In-flight upset - 154 km west of Learmonth, WA, 7 October 2008,

APPENDIX D: OTHER DATA-SPIKE OCCURRENCESOccurrence on 12 September 2006On 12 September 2006, an A330-303 aircraft, registered VH-QPA (QPA) and beingoperated as Qantas flight 68, was on a scheduled passenger transport service fromHong Kong to Perth, Western Australia. At 2052 Universal Time Coordinated(UTC), or 0452 local time, while the aircraft was in cruise at FL410, there was afailure of air data inertial reference unit (ADIRU) 1. The ADIRU was the same unit(serial number 4167) as on the 7 October 2008 flight.The operator’s maintenance watch log recorded that the flight crew contactedmaintenance watch and reported that they had a NAV IR 1 FAULT and ‘continuousECAM messages’ that could not be stopped, and that the problem was eventuallyresolved when the crew selected the air data reference (ADR) 1 pushbutton OFF.The flight crew entered the problem into the aircraft’s technical log, noting thatthere had been a NAV ADR 1 FAULT and that they had received numerouselectronic centralized aircraft monitor (ECAM) messages. Maintenance recordsstated that, in accordance with the manufacturer’s maintenance procedures for therelevant post-flight report (PFR) fault messages, an ADIRU re-alignment wasconducted and a system test of both the inertial reference (IR) and ADR parts wasconducted. No faults were found and the aircraft was returned to service.Following the 7 October 2008 occurrence, further information was provided by theflight crew regarding the 12 September 2006 occurrence. The crew reported that:• The event occurred at night and the aircraft was in clear conditions at the time ofthe event. The first officer was the pilot flying and autopilot 2 was engaged. Theautopilot and autothrust remained engaged throughout the event.• There were numerous ECAM messages, and the messages changed rapidly andcould not be properly read or actioned. There were also numerous stall warningsand overspeed warnings.• Discussions with maintenance watch could not resolve the issue. However, ascan of the overhead panel identified a very weak and intermittent ADR 1 faultlight, and the crew decided to turn the ADR 1 off. Following that action, thewarning and caution messages ceased and the flight continued without furtherincident. At no stage was there any effect on the aircraft’s flight controls.The post-flight report (PFR) was very similar to the PFR for the 7 October2008 occurrence. The cockpit effect messages from both occurrences aresummarised in Table D1, together with the cockpit effect messages for the thirdoccurrence on 27 December 2008. Key aspects of the PFR were:• a NAV IR1 FAULT at 2052, together with a series of other messages starting atthe same time• a NAV ADR 1 FAULT at 2122, probably associated with the crew selecting theADR 1 pushbutton OFF• no autopilot disconnection message, consistent with autopilot 2 being engagedrather than autopilot 1, and no flight control primary computer (FCPC,commonly known as PRIM) faults, consistent with there being no in-flightupset.- 235 -