On August 23, 1992, a Cessna 140 (registration N77073) operated by William H. Hall was involved in an aviation accident near Wasilla, AK. Investigators recorded the probable cause as: The partial loss of engine power due to a piece of the right-hand exhaust stack separating at the confluence of the carburetor heat extraction area. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot experienced partial engine power during cruise flight, resulting in a forced landing off-airport and substantial damage to the aircraft.
What happened
During cruise flight, the pilot encountered a partial loss of engine power. The situation required an immediate response, leading to a forced landing away from any airport facility. This emergency maneuver resulted in substantial damage to the airplane.
The investigation
Following the incident, a detailed examination of the aircraft was conducted to determine the mechanical cause of the power failure. Investigators discovered that a piece of the right-hand exhaust stack had separated. The separation occurred specifically at the confluence of the carburetor heat extraction area. This structural failure in the exhaust system is identified as the primary mechanical issue.
Findings
The investigation revealed that the engine operated normally after the accident, indicating that the power loss was not due to internal engine failure or fuel issues. The critical finding points to substantial damage caused by the separation of the exhaust component during flight.
Probable cause
The partial loss of engine power due to a piece of the right-hand exhaust stack separating at the confluence of the carburetor heat extraction area.