Italian investigators have concluded that an Alitalia Airbus A320's righthand main landing-gear failed to extend after suffering a jammed actuator. 

The aircraft carried out a landing at Rome Fiumicino on 29 September 2013 using nose-gear and left-hand main gear. 

Italian investigation authority ANSV has detailed the circumstances of the accident, concluding that debris in the gear-door actuator caused the jam. 

Analysis identified two components within the actuator as sources of the debris: the spirolox ring and damping ring. 

It says the failure appears to have been the result of a design flaw in the spirolox ring, which suffered premature deterioration, leading to metal contamination. 

Actuator failure had been linked to a Wizz Air A320 landing accident at Fiumicino, in similar circumstances, less than four months earlier. 

Airbus introduced a new actuator design in response while Europe's safety regulator ordered checks on the component in other A320s