​Pilots of an Air France Airbus A330-200 had been preparing to take off from Paris Charles de Gaulle, unaware of a ground collision with a Delta Air Lines A330-300, before air traffic control intervened to prevent the departure.

Pilots of an Air France Airbus A330-200 had been preparing to take off from Paris Charles de Gaulle, unaware of a ground collision with a Delta Air Lines A330-300, before air traffic control intervened to prevent the departure.

French investigation authority BEA states that the Air France aircraft (F-GZCI) had been taxiing for take-off from runway 08L on 31 October last year.

It had been travelling on taxiway R before turning left for the T4 holding point, waiting behind an Air France Airbus A320.

The Delta A330 (N817NW) was also moving along taxiway R, intending to join taxiway F and head for the opposite side of the airport, because it was due to depart from runway 09R.

BEA says the Delta aircraft needed to pass behind the Air France jet, and the Delta pilots mentioned in cockpit conversation the narrow distance separating the two.

The Delta aircraft initially stopped but then resumed taxiing at "very low" speed, says BEA, before the captain decided there was sufficient margin to pass – estimating the clearance at 10ft.

Six seconds later the flight-data recorders of both A330s registered movements on all three axes, consistent with a collision. Both crews felt a "jolt", says BEA, and queried its origin.

But the Air France crew interpreted the jolt as the result of jet blast from the A320 waiting ahead of them in the departure queue, because the A320 had started moving to enter the runway.

As the Air France A330 moved up to the holding point, the crew of the Delta A330 was being informed by cabin crew that a passenger had seen the left wing strike the other aircraft.

Damage to the wing was confirmed to air traffic controllers, and the Delta crew requested to return to the parking stand.

The Air France pilots also received a query from cabin crew, after a passenger in the aft cabin mentioned feeling a bump. But the crew initially responded that the A330 had been blown by jet blast from the preceding aircraft, says BEA.

Not until nearly 3min after the collision was air traffic control informed by ground personnel that the Air France aircraft had sustained damage to its aft fuselage and that this might relate to the Delta jet.

This message was passed to a tower controller, who relayed it to the Air France pilots and instructed them to hold position. The controller subsequently told the crew that the auxiliary power unit was damaged and should not be started.

Both flights – AF498 to Sint Maarten and DL97 to Detroit – were then cancelled. BEA says the Air France jet suffered damage to its tail cone, auxiliary power unit compartment, and horizontal stabiliser, while the Delta aircraft escaped with damage to its winglet.

Airbus analysis indicates that, had the Air France A330 taken off, the APU doors would probably have detached during departure. The damage to the tail and stabiliser would not have affected control of the aircraft, but would have caused additional fuel burn – although this would have been compensated by the captain's decision to take additional fuel.