Air France Flight 447 plunged into southern Atlantic Ocean killing all 228 people in 2009 . Investigators have released a report on what they believe caused the crash . Tests on instruments measuring air speed and pressure seen as one factor . Comment: The European Aviation Safety Agency issued a directive in late August requiring airlines to replace pitot tubes manufactured by Thales Avionics on Airbus A330s and A340s . Search for wreck `` unprecedented in terms of depth and sub-sea terrain ''
Air France Flight 447 plunged into southern Atlantic Ocean killing all 228 people in 2009 . Investigators have released a report on what they believe caused the crash . Tests on instruments measuring air speed and pressure seen as one factor . Comment: Search for wreck `` unprecedented in terms of depth and sub-sea terrain ''