Control Line: Aerobatics
Frank McMillan
12106 Gunter Grove, San Antonio, TX 78231
Choosing the next plane
It's time for me to get serious about my next plane. After watching World Champion Paul Walker, I had no doubt that the time had come to switch to a tuned-pipe power system. With that point settled, what plane to build became the next question. My experience with the O.S. .40 SPP showed conclusively that it could pull bigger planes like my base SuperTigre .60-powered ship, so that wasn't out of the question. But with the whole building season ahead, maybe I ought to take a look at the field.
Old Yeller — the Super Caudron conversion
What was supposed to be my Nationals ship for this year, a SuperTigre .60-intended Super Caudron, was in silver and ready to finish when I returned from the Nationals. Sometimes we all take the easy out, so "Old Yeller" got the pipe-conversion treatment and sits on its wheels waiting for the next O.S. An all-up weight of 63 oz. and 740 sq.-in. should make it a solid plane. But with the rest of the winter to go, I'm not going to sit on one plane. What to do next...
Bob Hunt's team trials bird
Bob Hunt was kind enough to send a core of his team-trials bird that I liked, and I had the cores skinned and the surfaces built. This is a 700-sq.-in. wing, and Bob had used the same engine to obtain really nice performance. He also brought the ship in at 56 oz.—a good weight.
The skinned wings came out at 109 and 106 grams. The stab and elevators were two ounces even, without horns, which is reasonable but not super. My thought on the fuselage was to make it simple and, if possible, make it look like the Caudron. Bob thought that would look nice; after all, a good plane is the airfoils and a set of numbers.
Bill Werwage's geodetic design
As I got ready to crank out the ship, I started thinking about Bill Werwage's team-trials bird with the geodetic ribs. The performance was on another level. The 55-oz. weight with 740 sq.-in., as well as the horsepower of the O.S., was just outstanding.
I knew I couldn't approach that without building up the structure rather than using foam. I hadn't done that on a pro stunt ship since 1987, so here was a real possibility for some excitement. Bill had provided information to build that ship, and I'd already built a stab/elevator combination at 1.75 oz. I also had the rib set made and a jig ready to assemble.
Paul Walker's Impact
Then of course there was Paul Walker's Impact, probably the most impressive of all the combinations—or was it just super flying? This ship also was built-up and was a take-apart. The numbers on this ship weren't all that different from the other ship, except in some key points. The aspect ratio was higher, and the airfoils were thicker at the root with more taper at the tip.
Trend toward 650-sq.-in. designs
By the time I had all this information put together in some kind of order, new thoughts on the next generation surfaced. Most focused on slightly smaller planes with about 650 sq.-in. wings and decreased overall weight of around 50 oz.
The thinking is that this size is less affected by heavy wind and turbulence. Also, the power-to-weight ratio improves, and the power reserve becomes more favorable. Easy to see why this approach is attractive. As always, the big problem is what Bill Werwage discussed in his June article—control of weight and that relationship to the structure. It is not linear; there are steps in the sizes. At 650 sq.-in. you are right in the middle between the 550–600 and 700–750 sq.-in. standards. I hope this problem can be resolved with new construction techniques and composite materials.
Now that I've gone through this discussion of some key numbers on some great planes, I've got a decision to make—and my head hurts! We all can't do everything! Maybe I'll just go build a Nobler with a Fox .35!
Club newsletters and a newcomers' video
Let me stop to thank all the clubs that include me on their newsletter mailing lists. I enjoy the newsletters and will use items when appropriate. I recently received a newsletter from the Orbiting Eagles in Omaha, Nebraska. Having spent nine years in that area, I wish this active club had been going strong when I was there. Keep up the good work.
The latest newsletter contained an item that may be of interest to beginning control-line fliers. It is a new video on Control Line Building and Flying, by Harding Productions, 4782 Unity Line Road, New Waterford, OH 44445. The video covers building and flying two of Sig's most popular control-line kits, the Skyray and Skyray 35. The production quality is excellent, and the video runs 75 minutes. Those who are new to the hobby will find this a good gift for someone who wants to get started.
Randy Smith and Aero Products
It's time to revisit one of the most reliable subjects to our hobby: Randy Smith of Aero Products. As many of you know, Randy has formed a highly productive relationship with Bill Werwage for the development and production of stunt-related items.
Their primary focus has been on the carbon-fiber tuned pipe, and they are recognized as a world leader. All three members of the U.S. team used these units. Paul Walker won the F2B world championship with one of the prototype four-chamber pipes now under testing and development. Bill personally builds all the pipes, and Bill and Randy stand by their products. These units work and work well!
Randy is a full-time supplier to our needs and is always working to expand his product line to fill the spectrum of our requirements. Highlights of his offerings include:
- Carbon-fiber tuned pipes (Smith–Werwage line), including prototype four-chamber designs.
- Carbon-fiber Bolly props and blades (two- and three-bladed versions), known for superior strength, thin blades, and the ability to be repitched.
- Full competition kits and a line of Old-Time and nostalgia planes; one well-known model is the SV II that Bill Werwage has flown with the reliable SuperTigre .60.
- New kits designed for tuned-pipe .40–.46 operations in the 650-sq.-in. size:
- Intrepid — a straight-taper design.
- Vector — a more unusual elliptical planform. Both are supplied as short kits (no wood except motor mounts) and include foam cores for wings and stab/elevators plus all hardware, including aluminum gear and control system.
- A supply of O.S. .35S parts and Nostalgia motors in varying tune stages, including some used but refurbished examples.
- A production run of A/C pistons and liners for the O.S. .40 SPP, featuring high-silicon, very light pistons.
I saw the Vector fly at the 1992 Nationals and it is a really good performer, especially in the wind. I've got an Intrepid kit and will work it this winter. There are also solid designs with winning performance.
If you want an O.S. .35S or one of the specialty items, get busy—these parts tend to go fast.
Contact
Randy at Aero Products 1880 Scenic Highway, Snellville, GA 30078 Phone: (404) 979-2035
Transcribed from original scans by AI. Minor OCR errors may remain.
