What happened
On 26 August 2003, a Jabiru UL-45 and registration G-LEEE was conducting a private flight from Herring's Farm to Old Sarum. Approximately 50 minutes into the flight, while cruising at 1,900 feet, the engine experienced a loss of power. The pilot attempted to rectify the issue by activating the fuel pump and applying carburettor heat, but the engine failed completely.
The pilot performed a forced landing in a field at Lockerley Farm. During the touchdown, the aircraft landed in a tail-down attitude with full flaps. As the nose wheel contacted the hard ground, a cracking sound was heard, and the aircraft's pitch continued to decrease. Upon exiting the aircraft, the pilot discovered that the nose landing gear had detached. The incident resulted in no injuries, though the aircraft sustained damage to the engine firewall and the nose landing gear.
The investigation
The investigation focused on the discrepancy between the fuel levels reported by the pilot and the actual fuel remaining at the time of the engine failure. Before departure, the pilot had visually checked the fuel level using an engraved rule, which indicated 20 litres remained. This was manually entered into the on-board fuel computer, which subsequently displayed 12.3 litres of fuel remaining at the time of the failure.
However, a post-landing inspection revealed that the fuel tank was empty, despite some fuel being present in the fuel drain. The investigation examined the aircraft's fuel system, noting that the sight gauge was not permanently fitted to the tank, preventing in-flight visual checks. The investigation also reviewed the fuel computer's functionality, noting that while it accurately tracks fuel flow, its remaining fuel calculation is entirely dependent on the accuracy of the pilot's manual input at the start of the flight.
Findings
- The engine failure was caused by fuel exhaustion.
- There was a significant discrepancy between the pilot's perceived fuel quantity and the actual amount in the tank.
- The on-board fuel computer's accuracy regarding remaining fuel was compromised by the reliance on manual pre-flight input.
- The lack of a permanently fitted sight gauge prevented the pilot from verifying fuel levels during the flight.