Aeronca 7AC N1478E accident near Jacksboro, Tennessee

Probable cause

The pilot's exceedance of the airplane’s critical angle of attack during takeoff, which resulted in an aerodynamic stall and loss of control.

NTSB analysis

According to a friend, the pilot had not flown for 20 years, and purchased the accident airplane the day before the accident flight. The pilot’s friend witnessed and recorded video of the accident takeoff, which revealed that the airplane became airborne and entered a slow speed, nose-high climb that continued into a left turn. The airplane then pitched nose-down and began descending while the engine could be heard operating smoothly and continuously to ground contact.

The airplane was found in a nose-down position in a field near the runway with significant damage to the engine and cockpit area. All primary flight control surfaces remained attached, and the empennage was bent upward and forward but remained partially attached. The wreckage examination did not reveal evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation.

Toxicology testing detected diphenhydramine in the pilot’s cavity blood and urine. The concentration of diphenhydramine in cavity blood was reported qualitatively, indicating a level below the laboratory reporting threshold. Given the potential for postmortem redistribution and contamination in cavity blood, it is unlikely that the pilot’s use of diphenhydramine contributed to the accident.

The takeoff described by the witness and video appeared consistent with entry into a low altitude aerodynamic stall. The distribution of the wreckage and relatively low energy signatures exhibited by the wreckage at the accident site were also consistent with an aerodynamic stall. Based on this information, it is likely that the pilot exceeded the airplane’s critical angle of attack during the initial climb, which resulted in an aerodynamic stall, loss of control, and impact with terrain.

Text from the NTSB. Open the NTSB docket for ERA22FA391 for the full record.