Almost every possible scenario has now been attached to the fragments of factual information know publicly about the crash of Air France flight AF447 13 days ago.

None of these scenarios look complete, or comprehensively convincing, even if some of the elements discussed prove to have been a material part of the causes.

But the silence that surrounds one item of information is notable. What exactly was said between the captain and the operations centre in Paris in the last voice communication, usually put at around 30 minutes before it crashed?

In the press conference held by Air France on 1 June, the airline said the pilot had mentioned flying through severe turbulence. What else was mentioned? In what context was this turbulence discussed? Was it accorded the most importance during the conversation, or was it of subordinate concern at the time? It may not be material, but everything that was said between the flight and the responsible personnel in Paris needs to be examined.

This was the same press conference where Air France made the ludicrous claim that lightning might have been involved, and the incorrect claims that the automated ACARS messages, immediately before all contact ceased, detailed a series of unprecedented electrical faults.

Why did Air France make these statements? It had the ACARS messages. They do not require decoding by its operations and maintenance personnel who would have read them for what they are as fast as they appeared. These messages did not support the public comments by the airline in a press conference it held many hours after it knew the jet had crashed.

And it took Air France 48 hours to issue an official statement about the pitot faults that had caused it late in April to decide to replace all of these external speed measuring devices by the end of June.

The bodies of 50 of the 228 people on board AF447 have now been recovered. Reports indicate that they appear to have lost their clothing, which is consistent with bodies flung into the slipstream of a disintegrating airliner. Reports also indicate no sign of a bomb blast or a fire on the wreckage so far collected.

No signals from either of the ‘black boxes’ have yet been detected by a French submarine or surface ships. US search equipment is expected in the area sometime today.