It’s not easy being green

CONTROL LINE COMBAT

As seen in the May 2018 issue of Model Aviation.

In light of Model Aviation’s special focus on beginners this month, I thought I’d share some thoughts about Control Line (CL) Combat equipment that might be useful for newcomers to the sport. For the seasoned veterans out there, I hope this article will plant some seeds that might help you get a newcomer up and running if or when someone comes to you for advice.

For those of you who are thinking that it would be fun to give CL Combat a try, you’re right! Congratulations on seeing the light. Now the question is, “Where do I begin?”

Your best bet is to find some local pilots who can show you the ropes and help set you up with some decent equipment. Even better, you could attend a local contest, where you will have a chance to see some Combat in person and meet a number of pilots who can help you out. To find a local contest, check the listings at the back of Model Aviation in the “Sanctioned Event Calendar.”

Another vital resource is the Miniature Aircraft Combat Association (MACA), the AMA Special Interest Group for CL Combat. One of the best ways to get in touch with active Combat pilots is to join the MACA group on Facebook. By sending a message to the group, you can quickly get in touch with more than 600 Combat pilots and enthusiasts who can provide you with useful information and help establish local connections for you. The group includes a variety of vendors that you will be able to contact privately to order airplanes, engines, propellers, and other essentials.

If you’ve never flown a CL model before, the first step toward flying Combat is to learn how to fly the model. This process can be greatly facilitated with the help of a good teacher. For potential flight instructors out there, if you’ve never done it before, the mechanics of teaching someone else how to fly can be surprisingly tricky.

When teaching someone else to fly CL, a new pilot’s posture is the highest priority. It’s crucial that he or she is able to keep his or her arm straight out, slightly leading the model, and is able to turn/walk the circle in a natural way. Invariably this means that you, as the teacher, will end up contorted, and somewhat scrambling to run around the outside of the aspiring pilot. This is how it has to be—you work hard so that the student gets the correct feeling of how it is to fly.

Every year, the Knights of the Round Circle CL club in Southern California attends AMA Expo West and provides the chance for visitors to try their hands at CL flying. Club president and CL Combat pilot, Mike Alurac, sent me the included photo of the training setup that the club uses.

This is an electric CL trainer setup used by the Knights of the Round Circle in Southern California. Note the special V-shaped training handle.

This is an electric CL trainer setup used by the Knights of the Round Circle in Southern California. Note the special V-shaped training handle.

The model, designed by AMA Hall of Fame member Larry Renger, is powered by an electric motor. The throttle is controllable via radio by the instructor. They fly indoors on 18-foot lines, with a special Joe Brownlee-designed doublegrip training handle that allows both the instructor and the trainee to control the model as needed.

The Knights have put together an excellent packet of informational materials to go along with their demos and lessons.

Getting Started in CL Combat

Let’s suppose that you already know how to fly CL models and want to get started in Combat. There are a few tips I can offer to help you get started.

As modelers, I’m sure we are all aware that having the right tools makes any job easier and more enjoyable. If you have an engine that is in good condition and a fresh starting battery, starting the engine by hand (as we must do in Combat) should be a breeze. If you are using a glow engine, it’s important that the glow plug is working for the engine to start and run.

There are various ways of setting up a meter on your battery to check your plug’s status in situ without having to pull it out and look at it. For a competition, this information should be as readily available as possible.

A simple and effective approach is to install an LED on your battery clip (see photo). The LED is wired in parallel with the ends of the glow clip. When the battery is disconnected, or connected to a dead plug, a small amount of current runs through the LED to light it.

A glow clip has an aftermarket LED installed to allow quick access to information about the glow plug status.

A glow clip has an aftermarket LED installed to allow quick access to information about the glow plug status.

When you connect the clip to an engine with a working glow plug, (nearly) all of the current will be short circuited through the plug and the LED will go dark. This gives you an instant reading of the plug’s status without ever having to look away from the engine.

One other peculiarity of Combat models compared with other types of models is the fuel system. In most other types of CL events, engines run on suction from a hard tank. In most Combat events, we run on pressure from a fuel bladder (see photo).

This shows everything you’ll need to make bladders (fuel tanks) for CL Combat. See the text for more information.

This shows everything you’ll need to make bladders (fuel tanks) for CL Combat. See the text for more information.

The bladder is basically a piece of surgical tubing with one end capped off. It is typically housed in a tube in the outboard wing of the airplane. When it’s filled with fuel, the bladder blows up like a sausage and provides a constant stream of fuel at high pressure, keeping the engine running strong through even the tightest maneuvers.

Making bladders is easy. The materials you’ll need are shown in one of the pictures. For bladder tubing I use 1/4- inch inside diameter, 7/16-inch outside diameter super-soft latex tubing from McMaster-Carr. The late Rich Lopez discovered that Goof Plugs, designed for drip irrigation systems and available at home improvement stores, make great bladder ends.

For the inlet/outlet end of the bladder, simply drill a small hole along the axis through the plug. For the cap end, I recommend trimming off the small end of the plug, as shown in the photo.

After you have all of the pieces ready, insert the plugs into the two ends of the tubing (2.5 inches is a good length) and secure them in place with a tight wrapping of string or metal binding wire.

I hope these tips have been helpful. I look forward to seeing you in the circle!