Basic Principles of Flight

Thrust is provide by the engine acting through the propeller.
Drag by the resistance of the air to the passage through it of the aircraft and all its component parts.
Weight is the total weight of the aircraft and its contents.
Lift acts at 90 degrees to the relative airflow

Angle of Incidence and Angle of Attack

Angle of incidence refers to te fixed angle between the plane of the wing chord and the longitudinal axis of aircraft.
Angle of attack which varies acording to the angle between the wing chord and the relative airflow.

Lift

The pressure differential between the upper and lower surfaces.
Bernouilli's theorem
As the velocity of air increases, its pressure decreases.

Due to the curvature of the wing surfaces, the airflow accelerates as it flows around the wing.
Upper surface having a greater camber that the lower surface, the air flowing above the wing will be accelerated more than the air flowing benath the wing. According to Bernouilli's theorem, this results in a relatively large decrease in pressure below the wing.
This resultant pressure differential produces the fore called lift.

Drag

Induced drag is a by-product of lift.
Parasite drag is made up of the other dr.

Induced Drag, Wing tip vortices

Parasite Drag, this is made up of all other. On the air that is not caused by lift. Parts of aircraft.

Roll, Ailerons, Longitudinal Axis

Pitching, Elevators, Lateral Acis

Yaw, Rudder, Normal (Vertical) Axis

Adverse Yaw

Any yaw, regardless of origin, having an effect contrary to the interests of the pilots called adverse yaw
For example,

Flaps

Flaps are controlled by the pilot. They improve the lift and other characteristics of an aerofoil by increasing the camber of a large portion of the wing.
Advantages are;
1. Stalling speed is decreased.
2. A steeoer approach to landing can be made without an increase in airspeed.
3. Forward visibility is improved on approach to landing ue to the lower posision of the nose.
4. The take-off run may be shortened.