Control Line: Combat
By Charlie Johnson
PUT A MARKER in the spot where you started this article, and turn quickly to the Competition Newsletter where the upcoming contests are listed. (Editor's note: The Competition Newsletter is a separate booklet again this month—it's not bound into Model Aviation like it has been for the past several years. RMcM.) There's something to do every weekend for the next four months! You don't have a thing to fly, you say? You can help officiate for the next four months (that should get you building!). Of special interest are the larger AAA meets that go on around Memorial Day. I received special flyers on the Eugene, OR meet which I attended last year. They'll feature all four categories of Combat on Memorial Day. The District IV Championships in Petersburg, VA will feature everything but FAI on May 15 and 16. These are but two of the many large meets going on in your part of the country. Start building now. You can read while the epoxy sets up.
Slow Combat and Slow Rat — engine restrictions
I noticed on some of the contest flyers I've received that there will be special restrictions in Slow Combat and Slow Rat. The biggest limiting factor has been the engine rule which requires only a Fox .35 Stunt engine. Northwest Sport Race has been super-successful using this engine, as has their Very Slow Combat using the same engine. It seems that on the local level most people are dissatisfied with the full-blown Slow Combat models and want a truly "slow" model—hence the Stunt-engine requirement.
FAI Combat — continued escalation
On the other hand is the continued escalation in FAI Combat. With the diesel a long-forgotten power plant, the quest for more power is leaving the potent Fox .15 (Schnuerle) in the dust. Rossi and ultra-light Nelson engines are going to be out in force at the CL World Championships this summer. Even if the popular Fox could make as much power as the hyper engines, it still can't compete on a weight basis because the ultralights weigh only 4 oz. The days of the bogging engine with a 7-6 prop are long gone, as 3–3.5 pitch becomes the norm and revs approach 30 thousand. The World Championship title is worth winning, and all the stops are being pulled out by the Europeans and others.
As in Team Race, there has been a lot of development work with props. The old wood or nylon sticks are several levels of performance below the new fiberglass and carbon-fiber props. I'd hoped to be able to give you price and other details on the prop Hoffelt Group will market, but there still are not enough manufactured to put on the market.
Props available and prices
John McCollum does make some very nice FAI and Fast Combat props that are available (if you hurry). His FAI Combat, Goodyear, and Team Race props are $6.50, and the Rat and Slow Rat (which make a good Fast Combat prop with a little work) are $7.50. John's on the U.S.A. team going to Sweden, so I know he'll be pretty busy as summer approaches. Write to him at:
21842 Bass Lake El Toro, CA 92630
As I always say, you'll greatly enhance your chances of a prompt reply from almost anyone if you enclose a stamped, self-addressed envelope (SASE).
Prop safety and flipping technique
A word of warning about using props. Don't flip fiberglass or carbon-fiber props bare-handed. Wear some sort of protection like a leather glove, rubber finger or, if you absolutely have to, a chicken stick. Tim Gillott uses a piece of hard balsa to flip all his racing engines and never seems to have problems with prop damage.
If you can learn the technique, the balsa stick is actually preferable because you can get terrific leverage against the prop and really spin over a loose engine. Tim says that his AAC engines won't start without the added kick the stick gives.
Fuel, tanks, and engine-head considerations
The tanks I reviewed last column (by Bob Nicks and Virginia Craftsman) worked as advertised. I intended to use them at Buckeye but received an offer to use one of Tom Zon's models in Slow Combat (actually three of us used it). So, no actual Combat wars are under their belts, but in practice both tanks ran clean and consistent. The head inserts from Virginia Craftsman look to be the most timely of all the items with the wide use of the Fox in Slow Combat and Sport Racing.
I just received another flyer which lists the Fox Combat Special as the only engine to be used in the Big Goodyear event. The other restriction is the use of contest management-supplied K&B 500 fuel. Head shape and volume will now be even more important as will the proper head clearance.
Sport Racing and Slow Combat development
Sport Racing events have a lot more in common with Slow Combat than Fast Rat does with Fast Combat. Dick Tyndall sent along a lot of suggestions on the correct clearances for various nitro loads and applications, so we'll see what comes of the development work. It's possible that a 100 mph racing airplane will translate into a 100 mph Slow Combat axe.
Filament control lines (Hoffelt Group)
Hoffelt Group also has some filament control line that is one-fourth the weight of our braided steel lines and supposed to be much stronger. I'm sure all of you are saying, "I'll bet," but the lines proved to be as light as promised, and they didn't break or kink or cause any problems. The weight savings in tip weight and overall line weight means quicker acceleration and better tracking through the turns. The only drawback seems to be a small amount more drag and their cost, around $12 per set.
Something as revolutionary as this will need a lot more testing before it's ready for the high-zoot market; possibly Stunt will benefit more than Combat. The smallest diameter is .018, so don't get excited about using them in FAI or 1/2A Combat.
Miscellaneous
Remember a few years ago when everyone with a hot-shot motor sent it to the Nats, and all the engines were run in one airplane? Some of the original instigators are up to it again—it sounds like a great after-hours activity! Hopefully more details by next column.
Charlie Johnson 3716 Ingraham St. San Diego, CA 92109
Transcribed from original scans by AI. Minor OCR errors may remain.
