Piper J3C-65 N88550 accident near Cynthiana, Kentucky

Probable cause

The pilot’s failure to maintain adequate airspeed and his exceedance of the airplane’s critical angle of attack, which resulted in an aerodynamic stall while maneuvering to land with approaching convective activity.

NTSB analysis

The pilot and his passenger departed the airport for a personal flight but shortly after takeoff, the pilot elected to return to the airport. Witnesses stated that a thunderstorm was coming in from the south. Meteorological data showed an approaching area of convection with tops at 45,000 ft. The pilot attempted to return to the airport and did not fly a standard airport traffic pattern; instead, he approached from the north, unusually low over the tree line, crossing midfield, then made a sharp left turn to join the downwind traffic, before turning left again to land. As the airplane crossed over the runway perpendicular to the runway numbers, it suddenly entered a left descending spiral and impacted terrain adjacent to the runway. The postaccident examination of the engine and airframe, combined with the examination of the impact site, revealed no anomalous findings that would have precluded normal airplane or engine performance. It is likely that shortly after the pilot took off, he witnessed the approaching convective activity and attempted to rush back to the airport to land before the storm arrived, as evident from his nonstandard approach to landing. About the time of the accident, witnesses described a rapid wind shift accompanied by an increase in wind speed and a rapidly decreasing temperature. Witness observations were consistent with experiencing convective outflow from the nearby convective activity and are validated by the weather radar and data that suggest the convective cell was decaying and nearby convection was forming; weather conditions were changing rapidly, and the winds were likely shifting. As the pilot performed the low and nonstandard approach, he likely turned steeply to the left after crossing over the runway numbers; exacerbated by a left quartering crosswind during his turn, he exceeded the airplane’s critical angle of attack and entered a subsequent aerodynamic stall and loss of control.

Text from the NTSB. Open the NTSB docket for ERA22FA354 for the full record.