0TreeLemur Posted 18 hours ago Report Posted 18 hours ago An A&P did some work on my Mooney today. He and I put the lower cowl on and he left for the day. While installing the upper cowl I encountered a problem. The upper cowl on my '83 J has a bunch of quarter-turn fasteners and three machine screws on each side. Two machine screws go into the stanchion around the propeller flange, and one on the forward corners. The screw on the right forward corner started normally but after a few turns started to get real tight... Those are stainless steel screws and it felt like it might be starting to spall. So I backed it out. It was tough to turn and definitely felt like it was spalling. The threads were definitely messed up. Looking in there, the threads on the inside nut plate are not perfectly aligned with the hole in the nut plate. The threads on the left front nutplate are centered. On the right hand side it seems that the nut is too high. Looking in there I could see a many threads in the bottom of the hole and none in the top. Question: are those nut plates with captured floating nuts? Why is it suddenly out of alignment, and how can I center it? Any ideas on how to fix this? One Idea I have is to run a tap in there and see if that centers it. Thought I would ask the collective about this idea before trying it. Thanks, Fred
Slick Nick Posted 17 hours ago Report Posted 17 hours ago Just drill out the rivets and put some new nut plates in.
0TreeLemur Posted 15 hours ago Author Report Posted 15 hours ago 2 hours ago, Slick Nick said: Just drill out the rivets and put some new nut plates in. Does not answer my questions at all.
N201MKTurbo Posted 14 hours ago Report Posted 14 hours ago There are floating and fixed nut plates. Just look at them and you can tell. You can also chase the threads with a tap.
Slick Nick Posted 4 hours ago Report Posted 4 hours ago 10 hours ago, 0TreeLemur said: Does not answer my questions at all. Q: "How can I fix this?" A: Install new nut plates. Not sure how that didn't answer your question? Most nut plates are squished at the end so they will retain the fastener. Tapping it out removes that, which is why it's best to replace them. Not sure if the cowl ones are like that, but replacing it would be the easiest and most professional solution.
N201MKTurbo Posted 4 hours ago Report Posted 4 hours ago 16 minutes ago, Slick Nick said: Q: "How can I fix this?" A: Install new nut plates. Not sure how that didn't answer your question? Most nut plates are squished at the end so they will retain the fastener. Tapping it out removes that, which is why it's best to replace them. Not sure if the cowl ones are like that, but replacing it would be the easiest and most professional solution. If you replace them, you will traumatize the fiberglass and paint. Chasing the threads will get it working without screwing up the appearance of the cowl. 1
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