Wings back on

Time: 2 Hours

I worked a little in the shop today after being gone for a week for my six month recurrent training in the Lear 45. I finished up the wheel pants where I had filled in some holes and reprimed them. I’m calling those done and removed them for storage until flying time. I helped my buddy Glenn remove his wings now that he has all gear leg Fairings done. After rearranging the shop plus a little sweeping we move my RV into position so I could put the wings on. I’m doing this for two reasons, first to be able to do the fairings from the top of the gear legs to the fuselage/wing and the second is one last fuel leak test. Glenn had 20 gallons of 100LL that he used for his test and he let me have it for mine.

So the fuel went into the left wing and will sit for a week while I’m at the NBAA convention in Las Vegas. If there is no blue stains on the bottom or the paper I laid out I’ll call the a passing test and transfer the fuel to the right wing for its test. I’m slowly getting tasks done ahead of my engine build school, 34 days and counting down.

Fuel Tank Bracket

Time: 2 Hours

Once the wings are removed you have access to the fuel tank attach bracket that is part of the wing structure. If you remember I drilled this bracket while it was mated to the bracket that is part of the fuselage. Now that the hole has been drilled in the wing side bracket you need to extend the hole to a slot. The theory for this is in the event of an emergency landing or accident you want the wings to shear away from the fuselage as they absorb some of the energy that you have during an accident. The wings are meant to break away aft or towards the tail so you want the forward part of the wing to be easily separated in this event. This slot allows the bolt to support the inboard end of the fuel tank up and down but will shear away as the wings are bent back in an accident. So I started with a mark 1/4″ wide and cut the slot just inside of those lines. I then used a file to clean up the edges and open until a 1/4″ bolt would easily slide through the slot. Filing this thick bracket is what took the most time but I wanted to make sure I didn’t take too much. All in all I’m real happy with how they turned out. 

Left Wing Leading Edge

Time: 6 Hours

Today’s task was to complete the left wing leading edge so that I can move on to the top skins. I started by putting the inboard rib in (this is the one that I had to replace) along with the spacer I made yesterday. I wasn’t sure if I would need it on this wing but figured it might be easier to put in before the other ribs were riveted as I had done yesterday. Well it was a little easier but not much. I put the leading edge on the spar with a few clecko’s and added the tank. I was happy to see that the alignment was pretty good so I’m glad I put the spacer in ahead of time. We will see how it all lines up after riveting as things tighten up with rivets compared to the clecko’s.

Unlike the right wing leading the left leading edge had holes punched in it on the forward edge for Van’s stall warning system. I decided to use an AOA (Angle of Attack) to determine an approaching stall. So these holes needed to be filled with rivets.

Next task was to grab the bucking bar and rivet gun and hit the skin to rib holes. I finished the top in about 45min before breaking for lunch.

After a short break for some lunch I got back at riveting. It took me about the same time to finish the bottom of the skin. I then put the leading edge on the spar and checked the fit. I repeated the process of yesterday by riveting the outboard and inboard rib with solid rivets while using the blind rivets LP4-3 & LP4-4 on the 3 middle ribs. The second outboard rib will also get solid rivets on both wings but I need help bucking those so they will wait for now. Next was to squeeze all the rivets along the aft edge on the top and bottom.

With the leading edge riveted on I grabbed the fuel tank and checked the seam alignment. I’m happy to say that it turned out really nice, a little better than the right wing.

The plans call for you to now put about half of the bolts in that hold the tank to the spar.

I wanted to complete one more task today before calling it a day. The next big step in the plans is to rivet the 3 pieces of the tops skins – the outboard, inboard and the doubler for the wing walk area. So I started with getting the doubler prepped for priming. I treated the edges and deburred all the holes before dimpling them with the DRDT tool. I wanted to get these pieces done since I decided that I was going to prime one side of them. I’m sticking to my plan of priming at least one surface where two bare surfaces come together. So one side of the the doubler will mate up to the inside of the skin, both of those would be bare hence my need for priming at least one of those surfaces. I got a couple of coats of primer on the side that needed it and will have a few days for them to cure.

I cleaned up the Hangar and headed inside to listen to a webcast presentation by aerobatic pilot Patty Wagstaff on an introduction to aerobatics.

Fuel Tanks Leak Free!!!

I forgot to mention in tonight’s post that I have had 100LL fuel in my wing tanks for 2 weeks and I am incredibly happy to announce that they are 100% leak free!!! I had the tanks in all positions over this time but mostly in the vertical position so that the rear baffles, the biggest problem area, had the most exposure to the leak testing. What a great feeling to be able to say “leak free”!

More Tank Testing

Time: 1 Hour

I had a long day at work and office time so I didn’t get much work done I the hangar tonight. What I did do was create two extensions for the tank vent lines with some parts I received from Aircraft Spruce so that I could control any venting.

I then removed 10 gallons of fuel from the right tank and put it in the left tank. With both tanks half fuel I put both if them on end to test the rear baffles for leaks. So far on the right tank after 3 days I had no leaks!

I will let these sit for a couple days to check for leaks then lay the tanks on their tops so the bottom skins are up so I can test the top skin rivets. That’s all I did tonight and will get to the left wing ribs tomorrow.