What happened
On 4 November 2020, an Aviad Zigolo MG12, registration G-CIUF, was conducting a private local flight departing from a farm airstrip near Rogate, West Sussex. The flight began normally, with the pilot reporting standard engine RPM and climb performance. However, upon reaching an altitude of approximately 900 ft AGL, the pilot noted fluctuations in engine speed accompanied by a flapping noise, indicating the onset of a propeller drive belt failure.
In an attempt to manage the situation, the pilot reduced the throttle, but the drive belt subsequently snapped. This led to an abrupt engine shutdown. The pilot attempted an approach to a grass field, but the glide profile deteriorated during the descent. The aircraft undershot the intended area and entered a narrow field, where it struck a willow bush. While the bush helped absorb the impact energy, the aircraft sustained damage to the fuselage tubes and the right mainwheel strut. The pilot sustained no injuries and was able to exit the aircraft unassisted.
The investigation
Investigators examined the aircraft following the impact and identified that the engine had seized. This seizure was attributed to the engine over-speeding following the initial failure of the propeller drive belt. Furthermore, the engine-driven belt pulley exhibited evidence of overheating, which was a result of the belt slipping prior to its complete failure.
As a single seat deregulated (SSDR) aircraft, G-CIUF was not subject to standard airworthiness regulations. The aircraft's maintenance manual specifies that the drive belt must be replaced every 100 hours. At the time of the accident, the failed belt had only been in service for 44 hours.