Casualties unknown

Student Pilot Forced Landing Due to Carburetor Ice at Cruise Altitude (N67992)

Yoncalla, OR, US

On August 8, 1988, a Cessna 152 (registration N67992) operated by Montague Aviation was involved in an aviation accident near Yoncalla, OR. Investigators recorded the probable cause as: The pilot's failure to use carburetor heat in conditions conducive to carburetor ice formation, which resulted in an engine power loss and a subsequent forced landing. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 11 related events involving the same aircraft type or operator are linked below.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 2026-06-10Data APIEditorial standards

A student pilot experienced a sudden power loss while cruising at 8,500 feet, resulting in a forced landing in an open field. The aircraft collided with a fence during the rollout, but the engine continued to operate normally afterward.

What happened

The accident occurred while the pilot was operating the aircraft at a cruise altitude of 8,500 feet. During this phase of flight, the engine experienced a sudden and complete loss of power. Unable to maintain altitude or airspeed, the pilot executed an emergency forced landing in an open field nearby.

During the landing rollout, the aircraft struck a fence located within the field. Despite the impact with the fence, the engine did not cease operation and continued to run normally after the mishap. The pilot successfully evacuated the scene without reporting any injuries.

The investigation

Post-accident examination of the aircraft revealed that the engine was still functional immediately following the collision. A sample of the fuel was taken and analyzed, confirming that it was clear of water or other contaminants. This finding effectively ruled out fuel starvation or contamination as the primary cause of the power loss.

Findings

The investigation focused on environmental conditions and pilot actions at the time of the incident. The surface temperature was recorded at 70 degrees Fahrenheit with a dew point of 53 degrees Fahrenheit. These meteorological conditions are known to be conducive to the formation of carburetor ice, even in relatively warm temperatures.

Crucially, the investigation determined that the pilot did not utilize carburetor heat when the power loss occurred. The combination of high humidity and specific temperature differentials within the carburetor likely led to ice accumulation, restricting fuel flow and causing the engine failure. The failure to apply carburetor heat in these conditions was a significant contributing factor.

Safety message

Pilots must understand that carburetor ice can form even when ambient temperatures are well above freezing. It is essential to monitor carburetor temperature indicators and use carburetor heat proactively, especially in humid conditions or during descent phases where the risk of icing increases significantly.

Probable cause

The pilot's failure to use carburetor heat in conditions conducive to carburetor ice formation, which resulted in an engine power loss 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/20001213X26712. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.