Dave’s RV-7A Building Log

Went down to the hangar early to work on the wheel fairings and get them fixed up. It was something like the 6th cruddy weather weekend in a row, so I figured there wouldn’t be much flying to do. Summer has got to start soon.

I used the cut off wheel in the Dremel to increase the size of the openings for the tires by 1/8-1/4″ in the areas that were too tight. I’ll probably increase them even more in a couple spots. I’m shooting for about 1/2″ clearance, especially at the back of the tire where any contact would cause the fairing to catch and fold inward. I also made cuts through the spots where the fiberglass cracked.

I had just enough fiberglass material left (ordered more from Spruce) to lay up some patches on the inside of the fairings after thoroughly sanding and cleaning the areas. I used some tape and clamps/wood blocks to hold the broken areas in alignment. The whole process went very quickly.

While that was setting up, I worked on the leg fairings. I installed them loosely and jacked up the plane to a level attitude. I wrapped a line around the fairing and tied it to my step ladder toward the back of the plane. Using a water level (just water in some plastic tubing), I made sure the line was level front to back. I then dropped plumb bobs from the center of the plane, front and back, and made sure the line was parallel to the centerline of the plane. I wrapped a tiny bit of safety wire around the line to pull it closer together and centered the fairing based on that. Took longer to explain than to do it. It ended up being very simple compared to some elaborate schemes I’ve heard of.

The wind was again very swirly, but I wanted to test out the leg fairings. To get a real accurate measurement I should have flown the same day with the fairings off. Instead I just tried to duplicate the conditions of my test flights on Wednesday. Based on that, it seems the main leg fairings alone added about 6 knots of speed. Not bad.

The flying wasn’t so great with ominous clouds everywhere and light turbulence, so I kept the flight short. The controller was very helpful calling out the current winds. They varied minute by minute from dead calm, to straight down the runway, to 8 knot crosswind. I semi-unintentionally stayed high on the approach. I was at 1000′ right up to where the Cessnas normally turn base to final. I pulled power, waited for the white arc, dropped flaps, and she lost altitude very quickly. The flare was perfect. Everything was looking really good until right before touch down the winds changed. The plane popped up and then dropped in to a bigger thud than I would like, but I kept the nosewheel off this time.

By the time I got back, the epoxy on the wheel fairings had set up. I removed the clamps and peel ply and was very pleasantly surprised at the result. A little filler and they will be literally as good as new. I just need to clean up the tire openings a little bit with the drum sander in the Dremel.

The good news is that I got the wheel fairings finished and installed.

The weather was good and the evening was free for getting down to the hangar. I went for a short flight to get a reference speed before installing the fairings. Arbitrarily choosing 5,000′ and using a 75% power setting (24″/2400 RPM/leaned to 50° ROP=max power), I was seeing about 143 knots true airspeed. It was varying between 142 and 144. I also took note of the slip/skid ball, which was just a hair to the left. I landed (one of my best yet), grabbed some dinner, installed the nut plates on the fairings brackets, and installed the fairings.

Major problem. I made the cut outs for the tires while I had the plane jacked. With the tires supporting the plane and bulging a bit, the clearance was no good. I swore at them profusely, took them off, trimmed them some more, and re-installed. I made sure there was a finger thickness all the way around.

I took off again and found the winds to be swirling wildly. A cold front was moving in and bringing more bad weather with it. Still plent of time for a test flight before things turned ugly. I got up to 5,000′ again in a few minutes (it’s so nice having a fast climbing plane) and set up the same power setting. I forgot to record the temp on the first flight and it certainly dropped some, but not enough to affect things very much.

True airspeed was about 149 knots. A 6 knot increase. Very cool! And the slip/skid ball was perfectly centered. I guess I didn’t perfectly line up the fairings, but I ended up cancelling out the very slight out of trim condition I had before. On top of that, it was a very nice evening flight with the sun setting in the west. It was a little bumpy down low, but smooth and cool above 3,000′ with no traffic around.

Now for the bad news. The winds were varying and gusting even worse than when I took off. I made one of the worst landings yet. I kept a little more speed on final to help with controllability. I touched down a little too hard, bounced back up, and then landed on all 3 tires rather ubruptly. It wasn’t a dangerous landing, just hard on the landing gear. Not sure what I could have done better given the circumstances.

I feared the worst for the wheel fairings, and sure enough they cracked at the back of the opening due to the tires bulging out. I guess I didn’t have enough clearance after all. Maybe my fingers are too narrow to be used as a gauge. Luckily, fiberglass is easy to repair.

Went back down to the hangar in the afternoon. Weather wasn’t great for flying (again), so I worked on the wheel fairings some more. The layups from yesterday turned out great.

I re-rigged plumb bobs and lines to make sure the wheel fairings were straight and then drilled the inboard holes out to #19. I then went through several iterations on each to get the wheel opening just right. I made sure I had a finger’s width all the way around the tire. I also countersunk the fiberglass for rivets and screws and installed the outboard brackets to the fairings.

Last step is to drill and install nut plates on the inboard brackets and these things will finally be done. I’m hoping to fly once without and once with the fairings and get some accurate numbers on the speed increase. Then I’ll install the leg fairings and fly again. I can also keep an eye on the yaw trim and make sure I haven’t introduced any problems there.

Then I just have to work on the nose wheel fairings and the intersection fairings. There’s always more to do…

There was some discussion on the forum about the Aircraft Finishing Systems primer. I prepped, primed, and installed this aluminum patch outside on my fence over 3 years ago. I cleaned it off with a rag, but it otherwise looks just like the day I put it there.

I was planning on flying down to the EAA 105 fly-in with Julie, but the weather didn’t look great. There was a slight chance of getting stuck down there due to a system moving in during the afternoon, plus it looked turbulent. Wasn’t sure Julie would enjoy the trip.

Instead I worked on the wheel fairings for a few hours in the afternoon. The left fairing is still too wide, so I added 3 more layers of fiberglass to each attachment point. Hopefully that will be enough. I also mixed up some filler to the consistency of frosting (actually started to look edible), and used it to fill the gap under the outboard bracket on the right side. I used some sticky Glad wrap (very handy stuff) to keep it from sticking to the fairing.

I almost have these wrapped up. One more session ought to do it.

I went down to the hangar Saturday and worked on the wheel fairings. The weather was miserable, so I didn’t even entertain the idea of flying.

First thing I did was take a look at the nosewheel. I’ve been noticing some black stuff oozing out of one side and the wheel is still pretty stiff. I removed the whole wheel and checked out the bearing, which looked fine. I re-greased the seals and re-installed. We’ll see if that fixes things.

I jacked up the plane to level the longerons, trimmed the fairings a bunch until they fit over the tires and gear legs, and spent a bunch of time aligning them to the centerline of the plane and making them level per the recommended orientation on the plans. After all of that, I finally drilled the fairings to the brackets. It would be nice if the two fairings were remotely similar to each other. The right side fits pretty good. The left side seems to be about 1/4″ too wide.

I went back down late on Sunday and laid up some fiberglass reinforcement patches where the inside brackets attach. I put a extra few layers on the left fairing in hopes of taking up some of that 1/4″ gap.

I even managed to fly a tiny bit. The weather looked decent, but a bit gusty. By the time I took off, the gusts were increasing. I flew around for about 20 minutes and decided it wasn’t fun flying weather. When I came back in the wind was worse, 20 to 70° across the runway gusting 10-18 knots. A bit over my personal comfort level, but the runway at Renton is long and wide. I had no problem keeping the plane aligned with the centerline, but the plane dropped in a bit harder than I like. I was trying to keep some extra speed on short final, but I think the slip stole some of that away. Next time I’ll keep even more speed on final. Still a fun flight. Even nasty weather is fun in a little rocket.

Almost forgot that I figured out the source of the whistle in my cockpit. It’s coming from the small gap between the canopy and rear window. I put some tape over the gap and the whistle was entirely gone. Much, much, much more pleasant in the cockpit. Time to order some aluminum for a “targa” style strip across the back of the canopy.

Got down to the hangar after lunch on Saturday, flew off the remaining 1/2 hour, made the official entry in the aircraft logbook, and test phase I officially ended. I spent an hour or so getting everything prepped for my first passenger, installed the passenger seat, cleaned the bugs on the prop and canopy, etc.

After putting up with this crazy project for almost 4 years and driving many of the rivets, there was no one else that I could consider for the honor. The plan was to take Julie up and if she was comfortable, attempt a flight up to Friday Harbor. We got into the air and she loved it. The take off surprised me a bit. Between the extra load and the high temps, the plane didn’t just leap into the air. Not a big deal. It just took an extra second to get up to speed and start climbing like crazy.

I let her have the plane as soon as I got it stabilized to help fend off any queasiness. I adjusted power as needed, navigated around our tricky airspace, and watched for traffic.

Julie snapped pictures along the way. She said I looked too serious. Ah, dah. I’m flying an airplane. Alright, I’ll smile.

Here’s part of the Microsoft campus.

Back toward Bellevue and Mercer Island.

Lake Sammamish and Sammamish proper.

Then we got into the more scenic area north of Seattle. Here’s Deception Pass and Mount Baker.

In my limited flying around here, there’s nothing as beautiful as flying up to the San Juans. The islands are clustered together sitting on the edge of the huge Strait of Juan de Fuca.

Looking back at Anacortes.

Island dead ahead, Mount Baker off to the right.

This is probably the best picture of the islands.

Lots of traffic around Friday Harbor, but an uneventful landing. Here’s the beautiful magic carpet.

For those unfamiliar with the area, Friday Harbor is on San Juan Island. It’s at least an hour ride by ferry on top of the ferry wait and 2 hour drive from Seattle. We did the short walk to town and had fish tacos on the deck at Downriggers overlooking the harbor. Very cool to watch the sea planes and ferry coming and going.

I let Julie fly most of the way back as well. We swung over North Seattle and by Snoqualmie Falls before heading into Renton. She had a great time.

Today I took Adele up for a short flight in the afternoon. We just cruised around the Duvall/Snoqualmie area a bit as I let her fly the plane. It was a really hot day, so we kept it fairly short. She’s been studying air and space flight in school the past few weeks, so I was very happy to let her put her knowledge of ailerons and elevators to use.

There was a funny exchange on the radio as we were taking off. Tower was talking to a Cessna that was entering the pattern, “Cessna XXX, enter the downwind behind the silver RV that is climbing steeply and turning crosswind.” Cessna: “I have the silver rocket in sight and will follow.”

Adele snapped a few pictures as well.

All in all, a great flying weekend. Makes all those hours of building (and even some of the frustrating ones) seem worthwhile.