Accident Details
During the takeoff roll, the pilot noted a partial power loss and made a precautionary decision to abort the takeoff and land on the remaining runway, which was 10,300 feet in length. While aborting, the pilot flared late, resulting in a hard landing.
Fuel System Investigation
An investigation found water and products of corrosion in the gascolator. The aircraft was equipped with auxiliary fuel tanks installed in the wings, outboard of the main tanks. To use the auxiliary tanks, fuel had to be transferred to the main tanks by a vibrator pump. Quick-drains were installed for the main tanks and the gascolator. The sumps in the auxiliary tanks could be drained by removing 1/8-inch plugs with a wrench.
Maintenance and Operational History
The flight manual recommended draining the auxiliary sumps every 100 hours of operation. At the time of the accident, 70 hours had accumulated since the sumps were last drained. The auxiliary tanks were used, for the first time in several months, on the flight preceding the accident. During the preflight inspection on the day of the accident, some quantities of water were removed.
Regulatory and Service Letter Compliance
Federal Aviation Regulations require that water be drainable from all parts of a fuel tank to a sump, and that the sump be readily accessible and easy to open and close. Maule Service Letter #32, which called for the installation of quick-drains within 25 hours of operation, had not been complied with.