WPR24FA014 · Piper PA-28-140

Two flight instructor-certificated pilots and a passenger on a personal flight departed from an airport in high density-altitude conditions with a slight tailwind. A witness located near the airport reported observing the airplane flying at a low altitude over the trees with its wings wobbling. He stated that the airplane climbed to a maximum altitude of about 100 to 200 ft above ground level (agl) before it began a left turn toward the airport road then fell straight toward the ground. The circumstances of the accident flight, the accident site evidence, and the witness account were consistent with the airplane entering an aerodynamic stall and uncontrolled descent at low altitude. Although the witness reported that he felt certain that he heard the engine shut down about 3 to 5 seconds before impact, propeller damage and propeller strike marks on the ground were evidence of engine power at impact. Further, postaccident examination of the airframe and engine revealed no evidence of mechanical failure or malfunction that would have precluded normal operation. Regardless, based on the witness’s description of the airplane’s wings wobbling in flight, the aerodynamic stall was imminent before the reported change in engine sound, and the pilot flying did not adequately adjust the airplane’s pitch to prevent it. The left-seat pilot’s toxicology results detected isomers of tetrahydrocannabinol (THC) and their metabolites, indicating that he had used one or more cannabis products. Whether the detected delta-9-THC, delta-8-THC, and cannabidiol (CBD) came from the same product or multiple products is unknown. Delta-9-THC and delta-8-THC have potential to cause cognitive and psychomotor impairment. However, the precise timing of the left-seat pilot’s use of these substances and whether the substances were causing significant impairing effects at the time of the accident cannot be determined from the measured levels of the substances and their metabolites. The measured levels of psychoactive substances were relatively low, but this does not exclude associated impairment. The right-seat pilot’s toxicology results indicated that he had used several medications commonly used to treat cold or allergy symptoms. The likelihood of these medications causing significant impairment was low. However, the presence of these medications might indicate a potentially distracting or otherwise impairing condition such as an acute upper respiratory infection or symptomatic seasonal allergies. Whether the right-seat pilot was experiencing such effects from an underlying condition at the time of the accident could not be determined from the available medical evidence. The airplane was equipped with dual flight controls, and both pilots were qualified to fly the airplane. However, based on the available video evidence from previous flights, during which the left-seat pilot was flying the airplane and the right-seat pilot provided comments and suggestions without intervening on the controls, the left-seat pilot was likely flying the airplane during the accident flight. Video evidence from previous flights indicated that the left-seat pilot had allowed the airplane’s airspeed to decay to the point of stall warning horn activation on three occasions during two previous takeoffs without the passenger on board.

Verbatim NTSB analysis and probable cause from the NTSB dataset