Author: Bill Bischoff
Edition: Model Aviation - 2015/06
Page Numbers: 31,32,33
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Margaret June CL Sportsman Goodyear Racer - 2015/06

by Bill Bischoff

What is CL Sportsman Goodyear Racing?

Control Line (CL) Sportsman Goodyear Racing is CL racing where two or three airplanes are simultaneously flown in the same circle. Each pilot must complete a prescribed number of laps and, within that time, make several pit stops. A pit stop means the engine is shut off, the airplane lands, the mechanic refuels and restarts the model, and the airplane takes off again. The airplane that finishes in the shortest amount of time is the winner.

Although the concept of CL flying is generally understood, CL racing may not be familiar to everyone. Goodyear refers to a specific AMA competition event formally named Scale Racing. The models must be 1/8-scale profile renditions of full-scale racing airplanes that compete or formerly competed in the international Formula 1 air racing class.

When this midget race airplane class was created after World War II, it was sponsored by the Goodyear Tire and Rubber Company, which gave the full-scale event the name Goodyear Racing. When the aeromodeling event was created, it took the same name. The Sportsman designation denotes a local or regional modification of the AMA Scale Racing event, usually with additional restrictions designed to limit performance.

As an example, a good AMA Goodyear model might reach approximately 120 mph, while a top-performing Sportsman Goodyear model may reach about 85 mph. The reduced performance is usually accompanied by reduced costs, which makes the event more appealing to novices and casual competitors. With a stock engine requirement, the emphasis is on team performance rather than equipment performance.

For the complete Dallas Model Aircraft Association (DMAA) rules, visit the club’s website listed in “Sources.”

Based on the success and popularity of the event in 2014, DMAA Sportsman Goodyear was chosen as a supplemental event at the 2015 Nats.

Choosing Margaret June

Margaret June was chosen as the subject of this construction article for several reasons: I wanted to model an aircraft that is currently competing, had not been previously modeled, and I wanted it to look good. After some internet research, I came across Margaret June. The aircraft met all of my preliminary requirements, and I found a small drawing that could be scaled up. The only problem was that, without any dimensions, I didn’t know exactly how much to scale it.

I also found the name and email address of Margaret June’s pilot, Kent Cassels. I sent him an email explaining that I wanted to build a model of Margaret June and needed some dimensions. Although he was actually driving home from the Reno National Championship Air Races at the time, he replied within approximately 10 minutes! He included pictures, dimensions, and a scale drawing. I was surprised and impressed, and with that I knew my project had to be Margaret June.

Engine and equipment

The engine of choice is either the ASP S15A or the Magnum XLS-15A. They are essentially the same other than the name on the crankcase and minor carburetor differences. These engines are inexpensive and start easily, even in the hands of a novice. Most people are buying the ASP from HobbyPartz.com for less than $45. The Magnum is available from Tower Hobbies and Hobby People at a slightly higher cost (prices may change at any time).

The engine must be used as stock, except for the venturi and spraybar. I can provide venturis and needle assemblies for $10 each or $20 for both (please contact me at the email at the end of this article), although mine are not required. Anything that meets the rules may be used.

Additional photos and the entire detailed construction article for Margaret June can be found on ModelAviation.com in the “Features” section.

Specifications

  • Type: CL Racing
  • Wingspan: 29-5/8 inches
  • Length: 23 inches
  • Weight: 21 ounces
  • Power system: ASP S15A or Magnum XLS-15A glow engine
  • Propeller: APC 6.5 x 5 or APC 6.5 x 5.5
  • Construction: Balsa and plywood

— Bill Bischoff [email protected]

Sources

Transcribed from original scans by AI. Minor OCR errors may remain.