What happened
On 30 June 2014, a Europa XS, registration G-FIZY, was conducting a local flight from Thruxton Aerodrome to perform an air test required for the revalidation of its Permit to Fly. While cruising at approximately 950 ft amsl and a speed of 110 kt, the left door of the aircraft suddenly detached. Following the event, the pilot verified that flight controls remained functional and proceeded to return to Thruptom, where the aircraft landed safely. There were no injuries to the two crew members on board.
Although the aircraft landed without further incident, the detached door struck the left tailplane, causing significant structural damage. The door itself was not recovered following the event.
The investigation
Investigators examined the door's attachment mechanism and the remaining hinge components. While the failure surface on the hinge appeared fresh, there was no evidence of damage to the shoot bolt guides, making a hinge failure unlikely. However, a post-flight inspection revealed that the door had impacted the tailplane.
Further analysis by the LAA indicated that the extended rear shoot bolt had been rubbing against the exterior of the door frame. The investigation focused on the gull-wing door design, which utilizes two tapered shoot bolts to secure the door into guides within the frame. It was noted that if the door is not fully seated at the rear, the locking lever can still be moved to the closed position, creating a false sense of security that the door is properly locked.
Findings
- The primary cause of the incident was the failure of the rear shoot bolt to properly engage with its guide.
- The locking mechanism allowed the pilot to believe the door was secure even when the rear bolt was not correctly seated.
- There is a known history of similar door detachment incidents within the Europa aircraft fleet due to this specific engagement issue.