CEN15LA215

The flight instructor was conducting an instructional flight with a student pilot. The student reported that the preflight engine run-up was normal and that, before takeoff for the flight, there was a small wait because they were the fourth airplane in line for takeoff. At takeoff, the engine power was not normal, but leaning the mixture returned the engine performance to normal. After performing several flight maneuvers at 4,500 ft mean sea level (msl), the flight instructor simulated an engine failure by applying carburetor heat and retarding the throttle to idle. After descending the airplane to 2,500 ft msl, the flight instructor attempted to clear the engine and pushed the throttle control to full power, but the engine power was not restored. Subsequent attempts to restart the engine were unsuccessful, and the student then transferred the flight controls to the flight instructor, who then conducted a forced landing to muddy terrain, which resulted in the airplane nosing over. The weather conditions at the time of the accident were conductive to moderate carburetor icing at cruise power and serious carburetor icing at descent power. Given the delayed takeoff, during which the engine would have been at an idle power setting, and that the mixture needed to be leaned at higher engine power to return to normal, it is likely that carburetor icing had accumulated. Although the flight instructor applied carburetor heat for the simulated engine failure to prevent carburetor icing, there would have been reduced heat output by the engine at the idle power setting, which would not have been effective in preventing carburetor icing.

On March 24, 2015, at 1605 central daylight time, a Cessna 172H, N8282L, nosed-over in muddy terrain during a forced landing following a simulated loss of engine power and forced landing near Circleville, Texas. The pilots were unable to regain engine power during the simulated forced landing. The airplane sustained substantial damage. The flight instructor and student pilot sustained minor injuries. The airplane was registered to and operated by the student pilot under 14 Code of Federal Regulations Part 91 as an instructional flight that was not operating on a flight plan. Visual meteorological conditions prevailed at the time of the accident for the local flight that departed from Austin-Bergstrom International Airport (AUS), Austin, Texas at 1530. The student pilot stated that the purpose of the accident flight was a mock checkride for the student pilot. The student pilot stated that the run-up prior to departure from AUS was normal and there was a small wait for departure, as they were the fourth airplane in line for departure. At takeoff, the engine did not have normal power and the mixture had to be leaned and upon doing so, the engine performance returned to normal. They departed toward the north and performed flight maneuvers at an altitude of about 4,500 feet mean sea level prior to performing a simulated engine failure. The simulated engine failure was performed by pulling the carburetor heat on and retarding the throttle to idle. The airplane was turned into the wind, about 180 degrees, and the best glide speed was established. The student pilot said there was a brief discussion of what other things were to be done i.e. find a field, squawk 7700, attempt a restart, etc. About 2,500 feet mean sea level, the flight instructor attempted to clear the engine and pushed the throttle control to full power and nothing happened. The flight instructor made attempts to adjust the mixture and restart the engine, which did not restart. The flight instructor took the flight controls and made landing to a field where the airplane got caught in the mud. The nose gear and propeller initially impacted the ground and the airplane flipped over. The AUS weather observation at 1553 recorded a temperature of 25 degrees Celsius and a dew point of 17 degrees Celsius. According to the New Carburetor Probability Icing Chart, a temperature of 25 degrees Celsius and a dew point of 17 degrees Celsius was in the moderate icing at cruise power and serious icing at descent power region.