What happened
On 26 September 1999, a DH82A Tiger Moth, registration G-AOES, was performing a private flight at Charity Farm Airstrip in Baxterley, Warwickshire. The pilot was operating the aircraft from the rear cockpit, leaving the front seat vacant. During the flight, the pilot performed several aerobatic maneuvers, including loops and barrel rolls.
As the pilot attempted to level the aircraft following a descent, the flight controls suddenly became jammed. At this moment, the aircraft was flying just above the height of the trees. The pilot managed to alert another aircraft in the vicinity before the aircraft struck the ground near a hedge and ditch. The pilot sustained serious injuries, including a cracked vertebra and internal bruising.
The investigation
The investigation focused on the cause of the control jam and the survivability of the impact. Investigators found that the front control column had been previously removed to allow for parachutist egress, leaving a protruding stub fitting. The investigation established that the front harness's quick release fitting (QRF) had become lodged in the gap between this stub fitting and the edge of the control compartment's plywood decking.
Regarding the injuries sustained, the investigation examined the aircraft's 'Z type' harnesses. While the harness itself remained intact, the transverse cable to which the shoulder straps were attached failed due to the force of the impact. This failure caused the pilot's head to strike the instrument panel.
Findings
- The primary cause of the accident was the jamming of the flight controls caused by the harness quick release fitting falling into the aperture of the control column compartment.
- The front cockpit's control column and protective leather gaiter had been partially removed, creating an opening for loose objects to enter the mechanism.
- The pilot's injuries were exacerbated by the failure of the shoulder strap attachment cable under impact loads.
- The existing transverse cable strength was insufficient to prevent the pilot's head from striking the instrument panel during the crash.