What happened
On 20 August 2006, a Reims Cessna F1t2N Skyhawk, registration G-DENR, was conducting a private VFR flight from Bournemouth to Truro. Prior to departure, the aircraft's fuel tanks had been refilled, with the right tank filled to capacity and the left tank left two gallons short of full. Following the owner's instructions, the pilot departed with the fuel selector set to the LEFT position.
During the flight, the pilot performed routine checks and transitioned the fuel selector to the BOTH position over Dorchester. However, while climbing through 2,800 ft amsl approximately 15 nm south-west of Exmouth, the engine began to run roughly before eventually stopping. The pilot executed engine failure procedures and declared an emergency.
Due to the undulating terrain of the Dartmoor area, the pilot had limited options for a landing site. During the forced landing attempt, the aircraft's elevator struck a tree line, and the left wing tip contacted the ground before the aircraft settled heavily on a downslope. All three occupants (one crew and two passengers) vacated the aircraft uninjured, though the aircraft sustained severe damage to the engine cowling, firewall, wing, and tail surfaces, rendering it beyond economic repair.
The investigation
The AAIB examined the circumstances surrounding the engine loss, considering both mechanical and human factors. Investigators looked into the possibility of carburettor icing, noting that the meteorological conditions—characterized by high humidity and proximity to cloud base—were conducive to icing. However, the pilot had applied carburettor heat prior to the failure with no immediate change in engine performance, and the pilot's previous checks suggested icing was unlikely.
Furthermore, the investigation considered the possibility of a fuel selection error. The pilot noted that while he could not definitively recall his specific cockpit actions during the emergency, he acknowledged the possibility that he might have inadvertently moved the fuel selector from BOTH to the OFF position. Because the aircraft was not inspected for mechanical failure due to the extent of the damage, the investigation could not rule out other unidentified engine issues.
Findings
- The engine failure may have been caused by an incorrect fuel selector position being moved to OFF.
- Alternatively, the failure could have been attributed to carburettor icing, though this was less likely given the pilot's actions.
- The heavy landing was exacerbated by the aircraft striking a tree line and contacting the ground on a downslope.