What happened
Shortly after departing on a medical transport mission, the pilot of the aircraft type was climbing through approximately 14,900 feet MSL when they notified air traffic control of smoke entering the cockpit. The pilot indicated an intention to return to the departure airport and was cleared to descend to 9,000 feet MSL. During the return procedure, the pilot reported an impending loss of engine power and officially declared an emergency, requesting that emergency services be notified. The final radio communication from the crew occurred roughly 75 seconds after the initial smoke report, noting that there were 3 fatalities on board.
Search operations located the wreckage approximately nine hours later within a heavily forested and brush-filled area. The debris field spanned roughly 2,400 feet, with fragmented and burned components distributed along the path, a pattern indicative of an in-flight breakup. While the cockpit and center fuselage remained largely intact without direct fire damage, the forward fuselage showed significant thermal damage. This damage was concentrated on the floor area between the two forward seats, specifically near the main bus tie circuit breaker panel and extending to the forward wing spar edge. Evidence of soot, localized melting, and thermal tearing of the aluminum structure was present throughout the area.
Findings
Investigation of the wreckage revealed that the floor panels beneath the pilot and co-pilot seats showed discolored primer, and an aluminum stringer exhibited broomstrawing, indicating it had reached near-melting temperatures. Investigators identified electrical arcing damage on wiring near the main bus tie circuit breakers, where some breakers were missing or heavily sooted. Additionally, four hydraulic lines for the landing gear system showed signs of thermal exposure, including melting and material loss.
An examination of six similar aircraft type models revealed a recurring unsafe condition where electrical and hydraulic lines were in direct contact. In these exemplar aircraft, wires showed signs of chafing against hydraulic lines. It was determined that electrical arcing caused by a wire chafing against a hydraulic line or structure initiated an in-flight fire, which was then fueled by leaking hydraulic fluid.