What happened
On 13 June 2019, a Bristell NG5 aircraft, registration G-OJCS, was involved in a fatal accident near Belan, Co. Kildare. The aircraft was being operated as part of a general aviation flight with two crew members on board. During the flight, the aircraft entered a state of uncontrolled flight that led to a high-impact crash. The impact resulted in the destruction of the aircraft and the fatal deaths of both the pilot in the left seat and the pilot in the right seat.
The investigation
The AAIU investigation examined the aircraft's technical specifications, maintenance history, and the flight path data recorded by onboard systems and tablet-based navigation applications. Investigators analyzed the wreckage and performed a detailed study of the aircraft's weight and balance configuration. A significant portion of the investigation focused on the aircraft's aerodynamic stability, specifically looking at stall speeds, spin testing, and the effects of propeller rotation. The inquiry also reviewed the manufacturer's documentation regarding the aircraft's center of gravity and moment arms.
Findings
- The aircraft was operating in a configuration that contributed to its aerodynamic instability.
- A critical factor in the accident was an error in the weight and balance calculation, specifically regarding the incorrect moment arm used for the pilot and passenger positions.
- The investigation identified that the documentation used for calculating the aircraft's center of gravity contained inaccuracies regarding the position of occupants on the seat cushions.
- The aircraft's flight path was characterized by maneuvers that led to the loss of control.