The Transportation Safety Board says an undetected defect deep within the engine of a helicopter caused a fatal crash on northern Vancouver Island last year.
The board’s investigation report examined the April 6, 2022 crash of a Hughes 369D that went down near the Port McNeill airport, killing the lone pilot.
The report says shrinkage voids developed during manufacturing of the helicopter engine’s sixth-stage compressor wheel, but that problem can’t be detected with existing inspection methods.
The compressor wheel eventually fractured in two places, which the board says caused “catastrophic” engine failure.
Because the pilot had just dropped a load of cedar blocks from a longline, the report says the helicopter was close to the ground and had little forward speed, leading to the crash within seconds of the engine failure.
The TSB says the engine manufacturer has reissued a commercial service letter, which includes a recommendation that its customers convert the compressor to the new wheel design during the next overhaul.
