Flaps2billion wrote:
"After looking at the facts, I do believe that the faulty filter may have been a reason for the third. Maybe something during the inspections triggered it?? Who knows??"
Actually the interim report report from the official Danish investigation suggests the o-ring fragment was probably introduced into the actuator with the swap-over when they replaced a corroded u/c actuator with a similar, but perhaps not identical, part used to open the front nose-wheel door. So it was (inadvertantly) put directly in the business end of the system and could not have otherwise passed through the system. Don't know the layout of the system but perhaps a filter, even if present, might not have been in the right place to catch it.
See:
http://www.hcl.dk/graphics/Synkron-L...K_03112007.pdf