What happened
On 21 October 2018, a Pitts S-1S aircraft, registration G-MAVK, was conducting a private flight from Turweston to Sywell. Shortly after departing Turweston at full power, the pilot throttled back to cruise speed. During the climb, the engine began to lose power. Despite attempts to restore power by advancing the throttle and cycling the mixture control, the engine ceased operation.
The pilot identified a suitable field for an emergency landing north-west of Towcester. However, the available runway length was insufficient to complete the maneuver, causing the aircraft to strike a hedge at the end of the field. The impact resulted in damaged wings, but the pilot escaped the wreckage with no injuries.
The investigation
The investigation focused on the cause of the engine failure and the circumstances surrounding fuel management. Prior to departure, the pilot had used a sight-level fuel gauge to estimate the fuel level at approximately half full, which was deemed sufficient for the short flight. However, the engine stopped only eight minutes after takeoff. Post-accident analysis revealed that no fuel remained in the tank, suggesting that the actual quantity at departure was significantly lower than estimated, or consumption was higher than expected.
Investigators noted that the aircraft had recently undergone an instrument panel installation, which left the sight-level fuel gauge without any quantity markings. Furthermore, while the pilot had completed aerobatic training on this type, the investigation found that no structured type-conversion training had been undertaken. During the examination of the aircraft, a loose fuel pipe union was discovered on the carburettor, though it could not be confirmed if this was a pre-existing issue or caused by the impact.
Findings
- The primary cause of the engine failure was fuel exhaustion.
- The absence of markings on the fuel gauge prevented the pilot from accurately monitoring the remaining fuel quantity.
- The aircraft's pitch attitude on a tailwheel design affects sight-gauge readings, making dual-calibration markings essential for accuracy.
- The pilot's lack of structured type-conversion training contributed to the unsuccessful completion of the forced landing.