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.
The Mighty Dakota
Just a very belated note to say thanks for the "Northwest Dakota" — I finally got around to building my copy! As a youngster, I flew my father's Dakota in 1957. I bought a kit for one at the Los Alamitos Nats in 1967. Though I never got a chance to fly the one I built, I always loved the looks of the bird. I took a long look at yours and made a whole bunch of changes. First, I added a radio. Next, I converted the nose back to the original inverted engine version. Now I had the Dakota I remembered! If that wasn't enough, I built a center section into each wing, lowered the dihedral, and added spruce spars. A good friend at Cox Hobbies built up a single-port .09 with a throttle sleeve for me to use, too. The motor turns 10,000 tops and will idle all day at 4,000 rpm. As a free-flighter, I will tell you it only weighs 21 oz. (TRUE!) I didn't need the power, just the nose weight! The model flies better than any trainer ever invented. It won't stall, spin, or do anything nasty at all. I find myself doing "flybys" one after the other, just to watch the model go by! If that isn't enough, the Dakota will thermal easily, too. Last Sunday, after running out of fuel, the bird blundered into some lift and would have flown out of sight if I had let it! To say I'm satisfied is an understatement! The enclosed picture doesn't do her justice, but just shows us RCers like simple stuff, too.
Randy Wrisley Santa Ana, CA 92701
Randy addressed designer Clarence Haught, whose Model Aviation plan was a scale-up of the Veco (then Dumas) all-wood Dakota (Joe Wagner original designer). We flew them years ago and our kids did, too. Randy has shown us plans of a 6-ft. RC he's cooking up. Kitted during the late forties, the Dakota is a kind of ghost rider in the sky. We haven't seen the end of it by a long shot.
Deserving Case
I own a one-channel radio control glider. It has a wingspan of six feet. I haven't flown it yet, but I hope to fly it this summer. I'm a grade seven student at a school called Venerable Kateri Tekakwitha. If it isn't any trouble could you please send me plans to your "Lightning Bug" and, if possible, the plans to the plane you have designed, "Miss America." I like them very much.
Stephen Bianco 48 Anna Capri Dr. Hamilton, Ontario, Canada, L8W 1M6
If a 7th grade student is this deep into RC, it would seem we should help him. The Lightning Bug was an .010 RC designed by the editor for Jetco and the Miss America, a 3/4A version cooked up for Scientific. Even we editors don't have plans and would love to have prints for old-time sakes. But if you have one, do help Stephen. They are both good flying machines. His full address is given—please don't ask us to forward anything—alligators up to the ears.
Inquisitive Mind
The short letter by Mr. George Clapp aroused my interest, having experienced the same problem he described relative to ineffective ailerons on flat bottom airfoils; however, I didn't grasp the solution based upon the photo and accompanying words.
Would you be kind enough to send me a simple sketch of the "collector" installation?
Bob Dittmer Huntington Beach, CA
Aileron Collectors
A few words for the beginners: aileron effectiveness is directly related to the amount of dihedral, the aileron shape, and the wing's position on an aircraft. A high-wing aircraft, such as "Spook," has a pendulum action that helps the effect of the dihedral. The more inherent dihedral the wing has, the more the dihedral fights the ailerons for lateral control.
Also, pressure distribution on a flat-bottom airfoil is not as equal top-to-bottom as on a symmetrical airfoil wing. This sometimes causes more drag on the lowered aileron of a flat-bottom wing and can make the aircraft turn in the opposite direction if rudder isn't added simultaneously. In some cases the aileron movement is short and the rudder area isn't large enough; adding rudder won't help much.
These collectors are only a means of getting the ailerons to function better on a wing already designed with too much dihedral or poorly designed ailerons.
The action of these collectors is (see sketch) to produce additional drag where needed to equalize, more or less, the drag between the two ailerons. This also has the effect of gathering air and compressing it to be jetted out between the aileron and the collector. The forward-projecting wire with a lead weight at the front (in the published picture) has nothing to do with the collectors. It is only a static balancer to correct aileron flutter which Spook also suffered from. The lead can't change directions as fast as the aileron can flutter, thus dampening the flutter.
Spook now has been completely rebuilt with alternate-type ailerons. Down thrust has been removed, the wing is symmetrical (airfoil), tail moment has been extended by 4 inches, vertical fin area has been reduced, and thrust, wing incidence, and stabilizer incidence are all zero degrees.
George Clapp Central Square, NY
We asked George Clapp to fill us in. While his sketch illustrated the installation, here are the key details and dimensions he used on Spook:
- The collectors do not run the entire length of the ailerons but are placed at the tips for more leverage—longer collectors would be even more effective.
- Dimensions (relative to aileron chord X):
- X = aileron chord
- A = 70% of X
- B (gap) = 8% of X
- C (collector thickness) = 12% of X
- D (overlap of collector) = 15% of X
Drawn as used on Clapp's Spook.
Sketch and caption should make everything clear; we urge you to read with care precisely what he said—don't jump to conclusions.
Loathes Pushbutton Aerobatics
I have been in RC for about 10 years now and have really enjoyed this great hobby. I'm mostly a sport flier with an occasional contest here and there.
I wrote this letter because I have become somewhat disappointed with the developments in RC pattern flying. It used to be that the whole idea of RC aerobatics was for the pilot and his/her model to perform a given set of aerobatic maneuvers. This was to show how well the pilot was able to control his/her plane in various attitudes.
When pattern was first introduced into the AMA rule book most of our radio systems were primitive by today's standards. With the development of more and more sophisticated radios and especially proportional control, the RC pilot was able to produce rounder loops, better eights and even slow rolls! This was a boon for the pattern pilot as well as all other types of RC applications.
However, now it seems with the advent of programmable RC equipment, we are gradually moving away from the human element. That is to say, there seems to be a button to do just about any, if not all, of the stunts in the AMA rule book. What chance does a person have doing a slow roll with a regular proportional system as opposed to someone who just has to push a button? Chances are that most of us would vote for the guy/gal with the button on his/her transmitter.
In full-scale aerobatics, the judges would never allow a computer-controlled aircraft in this type of contest. It would be the computer doing the flying instead of the pilot. The pilot would be along for the ride, more or less as a babysitter. Is this what stunt flying is all about?
What it all boils down to is this: do we continue to have more and more automated flying, or do we say to ourselves, "I am the pilot... I'm flying my plane!"
I would like to hear from others and their opinions in this column.
Carlos R. Grageda Moscow, Idaho
Imitation
I would like to get the Model Aviation magazine from October of 1979. I am interested in the second part of the article, designing the "IMITATION." I would also appreciate if you could give me some information on designing books for stunt model airplanes (control line and R/C). Where may I get those books?
Luis Morlote Miami, FL
Correct us if we are wrong, but we don't know of any single stunt book, although PAMP's Stunt News, in its accumulated technical coverage, would constitute a book. (Wynn Paul, aerobatics columnist—address at the end of his column—so why not subscribe?) As to R/C design books, we'll annoy some die-hards but RCM has a series regularly advertised, with a wide choice of titles.
FLY SAFELY!
Transcribed from original scans by AI. Minor OCR errors may remain.
