« Posts tagged fuselage

“Twas the Weekend Before Christmas, and All Through the Hangar…”

4 hours.

“Not a creature was stirring, save this rivet banger…”

This encompasses Saturday through Monday.

With the holidays in full swing, the schedule gets a little weird, but better, because I have a few days off.   I’m keeping a decent balance between building, home obligations, holiday festivities, and the occasional video game.   I’m also coming to terms with the fact that the endgame for this project is approaching rapidly, or so it seems to me.   Last weekend, I’d started on the gear leg fairings.   This weekend, I pretty much got them done.

The most important thing with the gear leg fairings is to build them without any twist in them.   They come taped together from the factory, but Van’s fiberglass is usually so crappy for fit, I didn’t trust them.   The way you verify no twist is to put the leading edge on a flat surface and using a square, insure that both trailing edges line up.   Once that’s done, you can use the full-scale template cut from the plans to mark all the cut lines.   Easier said than done, though.  You really need two squares, one for each end, and another pair of hands, or at least a boatload of tape.   But I found a solution in our hangar that worked very nicely:

IMG_1710That brass thing is a piece of channel from one of those godawful floor-to-ceiling mirrored sliding doors, usually found in cheesy SoCal apartments that saw their last renovation some time before Saddam Hussein rolled his tanks into Kuwait City.   But it makes a very nice, very straight jig for lining up the trailing edges of the gear leg fairings.   Not only that, it provides an excellent platform for match-drilling the hinges.   Some of you are looking at this and saying “hey, those are the wrong size hinges!”  Yes they are.   But it’s what I had.   I used up all my 1/16″ piano hinge on various attempts at the cowl.   If it should come to pass that these hinges cost me knots and fuel, I’ll change them out, but at this point, I want to be done.


A selfie, checking the alignment of the hinge.

With those done, I could check out the fit of my intersection fairings.


Upper intersection fairing fits, sort of.   It needs some work.   It’ll also need to be taped into position to hug the contour of the fuse and cowl, and then a couple of layups on top of that.   After that, it gets trimmed back to where it’s supposed to be.   Van’s fiberglass may be crap, but it’s better than mine and it sure beats fiddling around with modeling clay.

Monday was all about tying up as many loose ends as I could before starting on the wheel pants.   This meant, among other things, getting as ready for the inspection as possible.   I attached the ‘EXPERIMENTAL’ sticker to the roll bar:


This is a bit redundant because the baggage bulkhead cover that came with the interior has it embroidered into the leather, but that won’t be installed during the inspection.   The canopy frame covers this one up when the canopy is down, but I don’t think that matters.   If it does, those stickers are cheap.


This is required by the Feds to be in the airplane in plain view of the occupants.  It’s like a magic amulet to ward off the unadventurous.

Left Gear Leg

Left Gear leg

Left Gear leg works much the same way.

After this, I spent some time doing odd jobs.   I safety-wired the tailwheel chain hardware, then moved to the cockpit, where I zip-tied the wires made loose by the magneto troubleshooting and the addition of the OAT probe.    I also attached bolts in the center section per Van’s SB 12-08-14.   Apparently enough people forget this step that Van’s thought it merited a Service Bulletin.   Guess what?  I forgot it too.   In addition to the close-tolerance bolts that hold the wing spars to the center section, there are two on each side that secure the center section to the vertical bar on the wing spar.  These need some AN4 bolts in there to lock things down.

Part of getting airworthy is checking all the relevant SB’s and AD’s to make sure you don’t have anything hanging in the breeze that might kill you.   The rules on experimental aircraft and AD’s are fuzzy, and are interpreted by various people in various ways, because different sections of the FAR’s appear to contradict each other.    But the safe thing to do is check for AD’s and SB’s that apply to your stuff and fix them if you find any.   If I hadn’t gone through this process, I wouldn’t have found those missing bolts and the inspector would have.

When I moved on to the engine, I discovered some oil running down from the spacer on the right mag and at the oil drain fitting of the #1 cylinder.   This was alarming enough to merit a quick engine test.   I cleaned off the oil and wheeled it out to start up, to verify that the oil was new and not left over from the last time I had to loosen them up to get to one thing or another.

I did a quick runup and brought the cht’s up to operating temperature, but even with good, timed mags, it still stumbled off idle.   Advancing the throttle slowly would bring the RPM up, but moving it smartly, like I would for takeoff, killed the engine.   After consulting VAF and then my AFP manual, it looks like my idle mixture is set too lean.   This will need to be corrected, and I can probably do this tomorrow.  The good news is that I didn’t see any new oil in the spots where I found the drips, so it looks like the oil around the mag spacer was from when I had the mags off, and the oil from the #1 drain line is from the time I had to undo the fitting at the cylinder head to get at either the bottom spark plug or the EGT probe.



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.


The Skinner

3 hours.

And yes, it’s a shout out to Neal Asher, whose writing has gotten me through a tough couple of months. When you’re having horrible-seeming things happen to you, reading about truly horrible things happening to somebody else and the truly horrible people who cause them getting their comeuppance is very therapeutic.

As far as this aircraft project goes, yesterday was not horrible. I actually might have the temerity to call the firewall-forward process almost done. The only two things missing from the equation is a 2″ hose clamp for the cabin heat SCAT tubing (which is actually missing, I can’t find it right now) and the manifold pressure sensor fitting and tubing, both on order from McMaster-Carr. I can look at the engine installation and say with fairly high confidence, yes, this engine will turn the propeller repeatedly. Today I’ll go through my periodic shop purge/clean ritual and see if the clamp turns up.

I also took a long look at all the stuff just behind the firewall and ahead of the subpanel, to make damned sure there was nothing else I needed to put there, because as I’ve mentioned before, once you rivet that top skin on, you can’t get to anything below it without a flashlight, a mirror, and possibly tentacles. Satisfied to the limits of my ability with such things, I began riveting the top deck skin on. This is hard. This is hard because you have to have a rivet gun on one side and a bucking bar on the other, separated by a 3-foot sheet of metal and ‘awkward’ only begins to describe the process. There are two holes in the subpanel support capable of taking my hand holding a bucking bar through them, and it’s a little like the reverse of a monkey trap. There is much maneuvering into position, then there is riveting, whilst holding the bucking bar perpendicular to the rivet without being able to see it. This process enabled me to do the center row of rivets, and the canopy hinge support bracket, but failed on the outboard subpanel support rivets because to get my hand into the right position, I had to bend the skin away from the surface it was being riveted to, causing a gap. I couldn’t get the leverage I needed and the skin ‘pillowed’ on the support rib. Bah. Curses. Foiled. I’ll need to enlist a helper for this step, but as soon as it’s done, I can put the canopy back on and officially list the project as ‘more parts assembled than not.’

Oil Door.

6 hours.

Yesterday and today.
Yesterday I worked on the oil door. The finish kit comes with a fiberglass version, and it’s meant to be held down with an elephant-ear Camloc fastener, but it looks like ass if you do it that way. A better alternative is the Nonstop Aviation hidden hinge kit.

It mounts the door on a sprung hinge that opens up and out of the way of the cowl. You can use the fiberglass part from the kit for the actual door, but like some others have done, I made mine out of .032 aluminum. The reason? When the fiberglass part gets heated by the engine, the pressure from the hinge trying to open will warp it. Aluminum has no such limitation.

Once the door is cut, formed and drilled, the flush-mount Camloc release latch goes on. I actually made two of these things, because I screwed up the Camloc location on the first one. No biggie. I still have half of a .032 horizontal stabilizer I’m using for stock.

When it’s all in place, it closes flush and latches properly, but getting the hole for the latch handle was kind of a bear.

When it’s open, the spring keeps it out of your way so you can check oil, remove hinge pins, etc.

Today I was doing more checks of things under the area where the top skin will go, because that’s going to have to go on soon. I spent some more time securing wires and torquing down Adel clamps. In doing so, I found that I never riveted the row on the longeron right next to where the canopy closes. They leave them open at the QB factory because the slider canopy mounts a little differently. This isn’t all that easy to deal with when the panel and other things are installed, but it’s not that bad either. All I had to do was disconnect the vent hoses so I could get hands and bucking bars up inside the channel by the longeron.

After that, I started putting the baffles back on, but didn’t get very far. I’ll do some more of that tomorrow.

Another productive day.

4 hours.

Bunch of stuff happened today.  Shelley helped me get the fuel lines secured with Adel clamps, and I got the fuel pump reinstalled and wired up.  It works!   I also got the tunnel cover finished, but didn’t get to setting up the cabin heat cable.    The throttle quadrant also went back in.   It’s nice to finally see the ‘damage’ from the avionics install and wiring fiasco put right and parts that were languishing on shelves put back on the airplane.

There is no end to wiring.   I cable-wrapped the antenna  wires and worked on the GS/NAV splitter mounting.  Fortunately, there were two holes ready made for it (not really, they just coincidentally lined up).   But I stopped dead in my tracks when my cable stripper exploded.   I need a new one from Radio Shack ASAP.   But once that’s done, the avionics wiring is just about done.   Finished.  Fin.  The end.

Still have to figure out how to connect the marker beacon antenna.   It comes out of the audio panel as a single shielded wire, but it has to connect to a big, fat length of RG400.   How the hell do I do that?

It’s on again.

12 hours.

That’s today and yesterday.   Shelley helped me rivet on the cover plates to patch the holes in the hull I drilled in search of better antenna locations.  There were 3, total.  One down in the tail, one under the baggage floor, and the original one just forward of the spar under the EFIS.   Since I had her in the plane, i was able to reinstall the transponder antenna properly; I’d taken it out to see if that hole might be a suitable location for the COMM antenna.   It wasn’t.   When we got that done, I went to work on putting the pax side floor back together.  Since I had access, I was able to wrap and secure all the cables going aft under the floor, and I can still access the antenna connection under the seat floor.  After that, I spent a lot of time with cable wrap, securing all the loose wiring running down the tailcone.  I took the advice of someone on VAF, who said something along the lines of “start at the tail and work your way forward, finishing everything you can possibly finish.”   Practical matters preclude me from absolutely finishing the tail section right now, but everything else got done and done.   I torqued down the autopilot pushrod bolts (been driving me crazy for a while), and secured all the wiring of the ELT and strobe pack.  The ELT wiring got secured with a length of shrink tube around the idiot DIN connection (phone cables and stereo connectors?  WTF, ACK Technologies?)  providing NMEA GPS info to the ELT.

Alphabet soup, I know.   We airplane people love our acronyms and abbreviations.

I still have one or two loose ends: I need a special platenut to completely finish the baggage floor, but that should be here tomorrow.

Today I started seeing the end of all the disassembling necessitated by having to wire the aircraft.  I got the flap actuator and flap motor put back in, but this time wired in properly with wires secured in the tunnel.  Lo and behold, I was also able to install the flap arm covers in the baggage compartment, something that hasn’t happened since the interior was painted.    I also cable-wrapped the cables running forward of the spar past the fuel lines and locked those down with cable stays, so nothing’s rubbing on anything.

I also began work on reintegrating the control system on the sticks.   A while back, before I knew what I was doing, I overstretched my trim springs and had to get new ones.   I’ve since gotten them, and was working on getting the sticks all back in order.   I had to paint the steel connectors for the springs, so that stopped while the paint is drying.  I started futzing around with the hard fuel lines on the floor, but didn’t really get anywhere.

Tomorrow I should be able to finish the sticks and see if I can’t get the fuel lines secured (they need a couple of Adel clamps to keep them from vibrating too much) and install the fuel pump permanently.

Really? Really?

4 hours.

This is actually from last sunday, but this is the first chance I’ve had to actually write it down.    Happy Thanksgiving, everyone.    I give thanks for… The fact that MGL Avionics is being unbelievably awesome about fixing my EFIS.   Again.

I finished the connections for the SP2 and SP4, wired everything up, and started cleaning up the mess behind the EFIS.   I got everything wired in and properly arranged and the whole thing went south in a big hurry.

Over the last couple of weeks, I noticed a bit of flickering across the EFIS display, and sometimes the unit would crash, with the White Screen of Death.   This is usually solved by power-cycling the unit.   Not today.   Today the WSOD came on and stayed on.   So rather than a complete and utter freakout, I just resigned myself to sending the EFIS back to MGL for any necessary repairs.   There’s still plenty to do.

Get a grip.

1 hour.

I felt fat, stupid, and guilty for watching a hulu’d Sons of Anarchy episode with a big bowl of mac and cheese, so I went out to the shop to get something, anything done. I wound up replacing the microswitches in one of the Infinity Aerospace stick grips. The military style grip is really cool, it’s like an old F4 Phantom grip, with a trigger PTT, a four way toggle (‘china hat’ is not the preferred nomenclature, Dude), and 3 pushbuttons, one momentary, the rest on-off. I had to replace the toggle, because it sticks on in the up position and is momentary down. I want that to be my flap controller, so it needs to be momentary in both directions. I replaced it with one I bought from ACS a few weeks ago. I also got momentary pushbuttons to replace the on-off ones. I imagine those will become AP disengage, transponder ident, frequency flip-flop on the 430, and something else TBD. Maybe flip flop on my spare comm, whatever that winds up being. I might change one back to on-off and run the fuel boost pump with it, we’ll see. I can probably do the other grip tomorrow morning before work if I don’t dawdle on the internet for too long.

Wiring and fiberglass.

12 hours.

This is for yesterday and today. I finished up the elevator and HS fiberglass tips. You’ve heard me piss and moan about fiberglass before, so I’ll spare you that this time, but yesterday’s experience was not great. I got the HS off the futon in the other room and set it up on the bench so I could mount and balance the elevators. When I last left the HS, I’d done the fiberglass tips, but I hadn’t done much else with them, and they needed a good amount of shaping before the elevators could swing freely. One side was fine after some filing and sandpaper, the other had the foam too close to the edge so I sanded all the way through the filler and started taking out foam.. This isn’t good. Raw foam isn’t helpful, so I had to mix up some flox, both to fill in the elevator tips after balancing and reinforce the left HS tip. I had this cool thing set up where a thin piece of sheet was curved round the elevator tip, making a form for the flox that would guarantee the free motion of the elevator through its travel.

Would have worked too if the tape hadn’t popped loose, leaving me with a distorted lump of flox on the front of one elevator. I had to file/sand that back into shape, then glop in a load of micro filler to get the final shape.

So there it is curing away.

I busied myself with antenna mounts while the epoxy was setting up. First was the transponder antenna. I’ve decided to put this on the floor behind the baggage bulkhead. All antennae need doublers, even the stubby transponder antenna. The skin of the aircraft isn’t thick enough to provide structure on its own, so I had to take a piece of .063 and make a plate that the antenna can grip onto.

Today I did the final shaping and priming of the HS and elevator tips. While I was waiting for paint to dry, I worked on the doubler for the Garmin GPS antenna.

Installing these doublers aft of the baggage bulkhead is interesting. First thing you do is drill the holes in the plate at four corners, then one in che center. Then you go inside the ship, down the Jeffries Tube, and position the plate where you want it for proper antenna location. Don’t forget to bring your drill. Use the plate as a guide, and drill the skin using the center hole in the plate as a guide. Then measure to square the plate up with surrounding stuff, then drill the corners of the plate. Now it gets fun. You have to dimple all four holes in the skin that match the corners of the plate. You need to use your 3/32″ pop-rivet dimpler for this, but you do it by crawling into the ship, placing the dimpler, getting back out, making the dimple, then repeating 3 more times. In the case of the GPS antenna, there are also screw holes to deal with, which means platenuts. Oh, don’t forget to countersink the skin side of the plate.

Since I was in the tailcone a lot today, I figured I’d do some nagging things I was going to have to do anyway, like the restraint cable clevises and removing the ELT antenna cable. Yeah, can’t run the ELT cable through bulkheads. If you crash, the airframe might fold and sever the ELT antenna cable where it passes through a piece of sharp metal. I decided to run the trim servo wire down that run in its place. Then I ran the transponder antenna wire alongside the two GPS wires on the left side and did the BNC connector.

I don’t want to spend a lot more time down there. It’s cramped, hot, and dusty in there. If I can get enough servo wire slack so I can work on the connector outside the ship, that will make me extremely happy.

The Jeffries Tube.

3 hours.

In Star Trek, the Jeffries Tube (named after a member of the original series’ production crew) is a long, narrow tunnel from the engine room to the warp drive nacelles of the USS Enterprise. On the RV-7, it’s the space behind the baggage compartment going all the way down the tailcone to the 3rd-to-last bulkhead. Working down there really does make wish such things as aircraft elves existed. Unfortunately, they don’t, so I had to crawl down the Jeffries Tube to drill holes in bulkheads for wiring grommets, carrying a big cordless drill, a bit for the pilot hole, a bit for the grommets, a deburring tool, and the grommets themselves. I was able to get the grommets in and start the wiring run for the strobe cable and tail light power wire. It’s a slow process, and being mildly claustrophobic and crammed into a metal tube reminded me of my recent unsettling, yet action-packed U-boat dreams. I’m going to be spending a lot of time down there. I also have to drill grommet holes for the ELT coaxial cable and set up the wire stays for everything. I’m trying to avoid drilling more holes in the longerons and j-stringers, but I do have some adhesive-backed cable tie holders that will need to be placed.

As an aside, I finished the lower empennage fairing. These two stupid pieces of metal are supposed to have a rubber seal on them, but there’s no way that’s going to fit. Also, there’s no point in making these things removable, so I riveted them on. So now I have a 1/16 to 1/32 gap along the horizontal stabilizer at the root. So I lose a knot. Big deal. If it concerns me later, I’ll create a proper fiberglass lower fairing. Speaking of fiberglass, I got the empennage tips riveted on. they’ll need a coat of primer/paint, but they’re done.

Also, yesterday I got a call from Tim at Tim’s aircraft. My spam filter de-rezzed his pdf of the engine repair estimate, but I got a new one from him. Nearly eleven grand. Ouch. But now I have nitrided steel cylinders instead of that godawful cermichrome and it’s going back together as soon as the magnetos come back from the specialty shop. I just hope he doesn’t flinch at installing the AFP fuel injection system. But what that means, brothers and sisters, is that I’ll probably be hanging the engine in the not too distant future. At this point it’s now time to get down and dirty with the remaining amounts of money and see if there’s enough for avionics, remaining FWF, interior package, taxes, training, and hangar rental at my phase 1 airport.