What happened
On 20 November 2000, a Tipsy Nipper T 66 Series 2, registration G-ARDY, was being prepared for flight at RAF Brize Norton, Oxfordshire. The aircraft, which is powered by a single Martlet VW piston engine, requires the propeller to be hand-swung to initiate the engine start sequence. During a private flight operation, the pilot attempted to start the engine while the aircraft was stationary on a grassed area with the brakes applied.
After several unsuccessful attempts where the engine would fire briefly before stalling, the pilot increased the throttle setting and tried again. Upon this successful start, the aircraft began to move forward. In an effort to stop the advancing aircraft, the pilot attempted to reach the throttle but lost their footing, slipping and falling. The aircraft continued to move across a concrete area before eventually coming to a halt against a fabric-covered hangar.
The investigation
Investigators examined the sequence of events following the engine start. The investigation established that the aircraft was positioned on grass with the parking brakes engaged at the time of the incident. The pilot, holding an FAA Private Pilot's Licence with 70 total flying hours, had reported the details via an Aircraft Accident Report Form. The investigation focused on the transition from the engine firing to the unintended forward motion and the pilot's subsequent physical reaction.