It was , of couse, the birds who were responsible for the whole complicated story and business. A man with the brain of a scientist began to think seriouly about attainment of the dream. This was Leonado da Vinci (1452-1519), whose detail study of bird flight nevertheless led him to the erroneous conclusion that man's muscular power, so superior to that of the birds, should enable him to fly in a properly constructed ornithopter,or flapping-wing aircraft.
In 1680, Giovanni Alphonso Borelli's has a result of his detailed study of bird flight, man did not have the power output needed to lift himself and a machine into the air. This brought an end to practically all heavier-than-air experiments until nineteenth century.
On October 15, 1783, Jean-Francois had made a flight in a Mongolfier hot-air balloon tethered flight for 4 minutes 24 second. Lessthan two month later a hydrogen-filled balloon had completed a successful two-hours free flight.
German Otto Lilienthal(1848-1896), whose graceful and beautifully-constructed hang-gliders enable him to become the first man in the world to fly confidently and regularly, total more than 2000 flights.He did not develop control surfaces for his gliders, but rely on body movements to provide limited control in the three axes of pitch, yaw, and roll. He lost his life at age of 48 on 10 August 1896 due to one of his gliders stalled and crashed to the ground. The persons who pioneer of the gliders were Otto Lilienthal (German), Percy Pilcher (England) He also lost his life in a glider clashed three years after Lilienthal, and Octave Chanute (American)(1832-1910)
Wilbur (1867-1912) and Orville (1871-1948) Wright, had been interested in the possibility of mechanical flight in the early years. By 1900, they became freinds with Chanute . Chanute encouraged , providing information, and directly assisted the Wrights to achieve their goal of power flight later.First flight they flied the flyer was on 17 December 1903.This is generally accepted as the first man to accomplised the dream.Eventhrough there are some controversy over the first powered aircraft.
Alberto Santos-Dumont a little brazilian living in France. During 1906, with his No.14-bis which was power by a 50 horsepower Antoinette engine, he made a first flight of 60 meter at Bagattelle, Paris on 23 October 1906. Some people believed that Santos-Dumont really had made the first power flight in history.
PRINCIPLES
Forces Acting on An Airplane
There are four forces acting on the airplane all the time during airplane is flying.The four forces are
(1) Lift, (2) Gravity force or Weight, (3) Thrust, and (4) Drag.
Lift and Drag are considered aerodynamics forces because they exist due to the movement of the Airplane through the Air.
Lift: is produced by a lower pressure created on the upper surface of an airplane's wings compared to the pressure on the wing's lower surfaces,causing the wing to be LIFTED upward. The special shape of the airplane wing (airfoil) is designed so that air flowing over it will have to travel a greater distance and faster resulting in a lower pressure area (see illustration) thus lifting the wing upward. Lift is that force which opposes the force of gravity (or weight).
Lift depends upon (1) shape of the airfoil (2) the angle of attack (3) the area of the surface exposed to the airstream (4) the square of the air speed (5) the air density.
Weight: The weight acts vertically downward from the center of gravity (CG) of the airplane.
Thrust: is defined as the forward direction pushing or pulling force developed by aircraft engine . This includes reciprocating engines , turbojet engines, turboprop engines.
Drag: is the force which opposes the forward motion of airplane. specifically, drag is a retarding force acting upon a body in motion through a fluid, parallel to the direction of motion of a body. It is the friction of the air as it meets and passes over an airplane and its components. Drag is created by air impact force, skin friction, and displacement of the air.
Aircraft Flight Control
An airplane is equipped with certain fixed and movable surfaces or airfoil which provide for stability and control during flight. These are illustrated in the picture.
Aileron: may be defined as a movable control surface attached to the trailing edge of a wing to control an airplane in the roll, that is , rotation about the longitudinal axis.
Elevator: is defined as a horizontal control surface, usually attached to the trailing edge of horizontal stabilizer of an airplane, designed to apply a pitching movement to the airplane. A pitching movement is a force tending to rotate the airplane about the lateral axis,that is nose up or nose down.
Rudder: is a vertical control surface usually hinged to the tail post aft of the vertical stabilizer and designed to apply yawing movement to the airplane, that is to make it turn to the right or left about the vertical axis..
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