Dave’s RV-7A Building Log

The weather is not cooperating very well for a first flight. Yesterday morning was nice and clear, but the person I have doing the test flight, Terry Burch, was stuck in California. We’ll hopefully get another window of good weather soon.

Adele and I went down to the hangar this evening and re-installed the wing tips. I’m leaving most of the access panels and covers off so Terry can take a look at everything before flying. I also updated the software on the AF-3400 screens.

I read over my operating limitations for the first 40 hours again. My test area is indeed a 50nm radius around Renton airport. It also specifies a flight test corridor “in order to safely conduct the type of anticipated maneuvers and tests, as appropriate.” Here’s the test area and corridor displayed on Google Maps. I take that to mean I should do my initial test flights and any of the testing that is potentially dangerous within the corridor. For the rest of the time, I can use the 50nm radius. That’s great–much better than I thought from my first skimming of the limitations.

I have a slip of pink paper that says the plane is now legally able to fly! The DAR inspection went very smoothly. I was a little concerned when two people showed up. Turns out an employee from the FAA MIDO office decided to do an “over the shoulder” on my DAR today. I figured that couldn’t be good, but he really just stood back and hung out for the most part. The DAR found a couple of minor things. He said I needed spare fuses accessible to the pilot. I put some in a Ziploc bag in the seat pocket. (I didn’t ask any further into the logic behind this, since my fuse panels are up under the forward skin access hatches. I guess it meets the letter of the law, if not the intent. I wouldn’t want to mess with replacing a fuse in flight anyway.) My COM1 antenna wire was a little tight behind the panel. I freed up some slack from down below. And the final item was my landing light wires needed a little more securing out at the wing tips. Done.

Two minor issues in the paperwork. I asked for a 50nm radius around Renton for the test flight area, because so much of the area is Sea-Tac class B space and densely populated. Instead I got a 60nm by 25nm box, approximately 1/3 of which is over the Cascades. I ended up with even less room than the 30nm radius. Not good for an airplane that cruises at 200mph.

The other issue is that my operating limitations prohibit aerobatics. Supposedly I was supposed to request that in my program letter. Well I checked the box that said my plane is aerobatics capable. What more was I supposed to do? I’m not too worried about it. I’ll add aerobatics later via the FSDO when I’m ready to try flying upside down.

Unfortunately the weather took a real turn for the worse this afternoon. Plus Terry, the guy doing my first flight, is stuck in California due to weather. He might fly commercial back up here. We’re going to keep an eye on the weather. Hopefully we’ll get a window of decent weather later this week.

I stopped by the hangar again today. I pulled the plane out, fired it up, ran it up to about 1700 RPM, and tested the left and right ignition. There was about a 50 RPM drop, which is good. I also cycled the prop a few times. Everything is working very well. Idle was about 900 RPM. The engine is really running like a champ.

After shutting down and putting the plane back in the hangar, I was thinking there should be at least one minor issue on the engine. I was checking the engine over very carefully for leaks. Didn’t see anything at all. And then I noticed one drip near the firewall. Took quite a while for the next drip. Traced it down to the fuel pressure sensor. I tightened it down another 1/2 turn, and it stopped. Now I’m happy. I found the one issue.

I vacuumed and cleaned out the interior. I secured a few wires and a few other minor things left on the list. I removed the spinner and wing tips to prep for the inspection. When I removed the spinner, I found a little bit of grease was flung out of the prop. Totally normal.

I then spent about 2 hours doing a mini annual condition inspection. I used Dan C’s list. It went pretty fast as all the covers are already off and will remain off. And nothing needs lubrication and nothing should be cracked at this point. I went over all the controls, wiring, plumbing, etc. I found a couple of jam nuts on the engine control ends that were torqued but not marked with torque seal. I also didn’t correctly mark a couple push tubes on the ailerons. I left one side of the jam nut unmarked, so I took care of that. They were already torqued. Very, very minor issues. She’s ready.

I finished out the day by renting a Cessna for hopefully the last time. After the transition training in Mike Seager’s RV-6A, the 172SP was like driving a bus. It has the same 180hp engine as my RV, but weighs much more and is not nearly as aerodynamic. Still, it was good to do a few landings, including one at my new home field, Renton.

Took care of a few more things on the list. My order from Vans arrived, so I put the final two bolts in the wing spar web and put the final hinge pin in the flaps. I secured the flap hinge pins in the middle with some safety wire.

I made a little bracket and used an adle clamp to secure the canopy release.

I found a better set up for testing the pitot and static systems. A recent article in Kitplanes had a table that showed inches of water versus airspeed. Both the AFS unit and the analog gauge are right on the money. I tried several readings up to 100 knots, and they were all within 1-2 knots.

Testing the static system wasn’t as easy. I have a table of inches of water versus altitude, but haven’t found out a way to verify the numbers yet. I did verify there are no leaks in the system.

Chris stopped by again, as did Jim. I spent a while shooting the breeze about RVs. Always enjoy that.

I can’t even remember the other things I took care of, but it’s all little stuff at this point. Before I left I put a little bit of JB Weld under the front of the canopy fairing where the fiberglass lifted up a tiny bit. I weighted it down with some rivets in a baggie.

Primary goal for the day was to taxi the plane. I started off by installing a few bolts in the wing spar that showed up from Vans before I forgot about them. I then took the cowl down to the wash rack area. It had quite a bit of amine blush on it from when I applied a skim epoxy coat. Luckily, it washes right off. Back at the hangar, I started prepping the plane for taxiing. I attached the wing tips, removed all the junk from the wings, checked the engine over one more time, and then put the cowl on.

The engine started right up, but was idling way too high, around 1300 rpm. During the first engine start it was idling too low, so I gave the idle screw one turn. That was way too much. I had to shut down and completely remove the cowl. I backed the screw off about 2/3 turn. Put the cowl back on and fired her up again. Idle was 1100 rpm. I’m starting to think the low idle was an anomaly. It was probably set right to begin with. 1100 rpm was OK for taxiing, though. I carefully released the brakes, and she started moving forward. Turned the corner around the hangar and called up Renton Ground. Taxied a few thousand feet up the field dragging the brakes to break them in. Did a 180 and returned. Shut down the engine. Perfectly according to plan, except I was planning on doing a “mag” check. Next time.

I have to say the plane turns much easier than Mike Seager’s trainer RV-6A. Maybe because there’s less weight with just me in it and 1/2 fuel. Maybe I’m just used to differential braking now. I took several shots of the EMS, as it doesn’t seem to log anything until the airspeed gets above a threshold. Here’s a representative screen. Everything looks okie dokie.

I am totally stoked to fly this thing. FAA inspection is Tuesday. If all goes well, hopefully she’ll fly this week!!!

I didn’t get down to the hangar last night. I worked on the Pilot’s Operating Handbook and checklists on the computer. Need to get those finished up for Tuesday.

Tonight I again got a bunch of little stuff done. The plan was to do a taxi test, but it was spitting rain all evening. I started off by checking the air pressure in all the tires, and securing the cotter pins on the wheels (just remembered that I hadn’t done that yet).

The fuel pump overflow fitting is once again broken, I’m going to try fixing it one more time. It’ll be easier than figuring out which AN fittings I need.

I started working on securing the canopy release mechanism. I cut the handle short so it will stick out of the subpanel, but not the main panel. I’ll then secure it with an adle clamp.

I was messing around with the stick again, and noticed a strange clunking sound. Turns out the forward elevator pushrod was hitting the bottom of the opening in the F-705 bulkhead. Must be related to me securing the push rod during the last session. I’ve never noticed it before. I filed the opening a bit larger until it stopped hitting/rubbing.

I used a short section of vinyl tubing secured with Shoe Goo to create a chamber under the top AOA port. That will help guide the pin for draining it.

I replaced one spark plug. Many months ago, I accidentally dropped it on the floor. I was slightly concerned about it, but figured it was fine. Well, I read an article last week that said the insulator can crack causing all sorts of problems including pre-ignition. Not good. I remembered exactly which one it was, so I picked up a replacement at B&B Auto Parts and installed it (Shucks, the world’s worst auto parts store, doesn’t stock it).

I’m sure I did a few other things, but I can’t remember them at the moment. Lots of little details. My (hopefully) final order from Vans arrived, so I’ll take care of the last few items tomorrow and Saturday.

Chris Kleen, an RV-6 builder and flyer, stopped by. I figured we’d chat RVs for a while, but he was soon poking around in the engine compartment and spent the better part of an hour going all the way around the plane checking all sorts of little things. He had a bunch of suggestions and I wrote down a few things to fix. Thanks for stopping by Chris. It was great to have a set of experienced RV eyes look over the plane.

I keep crossing things off the list of items left to do, and I keep adding stuff to it. Luckily, the stuff I’m adding is pretty minor. For example, clean the canopy, secure the wing conduit pull string, etc. I took care of a bunch of little stuff like that today.

I tried fixing the canopy skin. It will no longer catch, but it definitely doesn’t look pretty. Still need to do some cosmetic work there.

I was messing around in the cockpit and decided to look into why there’s a tiny bit of pitch freeplay in the stick. Turns out I never tightened the jam nut on the forward push rod. Guess I thought I would need to adjust again. Once I noticed it, the loose nut seemed like a glaring omission. Of course, I’ve looked down there a hundred times over the past few months and never noticed it. Luckily, the push rod is designed such that even if the nut is loose, the push rod can’t get free.

I then decided to check the other end of the push rod. Sure enough, that nut was loose, along with the autopilot servo push rod. Getting back there was uncomfortable, but I tightened and torqued everything that was loose. I’m planning on doing a full check out of everything on Saturday, following an annual condition inspection checklist. I would have found these loose fittings anyway.

Tightening up all the push rods reduced the freeplay significantly. There’s still a tiny bit left, but it’s got to be less than 1mm. Very, very minor. There’s absolutely no freeplay in the ailerons. I went on to measure the elevator and flap angles. The elevators are within Vans published specs, but the flaps go down 44 degrees versus the 40 degree max specified by Vans. I’ll double check, but that shouldn’t be a big deal.

I also installed the fire extinguisher. I put it right behind the passenger seat. It’s out of the way and accessible. It was tricky reaching under the seat pan to tighten the nut, but it’s done now.

I confirmed my inspection appointment with Richard Tardif for March 20th. Woo hoo! And I confirmed Terry Burch will do the first flight as soon as the weather cooperates after that. Double woo hoo!!

I noticed the fuel pump overflow fitting broke a while ago. It’s just a brass plug with a hole drilled in it and a tiny copper tube soldered in. The solder joint broke at some point while I was installing it way back when. I tried fixing it yesterday by re-soldering the joint with a plumbing torch. I was down in Renton at lunchtime dropping off my airworthiness paperwork at the MIDO, so I stopped by the hangar to re-install it. In the process of wrapping the safety wire around the tubing, it started to jiggle again. Vans funky fitting is just a poor design. There isn’t enough contact between the brass and copper to make a good solder joint. The whole reason Vans created this fitting is that there isn’t much room between the engine and firewall in an RV-4. There’s plenty of room on an RV-7A. I’m going to switch to real AN fittings, eventually.

While I was at the hangar, I also wrapped the fire sleeve around the fuel flow sensor and secured it with safety wrap. Now that I know there’s no leaks, I’m comfortable covering it up. It’s not super pretty, but is functional.

The first task for today was to make and install the fuel tank vent lines. They’re a little tricky, but not too bad. I tie wrapped the tank sender wires to them.

I was never happy about the method I used previously to set the aileron neutral position. I decided today to use the established method of lining up the wing rib tooling holes with the aileron tip. I secured both ailerons in that position and then modified the push tube length until the stick was straight up and down. (The picture looks strange, but that’s just the wing tip sitting upside down on top of the wing.)

I then altered the flaps to match the aileron position. The flaps were hitting the fuselage, so it was not possible to get them exactly the same as the ailerons, but the top surfaces line up. The flap trailing edges have a slightly larger radius, so the bottom skins are slightly off (like 1/32″). Close enough. In that process, I noticed that I needed to enlarge the hole in the fuselage some more. The flap push rod bearing ends can swivel a bit, and in some positions they were catching on the fuselage side and bottom skins. A little filing took care of that.

Going back to the ailerons, I installed and tightened all of the bellcrank and stick hardware. The ailerons are now rock solid. There was a slight amount of play before I tightened everything up, but there is absolutely zero play now. Also figured out that I need to adjust the springs for the aileron trim. There’s not enough centering action with the current set up.

I measured the aileron deflection as 31 degrees up and 17 down on both sides. The max is 32 and 17, so these values are perfect.

This picture didn’t really turn out that well, but it shows condensation forming on the tanks. The temp and humidity both went up about 15-20 units over the course of an hour. Everything that was cold in the hangar, including the fuel tanks, tools, even the floor, formed condensation. Quite yukky. I’m going to make a homemade engine dryer after seeing this.

Just before I was about to leave, I decided to play pilot with the stick, and a strange thing happened. The stick wouldn’t go all the way forward. I checked all of the control mechanisms and surfaces. Couldn’t find a problem. It finally dawned on me that the aileron push tube was causing the problem. I had it tightened in such a position that it was preventing full elevator deflection. I adjusted the angles on the push tube bearings until it was fixed.

One of my candidates for DAR finally called back. I set up an appointment for next week. He’s not cheap, but at least he’s available. We’ll see if the MIDO can process the paperwork in time. Guess I should get that mailed in. And I confirmed that the MIDO does process the paperwork, at least for him.

The goal today was to finish everything in the wing tips. I connected the right nav light, and the VOR and marker beacon antennas in the right wing tip. I drilled and countersunk the lens. The fit isn’t perfect, but good enough for flight.

I found some aluminum duct repair tape for making a better ground connection between the wing skin and the antenna. I then used Shoe Goo in a few spots to glue the VOR to the wing tip. I think that stuff is just a fast-setting RTV.

I used the Shoe Goo on the MB antenna as well, seen here weighted down to hold it in place.

The right nav light is on in this picture, although it doesn’t look like it. It’s definitely bright when it’s on.

Next task was to attach the fuel tanks to the fuselage. It’s a pretty straight-forward process of bending the bracket a little, drilling the hole, installing a nut plate, bolting everything together, and then safety wiring. However, access in this area is not great. Got both sides done.

Last task for the day was to measure the fuel flow. I disconnected the fuel line at the servo and directed into my calibrated fuel can. On 3 separate trials, it took an average of 3.75 minutes to fill to the 3 gallon mark. That calculates to 48 gallons per hour, which is about what I expected–way more than the engine consumes. The strange thing is that the engine monitor was reporting a flow of 24.1 gph. The sensor is supposed to handle up to 70 gpm, so not sure what’s going on there. I’ll ask AFS about it. I used this opportunity to balance the fuel as well. There’s now 12 gallons on the left and 9 on the right. Should be good enough for first flight, although I’ll ask my test pilot what he prefers. Probably best not to fill them up completely.

At some point during the day, I decided to take a couple side pictures of the firewall forward. I’m not exactly sure I have the wires secured well enough, and was going to ask around about it.

Long, but productive day.