What happened
On 30 September 2015, an ATR 72-212A, registration EI-FAX, arrived at Dublin Airport from Manchester on a scheduled commercial flight. Following the arrival and engine shutdown, the crew prepared the aircraft for passenger disembarkation. The senior cabin crew member opened the rear passenger door and manually deployed the integrated aircraft steps, securing the collapsible handrail in the upright position using a quick-release pin.
As passengers began to exit the aircraft, one passenger used the handrail for support while descending the steps. During this movement, the handrail suddenly retracted to its stowed position. The sudden loss of support caused the passenger to fall from the top of the steps, resulting in one injury (a fractured right wrist).
The investigation
The AAIU investigation focused on the mechanical integrity of the door's handrail system and the procedures used by the crew. Investigators examined the aircraft's technical logs, which showed no prior reported defects regarding the door or steps, though a note was made immediately after the event regarding a faulty locking pin. The physical examination of the steps and handrail mechanism revealed no structural anomalies or external contamination like oil or water.
Technical analysis of the quick-release pin revealed that while the part met the required manufacturer specifications, the internal locking mechanism had failed. X-ray imaging showed wear within the spring mechanism that prevented the plunger from returning to the locked position, effectively leaving the pin in an unlocked state despite appearing to be inserted.
Findings
- The primary cause of the accident was the sudden retraction of the collapsible handrail while a passenger was using it for stability.
- The failure of the quick-release pin's locking mechanism allowed the handrail to collapse.
- The pin was an "on-condition" component, meaning it was not subject to routine scheduled maintenance inspections.
- At the time of the incident, there was no established procedure requiring the crew to verify that the pin was actually locked and functional after deployment.
Safety action
Following the investigation, the operator implemented new cabin crew instructions requiring a manual check of the pin's security by attempting to pull it from the external rim after installation. Additionally, the operator introduced a specific visual and functional inspection of the handrail mechanism during weekly maintenance checks. The aircraft manufacturer also updated its operational manuals to include a requirement for crew to verify the safety pin is correctly locked during every boarding and disembarkation process.