Air Accidents Investigation Branch
Summary:
While performing an aerobatic wing walking display over the sea at Bournemouth AirFestival, the aircraft experienced a reduction in engine power. The pilot stopped thedisplay routine and flew the aircraft west, along the coast, with the intention of returning toBournemouth Airport. The wing walker returned to her seat in the front cockpit. Althoughthe aircraft was initially able to maintain height, the engine subsequently experienceda complete loss of power and the pilot ditched in the entrance to Poole Harbour. Theaircraft flipped over on contact with the water, but both occupants were able to exit theaircraft unaided.
The investigation determined that during the display the engine suffered a loss of enginepower due to failure of the oil inlet pipe, most likely due to fatigue, which prevented oilbeing supplied to the engine. This was precipitated by a fatigue failure of the metal strapwhich supported the weight of the oil inlet pipe. The fatigue failure initiated at an area ofmechanical damage on the surface of the support strap, which had been caused by overtighteningof the retaining nut.