What happened
On August 1, 2024, a Cessna 208 operated by École de Parachutisme Sportif de Vannes Bretagne was performing a parachute drop flight near Vannes. During the climb, at an altitude of approximately 450 m, a skydiver sitting next to the aircraft door had partially opened the door by about ten centimeters to provide ventilation due to high cabin temperatures.
While the skydiver instructor was performing equipment checks on students, the skydiver positioned near the door moved his chest to allow more room. This movement caused the parachute's leather pilot chute handle to be squashed between the aircraft floor and the parachute, likely dislodging it from its housing. The airflow from the partially open door then caught the pilot chute, pulling it outside the aircraft and initiating the deployment of the main canopy.
The force of the deploying canopy pulled the skydiver toward the rear of the cabin and through the vertical sliding door slats. During the process, the right-hand riser caught on the door frame, causing the 3-ring system to sever and triggering the deployment of the reserve canopy. The skydiver sustained a fractured tibia and spinal injuries upon landing, though he managed to pilot the reserve canopy to the ground. The pilot, noting unusual vibrations and noise, returned the aircraft to the aerodrome.
The investigation
The BEA examined the aircraft, the parachute equipment, and witness statements from the pilot, the instructor, and other skydivers. The investigation focused on the sequence of events leading to the accidental deployment and the physical damage to the Cessna 208 and the parachute system. Investigators also reviewed the skydiving school's safety procedures and risk management protocols regarding door operation during flight.
Findings
- The primary cause was the untimely deployment of the main canopy caused by the pilot chute being partially pulled from its housing by external airflow.
- The movement of the skydiver's chest during equipment checks, combined with the door being open, allowed the pilot chute to be caught by the wind.
- The aircraft sustained damage to the door slats, the door jamb, and the left-hand horizontal stabilizer.
- The parachute's 3-ring system was severed when the riser snagged on the airframe.
- The risk of a parachute deploying accidentally while the door is partially open during the climb phase had not been previously identified in the school's risk assessments.
Safety action
Following the accident, the skydiving center has prohibited the opening or partial opening of the aircraft door during flight outside of the actual parachute drop phases. The school's Pilot Checklist (NCO.SPEC. PAR.100) has been updated to reflect this new safety measure.