What happened
On 24 May 2009, a CASA 1-131E Series 1000 Jungmann, registration G-JUNG, was conducting a series of private flights from Henstridge Airfield. Following several successful rotations, the pilot attempted a third flight with a new passenger. During the climb after departing Runway 07, the engine power decreased and eventually ceased.
The pilot maintained control and initiated a glide toward a field near Staunton Caundle. As the aircraft approached the landing site, it encountered a set of telegraph cables. The aircraft struck the wires, causing the plane to yaw sharply to the left and decelerate rapidly. The impact forced the aircraft into a nose-down attitude, striking the ground nose-first before flipping onto its back. The pilot sustained fatal injuries, while the passenger suffered serious injuries.
The investigation
The AAIB examined the wreckage and the engine components. Investigators found that the fuel tank was nearly empty, containing only 750 ml of fuel at the time of the crash. While the aircraft had been refuelled with 63 litres of Avgas earlier that day, the investigation looked into why the engine failed.
Testing of the engine revealed that the fuel pump was unable to produce sufficient pressure to maintain engine operation, likely due to internal wear on the rotating blades and the bush. Additionally, the engine exhibited low compression in several cylinders due to worn piston rings. The investigation also examined the impact with the telegraph cables, noting that the wires had been uprooted and the aircraft's structure was significantly distorted by the strike.
Findings
- The primary cause of the accident was the aircraft striking telegraph cables during an attempted forced landing following an engine failure.
- The engine-driven fuel pump was found to be defective, failing to deliver the required pressure to keep the engine running.
- The aircraft's engine had low compression in three of the four cylinders due to worn piston rings.
- The pilot's choice of landing field was appropriate in terms of terrain, but the presence of telegraph cables in the undershoot presented an unavoidable hazard during the descent.