What are these air force jobs like?

NDI is basically nondestructive testing. As a crew cheif, I bring parts to be x-rayed and stress tested, oil samples for analysis, and call them out to x-ray the jets after certain jobs to ensure everything is where it should be and nothing extra was dropped in. NDI should have a decent civilian counterpart after you get out, testing things for engineers. Electrical systems is basically an aircraft electrician. Fire protection (fire-fighters) is a good job, if thats your thing. They get some long days, but have a lot more time off than i get. Knowledge ops deals with a lot of reading/briefing people on stuff. You have to know what is going on, and brief the people in charge about it.