What happened
On 18 October 2020, a Rans S6-ES Coyote, registration G-CCJN, was conducting a permit renewal check flight near Insch airfield, Aberdeenshire. The aircraft was carrying two occupants during a private flight. Following an extended engine warm-up and power check on the ground, the flight proceeded normally until the aircraft reached approximately 180 ft altitude. At this point, the engine stopped abruptly.
Unable to locate a suitable landing site directly ahead, the pilot initiated a 180-degree turn to find an alternative location. During the descent, the pilot identified a field and prepared for a forced landing. Upon touchdown, the nosewheel struck waterlogged ground, causing the nose landing gear to collapse. There were no injuries to the two people on board, though the aircraft sustained damage to the engine cowling, the right landing gear leg, and the nose gear.
The investigation
The investigation focused on the cause of the sudden engine failure and the fuel system configuration. The aircraft had recently undergone maintenance, including the replacement of fuel lines and the fuel filter, following advice from an inspector.
During the recovery of the aircraft, the owner drained the fuel tanks and observed that fuel would not flow from the left tank when the aircraft was in a nose-high attitude, despite fuel being visible. Subsequent inspection of the fuel lines revealed a small sliver of material lodged within the pipe connecting the left tank outlet to the fuel selector valve. This obstruction prevented consistent fuel delivery during the flight.
Findings
- The engine failure was caused by a piece of material obstructing the fuel line between the left fuel tank and the selector valve.
- The aircraft's nose gear collapsed because the landing site consisted of waterlogged soil.
- While a ground power check was performed, a more comprehensive fuel flow assessment, such as those outlined in LAA technical guidance, might have detected the restriction before takeoff.