What happened
On March 4, 2006, an Airbus A310-300 was preparing for takeoff at Munich Airport. The aircraft, carrying 166 passengers and nine crew members, had undergone de-icing prior to departure. During the initial takeoff roll on runway 08R, the crew attempted to accelerate the engines. During the first thrust application, the left engine accelerated significantly faster than the right, causing the aircraft to drift to the right. The pilot responded by reducing thrust to ground idle.
During a second takeoff attempt, the engines again accelerated at highly disparate rates. The left engine reached an N1 of 96%, while the right engine only reached 5 and 56%. This asymmetric thrust, combined with slippery runway conditions, caused the aircraft to veer right at a speed of approximately 30 kt. The aircraft left the runway at a 45-degree angle, coming to a stop on unpaved ground about 60 meters from the runway. There were no injuries to the passengers or crew, and the aircraft sustained no damage, though there was damage to the surrounding area.
The investigation
The BFU examined the aircraft's flight data recorder, which revealed significant discrepancies in fuel flow and N1 speeds between the two engines. The investigation focused on the performance of the right engine and the operational status of the cockpit systems. It was noted that the Engine Trim system was inoperative due to a failure in the Power Management Control 2 (PMC 2) and the High Pressure Valve 2.
Investigators also reviewed the runway conditions, noting that while the runway had been cleared, continuous snowfall had covered the surface in a layer of wet snow, reducing braking effectiveness. The investigation also looked into the crew's adherence to the Minimum Equipment List (MEL) procedures regarding engine operation with an inoperative PMC.