What happened
On 13 June 2022, a Casa 1-131E Series 1000, registration G-BUCK, was performing its third flight of the day at Turweston Aerodrome in Buckinghamshire. The aircraft, which had recently undergone an extensive restoration, was operating a private flight. During the taxi phase on the grass Runway 27, the pilot was navigating at approximately 30 kt. Due to the restricted forward visibility inherent to this aircraft type, the pilot was looking over the left side of the engine to maintain clearance from the left-hand runway edge markers.
While taxiing, the pilot noticed tall grass appearing on the right side of the aircraft. In an attempt to correct a drift toward the right edge of the runway, the pilot applied left rudder. Almost immediately, an impact occurred, followed by a loud bang. The aircraft's landing gear collapsed, causing the plane to come to an upright stop. The incident resulted in no injuries to the pilot, but the aircraft sustained damage to the propeller, the right lower wing, and the engine was shock-loaded.
The investigation
The investigation established that the right mainwheel had struck a stack of four traffic cones positioned at the northern edge of the grass runway. These cones sat at the boundary between the grass runway and the adjacent asphalt runway. The pilot noted that the accident could have been avoided if a plan had been implemented to keep the aircraft within one wingspan of the left-hand edge markers. The investigation also noted that the aerodrome operator's website contains instructions for pilots to stay within marked manoeuvring areas, suggesting potential hazards exist when operating outside these boundaries.