Bracket for Rear Fuselage Inspection Plate

Time: 2.5 hrs

Today I also management to fabricate a bracket to allow me to screw in the small inspection plate on the rear fuselage. This plate is usually riveted in like some of the fuel tank mounting plates on the wing, but also like the wing I wanted to be able to remove it. The ones for the wing were easy since the holes could be enlarged enough to install M3 rivnuts, but the holes for this inspection plate were too close to the edge to do that. I decided to make an inner ring that I could install the rivnuts into and then the screws could just pass through the holes in the fuselage skin.

The bracket ended up coming out alright. It was a bit difficult to get the inside cut out nice, but that’s just cosmetic. Maybe I’ll see if I can have someone make one up on a CNC someday, but for now it works fine and doesn’t even require being mounted to the fuselage skin.

I also used the edging tool to put a slight tapper on the inspection plate since it was just flat (unlike the ones for the wings which already have a beveled edge.

Bracket is made up and M3 rivnuts installed

The bracket will just sit in like this and will stay removable so that you can get a little more space to work if needed.

This will work well. Because the bracket isn’t riveted in you just need to be a bit gentle getting the first 2 screws in. Seems to hold well though.

Tale of Two Air Filters

Time: 0.75hrs

Quite a few months ago when I has ordering a few things from Aircraft Spruce I also went ahead and ordered the engine air filter. It’s a standard filter made by K&N. Aircraft Spruce had listed one for use on the Rotax 914 so that’s the one I purchased and a quick test fit showed that is seemed to fit fine. Later I received the fiberglass airbox that fits around the air filter which has a hose connection to it that ties into a NACA duct on the cowling to bring in fresh air to the engine. A fit of the airbox onto the air filter revealed that the filter was too long. After a little research it seems there are 2 filters that will work on the 914, the K&N RU-0800  (4″ height) and the K&N-RU-0810 (5″ height). The one Aircraft Spruce sells is the 5″ height so that’s why it was too long for the TAF supplied airbox.

With that figured out and the correct filter ordered I installed the filter and hose. Installing the filter is a bit tricky because there’s a few hoses in the area and not much room to work. I was able to get the clamp for the air filter tightened down using a ratchet wrench rather then using a flat head screw driver. The hose was fairly easy to install after cutting it to the correct length.

The 2 air filters I have. Both are 2 7/16″ at the throat, but the RU-0800 (on the left) is 4″ in height while the RU-0810 is 5″. The one on the left is the one that fits into the TAF supplied air box.

The RU-0800 fits nicely into the airbox.

Hose is installed. There’s a few hoses in the area so I’m glad it fit in there without too much hassel.

Wing Lights Wiring

Time: 3.0hrs

I had installed the Aveo Ultra Daylight nav/strobe light for the right wing a few days ago so I figured I can use that as a guide for the left wing (since I don’t have the left wing tip yet) and decided to wire them both up with the TE CPC connectors.

I also wired up the taxi and landing lights. My kit came with the Kuntzleman LTR lights so I’m going to use those. I found though that the mounting brackets I have with my kit are for the standard lights so I need to see if I can get the correct brackets from TAF. In any case I wired up the connectors for the lights so they should be ready to go when I get the mounting hardware.

I used a 4 pin mini mate N Lok CPC connector made by TE. The connectors aren’t completely water tight and don’t really need to be, but they are IP67 rated so they protect against dust and limited protection from water.

For these lights the ground is a ring terminal that will attache to one of the mounting screws. For the power connector I just uses a spade connector and shortened the wire on the light light a bit. When these finally get mounted you need to use some thermal paste (hence the little bag on the mount screw) between the light and the mounting bracket to dissipate the heat I guess. Tested them and they all work as well.

GSU25 Install

Time: 4.5hrs

Over the past few days I got the GSU25C ADAHRS and GTP59 Temperature Probe installed. Nothing too exciting to report on the install. I was originally going mount the GSU vertically, but found there were 2 holes in the rib that would work and the GSU fit well horizontally so I changed to mount it that way. I used M5 rivnuts and M5 screws to mount it. The kit comes with AN3 hardware which is mainly used when mounting the GSU to the rear of the GDU though can be used for other situations, but I chose to use M5 screws to keep consistent with the way I mounted other avionics. For the pitot/static lines I decided to use the nyloseal fittings rather that the push in type that I used In the rear fuselage and pitot tube. They seem kind of cheaply made, but seem durable and install fairly easy, just remember to get the small inserts that fit into the end of the nylon tube if you’re not using the nyloseal tubing.

Also rerouted some wires and clean some things up and replaced some zip tie mounts with adel clamps

GSU installed with M5 screws also I used nyloseal fittings for the pitot/static lines. The pitot and static lines (not the AOA though) will continue on to the G5.

Wings Moved and Wing Tip Light Installed (Right Wing)

Time: 1.5 hrs

The good news is the wings are safely in the garage on the wing dolly. The bad news is I have no room to work. The dolly is a little short so it’s hard to move the wings around easily because you can’t grab it anywhere to move it. I guess even if it was easy to move them I wouldn’t want to so they stand a less chance of getting damaged. Well hopefully I can work around it. Most of the work will be inside doing avionics mounted to the rib and shelf behind the panel. I ordered and received my GSU 25C and the temperature sensor so I’ll get that installed and wired up this week.BTW I have and extra GMU11 if someone wants one at a discount :-). After the GSU I just need to do the VPX and the radio stack and the windshield can go on.

I also mounted the Aveo Ultra Daylight nav/strobe/position light on the right wing. I don’t have the left wing tip yet so can’t do that one. I had previously made up the backing plates for the lights so it was just a matter of figuring out where to put it and drilling a bunch of holes. The Ultra Daylights mount with a 4mm pin and an M5 bolt (provided) so I installed an M5 rivet on the mounting plate I have made. I used 2 3.2mm countersunk rivets to fix the mount to the inside of the wing tip. I also drilled out a 3/4″ hole to pass the circular connector through that I’ll be using to connect up the light. I made the hole in the fiberglass 1/16″ smaller just to minimize any issue with the wires rubbing on the metal edge oof the mount, though this isn’t really an issue since the wires have a bit of a grommet coming out of the light and are fairly stiff at that point. The Ultra Daylights are non TSO’d, but there is a TSO’d version called Ultra Galactica. I’ve heard that some DARs require TSO’d lighting to sign off on the plane as IFR capable. The TSO’d lights are about twice as expensive so if that’s required I can always get those and sell these. The mounting holes are the same so it would be a quick swap out.

The mounting plate which will be installed with 2 countersunk 3.2mm rivets on the inside of the wing tip. The holes in the fiberglass are countersunk as well so the light sits flush, the rubber seal is probably thick enough to accommodate regular domed rivets, but the countersunk is better I think. Also will be using the circular connector to wire up the light so I needed to make a 3/4′ hole for that to fit. The hole in the fiberglass is 11/16″.

And everything actually lines up and fits…. Yay!

Oil Cooler Hose Rework

TIme: 1 hr

I started doing a little rework of the hoses connecting to the oil cooler. The original hoses I had made up have 90 degree fittings on both ends, but then the clocking of the fittings have to be exact. Since I decided to run both hoses on the right side of the prop shaft rather then one one each side it made the clocking off. It ended up still working but the hoses had a bit of twist tension in them and it also pushed down on the oil cooler and the cowling a little.. I came up with an idea to instead use 90 degree fittings on the oil cooler so that the hoses could have a straight fitting on one end and not need to be clocked. It wasn’t easy finding an M14x1.5 male to 3/8″ NPT female fitting though. I originally wanted an M14 to -8AN 90 fitting to replace the straight one that came with the oil cooler, but that seemingly doesn’t exist… well at least in steel. So the M14 to NPT fitting was installed and then I have an NPT to -8AN 90 degree fitting . The angle can be adjusted to it’s pretty flexible to get it how you want the hose to run. I will need to get the current hoses cut and straight fittings put on. The only issue I see is that having to use 2 fittings has made the connector come up higher and the hose will be closer to the alternator belt. I can turn the hose a little more straight to get more distance, but I think it will have enough clearance.

Got the old M14 to -8AN straight fittings out without damaging the oil cooler. and put in the new fittings. The M14 to NPT fitting seals with an O-ring and I tightened that to 26 ft lbs same as the other fitting that I removed. The 90 fitting is a tampered NPT so I used Loctite 567 which is for high temperature

The new fittings are angled and the hoses are marked. I’ll have to send them back to Steve at Aircraft Specialty to cut and put the new ends on.

Fuel Tanks Installed

Time: 5 hrs

Today and yesterday I mounted the fuel tanks. All went along pretty well. I started by clecoing the rivets along the rib that joins with the wing. I then got the bolts in that attached the tanks to the spare. One thing to note to make it go a bit easier is to first run the bolts through the nut plates prior to installing the fuel tanks. A little light oil on the threads helps as well. This makes it much easier to get the bolts in when you’re working in the limited space in the wing. I also used a center punch to line up the threads with the holes in the spare and that also helped a lot in getting the bolts in. Once the bolts were all loosely in I went through and clecoed the 4mm rivets that run along the spar and also fit some rivets into the holes. Next I tighten up the bolts, not torqued, but just snug so that the tanks was pulled down onto the spar. I then pulled the rivets along the spar and then the rib that joins to the wing and then torqued up all the bolts.

The one issue I have is that I have very slight scalloping on 2 rivets on the top of the left wing at the rib that joins to the wing. This because I didn’t see that there was about a 32nd of an inch of space at the leading edge of the join. I’m guessing it’s caused by the joining rib not being exactly the same shape as the tank rib. The right wing is perfect so I’m a bit upset about it, but it’s not that bad. I didn’t catch it until all the rivets were installed on the spar so there’s not much I can do about it. Even so I don’t think removing all the rivets and pulling the tank down down would help because the tank is really as far down as it can be. I’m thinking I would need to unrivet the other skin and try to push it up a bit. I’m still wondering if it’s worth doing since it’s not that bad.

So the wings are pretty much done. I’m still waiting on the left wing tip. It’s been almost a year now. Hopefully will get the right (or should I say the “left”) one soon. So a bit anticlimactic because of the scalloping issue, but nice to know most of my riveting and priming is done. Now the next big challenge is to move the wings into the garage without destroying them. Then onto finishing up the avionics and installing the windscreen.

Tanks finally mounted to the wings. Yay!!!

Right wing has some slight scalloping on the top rib join. Not sure if it’s worth unriveting lots of stuff to fix it. I suppose I could add 2 rivets in between, maybe will talk to Jean about it. Note some of the rivets are filled but not sanded yet.

Left wing join came out great.