Originally Posted by AD No.: 2011-0069R1
Some operators reported slow operation of the MLG door opening/closing sequence, leading to the generation of ECAM warnings during the landing gear retraction or extension sequence.
Investigations showed that the damping ring and associated retaining ring of the MLG door actuator deteriorate. The resultant debris increases the friction inside the actuator which can be sufficiently high to restrict opening of the MLG door by gravity, during operation of the landing gear alternate (free-fall) extension system.
This condition, if not corrected, could prevent the full extension and/or downlocking of the MLG, possibly resulting in MLG collapse during landing or rollout and consequent damage to the aeroplane and injury to occupants.
Looks like you need to see Airbus AOT A320-32A1390 original issue dated 10 February 2011 and Airbus SB A320-32-1390 Revision 01 dated 21 September 2011 to see actual pictures of the problem.
I wonder whether or not Airbus has done any flight tests of methods to improve getting a down & locked indication? It would sure be a shame to have the means to get all rollers down but not the information on how to do it.
Perhaps positive g? Perhaps less than 1 g flight? Perhaps yaw?
Seems they have a new door actuator, but that too has problems. Lets hope the insurance companies get tired of this and put their feet down. Maybe the airlines need to bolt some oak runners to the bottom of the engine pods as an interim measure.
Where are all the real engineers when you need one? (And I'm not talking wrench turners, these are the ones with the pocket protectors.)
