Control Line: Aerobatics
Ted Fancher 58 Flying Cloud Isle Foster City, CA 94404
Hi, gang. You'll recall that a few months back I did a series of columns discussing my modification of the Sig Twister. I've received several positive letters from fliers indicating their desire to see more of that type of article. This is evidence that the majority of my readers are neither rank beginners nor top-five Nats fliers. Rather, they are competent pilots who are looking for information and projects with which they can improve their existing skills and enhance their competitive standing amongst their peers. To do this they are in search of good-flying, attractive aircraft—ones which don't require a year to build (and/or repair), yet provide better performance than the available commercial kits.
Among the best ways to do that is to modify one of the existing kits to improve its performance. My Twister project was one attempt to do just that. The modified Twister is a significantly better flier than the stock one and required very little ad-libbing to the basic kit.
Jim Armour has now gone one step beyond the Twister. Jim is a perennial top-10 finisher at the Nats and won the Concours d'Elegance at the 1984 Reno Nats. Check out the accompanying pictures of his highly modified Top Flite Tutor. While Jim's modifications closely follow those of the Twister—primarily increased wing area and a longer tail moment arm—there are some additional subtle and noteworthy changes. Let's let Jim tell us all about his gorgeous fun ship.
Jim Armour on the Tutor
"Although reluctant to build a 'kit ship' after all these years of scratch-building, I felt compelled to build the Tutor. The kit was a gift from a friend in thanks for teaching him the pattern.
"Because I didn't feel the stock kit would give me the performance I demand, I checked out the plans closely to determine what modifications would make it a better performer.
"Because the 45-in. span, 410-sq. in. wing just wasn't large enough for me, I respaced the ribs to three inches apart. I replaced the 1/4-in. sq. trailing edge cap with 1/4 x 1/2-in. balsa. In addition, I added three-inch, jet-styled wing tips and enlarged 4-in. flaps with a root chord of three inches and a tip chord of 1 1/16 in. These changes resulted in a 54-in. wingspan with a 10-in. mean chord, 540 sq. in. of area, and an aspect ratio of 5.4 to 1. The inboard wing is 1/8 in. longer to provide asymmetry. (This refers to the common practice of having the inboard wing slightly longer than the outboard. This compensates for the higher airspeed, and thus greater lift, of the outboard wing. —Ted)
"All of the tail feathers were also redesigned for more span and area. Again, I used 1/4-in. balsa instead of the 1/16-in. kit wood. The new tail has a span of 23 in. with a root chord of six inches and a tip chord of four inches. The hinge line is at 50% of the chord. The stab and elevator area is thus 115 sq. in., or 22% of the wing area.
"The fuse was not only lengthened to handle the longer moment arm between the flap and elevator hinge lines — five inches of balsa was grafted at the rear. The enlarged tail was then relocated to achieve the desired 17-in. hinge-to-hinge spacing.
"The nose was reshaped to allow the use of a radial-type RC engine mount instead of the stock profile side mount. This allowed the engine to be mounted in traditional inverted fashion, which makes for better engine runs. Thin 3/16-in. plywood doublers were added, and then 3/8-in. balsa struts on each side. Thus the fuselage is just over two inches thick at the nose. A 1/4-in. plywood firewall provides the mounting surface for the RC engine mount.
"A 1/4-in.-deep strip of balsa was removed from the fuse, starting at the top of the canopy and extending aft to the rear of the lengthened tail body. A 7/16-in. subfuselage was added to the bottom of the fuse to regain the lost side area. This resulted in a better-looking, more streamlined profile.
"The landing gear found a home in the wing, complete with Don's racing wheels and a set of wheel pants. This provides much improved ground handling on hard surfaces.
"After using five-minute epoxy for all the fillets, a bit of color was sprayed on for the trim, and Ditzler clear automotive enamel was used for the top coat, allowing the beauty of the wood grain to show through. (Note: The colors are typically Armour — red, white, blue, and silver with black letters and highlights. —Ted)
"The more this thing started coming together, the more it resembled a certain 'Fanchermobile,' although it was not intended to be so. (Aw, gee. Shucks. —Ted) Total weight came out to just 39 oz., including 3/4 oz. of tail weight required to adjust the CG.
"While the balsa chips mounted, a new OS Max .40 FP arrived at my door. I ran a gallon of 10% nitro, 25% castor fuel through it on the bench in a sloppy rich four-cycle and then bolted it into the ship. The cut-down Bolly 10 x 6 three-bladed prop shown in the pictures proved to be the powerplant for the FP. However, both the engine and the ship love a Zinger 10 x 6. With the properly set needle valve, the 40 runs perfectly and breaks only slightly at all the right places.
"Boy, does this ship perform! It will whip any full-bodied stunt ship in all areas. On low lines, it will pull like a 4-1/2-size ship and stays tight at the top of the hourglass.
"The only consideration for this project was just for fun. Besides, it has been a number of years since I built a .35-size ship. Well, Ted, it is so much 'fun to fly' that I take it to the field when I should be taking my .60 ship for some practice!"
Thanks for sharing your ship with us, Jim. After checking out the pix and reading of your enthusiasm for the project, I would not be surprised to see a few clones appear around the country.
Notes from Ted
I'd like to add a couple of thoughts to what Jim had to say. The "Fanchermobile" to which he refers is my old Imagination, which I mention periodically in those ramblings. Full-size plans are available (No. 260, RCMJ). It’s true that it bears some resemblance to Jim's Tutor. This similarity is more than skin deep.
Like Jim's ship, the Imagination is more than a match in performance to any of its full-bodied brethren. The Imagination was Nats winner in the Invitation (national champion in 1982) and the Citation 'Y' champion. In addition to flying well, it is also a much easier plane to fly and not coincidentally, much more fun.
Why is that? It is not exactly sure. The fact that you've only got 25% as much work involved certainly takes a lot of the anxiety out of flying experimental ships. However, that doesn't really tell the whole story. Because they are somewhat smaller (the Imagination is only 610 sq. in. compared to 660 for the Nats winner) and more draggy by virtue of their profile configuration, they are more nimble without being squirrely. They don't pull your arm off and don't require two strong men to box it up and take off your cell flight.
Items such as these have greatly influenced my current design thinking. My latest ship, under construction as I write this (or will be, once I get away from the word processor), will be smaller, lighter, and purposely less streamlined. By so doing I hope to recapture that nimbleness and ease of flight in a more attractive, full-bodied platform. I'll let you know if it works!
Vintage/Nostalgia Stunt
A couple months back I reported on an attempt by Doc Passer to establish a new event he has dubbed Nostalgia Stunt. I felt at the time (and still do) that this could be an idea whose time is ripe. Many of us still retain a soft spot in our hearts for those great ships of the late Fifties and early Sixties and would just love a reason to build one again. (I just found some pix of my then-future wife Sharen and myself with my first Ares circa 1960. If I get real guts I might try to get that published.)
Well, Mike and Jo Ann Keville, 6618 Dashwood St., Lakewood, CA 90713, and their new club, the Knights of the Round Circle, have taken the challenge. They are planning to hold the Vintage Stunt Championship (VSC) sometime in February of 1989. They are wisely planning to have a big PR campaign well in advance of the planned date to inform as many interested parties as possible in time for them to get something whipped together. (Except for Weragge and Aldrich, of course. I bet they still have the original Ares and Nobler in a state of suspended animation just awaiting such an opportunity.)
They are planning either a one- or two-day affair, depending on interest. A nice banquet would be part of a two-day affair. The location will be at Whittier Narrows in East Los Angeles, only a short drive from Disneyland (and many other interesting local attractions). It could be a great family affair. Even the competition would tend to be lower-keyed compared to the "Top Gun" atmosphere of the Nats or FAI team trials.
Planned events
- Olde Tyme Stunt using the Garden State Circle Burners rules (available from John Miscia, 415 Clifton Blvd., Clifton, NJ 07013). Stunt designs killed or published prior to December 31, 1952 are eligible for this event.
- Nostalgia event using rules from 1957 and open to designs from 1953 through 1963. A listing of eligible designs is expected; if you enter a favorite, document its heritage in case of questions. The organizers emphasize FUN and intend to be flexible about eligibility.
- Free-Style event — "run what you brung ... your time in the spotlight!" BYOHS (Bring your own Hot Stuff).
Additional awards and features
- Concours
- Most Outrageous Paint/Decorating
- Oldest and Youngest Contestant
- Best Costume — entrants are encouraged to come dressed in 1950s style
A fascinating possibility of the Nostalgia event is that some of Stunt's legends may find the idea irresistible and show up in person. You'd especially love legends like Dick Williams, Jerry McMillan, Wild Bill Nebenzek, Bob Palmer, Tom Warden, Bart Klapinsky — dust off those old T-Birds, Half-Fasts, Skylarks, and Tomcats, limber up the old Foxxes, Johnsons, and McCoys, and come out and teach us youngsters how it's supposed to be done.
Mike and Jo Ann are working hard to make this idea happen. If the idea appeals to you, drop them a line to get on their mailing list for updates and rules: Mike and Jo Ann Keville, 6618 Dashwood St., Lakewood, CA 90713.
Transcribed from original scans by AI. Minor OCR errors may remain.
