What happened
On a scheduled flight from Yellowknife to Norman Wells, a Buffalo Airways Curtiss C-46A, registration C-GTXW, encountered mechanical difficulties while cruising at 6,500 feet. The flight crew observed a simultaneous drop in the right engine oil quantity and a propeller overspeed. Upon inspection, the crew identified that oil was escaping through the engine breather vent at an extreme rate.
Efforts to manage the propeller pitch and execute the standard overspeed drill were initially unsuccessful, as the propeller failed to feather upon the first selection. After multiple attempts, the crew successfully feathered the propeller and shut down the engine. Due to the aircraft's descent rate, the crew determined they could not reach Tulita and instead opted to divert to Déline, where weather conditions were poor, featuring a 300-foot ceiling and 0.5-mile visibility.
During the approach to Déline, the crew chose to keep the landing gear retracted to maintain necessary airspeed. This resulted in a belly landing near the middle of runway 08. The aircraft overran the runway, coming to a rest roughly 700 feet past the threshold. While the aircraft was destroyed, the crew evacuated safely with no injuries.
Findings
- The right engine experienced a rapid loss of oil through the breather vent.
- The propeller failed to feather immediately during the initial overspeed drill.
- The decision to perform a gear-up landing was made to prevent a loss of airspeed during the emergency descent.