Le Monde is reporting that AF447 was flown at the wrong speed through turbulence from the moment problems arose with its flight control systems and until it broke apart in flight.
It also says Airbus is about to issue an advisory to all A330 operators to manually maintain recommended speeds when flying through adverse conditions. This presumably means the minimum manoeuvring speed although it doesn’t use that term.
Whether a jet is flown too fast or too slowly through turbulent air there are serious risks of loss of control and structural damage. Too slow a speed can cause a high altitude stall. Too fast a speed can break critical control surfaces especially if fierce changes in wind directions or updrafts and downdrafts are encountered. Airline operating procedures include company rules for avoiding or managing these risks based on manufacturer recommendations following certification.
However the now widely reported versions of the automated service messages that have been leaked to the media by sources in Air France imply that the pilots may no longer have been getting correct airspeed data because of problems with external sensors, including icing. (Icing at 35,000 feet is considered extremely rare, because it is generally too cold for water to exist and without water present ice particles would remain loose and not freeze on to surfaces.)
Le Monde reports that sources close to the official French investigation dispute the widely published chronology of automated messages received from AF447 in particular the timing of a message that reported breakdowns in the ADIRU units and other flight control computers. It repeats the most detailed of those reports as they appear in the Brazilian press and doesn’t report any alternative version that might have been offered by its sources near the French investigation.
However it does report that the last message, a cabin vertical speed alert, occurs either immediately before or after the jet broke apart, and was caused by the decompression that either led to or was a consequence of the breakup.
Morning update: Some of the debris collected in the search area is material washed off or thrown off cargo shipping. A large fuel slick has also been identified as maritime in origin. However real wreckage from AF447 is also being collected by helicopters and delivered to search vessels with many vessels still en route to the debris areas from France and Brazil. No bodies have been sighted and none are expected to be found this far into the search and recovery operation which is focused on looking for wreckage that may contain more clues as to what happened late on 31 May and early on 1 June.
Debate continues at the technical level as to whether the A330-200 was flown too fast or too slow through severe turbulence by pilots who appear to have been receiving faulty air speed readings. The automated messages received in the Air France operations centre in Paris via satellite confirm that the Airbus flight computers had been disabled early in the crisis and that it was being flown under manual rules until it broke apart and crashed.