On May 15, 1998, a Piper PA-22-160 (registration N198TP) operated by Michael S. Pavao was involved in an aviation accident near Clarksburg, CA. Investigators recorded the probable cause as: A total loss of engine power for undetermined non-mechanical reasons. A contributing factor in the landing nose-over was the presence of the soft terrain. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot reported losing engine power on base leg after applying carburetor heat and retarding throttle. Unable to reach the runway, he performed a forced landing in a soft field, causing the airplane to nose over. FAA examination found no mechanical malfunctions.
Accident Narrative
The pilot reported that prior to takeoff for a planned 10-minute flight, both fuel tanks contained over 5 gallons of fuel and all airplane systems were functioning normally. Upon arrival at the destination airport, the pilot entered the traffic pattern. Carburetor heat was applied, the throttle was retarded, and the airplane descended. After turning onto the base leg, the pilot moved the throttle forward to increase engine power. The engine then "blubbered and totally lost power." Unable to glide to the runway, the pilot made a forced landing in a soft field adjacent to the airport. During the landing, the airplane nosed over.
Examination
An FAA coordinator responded to the accident site and examined the wreckage. The FAA reported that it examined the powerplant, induction system, engine controls, and magnetos. The ignition switch and the carburetor were also functionally examined. No evidence was found of any mechanical malfunctions. The reason for the interruption of engine power was not determined.