A Boeing Co. 787 operated by Vietnam Airlines JSC had its brakes activated twice while barreling down the runway at Munich Airport, leading to a late takeoff and the plane’s tail striking the ground. The German Federal Bureau of Aircraft Accident Investigation found the movement of the two left brake pedals was recorded on the same side, where a highly-experienced captain with more than 27,000 flying hours was seated. The report cited data from flight recorders showing brakes were applied a second time before takeoff, though it’s unclear if this was due to crew or a technical issue.

Investigators seized brake system components and electric brake actuator controllers. The cockpit audio was overwritten. The Hanoi-bound 787-9, carrying 287 passengers and crew, lost acceleration halfway down the runway.

With insufficient tarmac to abort, the co-pilot increased engine power to lift off beyond the runway threshold. No injuries were reported. Four pilots were in the cockpit: the pilot flying (a captain) in the left seat, the co-pilot as pilot monitoring, and two others in jump seats.

The pilot in command, another captain with nearly 23,000 hours, took over after takeoff and performed the emergency landing. The aircraft was substantially damaged; the tail and main landing gear wheels collided with approach lighting. Four left main landing gear tires were damaged.

Before landing, the plane dumped 62 metric tons of fuel. It weighed 240,857 kilograms at takeoff, near the maximum of 247,207 kilograms, with fuel accounting for 68,783 kilograms. A suspected flat tire was reported during fuel dumping.

Vietnam Airlines was contacted for comment but did not respond immediately. The investigation is ongoing.