:eek:I have had a different but similar problem solved (eventually) by replacing one of the intergrated valves. I think you have done all the other possibilities already.

Mmmmm ....

Time to change the Hydraulic System Interlock control block ....

seems like the Hyd pressure when a/c is run above the 80% is a clue ... but snag not being there with the Hyd test rig running is the confuser.

There must be a leak-by somewhere causing the Hydraulic lock my guess is the interconnect block.


As usual I stand to be corrected as required!

Good Luck :confused:

final succesfull result
 

We installed a overhauled set of main rotor blades and that solved the problem. Still we've a questionmark how this problem occured from one day to the other. For now we are operational again and thats all whats matter.
Many thanks for all the reply.