What happened
On the day of the accident, a Piper PA-25-235 departed from Smith Center Municipal Airport using runway 35. During the initial climb, the pilot retracted a notch of flaps, which caused the tail to sink and the aircraft to exhibit poor performance, feeling as though it were on the edge of a stall. Despite the engine operating at 2,700 rpm with full throttle and mixture, the pilot continued the flight toward a pasture to begin chemical spraying operations, intending to reduce the aircraft's weight through spraying.
The aircraft was carrying an almost full load of chemicals, bringing its gross weight to approximately 2,993 pounds, which exceeded the maximum takeoff weight of 2,900 pounds. While performing spraying passes at approximately 20 feet above the ground, the pilot attempted a wide right turn but found the airplane could not maintain altitude. After a second pass, the pilot executed a wide left turn toward the southwest to return to the airport. During this maneuver, the aircraft descended to approximately 40 feet agl.
As the pilot attempted to climb approximately three-quarters of a mile before reaching power lines, the airplane entered a stall. The pilot leveled the wings and prepared for impact. The aircraft struck the ground flat and slid approximately 100 feet before hitting a pasture fence. There were no injuries reported.
The investigation
An examination of the aircraft revealed no mechanical anomalies. Investigators determined the density altitude at the time of the accident was 2,489 feet. While the aircraft's gross weight was approximately 2,993 pounds, investigators noted that per the Civil Aeronautics Manual (CAM) 8, establishing a maximum weight for an agricultural aircraft is not required.