AD for Airbus serien

EASA Issues AD for A320/330/340 Flight Manuals 

The European Aviation Safety Agency recently published an airworthiness directive (AD) for the flight manuals of the Airbus A320, A330 and A340 series to address an undesirable nose-down movement that could occur should an angle-of-attack (AOA) probe on the aircraft become blocked. The AD was issued as the result of a benign occurrence reported on an A321. The FAA followed up with emergency AD 2014-25-52. “When the alpha protection mode is activated due to blocked AOA probes, the flight control laws order a continuous nose-down pitch that, in a worst-case scenario, cannot be stopped with backward sidestick inputs, even in the full aft position,” stated EASA. The Airbus-developed interim actions that became effective December 11 begin with keeping one air data reference on, while turning off the other two. However, there is still a risk of erroneous stall warnings appearing on the speed display, EASA noted. For the A330/A340 models, on which there may still be a false stall warning, Airbus suggests “using the flight path vector” in the recovery process.