what standards we have to work to.
IMHO the maintainers are working to the inspections laid down, they would not be looking for design faults. I am sure that they are following the requirements most carefully as they have always done; when the aircraft is signed off it means that they are complying with the regulations in place. If test equipment was required for a check, I cannot conceive that an engineer would sign for compliance if the test gear was not available. It would probably require a red line entry by an eng. officer to clear it. It's a long time since I certified military aircraft as serviceable to fly but I do not think that the principles have changed that much.