Air France Flight 447 Crash

Rio de Janeiro–Galeão International Airport on 31 May 2009 at 19:29 local time (22:29 UTC),[10] with a scheduled arrival at Paris-Charles de Gaulle Airport at 09:03 UTC the following day, after an estimated flight time of 10:34.[11] The last voice contact with the aircraft was at 01:35 UTC, 3 hours and 6 minutes after the 22:29 UTC departure, when it reported that it had passed waypoint INTOL (1°21′39″S 32°49′53″W), located 565 km (351 mi) off Natal, on Brazil's north-eastern coast.[12] The aircraft left Brazilian Atlantic radar surveillance at 01:49 UTC.[13]

SOURCE: https://en.wikipedia.org/wiki/Air_France_Flight_447

The Airbus A330 is designed to be flown by a crew of two pilots. However, because the 13-hour "duty time" (flight duration, plus pre-flight preparation) for the Rio-Paris route exceeds the maximum 10 hours permitted by Air France's procedures for pilots to operate an aircraft without a break, Flight 447 was crewed by three pilots: a captain and two first officers.[14] With three pilots on board, each of them can take a rest during the flight, and for this purpose the A330 has a rest cabin, situated just behind the cockpit.[15]

In accordance with common practice, the captain had sent one of the co-pilots for the first rest period with the intention of taking the second break himself.[16] At 01:55 UTC, he woke the second pilot and said: "... he's going to take my place". After having attended the briefing between the two co-pilots, the captain left the cockpit to rest at 02:01:46 UTC. At 02:06 UTC, the pilot warned the cabin crew that they were about to enter an area of turbulence. Probably two to three minutes after this the airplane encountered icing conditions (the cockpit voice recorder recorded what sounded like hail or graupel on the outside of the airplane, and the engine anti-ice system came on) and ice crystals started to accumulate in the pitot tubes (pitot tubes are devices that provide critical information about how fast the aircraft is moving through the air).[17] The pilots turned the aircraft slightly to the left and decreased its speed from Mach 0.82 to Mach 0.8 (the recommended "turbulence penetration speed").[18]