Oil leak likely cause of 2017 plane accident in Manitoba, Canada

The Transportation Safety Board of Canada (TSB) released its investigation report Thursday into the November 2017 loss of control on landing involving an aircraft at Thompson Airport in Manitoba, Canada.

On Nov. 2, 2017, a Perimeter Aviation Fairchild Metro III (serial number AC-756B, registration C-FLRY) was operating on a ferry flight from Gods River Airport, Manitoba, to Thompson Airport, Manitoba, to reposition the aircraft for inspection and repair. As the aircraft neared the airport, the crew advised air traffic control that they had received a low oil pressure indication on the left engine. After consultation with maintenance, the crew considered the risks associated with landing single engine and without hydraulic pressure for the nose-wheel steering, and decided to continue the flight with both engines running. After touchdown, the aircraft suddenly veered to the right and exited the runway. The aircraft was substantially damaged. The two crew members received minor injuries.

The investigation found that the low oil pressure indication was likely the result of a steady oil leak past an air-oil seal in the left engine. The loss of oil pressure thus resulted in a loss of propeller control authority on landing and a runway excursion. The investigation also found that the decision to continue the flight with both engines running was not consistent with the quick reference handbook procedures for low oil pressure indications.

The aircraft was equipped with a cockpit voice recorder but was not equipped with a flight data recorder, nor was one required by regulation. The aircraft's integrated flight management system was capable of capturing engine parameters, but it was not configured to do so. If flight data, voice, and video recordings are not available to an investigation, the identification and communication of safety deficiencies to advance transportation safety may be precluded.

Following the occurrence, the TSB issued an Aviation Safety Advisory letter suggesting that Transport Canada review the Fairchild Metro III aircraft flight manual's emergency procedures for low engine oil pressure indications. In addition, Perimeter Aviation installed memory cards that store engine parameter data on its aircraft that are equipped with an integrated flight management system. It has also implemented crew resource management training for all of its air-taxi and commuter flight crews.