On September 14, 1997, a Piper PA-12 (registration N7894H) was involved in an aviation accident near Healy, AK. Investigators recorded the probable cause as: The pilot's inadequate preflight which failed to detect water contamination in the fuel tanks. Factors were the worn gaskets on the fuel tank caps, and the pilot's decision to abort the partial power precautionary landing. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During cruise climb, engine rpm decreased. Carburetor heat and mixture adjustments did not restore power. During a precautionary landing, the pilot aborted for horses; the main gear struck a berm, causing the airplane to nose over. Postaccident inspection found water in fuel and worn cap gaskets.
Event Summary
A pilot reported that during cruise climb, the engine's revolutions per minute (rpm) began to decrease. The pilot applied carburetor heat and varied the mixture setting, but these actions did not improve engine performance.
The pilot initiated a precautionary landing. During the landing attempt, the pilot observed horses on the airstrip and decided to abort the landing. The airplane's main landing gear subsequently struck a berm, causing the airplane to nose over.
Postaccident Inspection and Testing
A postaccident inspection of the airplane revealed an unknown quantity of water in the fuel system. Additionally, the fuel cap gaskets were found to be worn. Engine testing following the accident produced minimum static rpm as required by the type certificate, and cylinder compression was found to be low.