What happened
On a scheduled courier flight from Terrace Airport to Vancouver, British Columbia, a Mitsubishi MU-2B-36 operated by Nav Air Charter Inc. experienced a critical engine failure during the initial climb. Shortly after departing from Runway 15 at 18:34 Pacific standard time, the aircraft's left engine lost power. The plane began a descent while banking slightly to the left, eventually striking trees approximately 1600 feet east of the runway departure end on a magnetic heading of 072°.
The impact and subsequent fire caused the total destruction of the aircraft, registered as C-FTWO. Both pilots on board sustained fatal injuries during the accident.
Findings
Investigation into the crash identified that a fatigue crack caused the left engine's combustion chamber plenum to split, leading to an extensive rupture and subsequent engine flame-out. This mechanical failure was compounded by several operational factors. The crew failed to feather the left engine or retract the flaps during the emergency. Additionally, the use of flap 20 for takeoff, while following company protocol, increased the difficulty of maintaining control during the power loss.
Evidence suggested potential cockpit uncertainty, as the checklist was performed out of sequence and the first officer's handling of the failure may have been compromised. The captain's lack of experience managing such an emergency from the right seat was also noted. Furthermore, investigators considered that ice formation on the wing might have occurred due to 0°C temperatures and a wet wing surface, potentially reducing lift. A significant underlying risk identified is that cracks in the TPE331 series engine plenum can be extremely difficult to detect through standard visual or fluorescent dye-penetrant inspections.