What happened
On June 14, 2019, a Cessna 208B Caravan, registration SP-WAW, operated by Aeroklub Warszawski, was performing a series of skydiving jumps at the EPNC landing field. During the sixth flight of the day, the aircraft was carrying a group of 15 skydivers.
Upon reaching an altitude of approximately 4,000 m AGL, the crew began preparations for deployment. Contrary to established procedures, 11 skydivers moved simultaneously toward the rear exit door. This sudden movement shifted the aircraft's center of gravity beyond the allowable aft limit, causing the aircraft to exceed critical angles of attack and enter a stall.
The aircraft performed an uncontrolled roll toward the left wing. During this maneuver, 9 skydivers were separated from the airframe. As the aircraft entered a steep descent, an additional 5 skydivers exited the aircraft. During this phase, two skydivers collided with the horizontal stabilizer, causing structural damage and jamming the elevator in a downward position. The pilot managed to regain control at approximately 1,000 m AGL and subsequently landed the aircraft safely.
The investigation
The PKBWL examined the aircraft's weight and balance records, flight logs, and video footage recorded by the skydivers. The investigation analyzed the distribution of passengers within the cabin before and during the jump sequence. The investigators also reviewed the operator's standard operating procedures and the specific instructions provided to the skydivers for that flight.
Findings
- The primary cause of the incident was the simultaneous movement of 11 skydivers to the rear of the aircraft, which shifted the center of gravity outside of the permissible aft limit.
- The shift in weight caused the aircraft to exceed critical angles of attack, leading to a loss of control in flight.
- The collision of two skydivers with the horizontal stabilizer resulted in the jamming of the elevator.
- The skydivers failed to maintain their assigned positions and failed to maintain separation between groups during the exit process.
- A change in the planned seating arrangement for this specific flight contributed to the instability.
- The aircraft was mechanically sound and all weight and balance calculations prior to the jump were within limits; the imbalance was created dynamically during the movement of the passengers.