Piper PA-18-135 N7199K accident near Compton, California

Probable cause

An overstress fracture of the pilot’s seat, which resulted in the loss of control during takeoff and the pilot’s inadvertent movement of the fuel selector and subsequent partial loss of engine power.

NTSB analysis

The banner tow flight was in the initial climb after the pilot snagged the banner when the back of the pilot’s seat broke and the pilot inadvertently pulled back on the control yoke as he abruptly slid aft to a horizontal position. The airplane pitched up in a nose-high attitude, causing the pilot to further slide aft. The airplane was about 200 ft above ground level (agl) and at the onset of an aerodynamic stall. Using a crossbeam to pull himself forward, the pilot was able to push the flight control stick forward and recover the airplane. The airplane’s engine then began to “cough” and it sustained a partial loss of power. Unable to maintain altitude, the pilot made a forced landing to a nearby baseball field. The airplane impacted a fence along a concrete wash resulting in substantial damage.

Postaccident examination of the pilot’s seat fracture surface revealed characteristics consistent with an overstress fracture. Examination of the engine revealed no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation. The pilot reported that when he slid aft, the fuel selector lever may have inadvertently been moved out of the “both/on” position, resulting in the partial loss of engine power.

Text from the NTSB. Open the NTSB docket for WPR23LA336 for the full record.