What happened
On 5 June 2016, a Silence Twister, registration G-TWSS, was being prepared for a private flight at Wing Farm Airstrip near Warminster, Wiltshire. During the process of attempting to start the Jabiru 220 as piston engine, smoke was observed emerging from the engine cowling after approximately five seconds of engine cranking.
In response to the smoke, the pilot immediately deactivated the fuel supply and the fuel pump while maintaining the cranking action. The pilot then shut down the electrical systems and retrieved a fire extinguisher from a nearby hangar. Upon returning to the aircraft roughly 20 seconds later, the pilot successfully suppressed the fire.
The investigation
Following the incident, the aircraft sustained fire damage specifically to the engine and the engine bay. The investigation focused on the mechanical failure that allowed the fire to ignite during the start sequence. Technical examination of the fuel system revealed that the fire was caused by a sticking float within the carburettor.