History of the Flight
The pilot was flying a cross-country route and was conducting an overhead join to Leicester Airport. While adjusting the throttle to reduce speed, the engine speed dropped disproportionately to idle. The pilot immediately set best glide speed, checked fuel system settings and tank quantity, finding them satisfactory. Subsequent throttle movements produced no response from the engine, and the pilot noted that the throttle handle felt stiff and notchy. The pilot declared a PAN to Leicester air-to-ground radio, selected a suitable field, and executed a forced landing. During the landing roll, the nose landing gear collapsed, resulting in damage to the propeller and front fuselage underside. The pilot and three passengers evacuated the aircraft uninjured.
Engineering Examination
Post-accident examination of the aircraft revealed a slight stiffness in the throttle mechanism. This stiffness caused a restriction of the throttle cable when it was advanced towards the half-throttle setting at the carburettor throttle arm. The stiffness and its effect on the throttle cable were identified as the most likely cause of the power loss.
Conclusion
The forced landing was necessitated by a loss of engine power attributable to a throttle cable restriction. The aircraft sustained damage to the nose landing gear, propeller, and underside of the front fuselage, but all occupants were uninjured.