What happened
On 8 October 2008, a Thruster TST MK1, registration G-MVBT, departed from Chirk Airstrip in Clwyd under light easterly winds. Shortly after takeoff, while at an altitude of approximately 200 ft, the engine began to lose power. During this period, the pilot observed that the fuel pressure gauge had dropped to a very low level.
In an attempt to return to the airfield, the pilot initiated a 180-degree turn. However, the engine ceased functioning entirely as the maneuver was being completed. Realizing the aircraft would not reach the runway and was heading toward the A483 road, the pilot maneuvered the aircraft away from the carriageway. The aircraft subsequently struck a mound of earth short of the road, resulting in the destruction of the aircraft. The pilot, who was wearing a full harness, sustained a serious injury consisting of a fractured spine but was expected to recover.
The investigation
Investigators examined the aircraft's fuel system, which utilizes a pre-filter, a glass filter, a regulator, and two parallel automotive electronic fuel pumps. While the pumps and regulator were functionally tested and found to be operating correctly, the components were not available for physical inspection. The investigation also noted that during a previous flight, a surging issue had been resolved by activating the booster pump.
Findings
- The engine lost power at a low altitude of 200 ft agl.
- The pilot observed a significant drop in fuel pressure prior to total engine failure.
- A fuel system issue, such as contamination or a blockage, was the most likely cause of the power loss, although this could not be confirmed with certainty.
- The pilot's decision to attempt a return to the airstrip was influenced by the gradual nature of the power loss.