which material is beech 200 wing bolts ?they are no magnetic.what type of ndt do you carry out on them?
Years ago I used to build for Beech, and don't get the idea there is no steel in an airplane. There are stainless rivets, huck bolts, Cherry Max and Cherry Lock rivets by the hundreds, even steel patches that aren't stainless to correct a potential weak points due to short edge distances and oversize holes. These patches are covered with green epoxy primer by brush real thick to prevent the chance of any corrosion. Steel and aluminum don't play well together, instant aluminum corrosion if you don't protect against it. The wing/fuselage mate was done in another building, and even though I spent my share of time there, I never asked what they used for fasteners. (never know more than you need to, this always turned into mandatory overtime) I think it's a pretty safe bet to say they are steel though. Sometimes, you can't get around it, in some cases it's the only material that can do the job. it's not that steel can't be used in aircraft, it can, the secret is to NOT magnetize it. That's why you never use electric tools on aircraft, only tools powered by compressed air. NDT could consist of one or more things, eddy current, dye penetrant, magnafux, the list goes on. I was at Beech when engineers found a bunch of aluminum stringers in the horizontal stabilizers for the Beechjet 400A that failed eddy current testing. These planes were of course built, painted and awaiting delivery. Whew.talk about rework! My guess is that the bolts are probably life-limited and thrown away during wing removal during a D check and new ones are installed.
Inconel,a nickel-chromium-based superalloy
