RC Airplane

Flying Electric RC Airplane - Basics of Aerodynamics

By Dhaval Bhatt

This topic explains you the basics of aerodynamics and airplane parts. A lot more goes on behind the scenes when you fly your RC Airplane. Understanding the basics of aerodynamics and airplane parts can really help you gain the mastery in flying your Electric RC Airplane.

Why do you need to learn Basics of Aerodynamics to fly your RC Airplane?
The key difference between the experts and amateurs is that the experts understand their material from "inside-out".
If you enjoy flying your RC Airplane, you need to master these material to become an expert at flying it. Not understanding this material would make the art of flying as something very complex and difficult. Not understanding this material would make you feel like an outsider, merely using your RC Airplane as a toy. If you want to get good at flying it, you need to consider this as an art, not a hobby.
You don't need to be a science geek to understand it - it is presented in a fairly simple language and if you are attentive, you will really enjoy reading this material.
Here we go...Enjoy!

Parts of Airplane
Airplane can be divided into five main parts: Fuselage, Wing, Empennage, Powerplant, and Landing Gear. Each of these five parts have their own functions.

Fuselage is the central component of airplane - the other parts are usually attached the fuselage.
Wings make the aircraft fly - they generate essential force called "lift" that makes the airplane fly. Airplanes with single set of wings are known as monoplanes, whereas the ones with two sets are called biplanes. Wings contain two other parts of airplane known as aileron and flaps. Ailerons move in opposite direction and cause the airplane to roll. Flaps, when moved downwards, extend the lifting force during take-offs and landings.

The Empennage includes vertical stabilizer, horizontal stabilizer. Rudder is attached to the end of vertical stabilizer, whereas elevator is attached to the end of horizontal stabilizer. Rudder helps to move the plane left or right, whereas elevator is used to move the airplane up or down.

Landing Gear supports the airplane and absorbs the loads during landing. Landing gear mainly consists of three wheels, two main wheels located on the either side of the fuselage and a third wheel located either at the front or the back of the Airplane.

Powerplant includes engine and propeller. The main job of engine is to provide the power to turn the propeller which in turn translates the rotating force of engine into the forward-acting force known as thrust to help move the airplane forward in the air.

Forces Acting on Airplane
The four forces acting on airplane at any given time are Lift, Weight, Drag, and Thrust. In straight and level un-accelerated flight, lift equals weight and thrust equals drag.

What makes Airplane Fly?
In order to understand what makes airplane fly, we need to understand a simple scientific principle. Don't be too intimidated, this principle is fairly simple.
Bernoulli's principle states that "as the velocity of fluid increases, its internal pressure decreases." Surface of wing when interacts with the airstream, it generates lift.
The air moves a lot faster from the upper surface of the airfoil, which causes lower air pressure on top, whereas, low-velocity air flow through the bottom of the airfoil causes high pressure at the bottom of the airfoil. This difference in pressure is what causes the force of lift - that's how airplanes fly.

Aircraft Axes of Flight
There are three axes of flight: Longitudinal, lateral, and vertical axes. These three axes have a common reference point known as the center of gravity.
When the aileron's move, they cause rolling movement along the longitudinal axis of airplane. When the elevator's move, they cause pitch up or pitch down movement along the lateral axis of airplane.
When the Rudder moves, it causes rotational movements along the vertical axis of airplane.