Boeing B-29 Superfortress accident at Seattle, United States of America, 18 Feb 1943 (41-003)
On February 18, 1943, a Boeing B-29 Superfortress (registration 41-003) operated by The Boeing Company was involved in an aviation accident near Seattle, United States of America during landing or approach. 34 people were killed. Investigators recorded the probable cause as: A fire on engine n°1 was likely due to the rupture of a supply fuel line. When fuel contacted the engine nacelle and several other components whose temperature was high, a fire erupted that quickly spread across the wing. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 3 related events involving the same aircraft type or operator are linked below.
Probable cause
A fire on engine n°1 was likely due to the rupture of a supply fuel line. When fuel contacted the engine nacelle and several other components whose temperature was high, a fire erupted that quickly spread across the wing. On final approach, a violent explosion occurred on the left wing when fire contacted the valves of the wing defrost system which was mainly composed of magnesium. In addition, air flowing under the leading edge slats boosted flames significantly, which was considered as a contributory factor. Following this tragedy, Boeing technicians were forced to modify the engine fuel system as well as some others points.
— NTSB Determination
Accident narrative
The crew was performing a test flight on this second prototype. Ten minutes after departure from Seattle-Boeing Field, the crew informed ATC that engine n°1 caught fire and attempted to return. At an altitude of 2,400 feet, the pilot feathered the propeller and notified ATC that the fire was spreading quickly. One minute later, as it was about to land, the bomber struck a power line and crashed on an industrial butchery. Extensive emergency resources were dispatched to the scene where rescuers did not find any survivors among the debris scattered over a wide area. The building was destroyed and 34 dead bodies were found: all 11 occupants on board the airplane and 23 people on ground. Thirty people on the ground were injured. Crew: Eddie Allen, Chief test pilot by Boeing, Bob Dansfield, captain.
Probable cause (official findings): A fire on engine n°1 was likely due to the rupture of a supply fuel line. When fuel contacted the engine nacelle and several other components whose temperature was high, a fire erupted that quickly spread across the wing. On final approach, a violent explosion occurred on the left wing when fire contacted the valves of the wing defrost system which was mainly composed of magnesium. In addition, air flowing under the leading edge slats boosted flames significantly, which was considered as a contributory factor. Following this tragedy, Boeing technicians were forced to modify the engine fuel system as well as some others points.