Control Line: Aerobatics
BACKING up a couple of steps from last month's ideas on modifying two kits, let's start from the beginning and recommend four steps for the beginner to start in learning how to fly precision aerobatics. The beginner should start with a profile airplane and learn level flights, inside round loops, outside round loops, inverted flight, takeoffs and landings. This writer suggests beginning with a .35-size engine for these reasons: it will usually start easier, will last through the crashes, and will be used later in succeeding planes. Step One is profile plane without flaps; the writer suggests one of the following: (1) Flite Streak (Top Flite), 42 in. wing span, a good old flier that will perform well; (2) Cosmic Wind (Goldberg), 43 in. wing span, another veteran that will fly (actually the Buster and the Shoestring are about the same plane); (3) Mongoose (M & P); 36 1/2 in. wing span, a slow Combat plane but suited for learning; (4) Ringmaster (Sterling) 42 in. span, a plane used by thousands to learn to fly, recently modernized in construction methods.
Control Line: Aerobatics
AFTER several requests for information on adapting available kits to "real competition" machines, I will present the following data on the Sig Chipmunk and the Top Flite Gieseke Nobler. Next month I'll continue on some other kits. The Sig Chipmunk can be a devilishly competitive machine, as it has been in the hands of David Fitzgerald, who has won four National titles with a basically stick kit with a few modifications. Start by looking at the wood. David says to substitute engine mounts all the way out to the end of the cowl for better mounting of the plastic cowl. Replace the 1/16 plywood doublers with 1/32; use Contest light balsa on the bottom planking of the fuselage; use hardwood mounts for the bellcrank platform. Another big item that David suggests is making the top block in one piece from front to back; he has made a mold in one piece for the entire top block using 3/32 balsa for the block. This solid block on the top greatly reduces any flexing of the fuselage which evidently David considered a problem.
Control Line: Aerobatics
The solution is not simple. First, Bob should make certain that he has enough tip weight. Most .35 size profiles require at least 3/4 oz., but try one ounce or even 1.25 oz. to see if it helps. While we are talking about the wing, Bob had better make certain that his wing is not warped. The outboard wing may be twisted down relative to the inboard panel, or it may be the flap (if his plane has them) with the same problem. He could try shorter lines, which would make the plane more responsive and cause it to fly each lap faster for the same rpm of the engine, which could help with line tension. Actually, 60 foot lines on a profile are a little long, unless he is measuring from the handle to the center of the airplane; then the line length is the same as slow combat, but he is trying to fly the plane about 30 mph slower than slow combat. Make certain that the lines are .015 diameter, if .018s are used, more tip weight will definitely be needed.
AMA Nats Lincoln '79: CL Aerobatics
"HAIL, Hail, the gang's all here!" You bet they were: four World Champions, eight former National Champions. Overheard many times during the week was the exclamation, "This has got to be the greatest stunt contest ever held." It may well have been just that. And when the wind finally calmed down at about 2:00 a.m. Sunday morning, the "Old Bear" from Irving, Texas, Bob Gieseke, had the Walker Cup sitting in his motel room for the fifth time. Bob won this Nationals to add to his titles in 1966, '68, '74 and '75. Stunt fliers had been hearing for months that Lincoln would be hot and windy. This prophecy proved true for the 49 open fliers that turned out for the PAMPA revised format. Except for Wednesday's qualifying and Friday's semi-finals, which were near perfect flying days, the rest of the competition days were windy and Saturday's finals were flown in near gale winds. The Junior-Senior fliers did not enjoy good weather as 10-15 mph winds prevailed on Tuesday, the first day of competition; such a resounding disappointment (three juniors and six seniors) that both age divisions were flown on the same circle.
Control Line: Aerobatics
SOME more suggestions on the Max 40 FSR. According to two-time World Champ Bill Werwage, after several gallons of testing in the spring and summer, it seems that with conventional props (i.e. 12-6, cut down 13-5, etc.) the Max may work better on a large airplane (i.e. 675 sq. in. and over) that weighs in the 58 oz. area and over. According to Bill, this taxes the engine's power and helps to tame it down. Unfortunately, at the time of this writing, some top fliers have abandoned the Max for this summer in favor of the old reliable ST 46; for instance Whitely, Les McDonald, Fancher, Werwage, Jim Armour and Dave Hemstrought. However, Dave Hemstrought has some additional comments on the Max. He and Stan Powell were using Max in the spring and came up with two bits of modification that seemed to help. Firstly, they used an .005 in. head gasket to lower the compression. Secondly, they very carefully took the glaze off the chromed cylinder liner with an automobile brake cylinder hone by hand. This allowed the ring to seat better in the liner with the result that the engine did not tend to run away in the round maneuvers, the most common problem among users of this engine.
