The pilot reported that there were no irregularities noted with the Zenith Zodiac 601HDS during the preflight inspection, engine run-up, or taxi before departing from Runway 3 at Altoona/Blair County Airport (KAOO) in Pennsylvania.
The pilot intended to remain in the airport traffic pattern. However, during the initial climb, the engine started to “misfire,” then immediately stopped producing power. Unable to troubleshoot due to the low altitude, he lowered the nose and attempted a forced landing on the remaining runway.
The airplane landed hard and the landing gear collapsed, which resulted in the wings and airframe buckling. The airplane then skidded to a stop on the side of the runway.
Examination of the airplane revealed signatures to the propeller that were consistent with a lack of rotation during the impact. The engine was intact. Engine crankshaft and valvetrain continuity was established and compression was attained on each cylinder. Both magnetos produced spark at each of the posts.
A subsequent examination of the fuel system revealed 10 gallons of fuel on board.
The fuel gascolator was installed partially outside of the engine compartment, exposing it to the air slipstream. The gascolator exhibited features consistent with a fuel leak. The gascolator bowl was not completely secure to the upper portion of the gascolator, and it would leak fuel when lightly touched by hand. The gascolator was opened and the gasket at the top of the bowl was found to be stiff and cracked.
A review of maintenance records documented an annual condition inspection had been completed about 10 days before the accident. The logbook entry did not document any maintenance or inspection to the gascolator specifically, but the fuel system inspection was documented and tested, yielding no leaks.
Probable Cause: The total loss of engine power due to fuel starvation as a result of a deteriorated gascolator gasket. Contributing was the failure of the mechanic to replace the gasket during the most recent condition inspection.
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This October 2024 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
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