Amateur-built ACRO SPORT II N896JC accident near Loudonville, Ohio

Probable cause

A partial loss of engine power due to carburetor icing.

NTSB analysis

The airline transport pilot flew his experimental, amateur-built biplane on a cross-country flight with multiple legs and refueling stops. About 1 hour, 15 minutes into the flight and 15 miles from his destination, the pilot initiated a descent from 3,500 ft to 2,500 ft. When the pilot added power to level off, the engine began to run rough and experienced a partial loss of power. The pilot said that he immediately applied carburetor heat but observed no improvement in engine operation. The engine continued to lose power and "sputter." During the subsequent forced landing, the airplane touched down on unsuitable terrain at the edge of a soybean field, decelerated rapidly, and nosed over.

A postaccident examination of the wreckage revealed no preimpact anomalies that would have precluded normal operation of the engine. Nearby weather was conducive to serious icing at descent power about the time of the engine power loss. Although the pilot reported that he applied carburetor heat, it is likely that, at the time of application, the ice had already accumulated in the carburetor to the extent that the carburetor heat was insufficient to melt the ice and restore full engine power.

Text from the NTSB. Open the NTSB docket for CEN17LA295 for the full record.