Pilots of a Transall C-160 transport misunderstood a taxi clearance before lining up on a runway on which an Airbus A319 was departing in the opposite direction.
Investigators state that, although the German Armed Forces Transall had been given special approval for the runway 21 departure from Zweibrucken, it had only been cleared to a holding point.
Around the same time a Germanwings A319 bound for Berlin, having backtracked, was commencing its take-off roll along the opposite runway 03.
The A319 had already passed the V1 decision speed when an air traffic controller ordered its crew to “break up”, in a bid to abort the departure.
But the pilots did not understand the instruction and, after seeing the Transall positioned ahead on the runway, elected to continue the take-off. The A319 flew over the military transport at about 400ft, says German investigation authority BFU.
While cockpit-voice recordings were unavailable, BFU states that the Transall crew “misinterpreted” an instruction to taxi to the holding point as an instruction to line up.
Although the crew believed a line-up clearance had been given, investigators suggest there was confusion arising from the initial taxi instruction as well as similar instructions given to the Germanwings aircraft.
BFU says that “vagueness” in the communications led the Transall crew to line up. “It was not a single error but small inadequacies which added up,” it states.
In its inquiry report into the 14 May 2008 event – only just released despite occurring nearly six years ago – BFU says a “high risk of collision existed”, prevented by a “close call”.