ERA17LA120

The flight instructor and the student pilot departed for a local flight. After performing several takeoffs and landings, they departed the airport area to perform slow flight and stall maneuvers. While recovering from the second stall maneuver, the engine suddenly lost power completely. The flight instructor attempted to troubleshoot and then restart the engine but was unsuccessful. She performed a forced landing to a field and the airplane was substantially damaged when it struck trees. Postaccident examination of the airframe and engine was unable to identify evidence of any mechanical anomalies that would have resulted in the loss of engine power. Additionally, the temperature and dewpoint at the time of the accident were not conducive to the formation of carburetor ice, and the flight instructor stated that they had used carburetor heat during the flight. Based on this evidence, the reason for the loss of engine power could not be determined.

On March 5, 2017, about 1036 eastern standard time, a Cessna 150, N60939, was substantially damaged when it was involved in an accident in Argyle, New York. The flight instructor and student pilot sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. The flight instructor stated that, on the day of the accident, she conducted a preflight inspection and had the airplane fueled. Following an uneventful engine runup, the flight instructor and the student pilot departed. They then performed two touch-and go-landings before leaving the area of the airport and preparing to perform slow flight maneuvers. The flight instructor stated that they used carburetor heat as necessary. They performed a power-off stall, and recovered normally, followed by some slow flight maneuvers and another power-off stall. When the engine power was increased to recover from the maneuver, the engine rpm did not increase, and within a few seconds of applying full power, the engine lost all power and the propeller ceased rotating. After lowering the airplane’s nose and establishing an airspeed of about 65 mph, the flight instructor took control of the airplane. She then checked the mixture and verified that the carburetor heat was on and that engine primer was in and locked. She further attempted to restart the engine with the starter without success. After finding a suitable field, she “slipped” the airplane to land on it. After touching down on an uphill area, the airplane crested the hill and then rolled down the other side and struck trees. According to the student, he was receiving instruction during the accident flight, and the instructor had previously given him lessons a few times. The instructor performed a preflight inspection and then he performed another one himself. Before the flight, they added 6 gallons of fuel to each tank. After he conducted the takeoff, he performed two to three touch-and-go landings and then departed the traffic pattern for the practice area. After reaching the practice area, they performed “slow flight” and power-off stalls twice. After the second power-off stall, the engine lost power. The student added that he told the instructor about the power loss, that “she did the engine failure checklist,” and that “we tried to start the engine” without success. He further stated that they used carburetor heat during the touch-and-go landings, slow flight, and power-off stalls. A postaccident examination of the airframe and engine by a Federal Aviation Administration Inspector revealed that the airplane sustained substantial damage to both wings and the fuselage. The fuel shutoff was in the “on” position, the throttle was full aft, the carburetor heat was full in, and the ignition switch was off. Control continuity was confirmed from the cockpit to the engine for throttle, mixture, and carburetor heat control. Thumb compression was established on all four cylinders, and bothmagnetos produced spark. The gascolator contained fuel, and the screen was clean and unobstructed. The carburetor was unobstructed, and all of its controls were operative. No intake leaks were observed. About 5 gallons of fuel were recovered from the fuel system. The closest weather reporting facility to the accident site, Floyd Bennett Mamorial Airport (GFL), Glen Falls, New York, was located about 10 nautical miles to the northwest. At 1053, the reported conditions there included a temperature of -08° C and a dew point -19° C. The calculated relative humidity at that temperature and dewpoint was 41%. Review of the icing probability chart contained within Federal Aviation Administration Special Airworthiness Information Bulletin CE-09-35 revealed the atmospheric conditions at the time of the accident were not conducive to the formation of carburetor ice at any power setting.