It will benefit you best to become involved with others in the hobby. This will give you instant access to questions you may have as they arrive, as well as allow you to ask advice of your fellow RC pilots. This can best be accomplished by joining a club or regular visits to your local flying fields or hobby shops. Ask around and don’t be shy. Everyone had to start at the beginning.

Also keep in mind that you need to take all the proper precautions and adhere to rules of safe flight and operation of your RC airplane. If you do not, you can cause serious injury to others around you, or serious damage, including the damage to your aircraft, which can really set you back. Read the operators manuals thoroughly, check the rules at the field where you are going to fly, and follow those rules at all times.

Regardless of which path you choose -– flight instructor or flying solo with a beginner level trainer -- you will need to know these flight basics. In a later article, I cover “How to Survive your first flight” so stay tuned. For now, let’s get on with Basic Aircraft Concepts, where I discuss the basic flight fundamentals of a radio-controlled airplane. Specifically, we will discuss lift and the forces of flight you should be familiar with.

Part 2 - Learning the RC Aircraft Sections

First, let’s discuss the different parts of the radio controlled airplane. Refer to the diagram and try to memorize the important sections of the RC aircraft.

The diagram shows a typical remote control airplane with the important areas labeled. Your RC trainer will most likely look different, but the critical sections are typical of all planes.

· Fuselage: This is the main body of the aircraft. All other sections attach to the fuselage in some way. The fuselage also houses all internal components such as servos, linkages, receiver and battery packs.

· Landing Gear: Most RC aircraft has landing gear that consists of a set of wheels beneath the cockpit area, usually at or near the balancing point. The rear of some aircraft has a single wheel, or tail strut to provide additional stability during a landing, rather than riding on the tail, should it strike the ground first.

· Prop: The Prop is basically a combination of blades that provide thrust and are powered by the engine. Most RC aircraft have two or three blades, but some of the larger craft have more, the largest of which usually have more than one prop.

· Spinner or Cone: The cone provides a cover for the propeller, and acts as an aerodynamic guide to direct airflow directly to the prop blades. Without a cone covering the center of the prop, the flat area at the center of the prop would create wind resistance.

· Cowling: The cowling houses the engine itself. Some airplanes have no detachable cowling, but most kits do. This area of the RC airplane, including the prop, cone, engine and the cowling is most often referred to as the nose of the aircraft.

· Engine: (Located inside the fuselage and cowling, at the nose of the aircraft) is a gas or battery powered engine that provides thrust for the aircraft, and directly powers the prop (propeller). There are many engine types out there, and those are beyond the scope of this article. For now, just remember that an engine provides power, or thrust, to the plane, regardless of the fuel used.

· Wing: The horizontal section of the aircraft that provides lift.

· Aileron: This is the moveable portion of the wing. When lifted or lowered, it will cause a change in the plane’s roll axis (discussed later in this article) and controls the plane’s ability to roll left or right. The best way to think of the aileron is, for example, when the aileron lifts UP, it will cause that wing tip to lower, or tilt DOWN. The aircraft always banks or turns using the ailerons.

· Stabilizer: This section provides stabilization around the pitch axis of the aircraft. Think of the stabilizer as a similar, though smaller, wing section located at the tail of the plane.

· Elevator: The elevator is located on the stabilizer of the tail section and provides change around the pitch axis, which is used to control the plane’s ability to climb or descend. For example, UP elevator will cause the nose to LIFT, and therefore the tail to LOWER. The elevator’s main function is to control the attitude (nose up or down) for the plane.

· Fin: The fin provides vertical stabilization of the aircraft in its yaw axis. A very important section of the plane, as it houses the rudder.

· Rudder: The rudder is the moveable portion of the Fin that allows change in the aircrafts yaw axis, working much like the aileron and elevator do. The rudder’s main function is to control the aircrafts ability to move the tail of the airplane left or right.

These 12 sections of the RC airplane work together to provide stable flight, forward thrust, lift and control the turning ability of the plane, its’ ability to rise or descend and eventually land. Hopefully on it’s landing gear.

Next, we will discuss how all these things come together to provide lift.

Part 3 - Achieving and Maintaining Lift

There are many theories, books, flight manuals and debates on the principles of airplane flight. Luckily, it is a widely accepted theory that in order to fly, an airplane requires lift.

To better understand this, please refer to the diagram as we discuss what is needed to provide lift. The diagram illustrates the cross section of a wing section of the airplane. This would be the view of the wing if you were to look at the plane directly from the side, facing the wing tip.

Lift is created when the air moving over the top of the wing moves faster that the air underneath it. Air moving over the top of the wing must travel farther and because of this, that air must move faster to get to the trailing edge at the same time as the air traveling under the wing. As this air travels faster over a surface, it exerts less pressure on that surface. The pressure underneath is greater, which pushes against the bottom of the wing, causing lift. Actual flight is first attained when this lifting force overcomes the weight of the plane.

Since the plane is moving forward, it passes beyond the leading edge and thus continues to travel over and under the wing. This air must provide lift and not cause so much drag on the airplane that forward flight is halted. The air coming at an aircraft as it moves is called Relative Wind. This is not the same wind that exists due to current weather conditions, but rather the force of wind that exists because the plane is moving.

The best way to understand the difference is to imagine you are in car. As the car sits still, you may feel a light breeze against your hand as you hold it out the window. As the car increases speed, you can feel the resistance of the wind press harder against your hand. This is relative wind. Obviously the wind is not blowing that hard normally; it is caused by forward movement of your vehicle.

When relative wind strikes the wing, the angle that the wing is in is called the Angle of Attack. This angle, if too steep (too much angle) will cause the plane to lose lift too quickly and will result in a stall. For some, it is easier to understand what constitutes the chord line first. This is the invisible line that leads from the leading edge of the wing, to the trailing edge. Therefore, the AoA (angle of attack) is the angle that the relative wind strikes the chord line. (See the diagram).

The terminologies of parts for this lift theory are:
Airfoil: The wing itself.
Chord line: The imaginary line connecting the leading edge and the trailing edge.
Angle of Attack: The angle between the chord line and the direction of flight.
Leading Edge: The true forward edge of the wing.
Trailing Edge: The very rear edge of the wing.
Direction of Flight: The relative facing of the aircraft in relation to still air.

What does all this mean?
When air passes over the wing, it is split by the leading edge. Some air passes over, some under. The air that passes over the wing must travel faster, thus producing less pressure to the top of the wing. The air passing under the wing flows slower, thus creating more pressure to the underside of the wing, and this in turn lifts the plane once enough lift is created.

Once lift has been achieved, if the angle of attack is too great, or if the plane loses power, the plane will stall. All a stall is, by definition, is the loss of lift. This happens when not enough air can flow over the top of the wing, or if it cannot flow smoothly. Too much angle can cause turbulence, and thus loss of lift. Stalling most commonly occurs when trying to climb too quickly, or if the plane banks too sharply to turn. Almost all stalls can be recovered by simply lowering the nose. After all, planes need lift, and they need a sufficient amount to maintain stable flight.

How do you get more lift, climb into the air, turn, dive or spin upside down? Read on, because next we discuss the factors that further affects lift and maneuvering the aircraft once lift has been achieved.

Part 4 - Forces that affect Flight

There are four primary forces that affect an aircraft during flight. These are lift, weight, thrust and drag. While we covered lift on the previous page, it is important to continue to maintain lift in order to continue flight and gain altitude. In order to maintain lift, there must be an opposing force, which in the case of our airplane, is the weight of all its' sections, internal components, and its' fuel. If an airplane weighed nothing at all, it would be impossible to maintain flight. So, to maintain steady forward flight, lift and weight must be equal.

Thrust is the force applied to the aircraft to pull it forward against the Drag of the aircraft. The engine and the propeller provide thrust. Drag is caused by wind resistance against all forward facing surfaces, which includes the leading edges of wings, stabilizers, the fin and any landing gear present.

If you will refer to the diagram, these four forces of flight are indicated in black, with arrows showing the direction that each force will pull at the plane.

When an aircraft turns or banks in flight, there are three more forces that will affect the aircraft.

First is the longitudinal axis, or the Roll axis. To best understand this, imagine an aircraft with an unbreakable wire passing through the fuselage from nose to tail. Note the red line passing through the aircraft from nose to tail, in the diagram? You might notice that with this imaginary wire passing through, the plane could only roll around the wire, but the nose could not move left, or right, nor could it move up or down.

When flying your RC airplane, you use the ailerons to affect the plane on its’ roll axis. Ailerons work together to roll the plane left or right. To accomplish this, when you press the stick left, what happens is this: The left aileron is pulled upwards, reducing lift to that (left) wing. At the same time, the right aileron lowers, increasing lift to that (right) wing. This causes the plane to spiral left by rolling left, for as long as you hold the ailerons in this position.

To understand the Pitch axis, we will switch our imaginary wire and pass it through the wings, from tip to tip, as in the diagram again. This will allow the plane to move in the lateral axis and pitch the nose up or pitch the nose down. Pitch only affects this lateral movement, climbing or descending, increasing or decreasing lift. To do this, the airplane’s elevators will move up or down. Up elevator will cause the plane’s nose to pitch up and the plane with climb. Down elevator will cause the plane’s nose to pitch down, and the airplane will lose altitude, or dive.

For the Yaw axis, we use the aircraft’s rudder. Once more, use the imaginary wire to skewer the plane through its center or balancing point. The plane can now spin left or right, keeping the wings level and turn the nose left or right only. Left rudder will push the nose left, while right rudder will have the opposite effect, pushing the nose to the right. Too much yaw can cause the plane to spin out of control, not a good thing at all.

Part 5 - Wrapping it all up.

These are the basic fundamentals of flight. Knowing these things alone will not make you an expert pilot. Hopefully though, being aware of the forces put upon your aircraft will give you a better understanding of how to fly your radio-controlled airplane.

To summarize, we have learned the parts of the RC aircraft, the fundamentals of lift and what is required to maintain it. And we have learned about the forces of flight; lift versus weight and thrust versus drag. And lastly, we learned about the three forces of maneuvering; roll, pitch and yaw.

I hope that all of these concepts combined will allow you to better understand what an aircraft needs to get into the air and how to maneuver once it is aloft.

Before choosing your first aircraft, take the time to research your training craft. There are several articles here to help you, and many places on the Internet to research your first choice. Also, as mentioned at the beginning of this article, there is an invaluable resource available to anyone: Join a flight club, a local airfield, or RC Club. Check your local hobby shops and meet others interested in your hobby. Crashing your one and only airplane can be very frustrating and costly, so choose your first trainer wisely. Today’s manufacturers build ready-to-fly kits that much more inexpensive than they were 10 years ago, and there are many that can be flown without fear of wasting hundreds of dollars.

In future Flight School articles, we will discuss choosing your first trainer, basic radio controller usage, how to survive your first flight and how to keep a flight log.

Stay tuned and happy piloting!