Dave’s RV-7A Building Log

I didn’t get much done, as I wasn’t feeling well. I started the process of finishing the details in the left wing. It will take a little longer than the right wing because of the pitot tube and AOA ports. I tried to install the bellcrank, but didn’t have enough AN3-6A screws. I at least got the bushing trimmed down a bit.

Julie helped me flip the wing onto some saw horses. I installed the remaining tank screws and taped the Duckworks light template in place.

I started messing around some more with the flap sensor, when Julie volunteered to help finish the riveting on the left bottom wing skin. I jumped at that opportunity. It was just more of the same rivet pounding, with the minor complication of the pitot mount. It feels really good to finally have the riveting on both wings done. Thanks Jules. She caught a picture of me jammed in this tight space inspecting some of our riveting.

Spent some time figuring out exactly where I wanted the fuel flow sensor. The hose from the engine-driven fuel pump to the fuel servo looks like the best spot to me. I marked the hose and will send it out to get cut into two. I’ve agonized over this for hours. It’s a good feeling to finally have it decided. As long as I’m getting that hose altered, I’m going to get the hose from the firewall to the fuel pump shortened as well. The hose from Vans is simply too long and makes a real nasty bend. I’m going to get it cut down 3-4″.

Next sensor to deal with was the flap sensor. The wire in the AFS EFIS harness was way too short. Even if I ran it straight through the cockpit, it wouldn’t reach the flaps. Rather than put a connector in the middle, I yanked the wire from the harness completely and replaced it with a 22G wire all the way from the flaps to the EFIS connector. I also started on a bracket for holding the flap sensor. I’m doing something very similar to Larry Bowen, although altering it to work in the 7A.

While I was messing with the harnesses, I decided to move the wires connecting the GPS to the autopilot. Since the harness was pre-wired, I had to run the wire through the hole in the subpanel for the avionics. It was not ideal and has been bugging me for quite a while. It was easy to remove the pins from the autopilot connector, re-route the wire, and re-install them. Much better now.

Finally decided where and how to mount the manifold pressure sensor. I installed a couple of nut plates on the forward side of the firewall just to the left of the battery. I ordered some 1/4″ high-temp silicone tubing from McMaster to match the 1/8″ tubing that comes with the P-mags. That plus some polycarbonate T fittings made it all go together easily and cleanly. The fit of the tubing on the T’s is super strong. Nothing is going to pull those off. The sensor is a different story. I might use a mini hose clamp there along the lines of belt and suspenders. Also crimped the funky “WeatherTite” connectors on the wires from the EMS and installed the connector. Done and done.

Just a few more sensor wires to go and that harness will be done. Not much wiring left at all–at least until the wings get installed.

Since the remote compass mount is pretty much done, I figured it was time to put on the top skin for riveting later. I soon discovered that I hadn’t painted the underside of it. The very forward part of the skin is visible inside the baggage compartment. It amazingly wasn’t raining, so I quickly scuffed, cleaned, dried, and painted. I later put the skin onto the fuselage with clecos. Looooooking good.

Julie helped me some more with the left bottom skin riveting. We were both pretty tired from Adele’s birthday party last night, so we didn’t get too far. One more session should do it. I put nut plates on the access holes as well.

I also messed around some more with the firewall forward sensor wiring, hooking up the fuel pressure, oil temperature, and RPM (to the P-mag output).

One thing keeping me from riveting on the middle top skin is the remote compass mount. I wasn’t sure how big it needed to be. I asked AFS about it, and the dimensions are in the premliminary install manual. I made up a mount out of .040 sheet and temporarily installed it. I’ll probably end up using #8 brass screws (non ferrous) in some oversized holes so the mount can be adjusted a tiny bit to get it exactly in the same pitch and roll plane as the AF-3400 screen.

I also worked on the firewall wiring fittings. I installed them permanently with some #6 screws and the goop to seal them to the firewall

Spent a little time sorting and routing the sensor wires firewall forward and practicing my adle clamp skills. I don’t care for adle clamps, especially stacking up two of them. The routing of the wires is looking pretty good so far. I also hooked up the oil pressure sensor. In the picture, it looks like the wires are blocking the oil filter, but they’re not. They are a little bit in the way, but getting the filter on/off should still be easy.

Carl from NZ and I split an order of screws of various sizes from McMaster-Carr for securing stuff to the firewall. They are a socket cap head with a black oxide finish. They look really good.

I also ordered some seal material that DanC recommended on the canopy side rails. Looks like it will work well too.

I spent a little time looking over the rivets in the left wing from the last riveting session. A couple of them got horked up, so I drilled them out. Bucking access is not good and I was in a bit of a hurry. Haste makes waste. I also prepped the access holes for nut plates, but didn’t install them yet.

I’ve put this step off for quite a while. I’m always nervous about drilling through the firewall, but this is the best spot for the sensor wires to pass thru. It’s high enough that the battery can still be removed, and on a fairly direct path between the engine monitor and the sensors. I’m using the fitting from EPM.AV.

I had just a little time for the plane while Adele was playing with her B-day presents. I verified the layout of the panel labels, and tweaked things a bit more. I also gave the panel one more overall sanding in preparation for taking it to the powder coater tomorrow.