German investigators examine Vietnam Airlines 787 runway excursion at Munich

German investigators are looking into a runway excursion at Munich Airport involving a Vietnam Airlines Boeing 787-9 bound for Hanoi. The widebody was carrying 271 passengers and 16 crew members when it struck runway equipment during its attempted departure, damaging its fuselage substantially.

Preliminary findings from the German Federal Bureau of Aircraft Accident Investigation say recorder data shows brake commands being sent while the aircraft was still gaining speed along the runway.

The 787-9 began its takeoff roll on Runway 08R at a weight of 240.9 tonnes. The calculated speeds for the departure were 169 knots for V1, 175 knots for Vr and 180 knots for V2.

Data from the Enhanced Airborne Flight Recorder shows that at 11:56:15 UTC, moments after takeoff/go-around power was set, rudder pedal inputs were recorded along with movement of the brake pedals on both left-seat positions. Both brake system control units logged repeated braking commands as the aircraft continued down the runway. Pressure built toward a peak close to a minute later. The left unit recorded brake command of up to 27 percent and the right 17 percent. Maximum pedal deflection reached 7.2 degrees against a maximum of 12.5 degrees.

With the brakes acting against the accelerating aircraft, the pilot monitoring manually raised thrust from 100 percent to 101 percent N1, the findings state.

At 11:57:14 UTC the crew began rotation at 163 knots, 12 knots below the calculated Vr of 175 knots and close to the far end of the runway. The aircraft left the paved surface and became airborne from the grass beyond it, having struck runway equipment and suffered the fuselage damage described.

The investigation is ongoing. The preliminary findings released so far do not establish a cause.