Article and photos by the author. Featured in the Summer 2008 issue of Park Pilot.
Flying control line means that control of the airplane is imparted via two or more lines that run from the model to the pilot. In most cases, there is one for up (top) control and one line for down (bottom). An extra line is sometimes used to actuate other functions on certain models, such as engine/motor speed, flaps and tail hook deployment for the Navy carrier event. My Spring 2008 Park Pilot article showed how the leadout wires operate the bellcrank, transferring a rotational motion to a back-and-forth motion of the pushrod to actuate the elevator via the control horn. The remainder of the control system consists of the flying lines, line connector clips, the control handle and the safety thong. The flying lines used for control-line park flyers should be made from .008- to .012-diameter stranded music wire. Some pilots prefer to use solid, non-stranded wire, although I strongly suggest using stranded lines for now. Solid lines are more prone to bend or kink, and will require replacement more often than stranded lines.
Bob Hunt designed this handle to allow both neutral adjustment and adjustable line spacing. Note the safety thong and never fly without one.
Sullivan Products has always supported control-line flying. Factory-prepared flying lines and handle are from their Pylon Brand lineup.
Stranded lines can usually be purchased in hobby shops. Three major suppliers are Brodak Manufacturing, Sig Manufacturing and Sullivan Products (Pylon Brand). Each of these companies provides high-quality lines in a variety of lengths and diameters. You can purchase ready-made lines with “served” ends (eyelets at the ends) or plain ends so you can serve them yourself. Serving allows for custom length, and you can use thin copper wire to wrap the ends instead of having crimped tubing. Whether your ends are crimped or wrapped, check the ends carefully before each flying session. If you detect fraying or broken strands, don’t fly the lines; replace them. Most control-line models that meet the Park Pilot Program definition will require lines from 25 to 50 feet long. The determining factors in length of flying lines will be the size of the model, the amount of available power and the size of the area where you will fly. A typical CL parkie — like the Park Cat that was presented in the Spring issue of Park Pilot — should be flown on 35 feet of .008-diameter stranded lines. Experimentation will tell you if you can fly effectively on longer lines. If the lines are too long for the model, the amount of line bow between the pilot and the model will cause vague control feel and tend to make the model loose on the end of the lines. Always start with shorter line lengths, and gradually work your way up to longer lines. You will notice a degradation of line tension and control as the lines get too long.
Dick Sarpolus designed this custom handle and modified a Brodak Manufacturing reel for easier roll-up. Dick’s handle allows for finite neutral adjustment.
Lexon clip’s slider (left) moves to connect. AMA-type clips (center) are Brodak products. Sullivan line connectors are on the right. All three types work well for parkies.
While shopping for control lines, you are likely come across flying lines made from Dacron or some other type of synthetic materials. Do not use these lines. The AMA rule book strictly forbids their use by members. When you’ve finished reading Park Pilot, it would be a good idea to visit the AMA Web site to have a look at the Official AMA Control-Line Rules. Go to www.modelaircraft.org and look for the Competition/Events tab, then click on Rules. You will find a wealth of information about CL flying, including what you should and should not do concerning lines and all other facets of the sport. As a bonus, you’ll also find an illustrated how-to on wrapping line ends. I suggest adding this Web site to your favorites so you can refer to it anytime you have a safety or technical question. If you are not sure about something you find, do not hesitate to call AMA headquarters (800-435-9262) and ask for the technical director. Once you have your flying lines, the next item required is the flying handle. Many commercial handles are on the market, but most have been designed for use with larger models, and are a bit too heavy to use for control-line park flyers. Control-line flying requires feeling the model through the lines, and if the handle is too heavy or bulky, this feel will be severely diminished. Smaller, lightweight control-line park flyers require smaller and lighter handles, and most of the commercially available handles that fit the description were designed to be used with Dacron lines. You now know not to use Dacron lines, but these handles can easily be modified to accept steel lines.
This handle is in the neutral position, and this handle position should correspond to a neutral setting of the model’s elevator. Adjust the handle’s cable to achieve this setting.
Just like flying a full-size airplane, the CL pilot pulls back on the “stick” to go up. When the top of the handle is tilted back, toward the pilot, the elevator should move upward.
When the top of the handle is tilted forward, away from the pilot, the elevator moves downward. Beginning pilots should use limited movements until confidence is acquired.
Many CL enthusiasts eventually start making their own custom handles. Every pilot’s hand is a different size and shape, and making a custom, plywood handle allows a very comfortable fit to be achieved. Dick Sarpolus crafted a custom handle that allows for fine adjustment of the neutral setting, so that when his hand is at its natural neutral, the elevator is also at neutral. This is a very important adjustment, and every good control-line handle, whether custom or commercial, should allow this kind of fine-tuning. Adjustable line spacing is another desirable feature; it allows additional fine-tuning for the feel of the model. A model that is too responsive can often be tamed by bringing the line spacing at the handle closer together. I made a custom handle with adjustable line spacing as well as a fine-tuning feature for neutral. AMA-approved line connectors should be used to attach the lines to the handle and model. Do not use fishing swivels, which are unsafe and strictly forbidden by AMA rules. Approved line connectors cannot come undone in flight, and are more than strong enough to hold any model flown within the Park Pilot Program. Sullivan Products’ #148 connectors work well, even with the smallest line-end grommets. As an AMA member, you must use a safety thong between the handle and your wrist while flying. If you should let go of the handle for any reason while flying — something you should never do — your proper use of a safety thong will prevent the model from flying away. The thong can be made from a piece of thin Nylon cord. It should attach securely to the handle, and have a loop that allows it to be tightened gently around your wrist.
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