Investigators looking into the crash of a Canadian Forces Snowbirds airplane in early August found the cause was an improperly assembled oil filter that led to its engine failure.

The aircraft, a CT-114 Tutor, was on its way back to Moose Jaw, Sask., on Aug. 2 from Fort St. John, B.C., as part of that city's international air show, which was held in the last two days of July, according to the military investigator's Sept. 21 report.

When the pilot brought the landing gear up shortly after takeoff from the North Peace Regional Airport in Fort St. John, they heard a loud noise and the engine failed, according to the investigator's report. The plane began decelerating and descended toward the runway, the report says.

A defence source familiar with the accident but not authorized to speak publicly about it told CBC's Murray Brewster shortly after the crash that the pilot was able to turn the jet around and return to the airfield.

The landing gear hadn't locked when the aircraft reached the runway and the gear collapsed, sending the plane skidding across the tarmac and over the end of the runway, according to the report.

The report estimates the plane travelled about 300 metres — more than the length of two CFL football fields — before hitting the perimeter fence and slowing to a halt.

According to the report, the pilot — the only person in the plane — was uninjured, but the jet was seriously damaged.

The accident led the Snowbirds, who are the military aerobatics team of the Royal Canadian Air Force, to cancel their appearance at the Penticton Peach Festival, in Penticton, B.C. and, later, all of their other scheduled performances for 2022.

A week later, the Snowbirds grounded the fleet in an "operational pause" for airworthiness risk assessment. That pause was lifted on Sept. 20.

The CT-114 Tutor was the same type of aircraft involved in the fatal crash in May 2020 that killed Capt. Jenn Casey, the aerobatics team's public affairs officer.

That accident, which investigators determined was an engine failure from a bird strike, recommended additional training for CT-114 aircrew to better prepare them for engine failure.