In one of the early replies, One Tango mentioned the bending of the pushrod and rubbing on the fibreglass "rib." I have seen this but rather than a rib, it was the opening into the spoiler boxes on an SZD Junior. The thin fibreglass of the opening was rubbing on the pushrod and sawing through it like a hacksaw. It was happening primarily on one wing with the other side just starting to leave a mark. We discovered it because there was a problem with this aircraft where one spoiler would open at a slightly before the other so we tried adjusting it to get them to open and close at the same time as well as open to the same height. We started this process because the spoilers did not seem to want to stay locked and as we tested it noticed they were not actuating at the same time. Adjustment required removal of the pushrods and that was when we found it. A review of the logbooks showed that the aircraft had an accident early in its life and one wing was replaced with a brand new one. As the investigation continued, we also found that the pushrod actuating gears were "crunchy" on the original wing but smooth on the other new wing and when we pulled it out of the wing (not an easy task but can be done through an opening in the root rib) we could find no damage but they did not feel right. These gears do not have bearings so the initial thought was not the problem. I was able to discover online that there was a fatality when a Junior spun in after one spoiler opened. The conclusion was that the teeth on the nylon-like gears had sheared off. It may be that the tolerances were such that they did not mesh properly or it was a material fault. We decided to order a new gear set along with the a replacement pushrod. However, none of this explained the differing operation of the spoilers that was the cause of our initial investigation. In the end, we figured out that when the wing was replaced, the fittings had been improperly installed in the torque tube in the fuselage. Accuracy is very important. When a wing is replaced, the collars that are installed on the torque tube do not come predrilled. You have to fit the wing, mark the place where the holes are to be drilled from inside the fuselage and then take it apart and install the collars (anyone who has assembled a Polish glider knows what these are.) Anyway, we finally solved the problem after installing new collars on both sides, a new pushrod and a new gear set.

So, a real lesson here. An accident, an inaccurately installed new wing fitting, the wrong pressure on the pushrods to try to get them adjusted so they would lock (just barely), the resulting rubbing on the spoiler boxes that was swing the pushrods. Aircraft was flown like that for 10 plus years. Finally a new aircraft mechanic said he would not sign it off because it didn't feel right (but he didn't know what the problem was.) A lot of hours spent three aircraft mechanics and myself to discover and then resolve each of the issues described above. Now the aircraft is finally correct. Had the new aircraft mechanic not exercised a high degree of caution to start the process in the first place, it was only a matter of time (maybe many years, maybe soon) where the pushrod on the new wing or the gear set on the old wing would have failed, that is if an accident wasn't first caused by the spoilers popping open.

As an aside, it appears that two things happened around the same time: the fatality when the gear set failed and a change in the company that manufactured the Junior. Whatever the cause, the newer gear sets appear to be made of a different material than the old ones. The old ones were a white plastic and the new ones are black. I would suggest anyone with a Junior look to see what they have, keep an eye on it and inspect the lateral rear sides of the pushrods where they enter the spoiler box. It is tricky to do because if you pull the spoiler up to peek in, the pushrod is pulled deeper into the wing but with a small mirror or an inspection camera it likely can be done. The alternative is to remove the pushrod which is a pain because it is really hard to remove and replace the attachment inside the wing blind at the root end.