Hydraulic Filters
I agree with your assessment of the filter situation. We would'nt normally change a filter unless we have consecutive pop-outs over several days and it becomes an issue with the pilots getting bored and commenting on the yellow cross on the hyd. synoptic page when they get bored and pull it up during the flight. (AW139 pilots are often bored) I remember this was a problem from delivery in late 2005 and at the time we ran around changing filters and fluid, and even doing the same in the hyd. rigs and sending soap samples of each off to the dodgy local lab that had us even more confused. The other problem that became apparent was Agusta in their wisdom put a very fine filter in both pressure and return. 5 microns was what I heard from a tech.rep. I also heard Eurocopter had the same problem with the 365 when it came out and the fix was........put a 35 micron filter in it instead.......no more problem. Small things really.
I am more concerned with the two earlier BT's to address the servo pressure switch problem and remove serial number batches but still we have regular failures. This brings up a CAS as you know which can be a problem depending on the crew's interpretation of the fault. At least we can now quickly isolate the troublesome switch without a hydraulic rig. I read an article from AW suggesting that a permanent fix was in the pipeline for this problem possibly by using a different vendor, plus the one piece floor issue, and leaking servos both via wiper seals and static seals in the servo body, but haven't heard anything since. Maybe the tailboom problem has blindsided them so much everything else is on hold for now.
WC