ERA20LA121

After engine startup, the flight instructor and pilot receiving instruction discussed the soft field takeoff maneuver on the ramp for 12 to 15 minutes before taxiing to the turf runway. They did not perform an engine runup or apply carburetor heat before departing. About 900 ft down the turf runway, the airplane became airborne in ground effect. The pilot attempted twice to climb, but on both attempts the airplane settled back into ground effect. The instructor reported that the airplane did not seem to be producing sufficient power to climb. The pilot assessed the airplane's ability to clear the power lines at the edge of the airport property, made the decision to stay on the airport property, and initiated a left turn. The airplane descended and impacted the ground in a nose-low attitude. Postaccident examination of the engine revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. The atmospheric conditions at the time of the accident were conducive to the formation of serious carburetor icing at low engine power settings. It is likely that during the extended ground delay, when the engine was operating at low power, carburetor ice formed, which resulted in a partial loss of engine power during the initial climb. It is also likely that the carburetor ice would have been detected or prevented prior to takeoff had the recommended pre-takeoff ground checks been completed according to the pilot's operating handbook.

On February 28, 2020, about 1530 central standard time, a Piper PA-28-140, N79HA, was substantially damaged when it was involved in an accident near Pleasant, Tennessee. The flight instructor and pilot receiving instruction were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. According to the pilot receiving instruction, after engine startup, they discussed the soft-field takeoff procedure on the ramp for about 12 to 15 minutes. They then taxied to runway 35 and took off without performing an engine run-up. He stated that he did not note the engine rpm during the takeoff roll because his eyes were focused outside. About 900 ft down the turf runway, the airplane lifted off and he moved the yoke forward to maintain level flight while accelerating in ground effect. He attempted twice to climb, but during both attempts, the airplane settled back into ground effect. He told the instructor, "It's still not climbing," and assessed the airplane's ability to clear the power lines at the edge of the airport property, which were at his eye-level. He made the decision to stay on the airport property, initiated a left turn, and the airplane descended to the ground. According to the flight instructor, the airplane settled back into ground effect twice after the pilot attempted to raise the nose to climb. He instructed the pilot to make a left turn to avoid the power lines about 1,000 ft beyond the departure end of runway 35 and stated that the pilot banked more steeply than anticipated. He joined the pilot on the controls; however, the airplane descended and impacted the ground in a nose-low attitude. Examination of the wreckage by a Federal Aviation Administration aviation safety inspector revealed the airplane came to rest in an upright position, 650 ft and 313° from the departure end of runway 35. The airplane remained intact; however, the nose gear was separated, the left wing displayed buckling from the leading to the trailing edge, and the aileron was bent. Both propeller blades exhibited aft bending and chordwise scratching. The inspector noted fuel in both wing tanks. Examination of the engine revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. The 1535 weather included temperature 8°C and dew point -2°C. The calculated relative humidity at this temperature and dewpoint was about 49.3%. According to an FAA Icing Probability Chart, the atmospheric conditions at the time of the accident were "conducive to serious icing at glide [idle] power." According to FAA Advisory Circular 20-113 , "To prevent accident due to induction system icing, the pilot should regularly use [carburetor] heat under conditions known to be conducive to atmospheric icing and be alert at all times for indications of icing in the fuel system." The circular recommended that when operating in conditions where the relative humidity is greater than 50%,"…apply carburetor heat briefly immediately before takeoff, particularly with float type carburetors, to remove any ice which may have been accumulated during taxi and runup." It also stated, "Remain alert for indications of induction system icing during takeoff and climb-out, especially when the relative humidity is above 50 percent, or when visible moisture is present in the atmosphere." The examination of the engine revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. According to the ground check procedures section of the airplane's Pilot's Operating Handbook (POH): Carburetor heat should be checked prior to takeoff to be sure that the control is operating properly and to clear any ice which may have formed during taxiing.