On June 23, 1986, an Ercoupe (eng & Research Corp.) 415-C (registration N3220H) operated by William Buie was involved in an aviation accident near Planada, CA. Investigators recorded the probable cause as: The pilot's failure to maintain adequate airspeed during cruise flight, which resulted in carburetor icing and subsequent engine power loss. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
An aircraft experienced sudden engine power loss during cruise flight at 2000 feet. The pilot attempted to recover using carburetor heat but was unable to maintain altitude, resulting in a forced landing in a field where the plane nosed over.
What happened
During a cruise flight at an altitude of 2000 feet above ground level, the pilot reported that the engine began to cough. In response to this irregularity, the pilot applied carburetor heat. The engine coughed again and subsequently lost power completely. Unable to maintain controlled flight, the pilot executed a forced landing in a plowed field. During the impact, the landing gear dug into the terrain, causing the aircraft to nose over.
The investigation
A post-accident inspection of both the airframe and the engine was conducted to determine the root cause of the power loss. The examination failed to disclose any pre-existing mechanical failures or malfunctions that would explain the sudden loss of power prior to the landing.
Probable cause
The pilot's failure to maintain adequate airspeed during cruise flight, which resulted in carburetor icing and subsequent engine power loss.