What happened
On a scheduled cargo flight from Montreal-Dorval to Hall Beach, Northwest Territories, a DC-4 departed runway 10 at 22:44 local time. After departing, the aircraft maintained its runway heading and ascended to 6,000 feet before turning toward its assigned course and climbing further to 9,000 feet. By 22:59, the aircraft had reached its target altitude.
Shortly after reaching this level, the crew initiated an emergency descent due to a fire in the number two engine. During the descent, the final radio transmission occurred at 23:07, during which the crew reported that the left wing had separated from the aircraft and that the plane was in a spin. The DC-4 disintegrated while in flight, leaving debris scattered across an area measuring approximately 1.25 by 0.75 miles. There were five fatalities among the crew members.
Findings
Investigations determined that an unidentified fire began within the number two engine nacelle during the climb. The fire grew to a magnitude that exceeded the capacity of the onboard extinguishing systems. Several contributing factors were identified, including:
- The degraded state of the exhaust collector ring.
- Potential deterioration of flexible wire braid hose assemblies.
- The likely application of high power settings during the ascent.
- A possible failure in the fire detection and warning system to alert the crew before the fire breached the firewall and ignited the fuel feed and oil tank.
During the rapid descent, structural stresses caused by maneuvers or atmospheric gusts were sufficient to sever the left wing spar.