Engine Power Loss During IFR Clearance and Climb Leads to Forced Landing (N733LW)

Accident Overview

The flight was in a training scenario with a dual student and a flight instructor. While the aircraft was circling at an altitude of 600 feet above ground level (AGL) and awaiting an Instrument Flight Rules (IFR) clearance, the engine experienced a single sputter but continued running. After the IFR clearance was received, the student pilot added power to initiate a climb to the assigned altitude. At that point, the engine sputtered again and subsequently lost power. The flight instructor immediately took control of the aircraft and executed a forced landing in a field.

Post-Accident Inspection

Following the accident, investigators examined the aircraft's fuel system and engine. Uncontaminated fuel was found in both the airframe and engine fuel systems. The engine was successfully started and operated up to full power without any signs of mechanical failure or malfunction. The carburetor icing system was tested and found to operate normally. Despite the absence of mechanical issues, the operating conditions were evaluated using probability curves, which indicated that the aircraft was flying in an environment conducive to serious carburetor icing at glide power and visible carburetor icing at both glide and cruise power settings.