What happened
On 3 September 2000, a CEA DR400/2+2, registration G-BAGS, departed from Draycott Farm airstrip for a private photographic flight. The pilot and one passenger were flying over their local village at approximately 1,500 feet when the pilot initiated a left turn to reposition the aircraft. Upon attempting to level the wings following the turn, the pilot discovered that the control column would not move past the central position. Despite applying increased physical force, the restriction remained, and the pilot was unable to roll the aircraft level.
After declaring a Mayday to Lyneham ATC, the pilot searched for a suitable landing site. The pilot identified a large field to the west and began a descent on a northerly heading. During the final approach, the pilot shut off the fuel and master switch and deployed full flaps. Although the rudder provided some degree of control, the column remained stuck. The aircraft touched down with the left wing low while drifting to the right, causing the nose landing gear to shear off and bringing the aircraft to a sudden stop. There were no injuries to the two occupants.
The investigation
Following the accident, the aircraft was recovered to a nearby farm. While the ailerons appeared to function normally during initial inspection, investigators identified evidence of fouling between a bolt connecting the right-hand aileron horn to its operating rod and a glassfibre shroud on the wing. This contact occurred when the aileron was in a near-neutral position, which restricted upward movement.
Investigators noted that the rear of the shroud was only partially secured because a portion of the flange had broken off under a screw head. However, a member of the recovery team admitted to causing this specific damage while inspecting the controls after the accident. Consequently, it was determined that the primary cause of the restriction was likely an in-flight contact between the bolt and the shroud that left little visible damage to the shroud itself.
Findings
- The control column restriction was caused by mechanical interference between the aileron operating rod bolt and the wing shroud.
- The pilot's pre-flight checks did not detect the issue, as the aileron controls moved freely during the 'full-and-free' inspection.
- The aircraft had undergone a 50-hour inspection approximately 30 flying hours prior to the event, but no recent maintenance had been performed on the aileron system since that time.