Left hand elevator skin part-rivetting

I have a replacement right hand elevator skin on order - the original skin was rejected owing to a fold position error large enough to require upsizing of every rivet on the underside. The alternative: accepting a mild dip to the trailing edge (which would have been quite acceptable visually) resulted in a vicious oil-canning on the top side of the elevator skin.

So for now I am fitting the left hand skin, which is good.

Using the support jig and the laser level to ensure the elevator is perfectly planar.

I did a test fit of the trim tab, and found it did not rotate smoothly. The reason for this was a slight warp and twist in the trim tab resulting in the piano hinge axis not being perfectly straight. I derivetted the trim tab and was able to easily correct this when re-clecoing it. No further hole cleaning of the trim tab is required, and while clecoed for now I will eventually rerivet it while attached to the elevator, ensuring free movement.

I plan to use M4 bolts to hold the trim servo, so have matched drilled the skin holes to the holes on the servo mounting plate.

I found a slight bend tolerance of the end tab of the spar channel caused sufficient misalignment of the end rib relative to the rest of the structure to result in oil canning. I have removed these rivets for now, and find that when the skin is fully clecoed without oil-canning, the misalignment of these rivet holes is ~0.3mm. I expect to be able to re-rivet these without too much difficulty once the skin is fully attached, or at most need to upsize to 4.8mm rivets. I have contemplated reforming this bend, but this would entail de-rivetting the hinge, etc.

To prevent the hinge bearing holes from deviating from a perfect straight line, I am completing the rivetting with the HS attached. The HS hinge holes have previously been confirmed to be perfectly aligned.

When attaching the HS, one of the HS hinge 1 brackets was found to be misaligned by about 0.5mm with its mate due to a fold position error. Replacement on the way from TAF. Apart from this there is perfect free movement of the elevator relative to the HS.

I cut a 9.5mm - 3/8" hole in the skin leading edge for the servo cable slightly offset from the original rivet hole position to slightly optimse clearance with the HS spar lightening hole. I have supplemented with two additional rivet holes to better maintain the shape of the skin in this region.