Cessna 172P N53725 accident near Kahului, Hawaii

Probable cause

A partial loss of engine power due to the formation of carburetor ice, which resulted in the inability to maintain altitude in the traffic pattern. Contributing to the outcome was the pilot’s delayed use of carburetor heat in conditions conducive to the formation of carburetor ice.

NTSB analysis

The pilot reported that, after five touch-and-go landings, while on the base leg of the traffic pattern, the engine lost partial power. The pilot applied carburetor heat, switched the fuel tanks, and pumped the throttle, but engine power remained at idle. The pilot was unable to reach the runway and performed a forced landing short of the runway. Upon touchdown, the airplane nosed over and came to rest inverted, which resulted in substantial damage to the fuselage and empennage.

The atmospheric conditions at the time of the accident were conducive to serious icing at glide power. Although the pilot reported that he used carburetor heat after experiencing the loss of engine power, it is likely that the ice had already accumulated to the degree that the carburetor heat was insufficient to melt the ice and restore full engine power. Based on the available information, it is likely that the partial loss of engine power was a result of the formation of carburetor ice.

A postaccident examination of the engine revealed no preimpact mechanical malfunctions or failures that would have precluded normal operation.

Text from the NTSB. Open the NTSB docket for ANC24LA011 for the full record.