Casualties unknown

1991-06-02: Cessna 120 (N2858N) — David H. Birch — Delaware, OH

Delaware, OH, US

On June 2, 1991, a Cessna 120 (registration N2858N) operated by David H. Birch was involved in an aviation accident near Delaware, OH. Investigators recorded the probable cause as: The pilot's failure to anticipate and prevent carburetor icing under conducive weather conditions, which resulted in an intermittent loss of engine power and a subsequent forced landing. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

An aircraft experienced intermittent engine power loss at low altitude following a touch-and-go maneuver. The pilot executed a forced landing in trees after carburetor heat failed to sustain power, with conditions favorable for icing.

What happened

Approximately thirty feet above the ground, immediately following a touch-and-go landing, the aircraft engine experienced a sudden loss of power. In response, the pilot applied carburetor heat, which temporarily restored engine power. However, the power loss recurred shortly thereafter. Unable to maintain flight, the pilot performed a forced landing into a wooded area.

The investigation

Post-accident analysis focused on the mechanical integrity of the engine and the environmental conditions at the time of the incident. Weather data indicated an ambient temperature of 85 degrees Fahrenheit with a dew point of 69 degrees Fahrenheit. This specific combination of high humidity and temperature created atmospheric conditions highly conducive to carburetor icing.

Findings

The sequence of events suggests that carburetor icing was the primary factor in the engine failure. The intermittent nature of the power loss, which responded briefly to the application of carburetor heat but then returned, is characteristic of ice accumulation and partial melting within the carburetor venturi. The environmental data confirmed that conditions were ripe for such icing events, even at relatively high temperatures.

Safety message

Pilots must remain vigilant regarding carburetor icing during all phases of flight, particularly when operating in humid conditions with moderate temperatures. Regular application of carburetor heat as a preventive measure, or immediate response to rough engine operation, is critical for maintaining power and ensuring safe flight operations.

Probable cause

The pilot's failure to anticipate and prevent carburetor icing under conducive weather conditions, which resulted in an intermittent loss of engine power and a subsequent forced landing.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X17361. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.