Control Line: Aerobatics
Wynn Paul
SO YOU WANT to get into Stunt! So many times we hear the words, "What should I do to get into stunt?" For those contemplating stunt and who are not certain which way to go before selecting a kit, the writer will present some of his ideas on how to get started. It is entirely possible to use commercial kits and finish high in the Nationals; it requires some careful selection and some long nights of building.
The first thing is to use a profile kit and learn the basics of the pattern before going to a "built up" model. If possible, build two or three profiles with the same engine mounting so you can fly one while repairing another. My favorite profile (other people may prefer something different) is the Midwest Magician 35 ($15.95) with a 48-in. wingspan. This is probably the best all around kit for beginning stunt. Build it with flaps, be certain not to sand the wing spar or it will weaken the wing and substitute a 1/16 in. thicker stabilizer and elevator assembly. A big improvement would be to mount the engine upright with the tank in the middle of the fuselage. Upright engines run better, don't cut out, and have less vibration. This plane is capable of winning contests if built straight and light.
My second choice for a profile is the Sig Banshee ($12.95) with a 49-in. wingspan and flaps.
Third choice is the Midwest profile series with the P-51 my favorite, although the P-63 and ME-109 are good. All of these profiles will fly a lot better if the engine is mounted upright. Ringmasters have always been popular. As a learner's airplane the tried and true Ringmaster Profile ($11.95) is a good solid plane on which to learn inverted flight, inside and outside loops, and squares.
Presently there are about eight "built up" stunt airplanes on the market which can be built for competitive flying; most of them will come out a little heavy if you don't substitute contest balsa. The writer will review them according to his personal rating; there is no intention of criticism toward manufacturers, it's just that some kits are lacking in top-level competition characteristics.
The Sig Super Chipmunk at $19.95 is a really competitive machine. The wood is excellent. The 53-1/2 in. wingspan has enough square inches to do the job. It can come out weighing 48 ounces which is competitive. Several flyers have stated that "Chips" come out nose heavy; I would prefer this to coming out tail heavy. Tom Dixon (Atlanta, Ga.) suggests that the tail moment should be lengthened 1/2 to 1 in. and that a substitution be made of a 3/8 in. stabilizer and elevator. With a good .35 engine this plane can be flown well enough to win anything. Gerry Solomon from Cincinnati used a strictly stock Chipmunk kit in 1972 to place 8th in the Nationals. He used a .46 for power because of the excess weight he picked up with a good finish.
The Sig Akrobat ($19.95) with 550 square inches of wing and a 51-in. wingspan is at the same level as the Chipmunk. It has elevators and fin built up rather than sheet construction, which could save a little weight. Some builders have had trouble keeping the molded cowl together, but with reinforcing it will usually stay solid. Tom Dixon suggested that it be built with adjustable leadouts and also preferred building it with solid wing tips.
The next kit is the revered Topflite Nobler ($18.95). Build it exactly to kit dimensions, use kit wood and you will get 45-48 ounces that a good Fox or OS Max will pull. That is, you will if you are very careful using epoxy, paint and glue. Put a 1/32 in. doubler at the trailing edge portion of the fuselage; use a hollowed block rather than the sheeting ahead of the canopy; use different flap horns with bearings; sheet the leading edge top and bottom on one side at the same time to avoid a warp; use the appropriate part of an 8-9 in. Sig bubble canopy as a replacement; epoxy or fiberglass the nose and doublers. This is definitely not an easy kit. It will fly better than you until you get very practiced. Built straight and true, you can have a truly competitive airplane.
The next four airplanes need wood substitution to be competitive. They also need above average building techniques to come out competitive. However, they can be made to fly well if you follow reasonable building suggestions from someone who has been in competition.
The Jetco Dolphin ($19.95) has a 49-in. wingspan, with 516 square inches. This kit will usually come out very heavy and also tail heavy. Build it with a 1/2-in. longer nose and be very careful when building the tail so you can get a plane that will turn without being jumpy. Without substituting wood it will come out about 49 or 50 ounces, which is a little heavy for a .35 engine.
The Sterling Ruffy ($21.95) is a good old ship by McFarland which can really fly, but substitute contest wood or it will come out heavy. I flew one of these for a season and won some hardware; it will turn well.
The Sterling Skylark ($28.95) has probably sold more planes on the basis of the beautiful picture on the box than the plane. The price might scare off a lot though. The writer had one of these kits and found some differences between the kit plans and the magazine plans, mostly in the nose and tail moments. If contest wood is used the plane can be a very pretty one although probably over 50 ounces, and performance is the name of the game.
The Jetco Shark ($29.95) is one of the most famous of stunt planes by neighbor Lew McFarland, but again kit wood is just terribly heavy and the writer has seen Sharks come in at 80 ounces! Only a .45 or .46 engine should be considered. Substitute every piece over 1/8 x 1 and you may get a plane at 62 ounces which with its 700 square inches will probably fly. This is an impressive airplane, especially in the hands of old man McFarland, and the writer has flown several of his originals, but beware if you try one—substitute, substitute.
Just at this writing the local hobby shop got in the new Sig P-51 stunt kit with foam wing priced at $19.95, which is a good price. According to Tim Trimnell, fellow Lexington stuntner, the kit looks great, lots of good wood. The kit includes a lot of hardware, a large instruction sheet and ABS plastic cowl, radiator and turtle deck. The article by Mike Gretz in Model Airplane News (May, 1975) describes the airplane and its construction. The plane has an exposed elevator control horn for ease of adjustment. Tim suggests substituting for the stamped hinges in the kit. Also, the foam wing has two 3/8 holes cut in the left half for the leadouts, which would make it nearly impossible to install adjustable ones, a feature the writer feels is mandatory. This kit looks to be a definite winner and we will await some comments by builders.
This discussion is meant to be a guide to the novice and beginner. There are some excellent kits on the market to start into stunt. Anything not just should be built light and straight. Ask questions of experienced modelers. We need more people in precision aerobatics and want more people. The more the competition, the better the champions are and the better the U.S.A. will fare in the FAI championships.
Transcribed from original scans by AI. Minor OCR errors may remain.
