Event Description
During the takeoff roll, the pilot detected a loss of engine torque at approximately rotation airspeed, about 1700 feet down the runway. In response, the takeoff was aborted. The aircraft subsequently slid into a ditch off the end of the runway, resulting in collapse of the main landing gear.
Investigation Findings
A functional check of the right engine fuel pump, part number 4V146R002, serial number JX241439D, manufactured by Sperry Vickers, showed that at high pump speed, fuel flow was intermittent. Disassembly of the pump revealed that the rotor drive serrations on the main rotor drive shaft, part number 330205, were worn to the point that the rotor would slip on the shaft at high pump speeds.