with Airbus A321-211 F-GTAM, at Charles de Gaulle Airport, Paris. F-GTAM was substantially damaged while F-GZCP suffered only minor damage. The plane made 24 flights from Paris, to and from 13 different destinations worldwide, between 5 May and 31 May 2009.
Search effort

On 1 June at 02:20 UTC, Brazilian air traffic controllers contacted air traffic control in Dakar after noticing that the plane had not made the required radio call signaling its crossing into Senegalese airspace. The Brazilian Air Force then began a search and rescue operation from the Brazilian archipelago of Fernando de Noronha, and at 19:00 UTC on 1 June, Spain sent a CASA 235 maritime patrol plane in search and rescue operations near Cape Verde. French reconnaissance planes were also dispatched, including one Breguet Atlantic from Dakar, and the French requested satellite equipment from the United States to help find the plane. Brazilian Air Force spokesperson Colonel Henry Munhoz told Brazilian TV that radar on Cape Verde failed to pick up the aircraft over the Atlantic Ocean.
Later on 1 June, officials with Air France and the French government had already presumed that the plane had been lost with no survivors. An Air France spokesperson told L'Express that there was "no hope for survivors," and French President Nicolas Sarkozy told relatives of the passengers that there was only a minimal chance that anyone survived.
Search results

On 4 June, the Brazilian Air Force claimed they had recovered the first debris from the Air France crash site, 340 miles (550 km) northeast of the Fernando de Noronha archipelago, but on 5 June, around 13:00 UTC, Brazilian officials announced that they had not yet recovered anything from Flight 447, as the oil slick and debris field found on 2 June could not have come from the plane. Ramon Borges Cardoso, director of the Air Space Control Department, said that the fuel slicks were not caused by aviation fuel but were believed to have been from a passing ship. Even so, a Brazilian Air Force official maintained that some of the material that had been spotted (but not picked up) was in fact from Flight 447. Poor visibility had prevented search teams from re-locating the material.
2011 search and recovery

The Île de Sein, which participated in the recovery of the cockpit voice recorder.
On 3 April 2011, during Phase 4 of the search and recovery operation, it was announced that a team led by the Woods Hole Oceanographic Institution had discovered significantly large portions of debris believed to be that of flight AF447. Further debris and bodies, still trapped in the partly intact remains of the aircraft's fuselage, were located in water depths of between 3,800 and 4,000 metres (2,070 to 2,190 fathoms). The debris was found to be lying in a relatively flat and silty area of the ocean floor (as opposed to the extremely mountainous topography that was originally believed to be AF447's final resting place). Other items found were engines, wing parts and the landing gear. On April 27, 2011, it was announced that the chassis for one of the black boxes had been found.

The debris field was described as "quite compact", measuring some 200 metres (660 ft) by 600 metres (2,000 ft) and located a short distance to the north of where pieces of wreckage had been recovered previously, suggesting that the aircraft hit the water largely intact. The French Ecology and Transportation Minister Nathalie Kosciusko-Morizet stated the bodies and wreckage would be brought to the surface and taken to France for examination and identification. It was, however, not yet possible to quantify how many bodies had been discovered. The French government chartered three vessels – the René Descartes the Île de Sein, and an American-based vessel, the Alucia, which are normally used by telecommunications companies for deep-ocean cable-laying, to retrieve debris and bodies. An American Remora 6000 remotely operated vehicle and operations crew experienced in the recovery of aircraft for the United States Navy was on board Île de Sein.
Investigation

East-west cross-section of Atlantic Ocean portion in which Air France Flight 447 was thought to have crashed, showing depth of the sea floor. The vertical scale is exaggerated by a factor of 100 relative to the horizontal.

Investigators have not yet determined a cause of the accident, but preliminary investigation found that the crash could have been caused by erroneous airspeed indications, if the pitot tubes had iced over during the flight.
The French government has opened two investigations:

A criminal investigation for manslaughter was begun (this is standard procedure for any accident involving a loss of life and implies no presumption of foul play), which since 5 June 2009 is under the supervision of Investigating Magistrate Sylvie Zimmerman from the Paris Tribunal de Grande Instance. The judge gave the investigation to the Gendarmerie nationale, which operates it through its aerial transportation division (Gendarmerie des transports aériens or GTA) and its forensic research institute (the "Institut de Recherche Criminelle de la Gendarmerie Nationale", FR).
In June 2009, the DGSE (the external French intelligence agency) revealed that the names of two registered passengers on board corresponded to the names of two individuals thought to be linked to Islamic terrorist groups.

A technical investigation, the goal of which is to enhance the safety of future flights. As the aircraft was of French registration and crashed over international waters, this is the responsibility of the French government, under the ICAO convention. The Bureau d'Enquêtes et d'Analyses pour la Sécurité de l'Aviation Civile (BEA) is in charge of the investigation. The BEA released a press release on 5 June, that stated:
A large quantity of more or less accurate information and attempts at explanations concerning the accident are currently being circulated. The BEA reminds those concerned that in such circumstances, it is advisable to avoid all hasty interpretations and speculation on the basis of partial or non-validated information. At this stage of the investigation, the only established facts are:
the presence near the airplane’s planned route over the Atlantic of significant convective cells typical of the equatorial regions;
based on the analysis of the automatic messages broadcast by the plane, there are inconsistencies between the various speeds measured.

Airspeed inconsistency
Prior to the disappearance of the aircraft, the automatic reporting system, ACARS, sent messages indicating disagreement in the indicated air speed (IAS) readings. A spokesperson for Airbus claimed that "the air speed of the aircraft was unclear" to the pilots. Paul-Louis Arslanian, of France's air accident investigation agency, confirmed that F-GZCP previously had problems calculating its speed as did other A330 aircraft stating "We have seen a certain number of these types of faults on the A330 ... There is a programme of replacement, of improvement. The problems primarily occurred on the Airbus A320, but, awaiting a recommendation from Airbus, Air France delayed installing new pitots on A330/A340, yet increased inspection frequencies.

There have been several cases where inaccurate airspeed information led to flight incidents on the A330 and A340. Two of those incidents involved pitot probes. In the first incident, an Air France A340-300 (F-GLZL), en route from Tokyo, Japan, to Paris, France, experienced an event at 31,000 feet (9,400 m) in which the airspeed was incorrectly reported and the autopilot automatically disengaged. Bad weather together with obstructed drainage holes in all three pitot probes were subsequently found to be the cause. In the second incident, an Air France A340-300 (F-GLZN) en route from Paris to New York encountered turbulence followed by the autoflight systems going offline, warnings over the accuracy of the reported airspeed and two minutes of stall alerts. Another incident on TAM Flight 8091 from Miami to Rio de Janeiro on 21 May 2009, involving an A330-200, showed a sudden drop of outside air temperature, then loss of air data, the ADIRS, autopilot and autothrust. The aircraft fell 1,000 metres (3,300 ft) before being manually recovered using backup instruments. The NTSB is also examining a similar 23 June 2009 incident on a Northwest Airlines flight from Hong Kong to Tokyo.

Flight number
Shortly after the crash, Air France changed the number of the regular Rio de Janeiro-Paris flight from AF447 to AF445.
On 30 November 2009, Air France Flight 445 (F-GZCK) made a mayday call due to severe turbulence around the same area and time flight 447 crashed. Because the pilots could not obtain immediate permission from air traffic controllers to descend to a less turbulent altitude, the mayday was to alert other aircraft in the vicinity that the flight had deviated from its normal flight level. This is standard contingency procedure when changing altitude without direct authorization. After 30 minutes of moderate to severe turbulence the flight continued normally. The plane landed safely in Paris six hours, 40 minutes, after the mayday call.

Media
On 30 May 2010, BBC Two in the United Kingdom broadcast the documentary "Lost: The Mystery of Flight 447 a one hour documentary detailing an independent investigation into the crash employing the skills of an expert pilot, an expert accident investigator, an aviation meteorologist and an aircraft structural engineer. Using the available evidence and information, without the black boxes, a critical chain of events was postulated:
flying into an intense thunderstorm which had been hidden on the aircraft weather radar by a smaller nearer storm.
reducing aircraft speed to anticipate impending turbulence.

configuring the aircraft to avoid a stall by trimming aircraft pitch with the elevators, but not noticing that the autothrust system reduced aircraft speed (without corresponding thrust lever movement).
simultaneous failure of all three pitot tubes due to supercooled water very rapidly forming ice.
aircrew being unable to interpret a large number of flight deck failure alerts caused by the loss of air data.
suffering a catastrophic loss of altitude due to a stall.
falling uncontrollably to the sea and breaking up on impact.
On 1 June 2010, exactly one year after the crash of Air France Flight 447, it was announced that, in the United States, there would be a Nova TV series science/documentary episode about the accident. The documentary was broadcast on 16 February 2011