Accident Overview
A flight instructor (CFI) and a student pilot were conducting a simulated engine failure exercise. The CFI pulled the mixture control to idle cut-off to simulate the failure, then closed the throttle. He subsequently moved the mixture control to full rich but did not recall using carburetor heat during the subsequent descent.
Descent and Recovery Attempt
The student reported that the airplane descended for approximately 3 to 4 minutes during the simulated emergency. The instructor attempted to terminate the situation at an altitude between 100 and 500 feet above ground level (agl). When the instructor tried to add power, the engine did not respond.
Impact and Aftermath
The airplane struck a canal bank and nosed over into the canal. Temperature and dew point values reported by the pilot and the weather observation facility at Hailey, about 28 miles north-northwest of the accident location, indicated a potential for serious carburetor icing during descent based on a carburetor ice hazard chart.
Carburetor Icing Conditions
The recorded temperature and dew point values at the time of the accident were conducive to carburetor icing, according to the chart. The lack of carburetor heat application may have allowed ice to form in the carburetor, affecting engine performance when power was requested.