What happened
On December 17, 2014, a Tecnam P200 and6T, registration SP-MAC, operated by Ventum Air, was performing an approach to runway 25 at Łódź Lublinek Airport. Approximately 5 nautical miles from the runway threshold, the aircraft's control column suddenly deflected to the left. The crew was forced to apply significant physical force to maintain a neutral control position and prevent further deflection. Despite the difficulty, the crew successfully completed the landing on runway 25 without further incident.
Upon landing, a post-flight inspection revealed that the external hinge of the left aileron had become disconnected, with the hinge axis protruding. It was discovered that the retaining cotter pin for the hinge axis was missing.
The investigation
The investigation, conducted by the user's commission, examined the aircraft's maintenance history and the mechanical state of the flight controls. Records showed that a thorough pre-flight inspection had been performed prior to the flight, during which all aileron hinge pins were confirmed to be secured with their respective cotter pins. The investigation focused on how the pin could have been lost during flight.
Findings
- The primary cause of the incident was the displacement of the external hinge axis of the left aileron.
- The investigation could not determine the specific reason why the retaining cotter pin fell out of the hinge axis prior to the displacement.
- The aircraft was repaired and returned to service following the incident.