Aerodynamics a refresher

I will try my best to keep this guide without any special formulas and rules to explain the basic principle behind flying the plane. but its crucial that you should understand the basic before you begin flying. This will improve your chances of getting a successful flight every time and will help you while troubleshooting.

Before we begin lets go through some terminologies.

Thrust: The backward force exerted by the fast spinning propeller. the plane moves forward by the                           resultant(remember newtons third law)

Air speed: Speed of the plane in the air while its moving. this is a result of thrust exerted from the propeller   Airfoil: Special shape of wings of an airplane that gives lift to the plane as the airspeed increases. Read more on airfoil here     

Rate of Climb: the amount of height achieved by the plane as it moves forward. for eg, a plane is said to have a rate of climb of 10 ft/sec is said to gain a height of 10 feet every second.

How does a model airplane flies.

This is a chain reaction that start with the propeller.`

the propeller spins fast to move air in the backwards also known as thrust, this thrust pushes the plane forward and the plane slowly gains speed known as airspeed, as the airspeed increases the wing pushes the air down and moves the plane upward known as lift. So ultimately the plane will keep producing lift as long as it it moving forward, in this process the elevator controls the direction of upward movement and makes the plane to move forward or simply make the plane to climb. 

Okay, you plane is going fine and climbing good, as in the process of climbing the plane will start to lose airspeed and it will start decreasing if the engine is not enough to keep up with the speed loss. if the engine can supplement for the lost airspeed and can fairly keep the plane moving up even 90 degree upward then the plane is said to have unlimited verticals.

          If the engine is unable to compensate for the lost airspeed the speed will decrease to a level where to plane will also lose lift produced by the speed and will start to dive. this is called critical speed for lift. ie, the minimum airspeed required to keep the plane flying with good lift.

        Once the plane starts diving in the forward direction it gains airspeed and as a result will start flying again.

Lets suppose that the rate of climb is too high that the airspeed loses rapidly and the plane dives instantly it will take some time for the plane to recover the position and may not recover at all. the time taken to recover the lift will be very high and the plane might loses completely and will dive directly in the ground especially if you are flying very close to the ground. this is called Stall.

So this is in short how a model airplane flies. Pretty short right?