We used to say that government inspectors could be in an aircraft factory or a meat packing plant, it's all the same. Some AF inspectors that I saw were well qualified and some seemed to have been hired just to fill a space. That said, you can't inspect in quality; it has to be built in. A good inspector who watches the job in progress instead of just showing up for a final inspection and paperwork sign-off is invaluable but you also need the production workers to have quality as their goal instead of schedule and budget. Where I worked the union contract was changed so that hourly mechanics who took salaried supervisory jobs were no longer able to keep their union seniority. When they were able to keep their union seniority, you'd hear supervisors say that if their manager pressured them too much, they'd "go back to the toolbox". After the system was changed, experienced mechanics didn't want to become supervisors so people were hired off the street to be salaried supervisors and knew that their jobs depended on meeting schedule and budget. You might have a whole crew from supervisor on down with no experience on the particular aircraft and they could easily make honest mistakes that the inspector wouldn't catch because he was stretched too thin and could only come by for required "stamp off" inspections. There are also some people who will cover up bad work that they don't think will matter and they're often right, it won't be a problem for thirty years but sometimes they're wrong.