The wing ribs are done! It was all fairly straightforward. The big issue occurred when I riveted the aluminum angle to the torque tube bracket. The holes in the rib's web did not match the holes in the angle. This was a mystery since they were match drilled and should have fit perfectly. It was late when I discovered this problem and assumed it was because I had forgotten to install the spacers between the bracket ends when I did the match drilling. .... I even ordered new angle from Van's. But when I drilled out the angle from the brackets, I realized that I had installed the angle backwards from how it was match drilled. Now, I mark things meticulously to prevent this kind of thing from happening. But somehow, I mixed up what my marking meant and (on both wings) installed the angle backwards. Once I realized what really had happened it was no issue really – aside from the fact that I mangled several holes removing those rivets. When the back piece is relatively thin metal and not firmly fixed to some other structure, it's almost impossible (for me at least) to drill out rivets without damaging the holes. So, on almost every hole, I had to drill out to #21 and use 5/32 rivets. No big deal really. Just annoying.
The other issue was when I riveted the ribs to the left spar. For some reason I had a bear of a time installing those rivets correctly. The shop heads were all fine, but I kept bouncing the rivet gun and mangling the rivet heads. Then let me tell you, drilling out rivets with mangled heads is haaaard. Half the head breaks off and the other half is then extremely difficult to deal with. In total, there were 10 rivets out of 77 rivets that I had to drill out and several others than don't look great, but I felt were safe. And of those which were reinstalled, several had to go up to 5/32 because of damaged holes. That's about 13% replacement for those who care and that's a lot. I tried everything to correct the problem: reduce the pressure, use different heads on the rivet gun, hold the rivet gun lefty or righty. Seemingly, I could do nothing to get consistently good rivets. In the end, I spent four hours riveting and drilling and re-riveting the ribs on the left wing spar.
The next morning, I was fresh and ready to try again. I changed two things. First, I got Scott to help (I wish I had a picture of him helping, but forgot to take one). And second, I decided to drive all the rivets from the forward side of the spar. The night before I drove from the aft side and I think the constant interference from the ribs themselves against my hand or the rivet gun didn't help. I drove and Scott bucked. All 77 rivets went in without a single problem and every one looks perfect on top of that. The whole job with Scott's help took less than 30 minutes. Amazing what a fresh day, a fresh perspective, and a second pair of hands can do.
Getting started on the Wing Ribs. Got them all deburred and match-drilled to the wing spars. One fun thing was that I had to use my brand-spanking new right-angle-drill attachment. That was fun. I was hoping to have all the wing ribs and accessories (like the flap hinges) primed and ready for riveting, but I massively underestimated the amount of primer I would need. As a result, I've got less than half a can of primer left and 24 ribs (out of 30) still to be primed. Because I realized I would run out of primer early on in the process, and would have enough only for a few ribs, I chose wisely which ribs to prime first so that I could at least get the flap hinges attached while I wait for more primer. I believe I'll need about another 5 cans of primer for the ribs.
I forgot how much I don't like priming at night. It's really hard to get the primer to look smooth with only a flashlight (which I broke, incidentally, by dropping it). So it's really, really hard to get the primer to look smooth in almost complete darkness. Turned out just tolerable in the end (after a few brink-it-back-out-and-spray-it-again incidents that is.)
Zachary and I made a trip to the Air and Space Museum in Chantilly, VA. There we saw the SR-71 Blackbird prominently displayed with the sign telling that on its last flight from LA to Dulles on its way to the Air and Space Museum, it made the trip in 1 hour and 4 minutes. That's just amazing. But what does Zachary wonder? He wonders how long it would take to build that airplane in our garage. At least a few months we both agreed.
Although a ton of stuff has been done in completing the work on the main spars, it isn't really the photogenic sort of work. Mostly, it involved drilling out holes, then drilling out some holes and then drilling out some more holes followed by deburring said holes followed by countersinking said holes followed by more countersinking followed by installing nutplates which will hold the fuel tanks later. Then after that (there were over 1400 holes) each one had to be drilled and debured on one side and countersunk on the other. There was also some priming and did I mention the drilling? Yes there was match drilling some J-Channel pieces which will be used later on when we attach the skins. Also I fabricated (cut to size) the tie down anchors which were then primed and riveted and bolted to the spars.
The highlight of the work done this past few weeks has been the trip to the Air and Space Museum. For those who may not know, the original Air and Space Museum is on the mall in downtown DC. The bigger and better Air and Space Museum (also a part of the Smithsonian) is known as the Udvar-Hazy center and is in Chantilly, VA immediately south of the Dulles Airport. Many of the pictures for this installment are from the museum since the spar pictures are so boring.
Take note of probably the smallest home-built airplane. It was called, "La Cucaracha" or "The CrosleyFlea" Maybe we should have opted to build this one. Given we could probably build a Blackbird in just a few months, we could probably build one of these in just a few weeks.