EASA has issued the proposed AD mandating the removal of Thales pitot probes from Airbus A330s and A340s. The directive, which EASA announced last month based on an Airbus recommendation, would give operators four months to ensure that all Thales tubes with part number (P/N) C16195AA are removed from service, and Thales tubes carrying P/N C16195BA are installed only in the number two (first officer) position. The number one (captain) and number three (stand-by) positions should be outfitted with Goodrich pitot tubes. Industry has until Sept. 7 to comment on the proposed rule.
From the directive:
A new Thales Pitot probe Part Number (P/N) C16195BA has been designed which improves A320 aeroplane airspeed indication behaviour in heavy rain conditions. This same pitot probe standard has been made available as optional installation on A330/A340 aeroplanes, and although this has shown an improvement over the previous P/N C16195AA standard, it has not yet demonstrated the same level of robustness to withstand high-altitude ice crystals as the Goodrich P/N 0851HL probe.
The directive does not reference any specific in-service incidents. It does note, however, that:
Occurrences have been reported on A330/340 family aeroplanes of airspeed indication discrepancies while flying at high altitudes in inclement weather conditions. ... Airspeed discrepancies may lead in particular to disconnection of the autopilot- and/or auto-thrust functions, and reversion to Flight Control Alternate law, which would cause an increase of pilot workload. Depending on the prevailing aeroplane altitude and weather, this condition, if not corrected, could result in reduced control of the aeroplane. NTSB is examining
several of these occurrences. The role of the Thales pitot probes is one of many factors being closely examined by investigators
analyzing the June 1 crash of Air France Flight 447.