There’s still much attention being paid to pitot tubes and their potential involvement in the sequence of events that brought down Air France Flight 447.
The BEA lead investigator, Alain Bouillard, points out there’s still no evidence to require all Thales pitot tubes of the so called AA standard to be upgraded. Nor has the investigation found the pitot tubes were responsible for the loss of the Airbus A330-200.
For those that are curious, here’s what the BEA has to say about the history of A330/A340 pitot tubes (from the unofficial translation of the initial report issued today):
The conditions under which the probes that equip the Airbus A330/A340 have evolved are being examined by the investigators.
In 2001, following some inconsistent speed problems, it was decided to replace, before the end of December 2003, the Rosemount probes that then equipped the A330 by Goodrich 0851 HL probes or Thales C16195AA probes.
Service Bulletins, issued in 2007 then revised in 2008, had recommended the replacement on A330/A340 airplanes of C16195AA probes by C16195BA probes.
On the date of the accident, Airbus A330 / A340 aircraft were equipped with three standards of Pitot probe:
• BF Goodrich Aerospace probes, type 0851 HL,
• Thales Avionics probes of types C16195AA(22) and C16195BA.
It should be noted that any improvements that this change of standard could bring to cases of speed inconsistencies encountered in cruise had not been formally established.
In February 2009, at the request of Airbus, Thales carried out a comparative study of the behavior in icing conditions at high altitude of the two standards, C16195AA and C16195BA. This study concluded that the C16195BA standard performed better, without however it being possible to reproduce on the ground all the conditions that could be encountered in reality.
At the end of April 2009 at the suggestion of Airbus, Air France initiated an in-service
assessment on Airbus A330 of the C16195BA standard. The first batch of C16195BA Pitot probes had been received one week before the F-GZCP accident.