Incident Overview
A training flight involving a certified flight instructor (CFI) and a private pilot experienced an unexpected power loss during a simulated emergency procedure. The incident occurred at approximately 2,500 feet mean sea level when the CFI activated carburetor heat and reduced engine power to idle to simulate an engine failure.
Emergency Maneuver
The private pilot completed the emergency checklist items and maneuvered the airplane toward a field for a simulated forced landing. During the descent, the carburetor heat remained engaged, and the CFI periodically cycled the engine throttle to clear the engine. When the airplane was about 15 to 20 feet above the field, the pilot attempted to add power for a go-around, but the engine did not respond.
Response and Landing
The CFI took control of the airplane and executed a forced landing to the field. After the accident, a certificated mechanic examined the wreckage. The mechanic was able to rotate the propeller by hand and noted no discrepancies with the engine. An adequate amount of fuel was observed in the airplane.
Investigation Findings
The mechanic stated that he believed the power loss occurred due to carburetor ice. He noted that on the make and model of the accident engine, the carburetor is situated below the engine, making it more susceptible to carburetor ice accumulation. Additionally, the carburetor heat system relied on only two of the four engine cylinders, which may have reduced its effectiveness. The mechanic was confident that carburetor ice caused the power loss and did not disassemble the carburetor to confirm. A Federal Aviation Administration inspector did not examine the wreckage but accepted the mechanic's determination that carburetor ice was the cause.