On April 14, 1996, a Maule M-5-235C (registration N9177E) was involved in an aviation accident near Lake Havasu Cty, AZ. Investigators recorded the probable cause as: the pilot-owner's inadequate engine maintenance which resulted in a progressive ignition failure. Factors which contributed to the accident were the dark nighttime light condition and the presence of hidden obstructions in the forced landing area. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During a dark nighttime flight, a seaplane experienced engine surging and power loss, leading to a forced landing on the Colorado River shoreline. The airplane struck a tree trunk. Examination found sediment, valve issues, and ignition discrepancies.
Accident Narrative
The pilot, who owned and operated the seaplane and had accrued 803 flight hours in it, was conducting a cruise flight during dark nighttime conditions. The engine experienced surging followed by a gradual loss of power. The pilot executed a forced landing approach to the shoreline of the Colorado River. During touchdown, the airplane slid on the grass bank and struck a tree trunk approximately 3 feet high.
Examination Findings
A post-accident inspection of the airplane revealed the following discrepancies:
Sediment was observed in the fuel filter and carburetor.
The number 3 cylinder intake valve was found open and stretched in excess of 0.200 inches.
No compression was obtained from the number 3 cylinder.
The engine oil was black.
The magneto's drive end seal bearing was leaking oil.
The left set of ignition points were oil fouled, and the right set of points had oil on the contacts and were coked.
The left distributor gear was missing a gear tooth.