Control Line: Speed
Glenn Lee 819 Mandrake Batavia, IL 60510
Golden Anniversary Speed Contest
Next August 12 is a notable date — that's when the Golden Anniversary Speed Contest will be held at the Whittier Narrows site in California. Chris Sackett, editor and publisher of Speed Times, the newsletter of the North American Speed Society, sent this information along with a copy of Volume 2 No. 2 (April–June 1983), wherein he documented the first speed contest. The write-up was from the September 1941 issue of The Model Craftsman magazine; Hugh Frankenfield (Allentown, Pennsylvania) sent it to Chris, and I had forgotten about it.
I wasn't much interested in nostalgia speed then, so I guess I didn't pay attention. Now modelers in the U.S. are starting to talk about an event for the older airplanes and engines, and we are trying to decide what year to use for the cut-off date — both 1951 and 1957 have been considered. English modelers have been flying these older ships and having a good time; even some younger fliers have joined in. I'll cover this in a future column, so if you are interested, please contact me.
The first tether-control model airplane speed race was held at the Lakewood Recreational Park, Long Beach, California, on July 27, 1941. Sponsors of the meet included:
- Lakewood Model Aircraft Race Association
- American Junior Aircraft Company (Portland, Oregon)
- Hoppy's Hobby House (Long Beach)
- Bunch Motor Company (Los Angeles)
- Aircraft Industries (Glendale)
The American Junior Aircraft Company was started by Jim Walker. Dan Bunch produced the Tiger Aero engines, and Mel Anderson of Aircraft Industries produced the Super Cyclone engines.
An estimated 2,000 spectators crowded the grandstands from ten in the morning until ten at night. No one had agreed on what to call the new method of control, but it was generally referred to as U-Control, guide-liner, tether flying, or hand control.
Race rules were new, too, and engine-size classifications had not been thought of, so modelers had to qualify with a quarter-mile flight. Lines were 52 1/4 feet long, the model was timed for four laps, and the pilot had to stay within a six-foot center circle. The model was put into a speed class according to how fast it went on the first flight. If it flew 48 mph it was placed in the 40–50 mph class; if it flew 65 mph it was classed in the 60–70 mph class.
A contestant had to keep his speed within his class to win a prize; the prizes for the slower classes were the same as for the faster classes. Contestants were allowed two trials in each flight, with the best time used for placing. Test flying was allowed until about noon, when Contest Directors R. D. Hopkins and Dan Bunch got the first official flights going.
R. C. Beattie of Los Angeles was first up with his Fokker Special powered by a Bunch Tiger Aero engine. He qualified at a speed of 48.39 mph. The 37 other contestants took their turns, with 29 of them getting a timed flight — remarkable reliability considering those old engines, spark ignition, No. 70 oil and gasoline fuel, and hand starting!
Trouble showed up on the second attempts, however, when only nine contestants stayed within their classes: five went too fast, three too slow, and ten managed no times at all. Bud Warren was awarded a special prize for the fastest speed of the meet at 70.58 mph, although he could not get another flight within that class.
Other winners included:
- Don Hodgson
- H. E. Watrous
- Ernie Smith
- Bill Pavlovsky
- Dean De Gonia
- Foote Fields
Mr. Fields had purchased a kit on Friday, built the airplane on Saturday, and won third place on Sunday!
Two contestants, Dean McMillian and Dean De Gonia, entered the novelty event and astounded the crowd with loops, breathtaking dives, and zooming climbs. The judges couldn't decide who was best, so Jim Walker donated enough prize money so that each won. This sounds like it was the first control line aerobatic contest, too.
Hop-up tricks were in vogue at this first contest. The article stated that Don Hodgson qualified with a stock Super Cyclone engine at 65.60 mph, then replaced the head with a Dooling red-head and achieved 69.23 mph. Apparently this head was made for the tether car competition.
I'm sorry I neglected to mention the tether car competitors in my previous column when I talked about progress in engine design by speed fliers. They were the first to design true racing engines, and control line speed fliers were quick to adapt these hot engines soon after the first speed contest. Many different engines appeared — Dooling, Hornet, McCoy — and car racing had a large following with many tracks around the country. They rapidly declined, however, and never really advanced past the Dooling 61 until the Schnuerle speed engines with tuned pipes were adapted not long ago.
Head Chamber Design and Nitro Content
Successive test runs can be made, raising the head clearance with a shim for each run until the RPM starts to fall off. Example: using 0.003 shims, the engine may run fastest with five shims (0.015). If one more shim is added, RPM can drop by 200 revs. Quite often this gives the ideal clearance since that extra 0.003 head clearance allows the engine to unload more in the air.
This method will work with any nitro-content fuel. Note that when over 50% nitro is used, the head chamber surface will often look sandblasted. This is the glow element vaporizing due to high nitro/compression and, to some extent, a phenomenon where platinum reacts poorly with aluminum.
Just as methanol forms a catalytic reaction with platinum — the major component in glow-plug elements (which can cause a hot engine to start without the battery) — platinum is effectively "allergic" to aluminum. This often explains a blown plug in a new engine, even when it has been run rich. Some exotic racing engines now sport either chrome or electroless nickel-plated back plates to lessen the chance of flying aluminum particles getting to the plug.
Once the optimum head clearance is found, remember that it can change with the weather. If the original settings were made in cool, dry weather, be prepared to add more shims or drop the nitro if it's 90° and humid. These are the extremes of setting the head clearance for minimum pre-detonation versus maximum performance for a glow engine.
Ignition Engine Timing
For an ignition engine it's very easy to advance or retard the spark to get optimum performance. Here is an easy way to check the timing: with the piston at TDC (top dead center), set the points so that any further rotation will cause the points to open. This setting is the fully-retarded position.
An ignition engine can also show signs of being over-compressed in a manner not quite the same as a glow engine. With gasoline-based fuel, an overly compressed engine — or one that is too tight — may slow down, sag, and overheat when the spark is advanced. The normal sounds we relate to pre-detonation will seldom apply here; the noise is almost a wheeze, and the overheating will make you bring the timer advance arm down in a hurry. For example, an Orwick 6.4 with about a 12:1 compression ratio has only about 20 degrees of spark-advance travel. The Super Cycle at something less than 7:1 has over 80 degrees of travel. Each engine design will have its own limits.
Notes and Contact
For those of you who have written and sent SASEs, I now answer my mail. You're welcome to write or call (before 10:00 p.m. CST). I have added a FAX machine: 512-656-2021. It will answer after six rings; hang up after five and you won't be charged. Send letters to:
12822 Tarrytown San Antonio, Texas 78233
Personal: Trimming the Zipper
Early last summer I opened the gate to our flying field at 4:45 a.m. I drove down to my favorite spot for trimming and sat alone, sipping coffee while I waited for the sun to rise. At gray light I opened the van and put the Zipper together. It was a breathless morning; fresh hay bales littered the field and a heavy, pungent, fresh-cut grass aroma hung in the humidity. Howard and I trimmed the Zipper in seven flights — it was a fine morning.
Transcribed from original scans by AI. Minor OCR errors may remain.
