NTSB Factual Report

The pilot reported that he had full flaps extended during a low fly-by for the ground crew to inspect the banner. After the pass the pilot did not retract the flaps. During the climb, the airspeed deteriorated and the airplane stalled and impacted wires and a hillside. During the accident sequence, the right wing separated from the fuselage. The pilot reported no preimpact mechanical malfunctions or failures with the airplane that would have precluded normal operation.

NTSB Probable Cause

The pilot did not maintain adequate airspeed which resulted in an inadvertent stall and loss of aircraft control. Contributing to the accident was the pilot's improper use of flaps.