Jeff R
Well Known Member
Well, I got a brand new torque wrench so I could properly tighten all those bolts in my RV9. I first used it attaching the aileron bell crank mounting brackets to the wing spar. I looked up the suggested torque for an AN3 bolt and found 20 to 25 inch pounds (or at least that is what my brain thought it read). I set the wrench to 20 and thought as I was tightening the bolts that, "wow, that is a lot more force than I thought it would be". I tightened more than I was comfortable with and stopped before the wrench clicked.
Fast forward a week. I had to remove the bracket and I was surprised at how easily the bolts came out. I thougt "Didn't I really torque these in"? When I went to reinstall the bracket and bolts, I couldn't get the derned bolts to go in. I looked a bit closer and saw that all 4 bolts had sheared off inside the nut plate! Yikes! (I will avoid mentioning potential fates that could have befallen had I not discovered this.)
Did I use the right torque value or is my wrench terribly out of calibration (even though it is new and is supposedly in calibration)? And what is the best way to remove those bolts????
Fast forward a week. I had to remove the bracket and I was surprised at how easily the bolts came out. I thougt "Didn't I really torque these in"? When I went to reinstall the bracket and bolts, I couldn't get the derned bolts to go in. I looked a bit closer and saw that all 4 bolts had sheared off inside the nut plate! Yikes! (I will avoid mentioning potential fates that could have befallen had I not discovered this.)
Did I use the right torque value or is my wrench terribly out of calibration (even though it is new and is supposedly in calibration)? And what is the best way to remove those bolts????