Air France to replace speed sensors

By Crispian Balmer

Reuters

June 10, 2009 09:25am

The pitot tubes that gauge speed have become the focus of an investigation into the crash after messages showed they provided "inconsistent" data to the pilots and might have played a role in the June 1 crash.

One Air France union urged its pilots to stop flying Airbus A330 and A340 aircraft until the old sensors were replaced and the company has since committed itself to a swift change-out, a union official said.

"Air France has provided us with an extremely proactive and very accelerated replacement programme," said Erick Derivry, spokesman of the main SNPL pilots union.

"From today, all Air France A330 and A340 flights will use planes equipped with at least two new sensors out of three (on board)," he told France Info radio.

Air France, which has 19 A340s and 15 A330s, declined to comment.

An Air France A330 en route from Rio de Janeiro to Paris crashed into the Atlantic last week, killing all 228 on board.

The Brazilian Air Force and Navy said on Monday they had recovered 24 bodies from the Atlantic so far as well as an increasing pile of shattered debris.

The A330 sent 24 automated messages in its final minutes on June 1, detailing a rapid series of system failures.

The small Alter union, which represents 15 Air France pilots, said in a statement that the first of these messages pointed to a problem with the pitot tubes.

Iced-up tubes

The pitot tubes are small probes on the exterior of the fuselage that measure the pressure of air rushing into them and thereby gauge the plane's speed.

The French air accident agency has said it is too early to pinpoint any possible cause for the crash, but noted there were apparent problems with the jet's speed readings.

This has fuelled speculation that its pitot tubes may have iced up, feeding wrong data into the cockpit which might have confused the plane's fly-by-wire computer system and its pilots.

Air France said at the weekend it had noticed icing problems on the speed sensors in May 2008 and had asked Airbus for a solution to reduce or overcome the difficulty.

Airbus responded by reaffirming existing operating procedures, according to Air France in a statement on Saturday.

Air France said tests had later convinced it that probes developed for another model would be more efficient and that it had decided to go ahead and start fitting them from April 27 without waiting for further testing proposed by the planemaker.

The A330 that crashed had not yet been modified. Airbus has declined to comment on the Air France statement.

Airbus Chief Executive Tom Enders told reporters in Munich on Tuesday his company was working closely with authorities and was keeping clients informed.