Date:

October 24, 1947

Location:

Bryce Canyon, Utah

Aircraft:

Douglas DC-6

Reg:

NC37510

Airline:

United Air Lines

Flight No:

608

Fatalities:

53 : 53

Fire was reported on board the aircraft before it crashed. An almost identical accident with the same cause occurred on 11/11/47. The flight crew transferred fuel either intentionally or inadvertently from the No. 4 alternate tanks to the No. 3 alternate tanks and failed to stop the transfer process in time to avoid overflowing the No. 3 alternate tank. Gasoline flowed through the No. 3 alternate vent line, out the vent, and was carried back by the slip stream, entering the cabin heater combustion air intake scoop. When the cabin heater came on an explosion and fire occurred. The fire was fueled by magnesium flares strored in the cabin heater compartment. Caused by a design flaw in the aircraft which allowed vented fuel to be carried back into the cabin heater air intake.