Radio Control: Sport and Aerobatics
Ron Putte
111 Sleepy Oaks Rd. Ft. Walton Beach, FL 32548
This has been a trying time for me, but fortunately we usually learn from our experiences. Very briefly, I did a "Farmer Brown" with my Nats airplane (that means I planted it). For the first time in many years I dumb-thumbed an airplane into the ground.
The engine died with the airplane low and inverted during a square horizontal eight at a contest in Lafayette, La. I tried to quarter-roll quickly and pull hard to get it back to the landing area. Unfortunately I didn't roll the airplane (I don't know why), and when I did the hard pull the ground rose up and smote the airplane. What now do I do for a Nats airplane?
I managed to pick up a framed-up Atlanta on the way back from the contest and started to work on it on Monday night two weeks ago. The test flight was yesterday. That's 15 days from start to flight! I don't know how long it takes most people to build a Pattern airplane, but six to eight weeks is normal for me when I work on it diligently.
It is amazing what the human body will do if it's asked to go beyond normal limits. I averaged less than six hours' sleep a night. I often woke up in the middle of the night and was unable to get back to sleep, got up and worked on the airplane. Despite all that, I worked my normal job and did my daily training runs. I even ran in two races and did very well. Amazing!
The reason I mentioned all of this is because I always have a chance to use some untried building techniques when constructing a new airplane. Despite the need for speed in finishing the Atlanta, I still managed to try some new things.
New finishing techniques from Greg Grigsby
Four new ideas came from Greg Grigsby (Niceville, FL). Greg is a superb builder, and his airplanes always look great. He told me three secrets of how he finishes his.
- Observing that most of us use a white base coat on our airplanes, he decided to apply the glass cloth to the wing using white rather than clear K&B epoxy so the wing would already be white when the base color is applied.
- He uses K&B satin hardener with the white, because it makes the finish much easier to sand.
- When he applies all finish coats with his spray gun, he uses brushing gloss hardener. He claims that the paint flows on better than when he uses the standard gloss hardener.
He's right; I tried all three ideas, and they all work.
Greg's fourth idea concerned how to operate the plane's receiver switch. Like many of us, Greg mounts the switch on a piece of plywood inside the fuselage and operates the switch by means of a small wire going through the side of the outer skin.
His idea addresses how to attach the wire to the switch arm. He drills a small hole straight into the top of the switch arm, then squirts a small dab of cyanoacrylate glue into the hole and screws in a threaded Du-Bro 1/16 ball link. He then solders the small threaded coupler that comes with the ball link to the wire, screws on the nylon coupler and snaps it over the ball link on the switch arm. Placement of the hole for the push-pull wire in the side of the fuselage is not critical because of the way the ball link works. It's a really slick way to get the job done.
Connector security
Last summer I lost a new Atlanta because the receiver battery became disconnected when the battery shifted in the fuselage, even though the connectors were taped together. Since nobody (that I'm aware of) makes a connector retaining clip for Futaba J connectors, I decided to try something else. I tied a piece of dental floss around the middle of all the connectors. Anything capable of ripping connectors apart will now break the wires first.
Engine mounting technique from John Fuqua
Another technique I tried was suggested to me by John Fuqua (Niceville, FL). I wanted to mount my YS engine using MK soft mounts, but the fuselage just had a firewall in it, and I needed a platform to which I could bolt the soft mounts. John suggested that I cut a U-shaped piece of 1/4-in. plywood to fit the sides of the fuselage and butt up to the existing bulkhead, and epoxy it in. Then came the great idea. He suggested that I cut up a small piece of fairly heavy fiberglass cloth (three- to six-ounce-per-square-yard 1/2-in.-sq. pieces), pull the pieces apart, mix the resulting strands with 30-minute epoxy to get a slurry, and use it to form a fillet between the mounting plate and the fuselage. I was able to form it into whatever radius I wanted using a small throwaway brush, and it stayed put until the epoxy cured. That mount is in there to stay!
More on biplanes
I received an airmail letter from Milton (Billy) Girod (Garches, France), who had something to add to the biplane issue. He wrote:
"Reading your column in the May issue of Model Aviation, I can't resist sending you an extract from my column in the June issue of the French magazine RCM (yes, there is a French magazine with that name, and it has no connection with the American one), since I approached the subject you got stuck with.
"The fashion for bipes at the 1988 TOC was primarily due to the bonus they were given, and for the Ultimate in particular because of its qualities. Thus multiplication planes and appearance...
"1989 F3A World Championships — for the first time in 20 years true biplanes have charm of their own, whatever their maneuvering abilities. I am afraid a bipe will always drag, though it may sometimes have an advantage — more about that later. This is also due to the lower efficiency of their wings because of the aerodynamic interference between them. The latter point applies to model airplanes only. Induced roll and rudder applied are very apparent on full-size bipes as well. Models should forget either bipes — they are much more difficult to build..."
These facts did not deter Tony Frackowiak. He flew a bipe and did very well with it, but I suspect that this success is due primarily to Tony's flying ability. In fact, to come back to the advantages of a biplane's drag, I think that the Fyg Leaf would be improved by removing the curious cheeks that run on both sides of the fuselage, since I am afraid that they are a destabilizing factor, especially in pitch. Since they are there to produce drag to slow the plane, they might be replaced by flying wires.
An advantage of flying wires is that since they would be purely cosmetic drag producers, they might be removed in windy and turbulent weather when a faster flying plane is an advantage.
Of course the arrival of new and more powerful four-stroke engines will permit the elaboration of bigger planes within the weight limit and thus increase their Reynolds numbers; but, of course, the bipes won't be the only beneficiaries.
The same thing can be said of the greater visibility of a bigger plane. At the TOC, the larger size of the planes makes the Reynolds number less of a problem for biplanes, but the other shortcomings are still there.
"I agree with Tony Frackowiak when he says that biplanes can be very strong in rolls and point maneuvers. I know about the Ultimate (I own one), and I will trust him about the Fyg Leaf. Snaps are excellent, too.
There is no doubt that bipes have their good points, yet the shortcomings are there, and for the reasons stated above I think that monoplanes have the edge on biplanes, both model and full-scale planes, when confronted with the type of aerobatics we are flying now.
I know there will be a number of bipes at the next TOC, because even a 2% bonus is nothing to sneer at when you consider how close the competitors are.
And of course we love a bipe, and that in itself is enough. When Wessel was asked at the last Pattern World Championships why he chose to fly a bipe, he answered that he liked the way a bipe looks. Isn't that enough?"
Letter from Bill Tallman and Model Aviation response
I got a letter from Bill Tallman (Prineville, OR) who wrote, "I have been reading Model Aviation for about 13 years, and during this time I can remember possibly only one construction article concerning Pattern planes. It appears as if Model Aviation is concerned with continually publishing construction articles of sport/weird flying contraptions. What about our special interest as Pattern fliers? Can't you persuade MA to print some good Pattern construction articles as well?"
I honestly don't know what Model Aviation's policy is regarding construction articles. Maybe someone on the staff will comment.
(OK, Ron. Here goes: When we publish a construction article, we do it with some degree of hope that there is something about the design which will interest a significant percentage of our readers.)
Now I will address Pattern planes specifically.
It seems obvious to us that most Pattern fliers fly kit planes, and there are many excellent examples on the market. Also, a decade or more ago Pattern planes began to be predominantly constructed with fiberglass/epoxy fuselages and balsa-sheeted foam-core wings. Wing skins were also made of materials other than balsa. These techniques do not lend themselves well to the type of construction articles we choose to print, which are aimed at modelers with average skills and little if any special equipment in their modest workshops.
If Model Aviation prints any type of competition plane as a construction article, we seek those designs which have established a good track record in competition. In some cases we have sought out a particular plane, in other instances the designer has inquired whether we would be interested in buying a construction article.
Our only indicator of reader interest—or the lack of it—in a particular design is the volume of our plans sales. Our only R/C plane which even approaches being a Pattern plane and having significant plane sales is the Blue Max II, and it is actually designed as a fun-fly winner. The Neutron Star, a 40-size R/C Pattern plane, has sold only a fraction of that.
It would seem to me that if MA were to publish another Pattern plane, it would have to be suited to Novice and/or Sportsman fliers. Joe Bridi makes balsa kits (and darn good ones) suitable for these classes of fliers — as do several other manufacturers. Our published plane would have to offer performance, appearance, and features of a rank at least equivalent to existing kits.
Given the way the R/C Pattern skill-level advancement system works, it would seem that anyone with an original design suitable for Novice or Sportsman competition would not stay in those classes long enough to establish the desirability of his/her design before advancing to a higher class — and to using a much more sophisticated airplane. At any rate, we haven't been approached by a designer having a plane for these two classes who wants to sell us a construction article.
An interesting insight into our practice of attempting to publish designs that are of interest to a broad scope of modelers can be gained by surveying the results of our full-size plan sales.
Our best-selling plan (over 1,500 sales) is the small Hand-Launched R/C Sailplane. Right behind it is an R/C Schoolyard Scale model. Third through fifth places go to an R/C scale model of a Golden Age biplane, a scale-like Yak R/C ducted-fan model, and an R/C flying boat. The R/C Old-Timer series has done well, as have many R/C Old-Timer models. Our best-selling kit plan is Les McDonald's Stiletto Precision Aerobatics World Champion design. It has taken a full 13 years for it to attain that degree of prominence.
It is interesting to note that in its first month Jeff Troy's TAN?? R/C sport/trainer sold over half as many plans as the Stiletto has in 13 years! Oh, one last thing to mention: Our Full-Size Plan sales program was not initiated as a profit-making operation. The effort exists as a service to modelers. We can only assume that there is a correlation between plan sales and the overall popularity of a design. Yes, we do make a small profit on the plan sales over a year's time.
Quarter-scale gliders and ordering plans
As I've offered before, I'll send you a copy of Cliff's list of Scale plans if you send a self-addressed stamped envelope. In addition to the new Falke, quarter-scale gliders include:
- Ka3
- Ka8
- ASK 18
- Graupner Baby
- Hutter 17
- Ka? (?)
- DFS Reiher II
- Olympia 2b
- DFS Meise
- LO 100
- MU 13
Plans must be ordered directly from Cliff at 41 Spring Road, Frome, Somerset BA11 2JN, England. Cliff requires payment in British pounds sterling. This involves going to a bank here in the U.S. and buying either a bank draft denominated in pounds or an international money order.
Vintage Sailplane Association
The Vintage Sailplane Association is another item that should be mentioned as long as we're on the subject of vintage gliders. VSA is the national organization of full-size vintage glider enthusiasts. Quite a few modelers are VSA members, because they like to keep up with events in the "real" world and are also into full-scale soaring. In fact, SOAR club member Jack Ilner is the Northern District VP for VSA.
VSA membership is a bargain at $10 per year and includes the fine quarterly journal Bungie Cord. BC was edited and published by Charlie Morey, who, as you know, is editor/publisher of Slope Soaring News. I say "was," because while Charlie was doing a great job with BC, he found that he was stretched too thin and something had to go. But I'm sure the new editor will continue the fine work. Send your $10 check to VSA, Rt. 1, Box 239, Lovettsville, VA 22080.
Bob McGowan on contest flying
Bob McGowan won the 1990 Masters, so this is a guy you should pay attention to when he talks about contest flying. Bob wrote the following piece for the Diablo Valley Soaring Society (east San Francisco Bay Area) newsletter, The Thermal Tales (edited by Greg Vossgerdin). As I read Bob's words, I was struck by the similarity to what Fred Rehm wrote in the "How Fred Flies" article in my July column. Know what? The really successful pilots all use the same secrets! But it's still instructive to listen to all the pros, because slight differences in explanations may set off a light bulb in our own heads.
Transcribed from original scans by AI. Minor OCR errors may remain.
