Qantas, PRIM reset, erratic airspeeds & altitude
About PRIM1 & PRIM2 PRIM master changed from PRIM 1 to PRIM 2 between the two pich down events. PRIM master changed from PRIM 2 to PRIM 1 after the 2nd pich down event. About PRIM3, after the 2nd pich down The flight crew reported that, after returning the aircraft to 37,000 ft, they commenced actions to deal with multiple ECAM messages. They completed the required action to deal with the first message (NAV IR1 FAULT) by switching the captain’s ATT HEADING switch from the NORM position to CAPT ON 3 position, and then cleared that message. The next message was PRIM 3 FAULT. The crew completed the required action by selecting the PRIM 3 off, waiting 5 seconds and then selecting it on again. .../...
During one of the conversations, maintenance watch suggested that the crew could consider switching PRIM 3 off, and this action was carried out. This action did not appear to have any effect on the scrolling ECAM messages, or the erratic airspeed and altitude information.
----------------------------------
hence you are right augustusjeremy, there was already an ECAM message indicating a PRIM3 FAULT when this latter was reset. I am surprised to read that the Qantas flight had also erratic airspeeds & altitude information ? Jeff
PS) the Air Caraïbe PRIM reset:
PPS) Stall warnings are a typical signature of unreliable airspeeds events (Airbus):
http://henrimarnetcornus.20minutes-b.../196453185.jpg
Last edited by Hyperveloce; 5th Aug 2009 at 17:52.