The Air Accidents Investigation Branch (AAIB) has completed its report into the ditching of an aircraft after it lost power during a display at the Bournemouth Air Festival on 4 September 2021.

The Boeing A75N1 (PT17) Stearman experienced a reduction in engine power mid-way through an aerobatic wing walking display. The pilot stopped the routine and flew west, while the wing walker returned to her seat in the front cockpit.

The engine then experienced a complete loss of power and the pilot ditched in the entrance of Poole Harbour, just off Sandbanks. The aircraft flipped over on contact with the water, but both the pilot and the wing walker were able to get out of the aircraft unaided.

The investigation found that the loss of engine power was due to a failure of the oil inlet pipe, most likely due to fatigue, which prevented oil being supplied to the engine. This was precipitated by a fatigue failure of the metal strap that supported the weight of the oil inlet pipe. The fatigue failure was initiated at an area of mechanical damage on the surface of the support strap, which had been caused by over-tightening of the retaining nut.

Following this accident, the operator introduced additional hand signals to enable the wing walker to inform the pilot of any oil or fuel leaks and for the pilot to inform the walker that he intended to ditch.