Air France crash investigators focus on speed

By Crispian Balmer and Fernando Exman

PARIS/RECIFE, Brazil (Reuters) - Crews searching in worsening Atlantic weather on Friday faced the prospect they may never find bodies from an Air France crash, which may have been caused when the pilots acted on flawed speed readings.

Airbus, the maker of the A330 jet that crashed on Monday killing all 228 people on board, issued a warning late on Thursday that pilots should follow standard procedures -- to maintain flight speed and angle -- if they suspect speed indicators are faulty.

That reinforced an emerging theory that the experienced pilots operating the Rio de Janeiro to Paris flight may have inadvertently set the plane at a wrong speed as it passed heavy thunderstorms after leaving Brazil's northeastern coastline.

Going too fast in turbulent conditions risks damaging a plane's structure, while going too slow can cause it to stall.

Airbus said its message to clients did not imply pilot error or that a design fault caused the crash of Flight AF 447, the world's deadliest air disaster since 2001 and the worst in Air France's 75-year history.

"This Aircraft Information Telex is an information document that in no way implicates any blame," Justin Dubon, a spokesman for Airbus, said on Friday.

More than 300 aircraft similar to the Air France jet -- an Airbus A330-200 -- are in service worldwide.

The French air accident investigation agency aims to release an initial report by the end of the month. But finding the evidence contained in debris and, crucially, in black box flight recorders is proving a monumental task.