On 28 October 2009, an Airbus A330-202 (A330) aircraft, registered VH-EBA (EBA), was being operated as Jetstar flight 12 on a scheduled passenger service from Narita, Japan to Coolangatta, Australia. Soon after entering cloud at 39,000 ft, there was a brief period of disagreement between the aircraft's three sources of airspeed information. The autopilot, autothrust and flight directors disconnected, a NAV ADR DISAGREE caution message occurred, and the flight control system reverted to alternate law, which meant that some flight envelope protections were no longer available. There was no effect on the aircraft's flight path, and the flight crew followed the operator's documented procedures. The airspeed disagreement was due to a temporary obstruction of the captain's and standby pitot probes, probably due to ice crystals. A similar event occurred on the same aircraft on 15 March 2009.
The rate of unreliable airspeed events involving the make of pitot probes fitted to EBA (Goodrich 0851HL) was substantially lower than for other probes previously approved for fitment to A330/A340 aircraft. However, both of the events involving EBA occurred in environmental conditions outside those specified in the certification requirements for the pitot probes. The French Bureau d'Enquêtes et d'Analyses pour la sécurité de l'aviation civile (BEA) has recommended the European Aviation Safety Agency (EASA) to review the certification criteria for pitot probes in icing environments.
At the time of the occurrence, most of the operator's A330 pilots had not received unreliable airspeed training. Most of these pilots had transferred from the operator's A320 fleet, and the third-party training provider had not included the topic in its A320 endorsement training program, even though it was included in the aircraft manufacturer's recommended program since 2004.
The operator identified the problem and included unreliable airspeed in its recurrent training program for the A320 from May 2009 and the A330 from October 2009. The training provider included the topic in its endorsement program from July 2010. The operator, training provider and the Civil Aviation Safety Authority all initiated safety action to minimise the likelihood of similar problems in the future.
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Although the pitot probes fitted to A330/A340 aircraft met relevant design specifications, these specifications were not sufficient to prevent the probes from being obstructed with ice during some types of environmental conditions that the aircraft could encounter.
|Who it affects:||All owners and operators of Airbus A330/A340 aircraft|
By the time of the 28 October 2009 occurrence, many of the operator’s A330 flight crew had not received unreliable airspeed training. Such training started being introduced in the operator’s recurrent training program before the occurrence.
|Who it affects:||The operator’s A330 flight crew|
When revising or maintaining its A320 endorsement training program, the third party training provider did not use or have access to current versions of the aircraft manufacturer’s recommended training program.
|Who it affects:||Pilots undertaking an A320 endorsement|
|Date:||28 October 2009||Investigation status:||Completed|
|Time:||1537 UTC||Investigation level:||Complex - click for an explanation of investigation levels|
|Location:||710 km south of Guam International Airport|
|Release date:||27 January 2011||Occurrence class:||Environment|
|Report status:||Final||Occurrence category:||Incident|
|Highest injury level:||None|
|Aircraft manufacturer||Airbus Industrie|
|Type of operation||Air Transport High Capacity|
|Damage to aircraft||Nil|
|Departure point||Narita, Japan|
|Destination||Gold Coast, Qld|