What happened
On 27 July 2018, a Pilatus PC6, registration F-GOCC, was conducting a parachute drop mission at the Bouloc aerodrome in France. The aircraft, operated by the Midi-Pyrénées Parachuting School, was carrying ten passengers, including two wingsuiters who were scheduled to exit the aircraft last.
After the first seven passengers had exited, the two wingsuiters jumped from an altitude of approximately 4,400 m. Following the exit of the second wingsuiter, the pilot initiated a steep descent at a speed of approximately 100 kt. Eleven seconds after the first wingsuiter exited the aircraft, the plane collided with the flyer at an altitude of about 13,400 ft. The impact caused damage to the aircraft's left wing shroud and left flap, but the pilot was able to land the plane safely. The wingsuiter sustained one fatality upon impact.
The investigation
The investigation utilized data from the aircraft's GNSS receiver, the second wingsuiter's helmet-mounted HD camera, and the deceased's VIGIL system. Investigators analyzed the flight paths of both the aircraft and the wingsuiters, noting that the aircraft's vertical descent rate was extremely high, ranging between 5,800 and 6,700 ft/min during the period in question.
Technical analysis of wingsuit flight dynamics revealed that during the initial 15 seconds after exit, a wingsuiter is in an acceleration phase, converting vertical speed to horizontal speed. During this window, the flyer's ability to detect or avoid an aircraft approaching from behind and above is significantly limited. The investigation also reviewed the briefing procedures used by the parachuting school and the French Parachuting Federation (FFP).
Findings
Several contributing factors were identified in the collision:
- The pilot initiated an immediate steep descent without maintaining visual contact with the wingsuiters.
- There was a lack of a formal onboard briefing between the pilot and the wingsuiters to coordinate separation.
- The FFP's existing safety assessments had not adequately identified the specific risk of path intersection between aircraft and wingsuiters immediately following the exit.
- The flight paths of the aircraft and the wingsuiters were inherently conflicting during the first few seconds of the jump.