Airbus A320-family operators have been ordered urgently to check main landing-gear door actuators after previous directives aimed at resolving a potential gear-extension problem were discovered to be insufficient.
The issue centres on debris, caused by deterioration of the actuator damping ring, which could generate friction and restrict the opening of the doors by gravity. Gravity release of the doors features in the alternate landing-gear extension system.
While the issue is a long-running one, highlighted in directives dating back to 2006, the European Aviation Safety Agency says that a recent gear-extension problem revealed that certain combinations of modifications rendered the directives inadequate.
Some operators had reported messages on the centralised fault display system had been generated as a result of slow gear-door operation.
But Airbus analysis has found that these messages "may not be generated", says EASA, and directives requiring repetitive message checks are "not effective" for certain aircraft configurations.
EASA has distributed an emergency airworthiness directive ordering A320-family operators to determine the modification status of their aircraft and, if necessary, carry out repetitive inspection of the main-gear door actuator opening sequence within 14 days.
While EASA has not detailed the recent occurrence linked to this latest directive, a Wizz Air A320 suffered a gear failure on approach to Rome on 8 June, resulting in an emergency landing at Fiumicino airport.