« Posts tagged wings

A Fix and Some Finishing

7 hours.

Although the last three shouldn’t count because I spent them fixing something I should never have had to in the first place.

20130728-192738.jpgThat little corner of aluminum is the bane of my life.    Since I put the wings on, I’ve caught it on shoes, shirts, and finally, the belt on my jeans.   When this happens, it bends.   This time, I bent the crap out of it, so badly, that I had to remove the fasteners on the skin, peel it back, and hammer it flat again.  The light makes it look worse than it is, but it’s still pretty bad.   Fixed now, though.


20130728-192751.jpgThe day wasn’t all bad.   I got the fuel pump overflow plumbed.   I used some of the tubing I had from the MAP sensor install to create a flexible link between the output of the fuel pump to the hard line shown here.   The engine wiggles.  The aluminum tubing doesn’t.   I need a flexible line between the two.

20130728-192805.jpgThe fuel sensors concerned me for a minute.   When I connected the wings, I had some little extra wires that I thought I’d run for spares.   I guess this is why you label things.   After some pondering, I realized these were the fuel level sender wires.   Duh.  The good news is that I didn’t have to do any splicing and apparently I cut them to the right length.   A couple of connectors later and I had fuel level, which was, of course, zero.

No luck on the OAT sender though.   Either my EFIS or the probe is bunk.   OAT reads a steady 32 degrees F.  Have to contact MGL for a new one.

Still more connections.

6.5 hours.

A bit of a late start.   Since I took this week off, yesterday was my first weekday commute to OXR.   I went via PCH, which is nice enough, but it took a little longer, especially during rush hour.

I finished installing the rudder cable linkages to the pedals, so that’s another thing done.   I also got the pitch trim servo wired in.  I’ll need to adjust the throw on the trim servo, but that’s essentially done.

Then I went back to wing wiring.   I got the strobe and lights connected for the right wing, plus the autopilot servo.  It was lots of tedious, fiddly stripping and crimping in small, awkward places, which has an extra coating of suck because I did something to my right elbow and now operating hand tools like crimpers is fairly painful.

Left to do is connecting the VOR antenna wire (This may become an ADSB antenna wire if they phase out VOR) in the left wing and putting in a couple of pieces of UHMW tape here and there.  If I can have lights, strobes and VOR by the weekend, I’ll count myself lucky.


More connections and a flight

6 hours.

Today was spent tidying some wing attach stuff.   I got my order from ACS, so I was able to finish installing and torquing all the wing attach hardware.   I also did the fuel line on the left tank, remembering this time to put the rubber grommets on before flaring the ends.   There’s a $30 tool that will stretch those rubber grommets out so you can get them over flares and fittings, but I figure it’s good practice just to try to be less stupid.

The most interesting part of the day was the short flight I took in my hangar mate’s Luscombe.


I’m not sure which model this is, but I think it’s an 8C or 8D.   It burns 4 gallons per hour, which is probably about half of what the Pipers I learned on did.   It has no flaps, no lights, and only the minimum equipment of single radio and transponder to get around Southern California’s interesting airspace.


Now, I’ve never been in, much less flown a taildragger, and the oldest airplane I’ve even sat in was an old L-19 Bird Dog in Ft. Leavenworth KS when I was a little kid.    This aircraft was built some time during the early 1940’s, and Ron was kind enough to let me follow him on the pedals to get a feel for the quirks of a taildragger.   This shot is one out the right window, us taxiing to runway 22 at OXR.

20130616-093659.jpgAnd another out the front.


The instrument panel is simplicity itself.   Everything you need for day VFR, nothing you don’t.   The mount for the Garmin 296 GPS looks strangely out of place, over to the side out of frame.   There’s a single vernier cable control for throttle and a small one for carb heat.  I didn’t see one for mixture.  I don’t think there is one.   The fuel gauge is on the bulkhead behind me, between the two seats.


20130616-093736.jpgWe did a landing at Santa Paula, where I was able to get a picture of Steve McQueen’s old hangar.   I love this airport already.   I just wish we’d had the chance to buy McQueen’s old ranch when it popped up on Jalopnik last year and it was dangerously close to something we could afford at its fire-sale price.


20130616-093750.jpgThat adventure only took about 20 minutes to half an hour.   When I got back, I did most of the real work.   Here’s the right flap, on and conneted.  There’s some more rigging to be done,  and some more wiring, but the wings are nearly fully on and connected.   I also got the left rudder pedal connected to the cable, but ran out of time before I could do the right one.   I’ll hit that in a week.  Soon it will be time to mount the prop!

The Thing Has Wings!

3 hours.

This morning, Dave and Peg picked me up from home and we met Derek at the airport to fly up to OXR in his 177RG Cardinal.  It took a while to get out of SMO because somebody’s bizjet blew a tire and was stuck on the runway for half an hour, but we finally got off the ground and got to Oxnard.   There, we put the wings on the RV, which involved a lot of shuffling things around in the hangar space and trying not to bash the other occupants, the structure, or each other, with ungainly airplane parts.

The wings did go on, after a fashion.   Our time here was abbreviated because of earlier runway delays, so the wings are currently held on with the sacrificial hardware store 5/16 bolts I used during the initial alignment and the proper AN5 aft spar bolts.  My hangar mate Ron and a friend of his helped us get the overlap sorted out on the right wing, and all totaled it didn’t really take more than an hour once we arranged everything in the shop and actually began putting the wings on.

It truly was a 4-person job.   Derek, Dave and I wiggled the wing into place, Peg kept the wires from getting fouled, and then I bashed the 5/16 bolts through with the rest of the crew doing precision wiggling where needed.





One thing I should have done is left the flaps off.   We tried getting the left wing on with the flap on and that didn’t go so well, especially when it came time to line up the aft spar holes.   I wound up taking the flap off the left wing, then took the flap off the right wing before we tried to put that on.   So what you see here is the current state, which is the big flat bits that make the plane stay up in the air, stuck to the bit that holds the meatbags off the ground.

As an aside, I’m hoping that when I connect the control push tubes, the sticks are a little more limited in their side to side travel, because currently, my hand just barely grazes the quadrant.

Wings Closed, part 2

4 hours.

Wing skins are done! I reinstalled the flaps and got a strip of UHMW tape along the back of one, and I’ll do the other tomorrow. The other thing I have to do is find or refabricate the flap hinge pin fasteners. After that, I just have some minor wire tidying to do and the wings are done, done, done.

Wings closed, part 1

7 hours.

Yesterday, my friend Derek came by for a few hours and helped me rivet the bottom wing skins on. Derek is peripherally responsible for me being where I am today with regard to aviation: Flying leads to skydiving, skydiving leads back to flying and flying lessons, rental airplanes lead to homebuilts. Before he arrived, I did some pondering about the best way to rivet the wing skins on, and the first two things that needed to happen were the removal of the aileron push tubes and the flaps, so I did that.

Riveting the skins on the wings would have been really tough without help, especially the inboard rows near the bellcrank. As it was, I really had to stretch to get the bucking bar up in there far enough to reach the rivets closest to the aft wing spar. But it gets easier as you move outboard, and we finished off the left wing yesterday afternoon. Derek had to leave at around 3-ish: newborns really don’t care all that much about Daddy’s friends’ projects, but I kept going.

Before he left, Derek helped me get the double row of rivets on the right wing, then I got going on the rest. To say that riveting those big bastards by yourself is awkward would be like saying Stephen King sells a lot of books. Fortunately, the skins do bend quite a bit, and I wish I had a photo to show you how I did it, but the general gist of it this:

With the double row riveted, cleco the spar side and leading edge side holes together. Then climb in between the skin and the ribs, which will allow you to get a hand and a bucking bar in through the lightening holes to just about anywhere you need to go. And it should go without saying, remove the blue stuff from the inside of the skin before it gets riveted on, or you’re going to have a lot of fun later. Good thing I remembered this before we got too far along, but if you’re reading this, I hope it reminds you before you buy yourself a long night of failure-drinking.

I thought the autopilot servo was going to cause a lot of problems, but with the push tubes out of the way, it was really a non-issue. By myself, I got another row done, up to the access panel for the bellcrank, then quit for the day. I was sore and tired. Even with help, riveting wing skins on is like yoga for gearheads.

Left to do: the remaining skin rivets, and some minor wiring cleanup, since I replaced the puny 14-ga wire intended for the landing lights with a much beefier 10-ga flavor.

More odds and ends

4 hours.

A few things here and there. I installed the MAP tubing and put a couple of heat shields on the pipes to protect the throttle and mixture cables. I also installed the canopy seal, which is going to need some assistance from some RTV or proseal. I do think firewall forward is just about done, though. The cabin heat SCAT tube rubs on the engine mount a little, but some UHMW tape should fix that. The two things I did that were of major importance were the autopilot test and getting that ridiculous piece of lead off the flange of the left elevator counterweight rib.

A while back, I’d balanced out my elevators, or so I thought. You’re supposed to put the elevator tips on, then drill holes in the lead weight until the elevator balances. Well, guess what? You’re not supposed to have the elevators connected when you do this. I discovered this, freaked out, then riveted a flat piece of lead (cut from an extra counterweight) to the outboard rib.

When I put that away, thinking I was just about the smartest cat in the whole barn, I started imagining the kind of beating a control surface takes in flight. So what happens to a little piece of lead riveted to this structure with a couple of Cherry countersunk blind rivets? The piece of lead comes off and somehow jams the elevator in the dive position and I go screaming downward like a holed Stuka, straight into a busload of orphans on the 405. This has bothered me for months, but I could never find a good opportunity to fix it until Saturday. I drilled out the rivets and put the lead back in a drawer. I also read about a neat trick you can do when balancing your elevators: Pour some lead shot into the tip through the tooling hole in the rib until th elevator balances out, then stick it in place with epoxy resin. Even if it’s not perfect, bias it a little heavy, because paint will change the balance.

I also mounted the MGL GPS antenna on the top side of the glare shield. It works; I get an intermittent GPS position while still inside the guest house.

Oh and one other thing: I dragged the wing cradle over to the shop and tested out the bank servo of the autopilot. Since I actually followed a wiring plan and wired the fuselage-side and the wing side according to it, I was able to test out both servos simultaneously. I do need to make a new ground connection though. The ground from the servo bracket sucks and I was only able to get a good ground by cleco-clamping the ground terminal to a wing rib.

Wiring and wing conduit

4 hours.

I took a drive down to Earl’s on Hawthorne at the 405 freeway to pick up the fittings I need to plumb the purge line. I wanted to save the 11 bucks for shipping, which is ricockulous considering it’s all of 15 miles away from my house. I’m glad I went. The place is an absolute gold mine of high performance vehicle plumbing. They have everything, including the weird stuff, and best of all, they can custom-make hoses while you wait. Still a pricey run. The stainless steel bulkhead elbow for the firewall was not cheap by any stretch. After I got back, I pulled the wings out of the garage to finish up all the old business, which was fabbing conduit support angles, installing Adel clamps, fitting and plugging in the pitot tube, and wiring the autopilot roll servo. I also spent a good amount of time rubbing off old masking tape glue with MEK. Don’t leave masking tape on anything for too long, especially in a hot, dry place The tape turns brittle and the glue turns solid. On the right wing I got wise and heated up the old tape with a heat gun which let me get most of it off in one piece. The rest came off like the stickers Van’s still puts on every part, which never peel off cleanly. This process took a while and by then I was completely beat. I only got 4 hours of sleep last night for some reason, so I was a zombie all day. I figured I’d nap for an hour and go back too it, but I started reading the last chapter of William Gibson’s “Zero History” and I was asleep before the end of the first page. I woke up two hours later, still exhausted, but I went back out there and wired up the autopilot pitch servo.

Both autopilots got wired using the D-Sub method: Use barrel-crimp d-sub pins and sockets on the wires, then individually shrink-wrap them, then put a big shrink tube around all of them. I did this for a couple of reasons. First, the Molex connectors didn’t have a decent locking mechanism. I’m sure it’s fine, but I didn’t like it. Second, I somehow lost a couple of the pins. Embarrassing, but whatever, this should work fine.

I didn’t get around to plumbing my purge line, and common wisdom seems to be to wait until the engine is hung for this. But the longer I wait, the more stuff is going to be in my way when I do a triple-bypass on the fuel system, so I want to get the tubing roughed in as much as possible.

Heated Pitot done.

6 hours.

I finished up the pitot heat stuff, got the heat module mounted and the wires spliced in. When I get the Adel clamps from spruce, that process is done and done. It doesn’t sound like much, but it took some time. I had to use platenuts because I have to plan on an extremely limited amount of access once the skin is riveted on. And as an added bonus to my day, I found that some condensation or spray from the hose left some kind of deposits all over my left wing. This sucks. I might be able to buff it out, but it looks like the lime or whatever is etching the alclad. Flat Olive Drab paint it is.

I also got the MGL com extender mounted, and got a good start on mounting the IO extender, but the 6R8 screws I have are too short, so I need to get some longer screws from ACS. Always with ACS. I want to finish this plane so I can stop buying stuff from them for a while.

Firewall fail.

5 hours.

Yesterday, I should have stayed in bed. It was that bad. I started out the day by attempting to mount the RDAC (engine monitor module) on the firewall. I did this by drilling out one rivet in the F-601L stiffener along the top of the firewall, then match-drilling the rest of the holes. Would have been a great plan, except when I was drilling the second hole in the firewall and stiffener, something moved and I put the hole about 3/32 of an inch below where it was supposed to go. Boom, violated edge distance. I have an email in to Van’s tech support to find out whether I’m going to have to replace that stiffener, which would suck like nothing has ever sucked before. It would involve removing the engine mount and the landing gear. The other possibility, since I’m not really placing a load on the stiffener with the 5-ounce RDAC, is that they’ll tell me to “build on.” If that happens, I just have a slightly crooked RDAC, but otherwise it’s fine. So I’m kind of freaking out about that, and really hoping I haven’t bought myself a ton of work with this one stupid mistake.

Then it started to get better: The LA public library emailed and said my copy of William Gibson’s ‘Zero History’ was available for pickup, so Shelley and I rode our bikes down there to get it. But on the way home I almost got run over by an idiot backing out of the car wash. What does this have to do with airplane building? Not much, other than it’s difficult to work on critical things in a state of elevated stress. But I needed a win of some kind, so I decided it was time to mount the heated pitot tube in the wing. Of course, that ballooned into wing wiring.

This pic doesn’t show the tubes, but I originally had the AoA and pitot lines running through the two grommets in the rib in the bottom of the frame.

But it’s a couple of years later, and I now know a lot more about EM interference than I did back then, as well as what equipment I’ll have on board. I pretty much rewired the whole thing. First thing I did was pull out all the wires and cut a section in the PVC conduit to allow the pitot heat wires and AoA tube an exit to mid-wing. I rounded off the edges of the PVC to mitigate chafing, then ran AoA tube, NAV antenna wire, pitot heat, landing light, and position light wires down the conduit, breaking out the pitot heat wires and the AoA tube, while sending the rest down to the wingtip. The strobe cable I ran through one of the grommets from wing root to wingtip, which will help isolate the strobe pulses from the NAV antenna. Supposedly RG400 cable keeps this from happening, but I’m going to be making a lot of connections at the wing root (building in the guest house, remember?), so I want to keep the strobe cable and the antenna as separated as possible. Unfortunately, I can’t close the deal, because I need two more 1 1/16″ Adel clamps for the cut ends of the conduit, otherwise they’ll vibrate against the ribs. Those should show up from ACS in a couple of days, but it really irks me to leave things unfinished because I don’t have supplies. It makes more to double check later.

The other wing got the same treatment, but I’d already cut a break in that conduit to allow for autopilot wiring. I still ran the strobe cable through the grommets near the spar, because I’m not terribly interested in having the strobes make the autopilot twitch. Also, depending on the performance of the Archer NAV antenna, I might put another one in the right wing for a second NAV radio at some point.

After all that, I didn’t get the pitot heat module actually mounted. That’s next.