What happened
On 11 February 2004, a Jodel D117A, registration G-BIOU, was conducting a private flight from Compton Abbas to a landing strip located at Shrove Furlong Farm, near Princess Risborough. The weather conditions featured light winds originating from the north.
Upon landing on the strip in a westerly direction, the pilot successfully brought all wheels into contact with the ground. However, shortly after touchdown, the aircraft began to drift toward the left. The pilot attempted to counteract this movement by applying right rudder, which initially corrected the drift. The aircraft subsequently drifted left again, and despite the application of full right rudder, the aircraft struck a boundary fence. At the time of impact, the pilot estimated the speed to be between 1s5 and 20 kt. The aircraft came to rest in a north-westerly orientation.
There were two persons on board, consisting of the pilot and one passenger. The pilot sustained no injuries, while the passenger suffered one minor injury. The impact resulted in damage to both wings, the propeller, and a partial collapse of the undercarriage.
The investigation
The investigation was based on an accident report submitted by the pilot. During the post-incident assessment, the pilot initially suspected that a dragging left wheel might have been responsible for the directional drift. However, upon recovery of the aircraft, the left wheel was found to be rotating freely.
While the pilot had extensive flying experience, including over 17,000 total hours and 15 years of experience with this specific aircraft, the cause of the lateral drift could not be determined. The pilot had been utilizing the Shrove Furlong Farm landing strip for more than a decade.