Incident Overview
During a Part 91 skydiving flight, a tailwheel-equipped turboprop airplane carrying an airline transport certificated pilot and 10 skydiving passengers initiated a takeoff. As the airplane began its climb, the nose pitch increased until the aircraft appeared to stall at an altitude between 50 and 100 feet above ground level. The airplane then descended and impacted the runway in a left wing, nose-low attitude.
Post-Accident Inspection
Federal Aviation Administration (FAA) inspectors who responded to the accident site documented the scene and examined the airplane's systems. They established flight control continuity and observed that the horizontal stabilizer was positioned in a nose-up trim setting. Measurement determined that the stabilizer trim was set at 56.5 percent of the nose-up range. The airplane's horizontal stabilizer trim system is electrically operated. An electric trim indicator and a trim warning light were installed on the upper left portion of the instrument panel. The warning light is designed to illuminate when the stabilizer is in the full-up trim position and the engine is producing more than 80 percent power.
Placards and Manual Guidance
A placard reading "Set Correct Trim for Takeoff" was affixed to the lower instrument panel directly in front of the pilot. The airplane's flight manual contains a "Before Takeoff" warning that states: "Warning - An extreme out-of-trim stabilizer can, in combination with loading, flaps position and power influence, result in an uncontrollable aircraft after the aircraft leaves the ground." Additionally, a caution in the manual states: "Caution - Failure to set correct trim settings will result in large control forces and/or unrequested pitching/yawing." The "Before Takeoff" checklist includes pilot actions for stabilizer trim settings.
Occupant Restraints
The airplane was equipped with seat belts for all passengers. However, the pilot's shoulder harness was not used; it was found folded and secured with a tie-wrap near its upper attachment point.
Probable Cause and Contributing Factors
According to the official findings, the probable cause of the accident was the pilot's incorrect setting of the stabilizer trim and his failure to maintain adequate airspeed during the takeoff initial climb, which resulted in a stall. A contributing factor to the accident was an inadvertent stall. A factor contributing to the severity of the pilot's injuries was his failure to utilize his shoulder harness.