Basic Aeronautics Know the principles of basic aeronautics. 1. Describe the theory of flight. 2. Describe airfoils and flight. 3. Describe the effects of relative wind.

Overview 1. Theory of Flight 2. Airfoils and Flight 3. Relative Wind

Theory of Flight Aerodynamics The science relating to the effects produced by air or other gases. The term comes from the Greek words aero meaning air and dynamics meaning power. Ancient Greeks described air as having the qualities of moisture and heat. It was observed to shift in response to heating and cooling.

Theory of Flight Aerodynamics A lifting force is required for heavier-than-air flying. An object can be pushed upward by applying muscle power, an explosion, a hoist, or other means of force. It cannot remain aloft without decreasing the air pressure from above and increasing lift pressure from below. Increasing the speed of the object can increase the flow of air. The flying object must be shaped to form an airfoil. Air flows faster over the curved surface of an airfoil.

Theory of Flight Aerodynamics Bernoulli principle “As the air velocity increases, the pressure decreases; and as the velocity decreases, the pressure increases.”

Airfoils and Flight Airfoil Design An airfoil is designed to produce lift. An airfoil has a leading edge, a trailing edge, a chord, and camber.

Theory of Flight Aerodynamics Aristotle The first useful studies of motion are attributed to Aristotle. He believed there were two kinds of motion: natural and violent. He concluded, and later stated as a natural law, that the velocity or speed of an object depends entirely on the force being applied to it and the resistance it meets. This law was later proven to be inaccurate.

Theory of Flight Aerodynamics Galileo Galilei Observed that an object in horizontal motion would continue to move at the same speed with no additional force. This truth was accepted by Sir Isaac Newton and became the first of three laws of motion stated by Newton.

Theory of Flight Newton’s Laws of Motion First Law of Motion “A body at rest tends to remain at rest, and a body in motion tends to stay in motion, unless an outside force acts on the body.” It is sometimes referred to as the Law of Inertia.

Theory of Flight Newton’s Laws of Motion Second Law of Motion “The acceleration of an object as produced by a net force, is directly proportional to the magnitude of the net force in the same direction as the net force and inversely proportional to the mass of the object.” Force = Mass x Acceleration F=MxA

Theory of Flight Newton’s Laws of Motion Third Law of Motion “Whenever one body exerts a force upon a second body, the second exerts an equal and opposite force upon the first body.” Simply stated, For every action there is an equal and opposite reaction.”

Theory of Flight The four forces in balance with one another hold the plane in the air. The four forces are lift, weight, thrust, and drag.

Relative Wind The movement of the aircraft through the air creates the relative wind. The term relative wind means the wind that is moving past the airfoil and the direction of the wind is parallel to the flight path and relative to the attitude of position of the airfoil. The pilot controls the direction of the relative wind.

Summary 1. Theory of Flight 2. Airfoils and Flight 3. Relative Wind