Background
The T-6A Texan II, tail number 08-3915, was operated by the 80th Flying Training Wing, Euro-NATO Joint Jet Pilot Training, 89th Flying Training Squadron at Sheppard Air Force Base, Texas. The mishap instructor pilot (MIP) was a captain serving as a First Assignment Instructor Pilot. The mishap student pilot (MSP) was a first lieutenant international student pilot.
Sequence of Events
The mishap sortie was the second of the day for the MIP and the first for the MSP. After a formation flight and local maneuvers in a Military Operations Area, the mishap aircraft recovered to Sheppard single-ship and landed on runway 33R at 1342 local time. The MSP taxied clear of the runway and initiated the After Landing Checklist, which included steps for both pilots to install seat safety pins. The MIP failed to fully install the seat safety pin in the rear cockpit ejection seat.
During taxi, the MIP partially disconnected from the ejection seat system, including the parachute. At 1353 local time, the MIP inadvertently actuated the ejection handle and ejected. The MIP remained partially connected to the seat until automatic seat/pilot separation occurred 100 feet above ground. The MIP fell headfirst through an aircraft sunshade and landed 261 feet from the aircraft. The MIP sustained non-survivable injuries and died the next morning at a local hospital. The MSP did not eject and was uninjured. The aircraft sustained significant damage.
Investigation Findings
The Board President determined two causes of the mishap: (1) the MIP failed to fully install the rear cockpit ejection seat safety pin during the After Landing Checklist; and (2) the MIP partially disconnected from the ejection seat, allowing the harness chest strap V-ring to unknowingly get caught on and inadvertently actuate the ejection seat control handle.