Incident Overview
A scheduled air taxi flight with five passengers experienced an in-flight electrical issue shortly after departure. The pilot detected an electrical burning odor and promptly decided to return to the departure airport. Approximately one minute later, the smell intensified, and visible smoke entered the cockpit. The pilot declared an emergency to the tower and landed the aircraft.
Post-Landing Fire
After landing, all passengers safely exited the aircraft. Shortly thereafter, heavy smoke filled both the cockpit and passenger compartment. The pilot observed a candle-like flame located just behind the pilot and co-pilot seats, beneath the floorboards. Moments later, the entire aircraft was engulfed in flames.
Investigation Findings
A post-accident examination of the airframe revealed that the fire originated behind the pilot’s row of seats. Investigators found a wire harness improperly installed on top of the aft fuel line from the left fuel tank. Examination of the wire harness showed a range of thermal and electrical damage consistent with chafing caused by contact with the fuel line. The improper installation allowed the wire harness to rub against the fuel line, leading to chafing, electrical arcing, and the subsequent fire.