Theory of Flight

Theory of Flight

History of Flight

  • Bird, kite, hot-air balloon, airplane, and glider are all examples of early flight attempts.

Aircraft Fundamentals

  • The study of flight includes topics such as atmosphere, aerodynamics, operation, airfoil theory, wing theory, and aircraft performance.

Early Flight Attempts

  • Bellerophon the Valiant

    • captured Pegasus, a winged horse, and used it to battle the triple-headed monster, Chimera.

  • Daedalus and Icarus

    • an Ancient Greek legend, made wings of wax and feathers. Daedalus successfully flew from Crete to Naples, but Icarus flew too close to the sun and fell to his death.

  • Alexander the Great

    • harnessed six mythical winged animals called Griffins to a basket and flew around his realm.

  • The Chinese

    • discovered the kite, which led to the invention of balloons and gliders.

Leonardo da Vinci

  • Leonardo da Vinci made the first real studies of flight in the 1480s.

  • He created over 100 drawings illustrating his theories on flight, including the Ornithopter, a flying machine that was never built.

  • The modern-day helicopter is based on da Vinci's concept.

Montgolfier Brothers and Hot Air Balloon

  • Joseph Michel and Jacques Etienne Montgolfier invented the first hot air balloon.

  • They used the smoke from a fire to blow hot air into a silk bag attached to a basket, making the balloon lighter-than-air.

  • The first manned flight of the hot air balloon took place on November 21, 1783, with Jean-Francois Pilatre de Rozier and Francois Laurent as passengers.

George Cayley and Gliders

  • George Cayley designed various gliders that used body movements for control.

  • The first person to fly one of his gliders was an unknown young boy.

Otto Lilienthal and Aerodynamics

  • Otto Lilienthal

    • a German engineer, studied aerodynamics and designed a glider that could fly a person long distances.

    • His book on aerodynamics, published in 1889, served as the basis for the Wright Brothers' designs.

    • died in a glider crash due to a sudden strong wind.

Samuel Langley and Power-Driven Flight

  • Samuel Langley

    • an astronomer, built a model of a plane called an aerodrome with a steam-powered engine.

    • His model flew for 3/4s of a mile before running out of fuel.

    • Langley's major contributions involved attempts to add a power plant to a glider.

Wright Brothers

  • Orville and Wilbur Wright

    • American brothers, inventors, and aviation pioneers.

    • They were the inventors and builders of the world's first successful airplane.

  • Orville

    • piloted the first powered airplane flight on December 17, 1903, lasting 12 seconds and covering 120 feet.

  • Wilbur

    • piloted a record flight lasting 59 seconds over a distance of 852 feet.

Types of Aircraft

  • Aircraft can be classified as lighter-than-air (aerostats) or heavier-than-air (aerodyne).

  • Aerostats

    • Lighter-than-air aircraft, such as balloons and airships, use buoyancy to float in the air.

    • Airships have means of controlling their forward motion and steering, while balloons are carried along with the wind.

  • Aerodyne

    • Heavier-than-air aircraft include autogyros, gyrodynes, helicopters, powered lifts, and conventional fixed-wing aircraft (airplanes).

    • Autogyros, gyrodynes, helicopters, powered lifts, and airplanes are all examples of heavier-than-air aircraft.

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  • Fixed-wing aircraft

    • generally use an internal-combustion engine in the form of a piston engine or a turbine engine to provide thrust.

    • Piston engines with propellers or turbine engines (jet or turboprop) are used in fixed-wing aircraft.

  • The movement of air over the wings

    • produces lift that causes the aircraft to fly.

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  • Gliders

    • have no engines and initially gain thrust from winches or tugs and then from gravity and thermal currents.

    • rely on winches or tugs and gravity and thermal currents for thrust.

    • For a it to maintain its forward speed, it must descend in relation to the air.

  • Helicopters and autogyros

    • use a spinning rotor to provide lift.

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  • Helicopters

    • also use the rotor to provide thrust.

  • Gyrodynes

    • are intermediate aircraft between helicopters and autogyros, with a powered rotor but no tail rotor.

  • Heliplanes

    • are a combination of aircraft with both a rotor and wings.

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  • Heliplanes

    • can take off and land vertically, hover like a helicopter, but use their wings for high-speed flight.

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  • Aircraft

    • can be categorized by design, propulsion, and use.

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  • Examples of aircraft include the Airbus A380-800, Boeing 747-8, Antonov An-225, and Hughes H-4 "Spruce Goose."

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  • Steerable airships include blimps and rigid airships.

  • Other possibilities include the delta wing and the flying wing.

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  • Examples of aircraft by design include F-111, Panavia Tornado, F-14 Tomcat, B-1 Lancer, and helicopters.

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  • The majority of aircraft still use piston engines, which are efficient at lower altitudes.

  • Piston engines become less efficient above

    • 7,000-8,000 ft due to less available oxygen.

  • Pressurized aircraft and helicopters typically use

    • turbine engines, which are naturally efficient at higher altitudes.

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  • Aircraft usage can be categorized into

    • military aviation and civil aviation.

  • Combat aircraft

    • represent only a minority of the military aviation category.

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  • Airplane

    • a vehicle heavier than air, powered by an engine, that travels through the air by the reaction of air passing over its wings.

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  • The major components of an airplane

    • the fuselage

    • wings

    • empennage

    • landing gear

    • powerplant.

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  • fuselage

    • the body of an airplane that holds all the pieces together.

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  • fuselage

    • the aircraft's main body section that holds crew and passengers or cargo.

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  • Wings

    • provide lift and keep the airplane afloat.

    • Airfoils attached to each side of the fuselage are the main lifting surfaces.

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  • The empennage

    • also known as the tail assembly, gives stability to the aircraft.

  • The horizontal stabilizer and vertical stabilizer or fin

    • fixed parts of the empennage.

  • The horizontal stabilizer

    • balances the airplane and has elevators attached to it.

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  • The vertical stabilizer

    • provides directional stability to the airplane and is where the rudder is attached.

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  • Airplanes require landing gear to support movement on the ground during taxiing, takeoff, and landing.

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  • The tricycle type landing gear

    • has two main wheels and a nose wheel, making the aircraft easier to handle on the ground and landings safer.

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  • Conventional landing gear

    • consists of two wheels forward of the aircraft's center of gravity and a third small wheel at the tail.

    • This type of landing gear is commonly seen in older general aviation airplanes.

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  • Without a wheel at the nose of the plane, it easily pitches over if brakes are applied too soon.

  • Tailwheel landing gear

    • makes the plane difficult to control during landing or takeoff.

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  • Tandem landing gear

    • used for very large aircraft like the B-52 bomber and U-2 reconnaissance/research aircraft.

    • The main landing gear is located one behind the other on the fuselage, allowing for a highly flexible wing.

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  • The powerplant

    • refers to the engine that provides thrust for the airplane.

    • It can be an engine and propeller combination or a jet engine.

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  • The three primary flight control surfaces

    • ailerons, elevators, and rudder.

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  • Ailerons

    • are movable surfaces that control the roll movement of the airplane.

    • They are located at the outer trailing edge of each wing.

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  • Rods or cables

    • connect the ailerons to each other and to the control wheel or stick in the cockpit.

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  • Elevators

    • control the pitch movement of the airplane.

    • They are located at the rear part of the horizontal tail assembly and are hinged to the horizontal stabilizer.

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  • Elevators

    • are connected to the control wheel or stick by control cables.

    • They also control the angle of attack of the wings.

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  • The rudder

    • controls the yaw movement of the airplane.

    • It is a movable surface hinged to the trailing edge of the vertical stabilizer or fin.

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  • Flaps

    • are movable sections of an airplane's wings closest to the fuselage.

    • They are mounted on the trailing edges of the wings to reduce the speed at landing and shorten takeoff and landing distances.

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  • Trim

    • tabs are small, adjustable hinged surfaces on the trailing edge of the aileron, rudder, or elevator control surfaces.

    • They relieve pressure on the control wheel or rudder control and enable the pilot to release manual pressure on the primary controls.

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  • The basic parts of an airplane

    • the right and left flaps

    • horizontal stabilizer

    • vertical stabilizer

    • aileron

    • cables

    • fuselage

    • rudder

    • trim tab

    • cabin

    • wing

    • propeller

    • ribs

    • engine

    • pedals

    • navigation light

    • landing gear.

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  • The three axes of an airplane

    • longitudinal axis

    • lateral axis

    • vertical axis.

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  • The longitudinal axis

    • extends lengthwise through the fuselage from the nose to the tail.

    • Movement around the this axis is known as roll and is controlled by the ailerons.

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  • The lateral axis

    • extends crosswise from wingtip to wingtip.

    • Movement around the this axis is known as pitch and is controlled by the elevators.

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  • The vertical axis passes vertically through the center of gravity.

  • Movement around the vertical axis is known as yaw and is controlled by the rudder.

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  • Roll motion is an up and down movement of the wings of the aircraft.

  • It is caused by the deflection of the ailerons.

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  • Ailerons are hinged sections at the rear of each wing.

  • They work in opposition; when one goes up, the other goes down.

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  • Pitch motion

    • is an up or down movement of the nose of the aircraft.

    • It is caused by the deflection of the elevator, which is a hinged section at the rear of the horizontal stabilizer.

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  • There is usually an elevator on each side of the vertical stabilizer.

  • The elevators work in pairs; when one goes up, the other also goes up.

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  • Yaw motion

    • a side-to-side movement of the nose of the aircraft.

    • It is caused by the deflection of the rudder.

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  • The rudder is a hinged section at the rear of the vertical stabilizer.

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  • Control surfaces

    • aileron

    • elevator

    • rudder.

    • They are controlled by the control stick or yoke and the rudder pedals.

    • They control the roll, pitch, and yaw movements of the airplane.