Tonight was a research night for several things

As I am drilling out the rivet holes in the wing skins, there are a couple of things that I need to address. I was not quite sure how to attach the bottom supports to the trailing edge of each wing while it is in the stand. This needs to be done so that the wing can be kept square without any type of twist or bend.

Vans has a very straight forward method for doing this which involves hanging two plumb bobs from lines suspended vertically from clecos holding the two end ribs at the main spar. You then measure the distance between the suspended lines and the top-rear corner of the rib/skin at each end. The measurements between the plumb line and the corner of the rib at the root and the tip of the wing should match if no twist exists. If they do not match, then there is a twist, and you need to use the bottom brackets and some clamps to secure the trailing edge of the wing after removing the twist.

After reviewing some other build sites online, I think I have figured out how I will set these up. I think I can do it using only C clamps, a couple more metal brackets, and some wood braces where needed. Anything to avoid drilling more holes in the wing stands, which was a laborious process the last time that I had to do it.

Next, I noticed some oil canning in the last bay of the bottom wing skin for the left wing (at the tip). There are other posts on VAF that report the same phenomenon, as well as potential solutions that range from self correcting when everything is riveted, to attaching stiffeners to the affected area, to double checking and correcting the bends in the rib flanges in that area. The main thing is that apparently Vans is aware of this, and says it is a cosmetic issue and is not a structural concern. So I will spend a little time checking the rib flanges and checking that the wing is level on the stand, as well as correcting for any twist that may also be causing this to happen. Otherwise I am not too concerned.

The weather turned cold again for a few days as winter tries one last time to hang on. So it was a good night to stay inside. The forecast says that we might even get snow on Mother's day this Sunday, which will not make my mother very happy at all.

Also saw that Dynon issued a service bulletin for their heated pitot tube system because they confirmed what several well known and respected RV drivers have been telling them for a while now: ice can form in the lines beyond the pitot tube because it does not do a very good job of separating and draining water from inside the tube. The water travels up into the lines and freezes in the lines causing erratic or no airspeed indication at all. I am expecting a recall and a full replacement with a new pitot tube sometime in the future when they come up with a solution.