Accident Overview
On February 28, 2020, at about 1530 central standard time, a Piper PA-28-140, registration N79HA, was substantially damaged when it impacted terrain near Pleasant, Tennessee. The airplane was engaged in a Title 14 Code of Federal Regulations Part 91 instructional flight. Both the flight instructor and the pilot receiving instruction were uninjured.
Flight Sequence
According to the pilot receiving instruction, after engine startup, they discussed the soft-field takeoff procedure on the ramp for approximately 12 to 15 minutes. They then taxied to runway 35 and initiated a takeoff without performing an engine run-up. The pilot stated that he did not observe the engine rpm during the takeoff roll because his attention was focused outside. About 900 feet down the turf runway, the airplane lifted off, and he moved the yoke forward to maintain level flight while accelerating in ground effect. The pilot attempted to climb twice, but on both occasions the airplane settled back into ground effect. He reported to the instructor, "It's still not climbing," and assessed the airplane's ability to clear power lines at the edge of the airport property that were at his eye level. He decided to remain on airport property, initiated a left turn, and the airplane descended to the ground.
The flight instructor reported that 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 power lines located about 1,000 feet beyond the departure end of runway 35. The instructor noted that the pilot banked more steeply than anticipated. He joined the pilot on the controls, but the airplane descended and impacted the ground in a nose-low attitude.
Wreckage Examination
Examination of the wreckage by a Federal Aviation Administration aviation safety inspector revealed the airplane came to rest upright, 650 feet at 313° from the departure end of runway 35. The airplane remained intact, though the nose gear had separated. The left wing displayed buckling from the leading edge to the trailing edge, and the aileron was bent. Both propeller blades exhibited aft bending and chordwise scratching. Fuel was present in both wing tanks. Examination of the engine revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation.
Weather and Carburetor Icing Guidance
Weather observed at 1535 included a temperature of 8°C and a dew point of -2°C, yielding a calculated relative humidity of about 49.3%. According to an FAA Icing Probability Chart, the atmospheric conditions at the time were "conducive to serious icing at glide [idle] power." FAA Advisory Circular 20-113 states that to prevent accidents due to induction system icing, pilots should regularly use carburetor heat under conditions known to be conducive to atmospheric icing. The circular recommends that when operating in conditions where relative humidity exceeds 50%, pilots should apply carburetor heat briefly immediately before takeoff, particularly with float-type carburetors, to remove any ice that may have accumulated during taxi and runup. It also advises remaining alert for indications of induction system icing during takeoff and climb-out, especially when relative humidity is above 50% or when visible moisture is present. The airplane’s Pilot's Operating Handbook (POH) specifies that carburetor heat should be checked prior to takeoff to ensure proper control operation and to clear any ice that may have formed during taxiing.