Accident Sequence
The accident airplane, a single-engine tandem aircraft, departed to join a similar aircraft for a local flight. While maneuvering at an estimated altitude of 1,000 feet, the pilot reported, 'going down, engine quit.' The pilot of the other airplane observed the accident airplane entering a left turn to try to make a field. The witnessing pilot added that 'the pilot tried to extend his glide, experiencing an accelerated stall.' The aircraft impacted the ground wings level in a 20 to 30 degrees nose-down attitude, bounced, and caught on fire. The initial point of impact was approximately 50 feet beyond a line of tall trees.
Aircraft Examination
Examination of the carburetor revealed that the throttle plate was jammed in the full open position and the diaphragm assembly was found to be ruptured and very brittle, giving the appearance of being 'dry-rotten.' Particles of the broken diaphragm were found throughout the carburetor assembly. The airframe and engine logbooks for the airplane were stored in the airplane at the time of the accident and were presumed destroyed. The investigation was unable to establish the date of the last overhaul or repair on the carburetor assembly or when the failed diaphragm was installed.