Project Patrol: Dave Conrad's Tailwind W10
By Chad Jensen, EAA Homebuilders Community Manager, EAA 755575
How does one fly with a tailwind 100 percent of the time? When flying a Tailwind! I’m sure that little question and answer has been around the block a time or two, but I can’t help myself sometimes. For my first report in a series called Project Patrol, I chose a project that’s close to my heart - one I was already somewhat biased toward - the Wittman Tailwind W10.
I happen to be building one of my own from a set of plans (the only way possible), and it’s an airplane for which I’ve long had an affinity. You see, when I first came to the world of experimental aviation, the Wittman Tailwind was actually one of the first homebuilts that caught my eye. A former co-worker mentioned this little aircraft as one that he had always wanted to fly and said it was the plane to have if one were to build and own an experimental. I didn’t know much about it, but from the moment I saw the lines, I had similar feelings.
I set out to find a Tailwind for my first column in this series. There are a number of Tailwinds in my neck of the woods here in Wisconsin. The folks over at Baraboo, namely Jim Clement, who is well known among the Tailwinders for completing 10 Tailwinds at current count, are among a few who building them near me; they have several projects to look at. However, the one that I chose to visit and write about is a Tailwind that is very fresh from the project stage was and amid Phase I flight testing when I visited.
Dave Conrad, of Wausau Wisconsin, EAA 206314, and Technical Counselor 4781, has a very nice Tailwind W10 that was 26 hours old on the day of my visit. His other completed airplane is a Hatz biplane that’s been flying for 18 years! Dave is a scratchbuilt kind of guy and when asked how he did this-or-that, he calmly says, “Oh, I made that.” I’ll get to a few of those things shortly.
I met Dave at Wausau Downtown Airport (KAUW) on a Sunday, and it proved to be a picture-perfect day for being at the airport. When I arrived, Dave was flying his Hatz in the pattern. It didn’t take long after he landed to offer me a ride in his little blue and yellow biplane.
Dave Conrad’s Hatz.
After a great flying tour around the area of Wausau, we returned to his hangar and pulled out his Tailwind. Before having a close look at the aircraft, Dave wanted to give me a ride in it. Not a flight (since it’s not out of Phase 1 yet), but just a taxi ride so I could get a sense of its visibility and ground handling. I’m still a fairly new tailwheel pilot (100 hours or so since I got my endorsement four years ago), but I’ve flown a handful of airplanes with the little wheel in the back.
The Tailwind felt exactly like my RV-7 does on the ground, as well it should since they share the same style of main landing gear legs - a solid round (tapered) steel rod, first patented by Steve Wittman. Visibility was good, but not as good as the bubble canopy I had become accustomed to. However, I was pleased with it overall with visibility over the nose a nonissue and actually slightly better than the RV-7.
The view out the Tailwind window - good, but not like a bubble canopy.
The Tailwind is a cozy airplane for two people, but so is the RV-7. I’d say the two advantages the RV has over the Tailwind in flight deck room is in the area of elbow room and footwell volume. The RV has a couple of inches of usable elbow room on either side, but the shoulder width is nearly the same due to the canopy deck railing on the RV.
The Tailwind fuselage is standard 4130 steel tube and fabric. Dave was able to keep the shape of the fuselage true with the aid of cross-braced 2-by-4s while he welded the parts together.
The footwell in the Tailwind is taken up by the fuel tank, which hangs down near the knees. There’s still plenty of room to move your feet and legs around, but it’s not as open under there as it is in the RV. Both of those issues become a distant memory when cruising along at speeds tripling the ground-bound traffic. After the taxi ride, I asked Dave several questions about various details of the airplane that he either changed from the plans or simply modified to make it more user-friendly.
Once the ribs are located on the spars, 1/16-inch plywood skin, typically mahogany or okoume, is used to close out a completed wing. To protect the wood and to provide an extremely smooth surface, lightweight fiberglass cloth is epoxied over the entire wood surface.
It’s in the details
As any builder will attest, flaws are in the eye of the beholder and most of them are so insignificant on this airplane that only Dave will ever know. We began our walk-around at the tail of the airplane. Dave has designed and built his own direct-steering link for the tailwheel using a spring-loaded cylinder. There are designs out there available for purchase (such as the one I used on my RV), but Dave never really gave a thought to buying one.
Most scratchbuilders usually don’t regard things they built, rather than bought, as mods. They are just done because it makes sense. Take for example the wing strut lower attach point on Dave’s plane.
The plans call for airfoil-shaped tubing to be joined at the lower fuselage. The fuselage stub is typically squeezed and welded together, then drilled for the attachment bolt. That can potentially lead to water intrusion. Dave decided to make his lift strut slide over the stub, and the stub has been capped off and welded shut, making water intrusion impossible.
Other ideas flowing from Dave’s mind include a fully adjustable door hinge, where the hinges are mounted on threaded rod that can be adjusted fore and aft as well as in and out, allowing for a perfect fit of the door to the opening.
The pitot tube is made from brass tubing and is easily removable for cleaning when necessary. The tube has a reduction soldered to the aft end allowing for easy alignment when inserting it into the leading edge of the wing.
Simple things make life easier
Dave didn’t try to reinvent how cabin heat is done; he used the heater slider valve that can be found from nearly any single-engine Cessna. These are available at almost any salvage yard and are a breeze to install.
When considering fuses or breakers, I’m a fan of using automotive-style fuses, and Dave is of the same mind. When I built my RV, I mounted my fuse blocks on a tray behind the panel that would swing down to allow access during flight if a fuse needed to be replaced. This worked, but it made things sort of clumsy in real-world circumstances because of the unusual angle my upper body would need to be so that I could see the fuse blocks put my head down in the flight deck, making it impossible to see outside.
Dave took an approach that I will certainly copy when I get to this point with my Tailwind: mounting the fuses right in the panel. It gives access to all fuses while keeping your head up, increasing safety. Not to mention it adds some nice color to the panel.
Dave’s electrical system is a simple one with only a handheld radio, lights, starter, a few electric gauges, and two 12-volt out panel sockets. He does, however, plan to install a panel-mounted comm later on.
Another borrowed automotive idea in his airplane is the use of a parking brake handle from a Dodge Neon to actuate his flaps. This setup allows for very precise flap settings and removes the fairly obtrusive flap handle that are called for in the plane. The original design works great, but Dave’s integration of this parking brake handle really cleans up the area between the seats in the Tailwind.
Speaking of seats, Dave used a very simple wood block to allow for two seat-height adjustments. Loosen the butterfly nut, flip the block 90 degrees, and there’s another 1/2 inch of headroom.
Dave has even taken his custom touch to the paint scheme on the airplane. He used the angle of the lift struts as a recurring theme and put the three Tailwind echelon formation graphics at the exact angle. Those match the paint stripe cutoffs and the rear windows as well.
Moving forward to in front of the firewall, Dave set out to make his own exhaust system. This is a huge cost-saving measure, and with his skills, taking this route was a no-brainer. The design is typical of many homebuilts in that it does not have a muffler - straight pipes is the way to more power!
Here you can see the exhaust being fitted on the day it was tack-welded into position.
So how does it perform? With a 160-hp O-320 and an Ed Sterba 68 by 76 wood prop, it flies as a Tailwind should. His cruise speed through 26 hours of test-flying has settled at 175 mph at 2250 rpm, and he has seen the airspeed climb to 217 mph at full throttle. The airplane burns fuel at 8 to 8.5 gallons/hour. On pavement with takeoff flaps, he’s off in 700 feet, and only 900 feet with a clean wing. Dave reports landing rolls are about the same once the wheels are on the ground and that a 2,500-foot strip is his comfort level at this point due to his flat approach technique.
This Tailwind features an Ed Sterba 68 by 76 wood prop.
My jaw hit the floor when he told me that his bird climbs at 2,000 fpm at 100 mph but typically climbs at 120 mph for better forward visibility. Dave said that his plane will stall straight ahead with no tendency to drop a wing. Aileron control is good through the stall, seeing speeds around 64 mph with flaps, 69 mph clean.Dave has built a very nice example of the Tailwind W10, and he has promised me a ride in the airplane once he’s out of Phase 1 flight testing. There’s great activity and a strong sense of community at the airport in Wausau; I found several other projects that would be great subjects for future editions of this column. If you have a project that is near completion, or if you’ve recently flown one that I can visit, drop me a line at firstname.lastname@example.org and let’s get together!