We have had several questions about wing bolts, do they break, what happens if they break etc.

The wing bolts are extremely strong. Longitudinal load such as that induced by a wing in flight (lift or descent) will not break the wing bolts. Only shear either horizontally (crash damage) or by twisting the bolts under high load will break or weaken the bolts. In order to break the bolts they must be excessively overtightend using either a nut driver, electric drill with socket or a battery operated electric screw driver. Cross threading the bolts into the wing bolt block inserts will strip the bolts and or the wing bolt block inserts.

Our strong recommendation is to tighten snugly only using hand tools. Do not overtighten. Do not use a power tool of any sort. When using a hand tool, tighten until the wing is seated in the wing saddle of the fuselage and then snug down about 1/8 turn more. That is all that is required. If you hold the fuselage in your hand near where the bolts engage the wing bolt blocks in the fuselage you will feel the fuselage sides between to warp inwards just inboard from the wing bolt blocks if you overtighten the bolts. If you feel the fuselage sides begin to warp or see the wing bolt heads beginning to sink into the bottom of the recesses in the wing, you are too tight. Back off on the tension on the bolts. If you persist in overtightening the bolts, you will strip or shear them off or pull out the mounting blocks or in some cases pull the head of the bolt right through the wing! All of these situations can lead to wing damage, fuselage damage and/or wing separation from the fuselage in flight.

Cross threading the bolts into the wing bolt block inserts will damage both the bolts and the inserts. If you persist in forcing the wing bolt in spite of the cross threading, you can damage the threads beyond repair and/or over stress the wing bolt.

Check the bolts before and after each time you install the wing. If the bolts look stripped, replace them. If the bolts appear to bind or require a great deal of torque to tighten them, lubricate the bolts with light oil and make sure they are not cross threaded. If you have any concerns that the bolts may have been damaged due to overtightening, cross threading or crash damage, change the bolts and check the wing bolt mounting blocks and inserts in the fuselage to make sure the blocks are secure and the inserts have a good thread. Do NOT fly without checking the wing bolts, handtightening them and making sure the wing is secure. Mounting blocks and bolts can be damaged by overtightening or crashes and may not be obviously loose upon cursory inspection. Check carefully and remove the wing after any crash so that you may examine the wing bolts and the mounting blocks carefully.