The flight was carried out by Propair, a charter airline based in Rouyn-Noranda, Quebec, using a Fairchild Metroliner SA226.

On 18 June 1998, the aircraft suffered an in-flight fire shortly after take-off from Dorval and the crew elected to conduct an emergency landing at Montréal–Mirabel International Airport.

The intense heat of the fire caused a structural failure in the left wing during the landing and the aircraft crashed, resulting in the deaths of all 11 passengers and crew on board.

The investigation conducted by the Canadian Transportation Safety Board revealed that the left brakes of Flight 420 had overheated during take-off, causing a fire inside the wheel-well which destroyed warning systems, as a result of which the crew was unaware of the severity of the fire, which subsequently ruptured hydraulic pipe-lines and spread to the left wing.

The flight was chartered by General Electric to transport personnel to a GE facility in Peterborough, Ontario.

[1]: 1 At 07:13, the crew of Flight 420 informed the tower that there was a decrease on the hydraulic pressure and requested to return to the airport.

Dorval Tower cleared Flight 420's request to return and ordered them to descend to 8,000 feet (2,438 m) and make a 180-degree turn.

[3][1]: 1 The flight was chartered by General Electric to transport their workers to their facility in Lachine, Quebec and Peterborough, Ontario.

He served as captain and as check pilot on similar aircraft types for several air carriers.

Constable Gilles Deziel, who had toured the crash site, stated that "three quarters of the plane was all burned and all black".

[4] Investigators found out that when pressures were added to the brakes, then there would be an increase in drag force and temperature on the assembly.

[1]: 22-24 Another test was conducted by investigators to determine if hydraulic fluids of Flight 420 would ignite when it contacted the hot surface of the brake assembly.

The wheel wells did not have sufficient cooling, and so the temperature of the brakes continued to rise, reaching as high as 600 °C (1,112 °F).

Tests conducted by investigators revealed that when tire fragments came into contacted with overheated brakes, they ignited.

[1]: 29-33 The crew never realized the severity of the fire, which had grown out of control and begun degrading the structural integrity of the left wing.

[1]: 29-33 Propair Flight 420 was featured in the ninth episode on season 21 of Mayday titled "Seconds from Touchdown"[5]