Flying model airplanes is arguably one of the most exciting outdoor activities. No matter the age, flying model planes bring together people of all ages, from kids to full grown men. But what do you need to enjoy all the fun this sport can offer?
THE AIRCRAFT – obviously, a RC scale model aircraft is an essential element for this hobby. There are many tips on choosing the right RC model aircraft if you are a beginner. However, you are new to flying model airplanes, you should pick something nice, not expensive, easy to handle and robust.
RADIO SYSTEM – In addition to a good reliable trainer aircraft, you also need a radio system – a transmitter and a receiver – to control your airplane; and this device is extremely important for flying RC airplanes. It’s a pilot’s link to his airplane, and a typical radio will control it farther than you can see; you can be confident about controlling the actions of the surfaces even when you can’t actually see them. In a full-size aircraft, the pilot sees and feels everything the airplane is doing, but, when flying scale models, the R/C pilot must learn to judge his airplane’s actions from a distance. Develop your depth perception through practice, and learn to anticipate the aircraft’s movement through the air. This is a skill that can be developed through training, by flying model airplanes and using the buddy system.
A basic radio package consists of a 3- or 4-channel transmitter (TX), a receiver (RX), three or more servos (the “muscles” that move the control rods that move the control surfaces), a battery pack that powers the RX and a switch harness that turns it on and off. There’s usually a battery charging jack wired into the switch harness. The radio system also comes with instructions, a charger, servo mounting hardware and a red flag and set of radio frequency (RF) numbers that have to be attached your TX antenna. These numbers identify your radio’s transmitting frequency-very important when you’re at the flying field. Radios are available with FM (frequency modulation), AM (amplitude modulation) and PCM (pulse-code modulation) systems. AM systems are the least expensive, but all will control your train equally well. Talk to your hobby shop about the bells and whistles offered by the other systems.
All modern R/C radios have plug-and-socket connectors to complete the wiring connections-no soldering required. Some brands have their own unique wire-plug connector, and some have connectors that are compatible with several brands of radio. All operate on the same electronic principles. The major aircraft radio brands include Airtronics, Futaba, Hitec RCD and JR, to name a few.
TRANSMITTER (TX)- the “box” you hold in your hands and from which you operate (control) your model. It has a long antenna, one or two control sticks, trim levers, an on/off switch and a battery-charging jack. Most transmitters h ave a radio-frequency (RF) meter that indicates voltage and thereby tells the strength of the transmitter’s signal. The RF meter’s face usually has green and red areas in it’s display; when the needle enters the red area, it’s time to stop flying and charge the batteries.
The most popular type of transmitter has two main control sticks that allow you to control the four basic functions. Typically: Left stick controls: throttle: push it forward to increase throttle; pull it back to decrease throttle; rudder: move it to the left and to the right. Right stick controls: – elevator: move it forward and backwards; ailerons: move it left and right. Radios with more than four channels can control additional functions: – retractable landing gear – flaps – spoilers – bomb drops – lighting systems.
RECEIVER (RX)-the part of the radio system that receives the TX signal and converts it into electrical impulses that control the system’s “muscles”- the servos. A long, thin wire – the antenna comes out of it. Never cut this wire or coil it, or you’ll greatly reduce your radio’s operating range, and that might cause you to lose control of the model shortly after takeoff.
Both the RX and TX have crystals that determine the radio’s frequency, or channel. You can buy extra receivers and servos, so you’ll be able to operate two or more model airplanes without having to buy another complete radio system. The more sophisticated radios can “remember” the settings for several models, so if you use your radio for more than one model, you can flip to the appropriate setting for each one.
SERVOS – the radio system’s “workers”; they are used to move the control surfaces; actually, flying model aircraft would be impossible without these tiny little devices. Each servo consists of a small motor, a gear train, an electronic control circuit and a feedback potentiometer (pot). The servo has an output arm or wheel, that is connected to a push-rod inside the model. When the servo moves, it pushes or pulls the push-rod, which, in turn, moves the control surface. The TX is always sending a signal. When you move a control stick, the signal is changed slightly, and the RX picks up this change. The RX then decodes the signal and sends it to a specific servo. The results are “proportional” control: move the stick a little, and the control surface moves a little; move the stick a lot, and the control surface moves accordingly.
BATTERIES, R/C systems typically use nickel-cadmium (Ni-Cd) battery cells to power the TX and the RX. The TX typically requires a 9.6 volt (9.6V) battery, and the RX usually operates on 4.8 volts. Each Ni-Cd cell is rated at 1.2 volts, and the cells are wired together to make battery packs. Typically, the RX for a trainer requires a 450 to 600 milliamp-hour (mah) pack while the TX requires an 800 to 1000 (mah) pack. They will come with your radio system. The chargers that are included with most radio systems will charge the RX and TX batteries at the same time. Simply plug the charger into the wall and then connect the leads to the TX and RX. On the day or evening before you plan to fly, charge your radio system for between 15 and 24 hours for a full charge. After that, you can expect the system to operate safely for about 2 hours of flying time before you’ll need a new receiver pack charge.
Considering that an average flight lasts between 10 and 15 minutes and that you’ll probably fly three or four flights on a typical day, that’s a large safety margin. You’ll be checking battery power levels along the way in any case.
Go – get that bird up in the air! Practice flying model airplanes a lot and don’t forget to come back here for more model airplane flying and maintenance tips. In the meantime Happy Flying and Smooth Landings!
This is a slightly updated version of an article originally published on “Flying RC Airplanes” – flyingrcairplanes.com