What happened
On 14 June 2009, a Jodel DR1051-M1 Sicile Record, registration G-BHTC, was conducting a private flight from Beccles, Suffolk, to Turweston Airfield, Northamptonshire. The flight proceeded without incident until the landing phase. The wind conditions were light and aligned with Runway 27, and the aircraft touched down on the centerline shortly after passing the threshold.
Once the main and tail wheels were in contact with the ground, the pilot utilized the hand-operated wheel brake lever. Upon application of the brakes, the aircraft began to swing toward the right. The pilot attempted to correct this with left rudder input, which caused a larger swing to the left, followed by a sharp swing to the right after applying corrective right rudder. These oscillations eventually caused the aircraft to veer off the right edge of the runway at approximately 10 knots, coming to rest in an adjacent crop field. The incident resulted in a broken propeller and slight damage to the right landing gear, with no injuries to the pilot or the two passengers on board.
The investigation
The investigation examined the braking mechanics of the aircraft and the pilot's observations regarding the aircraft's handling prior to the event. The aircraft features a hydraulic braking system controlled by a hand lever, which provides differential braking via the rudder pedals when the lever is pulled to approximately half-travel.
The pilot noted that while moving the aircraft by hand the previous evening, the left wheel appeared to rotate much more easily than the right, leading to a suspicion that the handbrake might have developed a bias toward the right wheel. However, because the brakes had been dismantled for repairs by the time this was reported, this specific bias could not be verified. The pilot also suggested that the use of the handbrake might have been unnecessary given the amount of runway remaining.