Mustang's mysterious power loss
The P-51DMustangwas part of a large number of war birds that had been flying in close formation at a Duxford airshow and then broke into the...
The P-51D Mustangwas part of a large number of war birds that had been flying in close formation at a Duxford airshow and then broke into the circuit for landing. Its pilot chose the parallel grass runway as the aircraft ahead was using the paved surface.
On final approach at 120mph, with landing gear down and landing flap selected, the Packard Merlin engine started to run “slightly rough” and, as the aircraft started to sink, the pilot moved the throttle three quarters of an inch forwards. There was no increase in power but a puff of white smoke emerged from the left side of the engine and a puff of dark smoke from the right. A further half- inch increase in throttle resulted in a marked decrease in power.
The pilot raised the flaps two notches to 30� and changed fuel tanks, which had no effect, but it appeared that the aircraft would now reach the airfield, though not the runway. It crossed the boundary at between 95 and 100mph and touched down in a three-point attitude some 210 metres before the start of the grass runway, striking the lip of a raised taxiway which launched it back into the air in a nose-high attitude. It touched down again almost in a three-point attitude but starboard main wheel first, and the port main wheel then dug into the ground causing the axle mounting casting to bend outwards, the oleo to press down onto the tyre and the aircraft to yaw left.
The main wheels left the ground again and the pilot applied full right rudder to counteract the yaw. He also applied right brake after the main wheels contacted the ground once more. The aircraft began to skid right while still yawing left and during the deceleration the tail wheel rose and the propeller struck the ground. The pilot released the right brake and the tail lowered back to the ground.
The Mustang came to a halt in the normal landing attitude pointing 90� left of the runway and displaced about 70 metres left of the centreline. The day before the accident, the pilot had flown two display sorties. On the second the engine began to “run slightly rough” on final approach, and stopped on the runway after landing when the throttle was opened slightly.
Investigation found no obvious cause, and ground runs and a flight test revealed no symptoms of rough running, so the aircraft was returned to service for that day’s display programme. The cause of the rough running and power loss had not been positively determined at the time of publication of the accident report.