What happened
On 27 April 2015, a Rans S10 Sakota, registration G-BRPT, was conducting a short local flight near Henstrately Airfield, Somerset. While descending from approximately 2,000 ft AGL to establish a wide left base leg for Runway 25, the engine began running erratically. At an altitude of roughly 1,500 ft, the engine ceased operation entirely.
The pilot attempted to glide toward the airfield but determined the runway was unreachable. Consequently, a field was selected for a forced landing. During the approach to the field, the aircraft's main wheel struck a protruding hedge branch. This impact caused the aircraft to yaw and subsequently ground loop upon touchdown, resulting in damage to both main landing gear legs and minor scrapes to the fuselage. The pilot sustained no injuries and exited the aircraft without incident.
The investigation
Investigators examined the aircraft's fuel system following the accident. While the pilot had observed fuel moving in both wing tanks during the descent, a post-accident inspection revealed that the gascolator was empty. Furthermore, while the forward carburettor float chamber contained fuel, the rear chamber was empty.
Because the aircraft lacks a collector tank or an electric fuel pump, the investigation focused on the possibility of fuel starvation. The inspection confirmed that fuel was present in the tanks and the lines leading to the primer, but the lack of fuel in the rear float chamber and gascolator suggested a disruption in the fuel supply.
Findings
- The engine failure was likely caused by fuel starvation.
- Low fuel levels in the wing tanks may have allowed the fuel ports, located toward the rear of the tanks, to become uncovered during the preceding steep turns or the descent.
- The absence of a collector tank or electric pump may have allowed an airlock to form, preventing consistent fuel flow to the engine.