On July 6, 1984, a Bellanca 7GCBC (registration N57396) was involved in an aviation accident near Gorst, WA. Investigators recorded the probable cause as: The pilot's failure to maintain aircraft control during a climbing turn, which resulted in an aerodynamic stall, due to worn spark plugs and a missing stall warning system fuse. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
Witnesses observed the aircraft depart runway 19 and initiate a climbing left turn before entering an uncontrolled descent at low altitude. Investigation found five of eight spark plugs were worn and the stall warning light fuse was missing.
What happened
According to witness accounts, the aircraft departed runway 19 and initiated a climbing left turn. During this phase, observers noted the aircraft increased its angle of bank to the left while maintaining a climb rate. At an altitude of approximately 50 to 75 feet, the aircraft entered a steep, uncontrolled descent and collided with the ground.
The investigation
A physical examination of the wreckage provided critical mechanical insights into the failure. Inspectors found that five of the eight spark plugs were worn. Additionally, the fuse for the stall warning light and horn was missing from the electrical system.
Probable cause
The pilot's failure to maintain aircraft control during a climbing turn, which resulted in an aerodynamic stall, due to worn spark plugs and a missing stall warning system fuse.