What happened
On 24 April 2004, a private flight involving a Stolp SA-30 and Starduster TOO, registration G-KEEN, resulted in a serious incident near Quigleys Point, Co. Donegal. The pilot was conducting aerobatic training, specifically focusing on roll maneuvers, in the area of Lough Foyle. The flight originated from Eglinton Airport, Derry, with the pilot operating from the rear seat and a passenger in the front.
Following a successful practice stall, the pilot attempted a climbing maneuver that transitioned into a vertical ascent. During an attempt to execute what was intended to be a stall turn, the aircraft entered an unintended spin. The loss of altitude during the recovery process led the aircraft to strike three-phase 10,000-volt overhead electricity lines. While the crew escaped without injury, the impact caused significant damage to the aircraft and disrupted the local power supply for hundreds of customers.
The investigation
The investigation examined the flight sequence, the aircraft's airworthiness documentation, and the pilot's credentials. Investigators found that the aircraft sustained substantial damage, including torn wing fabric, a punctured lower wing, and a damaged propeller. The strike also caused extensive damage to the electrical infrastructure, requiring the replacement of 150 meters of conductor.
Regarding documentation, the investigation revealed that G-KEEN was being operated in violation of its UK CAA Permit to Fly. Specifically, the permit required that aerobatic maneuvers be performed solo from the rear cockpit with the upper tank empty; however, the aircraft was carrying a passenger. Additionally, the pilot's JAA Class 2 Medical certification had expired prior to the flight.
Findings
- The primary cause of the incident was poor pilot judgment regarding altitude management, specifically failing to ensure maneuvers were completed by 3,000 feet AGL.
- The pilot inadvertently applied control inputs that promoted a spin rather than a controlled stall turn.
- The aircraft was operated in breach of its Permit to Fly conditions regarding passenger occupancy during aerobatics.
- The pilot was flying with an expired medical certificate.
- There was no evidence of mechanical failure or adverse weather contributing to the event.