Letters to the Editor
All letters will be carefully considered; those of general interest will be used. Send to Model Aviation, 815 15th St., N.W., Washington, D.C. 20005.
Missing Persons Bureau?
Thanks for running my letter requesting information on an old-timer biplane in the May issue of Model Aviation. I not only identified the biplane and its designer but I also have made contact with Fred Tuxworth.
The biplane pictured turned out to be a design by Dean Barry with which he competed in the 1940 Nats. It is strange that no magazine ever picked up this design since it was so unique for its day, and apparently it flew quite well according to the write-ups about it. If Dean Barry is still around perhaps he can supply drawings for the design for us. The span is 66 inches which would probably make it about a .35 engine size for SAM competition in RC assist. So far in the SAM Champs (or any other SAM competition), I have not seen anyone fly a biplane design, yet they have universal appeal.
Fred Tuxworth has agreed to help me work up plans for his Sportster biplane version in a 1.5 scaled-up size which I will fly in RC assist. This is a very beautiful biplane design, and as soon as I have the plans completed and a prototype built and flown, I will submit it for publication so that others may enjoy building and flying this unique example of Fred's creativity.
I received many letters from people answering the letter in the magazine with information on his requests and some asking for information on the biplane in the drawing if I ever found out about it. Apparently there is a desire among old-timer builders to locate some of the biplane designs of that era. Except for scale models I myself cannot remember very many being built for gas competition. Aside from the lower efficiency I suppose they felt that building two wings was a waste of time and the inevitable end was the scrap bin. Today, with RC possibilities, models last much longer, and the potential for biplanes to catch on is much greater.
I know your column is not a missing persons bureau, but there are two other old-time designers I would like to locate because I am also working up drawings of their designs: Harold Coovert, who did some work for the old Peerless company in Cleveland, and Art Horak, who designed a model called the Kid which was printed in MAN in 1946. But, if anyone knows of these two, please write—do not telephone; it costs too much. If you get me on the phone talking about the 'old days' you will find out what I mean. I appreciate the phone calls I got in regards to the biplane and Fred Tuxworth (one from Vermont), but it may have cost them a bundle. It shows, however, the extremes to which the people in this hobby will go to assist each other.
Ralph E. Turner 35283 Keller Dr. Avon, OH 44011
Ah, Those Winglets
I would like to thank Chuck Anderson for sharing with us the results of his winglet research (May '80). It was a fine piece of work, especially the comparisons between winglet-equipped short wing and long conventional wing.
The article mentions that winglets cause an increased wing-root bending moment—the force that causes wing rods to bend at the fuselage sides. A subtle structural point that might be missed by other experimenters is that winglets also produce a large bending moment at the wing tips. Conventional wings do not feel bending at the tip, so wing spars are tapered and shear webs are omitted in the outer parts of the wing, without ill effects. Anyone trying winglets should consider using untapered spars and shear webs tip-to-tip. Wing construction like that used on Cecil Haga's Legionair Shuttle (aluminum tube spar) would be ideal.
Two other notes of caution: the increased "dihedral effect" Mr. Anderson noted—resulting in "wing rock" (was this Dutch roll?) and difficulty in turning—may require reduced dihedral of the wing and/or a different fin size. Preplanning is needed to allow these changes without major rework of the fuselage. Also noted was that winglet effects changed with speed. The "perfect" winglet angle will change both with airspeed and with ballast carried (weight). A fixed winglet design really has only one ideal operating condition. A workable, contest-winning winglet would be adjustable in angle for different tasks.
The final question—are winglets a violation of the intent of 2-meter/100-in. span limits? My own feeling is that they should be allowed now by AMA rules.
R. Gregg Lovick Grapevine, TX
Washin', Washout
Letter: I certainly appreciated Brad Powers' first installment on CG. I certainly did not understand CG before. Another item continually mystifies me: washout of wing tips. Most stick-model authors talk about using, say, 2° washout to make a stable plane, yet I am unable to understand how it works.
Pat Rose (no address given)
Reply: It's really simple, Pat. Washout means that the wing tip is twisted down—say, two degrees—so that the tip has a lower angle of attack than the wing root, and therefore is less likely to stall first. An airfoil has a stalling angle—it quits lifting at roughly 16°, though this varies. So, when the center of the wing reaches that stalling angle the tip, with 2° washout, will still be below stall and will continue to produce lift. Thus the inner portions of the wing stall first, giving aileron control and warning, rather than the tip stalling first, which can lead to a sudden roll or spin.
Especially relevant are speed effects: warps, washin, or washout all have increasing effects with higher airspeeds, which is why a dive, or diving turns, often causes things to go totally haywire.
Word to the Wise
I enjoyed your articles on Milestones in RC in the July '80 issue; they brought back memories. Although some of the planes were unfamiliar, I did manage to build (and fly) a Smog Hog when it and Bonner Varicomb were the latest thing.
Although there are probably sources for some or all of these plans available in different places, I notice that Jim Newman (International Scale Plan Service, 4 Cleveland Terrace, Hobart, IN 46342) has the Smog Hog, Astro Hog and Rudderbug listed on page 74 of his Radio Control Aircraft Handbook number 4. These plans are listed as available, but with delayed delivery, so this may be a possible supply source.
B. Thomson San Angelo, TX
Editor note: We didn't know that! We shall get the Smog Hog plan and hope to build it—someday. Also have an original Little Wing Senior plane—and what an old-timer RC that should be. DeBolt built it light and we mean light—also simple. It will float like a ghost—we know because we flew them. You could stretch a desperate approach forever by wiggling rudder, setting up quick changing yaw—and it would "walk" over the grass or weeds or corn for 50 to 100 more feet. Just lovely. We don't refer to the Little Wing shown in Milestones—that was a .09 and loaded to the gills with batteries to feed the hungry Citizen-Ship single channel on 465.
A Man For All Seasons
I'd like to compliment you on the excellent article on variable-geometry Free Flight models presented in the June issue. Mr. Stoy presents the argument for the design very well.
He's right, though, that it isn't new. I came to model aviation through the occasionally-maligned hobby of model rocketry. As your readers may know, we fly a lot of models that ascend under thrust and glide back. I recall building a design that was published in the Model Rocketeer Magazine, the official journal of the National Association of Rocketry, that featured a similar folding wing. It was designed by one Harold Youngren, and called a "flip-wing." This was eight years ago.
I don't want to sound like I'm tooting anyone's horn; the point I'm trying to make is that people can get too centered into their own hobbies and miss opportunities in others. I've experienced a tendency in airplane people to look down their noses a bit at us rocket types, and regard what we do as kid stuff. All I can say is that this attitude keeps us from learning from each other.
Douglas R. Pratt, Editor Model Retailer
Editor note: Will have much to say about this in future Just For the Fun Of It columns, starting in the next issue. Boost/gliders have become very impressive, and these guys fly radio—same frequencies!
Transcribed from original scans by AI. Minor OCR errors may remain.
