Flaps - Ailerons - Fuel Tanks

Things are getting pretty hectic in the factory over this long weekend. I feel like we're simultaneously working on 3 or 4 sections at the same time, and all of them are only "half" done. We're halfway through the wing bottom skins but on hold to go any further until we're ready to seal up the wing, we're halfway through with the flaps, we're mostly through the ailerons (except trailing edge), we're mostly done with the tanks but still need to pressure test them... time to move some of these to "complete" status!

Not today, unfortunately. However, we did make leaps and bounds of progress towards this goal. Started this morning with riveting the L and R flap leading edge and top skins to the skeletons. We again installed the flaps onto the wings to check for straightness. They are much more rigid now but can still be influenced one way or the other, albeit only slightly. Still looking straight, which is great news! Then we took them back off the wings and started installing the bottom skins. The flaps are now to the same point as both ailerons: Complete except for trailing edge, and perhaps a few blind rivets that need to wait until the trailing edge is assembled.

With talk of the trailing edges comes talk of Proseal. With talk of Proseal, of course, comes talk of our fuel tanks, namely the goof-up we did with the R tank attach zees being all backwards. So, with the sealant all fully cured it was time to bust out the drill and attempt to carefully remove the seven zees and extract all the rivet tails from the tank. Surprisingly, drilling them out was quite easy (finally, something seemed to go right)! I was also able to fish out about 2/3 of the rivet tails with little issue. The rest of them are still floating around in there for now, but I think the best bet is to try to rinse them out once the tank is sealed up again. We'll keep count, and make sure we get them all.

With the R tank zees removed, cleaned up, and oriented properly, we mixed up a batch of proseal to do the aileron trailing edges and re-attach the zees in the correct order. Happy to say that both efforts seemed to go quite well, and now all that's left to do proseal-wise is the flap trailing edges.

Last thing for the day, it was the "moment of truth" for the L fuel tank. I had bought some fittings, tubing, and valves a week or so ago to make a pressure testing system to connect to my compressed air supply and pressurize the tanks to around ~1psi. This is a higher pressure than what the proposed balloon method allows, which I've read only pressurizes to around 0.5psi. That comes up a little shy of nominal tank pressures during flight when filled with fuel, so I decided to go with this method.

The results were good overall, I'd say. The tank initially held the 1psi pressure, but over the next 10 minutes I noticed it was definitely dropping slightly. A soapwater spray of the tank's exterior quickly revealed the apparent only leak-- at the outboard-top corner where the end baffle meets the aft baffle. Van's points this area out as a common leak source (all four corners, actually), but this particular corner is a sort of "best case" scenario for leaks, as it is the top-most part of the entire tank and theoretically needs to be the least leakproof, so to speak. From the looks of it, we should just be able to goop a bit more proseal on that corner and it should resolve the issue. We'll see if it's that simple... fingers crossed!

Now we wait for some proseal to cure... maybe tomorrow we'll get started on Section 23 - Aileron Actuation! That would be cool, because it's the last chapter of the wing kit! (Except tips, which we're putting off for now...)

Stay tuned!