Story 1: The AH1J helicopter had a maintenance access panel on the right side in the cockpit area. It was a structural panel, which was retained (if memory serves me right) by 72 screws. If you removed the panel in the field first of all it would be difficult because of some of the screws binding and being rendered useless because of the binding. Once you got the panel off you could not get the screw holes to lign up. The helicopter had to be completely unloaded dynamically which meant that it had to be on jacks and in a hangar away from the wind. It was difficult to do this when operating in the field so a lot of maintenance was deferred.
Story 2: I worked for a firm that did cargo conversions. They worked on the cheap so instead of using aircraft manufacture supplied parts in the conversion they would contract them out to backyard mechanics. Some of the cargo door actuators had very complex kinematics which were not reflected in the cheaper parts so, when the doors were opened or closed there was serious binding which really ran up the maintenance charges. They also modified a US Navy DC-9 Nightingale into a combi. When the aircraft went into service the pilots said that when on autopilot the aircraft was like a porpoise. They traced the problem to the fact that the modification firm did not tie the new reinforced cargo deck into the fuselage, which allowed the fuselage to flex to a very high level.
