Greek investigators are probing a terrain-warning incident involving a Condor Airbus A320 which had been executing a collision-avoidance manoeuvre at the time.
The aircraft had taken off from Kavala airport, on a service to Munich, when it its crew received a collision-avoidance system instruction to climb.
French investigation authority BEA, citing Greek counterparts, states that the aircraft had been passing 2,650ft at the time of the alert.
The crew responded to the order but, as the A320 passed through 2,770ft, the collision-avoidance system issued a different instruction, telling the crew to descend.
As the pilots followed the new order, the aircraft descended through 2,450ft and this subsequently triggered a terrain alert from the ground-proximity warning system.
The crew then executed a terrain escape manoeuvre, says BEA.
Kavala is situated on the coast with a ridge of terrain on its northern flank, with peaks rising to 2,000-3,000ft in the vicinity of the aircraft’s flightpath. BEA says the lowest critical altitude, during the critical phases of flight, was 2,529ft.
BEA describes the 16 August incident as “serious” but says no-one was injured. It identifies the A320 involved as D-AICD, which Flight Fleets Analyzer lists as a CFM International CFM56-powered airframe.