Apologies in advance if this topic has been covered already, but I didn't find it in a search of the forum...
So while installing a new wing root seal, I noticed two rivet heads where the paint around the heads had cracked, usually indicating that the head is loose or has moved slightly. The two rivets are the first ones on top of the wing where it attaches at the fuselage, one rivet each in the forward and rear top spar cap attaching the skin to the spar cap. I checked under the wing root seal on the pilot's side and noticed the one on the rear top spar cap exhibited the same cracking. When I left my hangar I looked at about a dozen Piper Cherokee's/Warriors around my field and noticed about half had the same issue, to a lesser or greater extent. The half that didn't was because the wing root seal was so deteriorated that I didn't want to pull it back, or the plane had been painted relatively recently. Of the ones that did exhibit the same issue, it was always worse (more rivets) on the wing walk side of the plane. I didn't notice any similar issues on the underside of my ship's wings, and I didn't check the ones tied down around the field. Since these rivets attach the skin to the spar, I'm assuming the wing walk side is stressed more from walking on it. But I'm still curious to know why these rivet heads, on both wings, tend to exhibit signs of being loose or moving, and all at the base of the wing. Repeated stressing of the wing over time, or some other issue? 1st photo is on my plane; 2nd photo is one example I found on one out on the tarmac.
So while installing a new wing root seal, I noticed two rivet heads where the paint around the heads had cracked, usually indicating that the head is loose or has moved slightly. The two rivets are the first ones on top of the wing where it attaches at the fuselage, one rivet each in the forward and rear top spar cap attaching the skin to the spar cap. I checked under the wing root seal on the pilot's side and noticed the one on the rear top spar cap exhibited the same cracking. When I left my hangar I looked at about a dozen Piper Cherokee's/Warriors around my field and noticed about half had the same issue, to a lesser or greater extent. The half that didn't was because the wing root seal was so deteriorated that I didn't want to pull it back, or the plane had been painted relatively recently. Of the ones that did exhibit the same issue, it was always worse (more rivets) on the wing walk side of the plane. I didn't notice any similar issues on the underside of my ship's wings, and I didn't check the ones tied down around the field. Since these rivets attach the skin to the spar, I'm assuming the wing walk side is stressed more from walking on it. But I'm still curious to know why these rivet heads, on both wings, tend to exhibit signs of being loose or moving, and all at the base of the wing. Repeated stressing of the wing over time, or some other issue? 1st photo is on my plane; 2nd photo is one example I found on one out on the tarmac.