Read an Excerpt
Building and Flying Model Aircraft
By Robert Schleicher, James R. Barr
Dover Publications, Inc.Copyright © 1988 Robert Schleicher
All rights reserved.
The Wings of Man
The dream of freedom often includes the dream of flight. The whole concept of being "as free as a bird" is so strong in many of us that one wonders if, perhaps, man really was meant to fly. The fantasy of flight has haunted man since the beginning of recorded time; countless legends, gods imbued with the power to fly, and biblical references to man's flight predate the actual event. For those of us who would rather risk time and money, rather than life and limb, building and flying model aircraft may be the ideal fulfillment of a fantasy.
The hobby encompasses a number of delights and certainly is not limited to "toy" airplanes. This is one leisure activity that involves enough time outdoors to qualify as a sport for the whole family. You'll get about as much exercise flying a radio-control (R/C) or a control-line (C/L) model aircraft as you would sailing a small boat. Flying model aircraft can be a more fascinating hobby if you build your own models, but there are dozens of truly excellent quick-to-build and almost-ready-to-fly models, and almost every hobby shop offers built-up kit models and often provide a building service. If you prefer the hobby aspect, there's plenty of challenge available, ranging from the assembly of simple kits that can be completed on a single Saturday to built-from-plans exact-scale models that might take a year or more to finish.
Many pilots of full-size private and commercial aircraft feel that flying a model aircraft actually provides more freedom and enjoyment than flying the real thing. There are, for example, no complex regulations to worry about with model aircraft and only a fraction of the investment to risk when you attempt an aerobatic maneuver. Hundreds of hours of very expensive practice are needed to solo in a real aircraft and you have to pass some pretty grueling written and flight tests. You can duplicate those flying maneuvers with a model aircraft, however, after only a few months of practice. Potential insurance problems are taken care of when you join the Academy of Model Aeronautics (AMA). The AMA membership provides liability insurance as part of the package, and it applies anywhere you fly as long as you are flying according to the AMA safety code, a copy of which you'll receive with your membership (it is sometimes changed, to comply with the insurance company regulations, so don't rely on just the "safety code" shown here). In all, there's more freedom, relaxation and exciting fun in flying model aircraft than you'll find anywhere.
You can envision your model aircraft any way that pleases you. Consider it your own little bird who flies exactly where and how you wish you could, or consider your model to be full-size and shrink yourself enough to imagine yourself in the cockpit. Most model aircraft enthusiasts imagine both situations at one time or another. The choice of model aircraft will place more or less emphasis on the "bird" or "cockpit" flights of fancy. The airplanes that are launched with no form of remote control are called "free-flight" models, and they are certainly the closest thing you'll get to a bird. The other extreme of the hobby is occupied with flying model aircraft where the rudder (for right and left turns), the elevator (for up and down movements), the ailerons (the movable flying surfaces that roll the plane into a right or left bank), the engine speed, and sometimes even retractable landing gear, dive brakes, or bomb bay doors are all controlled by a radio transmitter sending signals to a radio receiver on board the aircraft. There are, to be sure, less complicated radio-control model aircraft, just as there are more complex free-flight models, but this will give you a hint of the possible range this hobby encompasses.
More control-line model airplanes are sold than any other. Firms like Cox and Testors sell millions of their inexpensive fuel-powered plastic model airplanes in toy and hobby stores and departments every year. Most control-line models have a simple lever inside the plane (called a "bell crank") that is pushed or pulled by a lever in the full-size flier's hand. The two levers are connected by two nylon cords or steel cables that are each 10 to 70 feet long. When the flier cocks the lever (called a "control handle") forward or backward, the tow lines force the bell crank in the model airplane to move a corresponding distance. The bell crank is, in turn, connected by a steel rod (called a "push rod") to a pivot point on the elevator to give the flier full control over the plane's up-and-down movement during flight. The engine speed remains on full until the power plant runs out of fuel. The rudder is canted to the right to keep the two flying lines taut for full flier control. The airplane will then fly around and around the circle until it runs out of gas or until the flier forces it to land (or crashes it). The flier has only elevator control with a control-line model aircraft, but that is enough to allow virtually any type of aerobatic maneuver from a simple loop to advanced stunt flights. Experienced control-line modelers can even place two or more fliers in the center of the circle so each person controls one plane. The two fliers then stage mock combat or duplicate the maneuvers of aerobatic formation flying.
Air Power Plants
You can duplicate just about any type of full-size aircraft you wish with a flying model. Almost any of them are available as inexpensive ready-to-fly models, simple kits, or complex kits including both powered and non-powered types. The limitations of the control lines restrict this type of model aircraft to the powered types, but you can find just about anything from a scale-model piper cub to a multi-engined bomber to special "stunt" planes that will actually outperform the prototype aircraft. Most modelers, even the most experienced, use the simple single-cylinder two-stroke engines, but there are some ducted-fan two-strokes that perform like jet engines and a few planes that utilize actual jet engines. Stick to the simple engines with propellers for now; if you need blinding speed, then try model rockets with "vehicles" designed for ultimate speed, performance—you'll have trouble enough learning to fly an aircraft at the speeds that the tiny .020 or .049-cubic-inch displacement engines allow. Engines up to about 2.6-cubic-inch displacement are available for those who demand really gigantic planes, and some of the .61-cubic-inch engines have enough power to pull a lightweight model to a genuine 150 miles an hour.
The free-flight and radio-control model aircraft ready-to-fly and kit selection includes every imaginable type of full-size aircraft from biplanes of the World War I era to helicopters to four-engined bombers to powered gliders or sailplanes. The same two-stroke internal combustion power plants that power the control-line models are used for the radio-control models and many of the free-flight aircraft miniatures. Electric motors, powered by rechargeable on-board ni-cad (nickel-cadmium) batteries are becoming increasingly popular with radio-control modelers, thanks to the quiet simplicity of the motors. The non-powered gliders are launched by on-the-ground "engines" like the elastic band (actually surgical tubing) "Hi-Start" sold by Cox and others or by electric winches. These "engines" simply pull the aircraft forward, and lift created by the model's wings carries it upward about 400 feet into the air. An experienced free-flight modeler can build and launch an airplane that will stay in the air for 10 minutes or more; a radio-controlled sailplane can be kept in the air for an hour. Most sailplane modelers are happy enough with five-minute flights, however.
The amount of money you spend on a flying model aircraft will depend mostly on how much control you expect to have over it and just how closely you want to match (or improve on) the performance of the full-size aircraft. The least expensive models are the balsa wood hand-launched gliders that sell for about a dollar. The cost can range upward to $1000 or more for an exact-scale twin-engined bomber with a seven-channel radio-control rig. The cost will depend somewhat on whether you are willing to build the model from a kit or if you want it to be ready to fly. If we were to rank model airplanes by cost category, then the free-flight aircraft would certainly be the least expensive, followed by the control-line powered models, then radio-control gliders or sailplanes, and finally the most expensive radio-control powered aircraft. There's a considerable amount of price overlap among the categories; the best free-flight models with timers can cost as much as $200, while you can buy a ready-to-fly Cox R/C "E-Z Bee" powered radio-control trainer or an inexpensive kit and a two-channel radio for only $150 to $200.
That dollar hand-launched glider is the simplest form of a free-flight model. There are kits that will allow you to carry the concept of non-controlled flight all the way to a 12-foot wingspan. The larger gliders can be launched by hand just like that simple balsa wood sheet model, but there are better ways of doing the job, including a 150-foot-long line on a reel to pull the model over your head while you run into the wind in much the same way you would launch a kite. There are also some free-flight models that have fuel-powered ,.049-cubic-inch displacement (also called "Half A" or "½ A") engines to carry them into the air. Free flight includes those balsa wood stick models with tissue paper coverings and rubber band-powered propellers. The smaller balsa wood stick models can even be flown indoors. Most free-flight kits range in price from about $2 to $12, but some of the larger models of real aircraft and the "competition" free-flight kits can run as much as $80. Most of the kits that have rubber bands to power the propeller can be modified to accept the fuel-burning engines. The engine will run between $10 and $100, depending on the size and whether or not you have to have one of the hand-fitted and tuned "competition" engines. A timer, for the release of the stabilizer to "dethermalize" the model so it won't fly completely out of sight, can run another $2 to $50, again depending on whether you want a simple cloth rope "fuse" or a complex wind-up "competition" timer.
For a beginning control-line model $25 to $35 is a good range to consider. You can buy one of the Cox or Testors ready-to-fly plastic planes for as little as $15. The lantern battery to provide ignition power for starting and fuel will run another $5 or so. The larger Cox ready-to-fly planes run in the $25-to-$30 range and, for that price, you can buy one of the simple sheet balsa wood kits (that can be assembled in about three hours or less), an .049-cubic-inch displacement engine, control lines, control handle, cement, colored paint, and clear paint. Be certain that your first control model is either marked for "beginners" or that it is called a "trainer" so you'll stand a chance, at least, of learning to fly it before you crash it. Intermediate and "stunt" control-line models with larger engines will run in the $50-to-$100 range and that's about where most modelers stop. If you're really bitten by the control-line bug, you may want to advance to control-line scale, speed, or combat models and invest more in a single aircraft and engine.
Most books and magazines lump all types of radio-control models into one category. We feel, however, that there is such a vast difference between powered radio-control model aircraft and radio-control sailplanes that the sailplanes are virtually in a category of their own. We do feel that the electric motor-powered sailplanes, like those made by Cox, Graupner, and Astro Flight, belong in the non-powered category. The electric motors, like the engines in the free-flight aircraft models, are there strictly to get the plane well clear of the ground where winds and rising air currents or thermals can sustain its flight. The major item of expense with any radio-controlled model is going to be the radio transmitter and receiver. You can keep that cost to a minimum with a sailplane, because you really need only two channels—one to operate the elevator (for up and down control) and another to operate the rudder (for right and left). Some of the more advanced sailplane modelers add a third channel for the control of ailerons (for banking) and even a fourth for the control of the tow line release or, perhaps, retractable landing gear. Frankly, we feel that the third and fourth channels are a luxury that's not really worth considering for the newcomer. That simple two-channel radio and receiver setup will cost between $80 and $150 (depending mostly on the quality and power or range), and you can use it in every sailplane you make, since the radio will usually survive crashes that can destroy the aircraft. The glider or sailplane itself will run between $20 and $100 as a kit.
Powered Radio-Control Aircraft
Radio control allows the modeler to build an aircraft that looks exactly like the real thing with no control-line wires to spoil its effect. The recent advances in electronic circuitry also permit the modeler to control his aircraft with virtually the same amount of precision as if he or she were in the cockpit. The cost of a powered radio-control aircraft can be less than $150 if you're willing to settle for the single-channel (rudder) control of a beginner's ready-to-fly like the Cox "E-Z Bee." If you build your own from a kit designed for one of the .020 or .049-cubic-inch engines and a two-channel lightweight radio receiver and transmitter, you may get by for less than $200. These smaller aircraft will probably have a wingspan in the 30-to-50-inch range. The typical radio-controlled aircraft have wingspans in the 50-to-60-inch range with designs that call for an engine with .20 to .61 cubic inch of displacement. Most modelers want aileron control for banked turns and throttle control as well as elevator and rudder control, so a radio transmitter and receiver with four or more channels is necessary. These aircraft are built from kits, and the model and engine will run $70 or more while the radio will cost $200 or more.. Most modelers end up spending closer to $500 for their second or third powered radio-control model. Remember, though, that the radio transmitter and receiver can be used in your next aircraft simply by disconnecting and removing the receiver, the servos (that actually operate the control surfaces), and throttle from the aircraft.
If you spend more than $500, you can get into some of the truly exotic radio-control aircraft like twin-engined models, ducted fan-engined "jets", or radio-control helicopters. With few exceptions, however, these more costly aircraft are far more difficult to fly than the "beginner" models in that $100-to-$500 price range. This is one hobby where investing more dollars can actually make the flying more difficult—but that greater degree of difficulty is just the kind of challenge a hobbyist often desires. Just be warned that you're much wiser to learn to fly with one of the inexpensive powered radio-control models before writing a check or signing a charge slip (or taking out a loan) for $500 or more worth of flying model aircraft.
One of the major reasons why you buy a book like this one is the hope that the authors just might make some of your buying decisions for you. We can't blame you for hoping for a guide through the hobby of flying model aircraft, because it really is an extremely broad pastime that can demand anything from a dollar a week for lost hand-thrown balsa wood gliders to a $2000 investment in a quarter-scale radio-control aircraft that burns more expensive fuel than your car and more of it.
Our best advice is this: try to examine your reasons for wanting to get involved in the hobby. If you think you'd rather fly than build, for example, then start with one of the almost-ready-to-fly aircraft or one of the simple foam plastic kits that can be assembled in an evening. If you'd rather build, then start with something simple like one of the sheet balsa kits that require only an evening's worth of time to assemble, so you'll know for certain your efforts will result in a flying model aircraft. Far too many potential enthusiasts are lost because they felt they had to start out with the more expensive models or the most complex kit and they never got beyond the buy-it-for-the-shelf stage. Take a stronghold on your ego and buy one of the beginner models, even if you have to tell the hobby shop owner it's for your nephew's birthday.
Excerpted from Building and Flying Model Aircraft by Robert Schleicher, James R. Barr. Copyright © 1988 Robert Schleicher. Excerpted by permission of Dover Publications, Inc..
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