What happened
On 6 December 1998, a Beech M35, registration G-ATSR, was conducting a private flight when the pilot encountered a significant loss of engine power. After taking off and climbing to 3,000 feet, the aircraft was established in cruise with the right main fuel tank selected. As the pilot approached the destination airfield and leveled off at approximately 1,800 feet to avoid another aircraft in the circuit, a lack of power became apparent upon increasing the throttle.
In an attempt to restore power, the pilot transitioned the fuel selection from the right main tank to the left main tank. When this failed to improve engine performance, the pilot attempted to engage the auxiliary tanks. This process required moving the main fuel selector to the AUX position and then engaging the auxiliary tanks by feeling for a specific detent. Despite verifying that the engine controls and fuel selections appeared correct, the engine power did not recover. Realizing the destination airfield was likely unreachable, the pilot performed a forced landing in a field near Kingsland Church, Hereford & Worcester. While the landing was successful, the aircraft sustained substantial damage to the nose landing gear.
There were no injuries to the pilot or the single passenger on board.
The investigation
The investigation examined the pilot's fuel management procedures and the mechanical operation of the fuel selector. The pilot noted that the procedure for switching from main to auxiliary tanks was complex and potentially distracting. Furthermore, the investigation looked into the physical feedback of the fuel selector mechanism.
Findings
- The pilot failed to select the tank containing the highest fuel volume during the cruise phase.
- The pilot did not activate the electric fuel booster pump when transitioning between fuel tanks.
- The fuel selector detent was not sufficiently positive, making it difficult to confirm the correct position when switching to auxiliary tanks.
- The complexity of the fuel selection process contributed to the error during the emergency.