1. The Physics of Flight

2. Ancient Dreamers Legends of flight attempts date to 2000 B.C.
Many believed flying was for the mythical gods
Others tried to copy bird flight-unsuccessfully
Chinese invented kites about 1000 B.C.
17th century A.D. kites carried soldiers aloft
Leonardo da Vinci, 15th century Italian artist
First recorded scientific study of aeronautics
Experimented to prove feasibility of mechanical flight
Drew sketches and plans to construct flying machines
1700 BC Crete
Icarus and Daedalus's fabled escape from King Minos (of Minotaur fame)
1010 Wiltshire England
Eilmer a monk attempted to fly by strapping rudimentary wings to his hands and feet and launching himself from the tall tower of Malmsbury Abbey. It was reported that he managed a controlled flight of some 200 yards. Further improvements to this flight were not attempted however due to the crippling injuries he received during the uncontrolled landing.
1300 China
Marco Polo the Venetian merchant reported seeing man carrying kites during his travels through China. Source: Strickland
1500 Florence Italy
Leonardo da Vinci sketches flying machines including a helicopter based on a helical screw. He produced in excess of 500 sketches and drawings and over 35,00 words on the subject and showed understanding of the need for stability and control by including rudimentary control tailplane on his designs. Da Vinci is also accredited with the invention of the parachute.

3. Ancient Dreamers
Leonardo da Vinci
Daedalis & Icarus
According to Greek Mythology, Daedalus was the first to master the art for flying like a bird. His son, Icarus died when he failed to “wing your course along the middle air.”
Leonardo was interested in mechanics (the science of motion and force), and many of his ideas and designs were far ahead of their time. For example, he drew plans for aircraft, including a helicopter, and for a parachute. Like many Renaissance artists, Leonardo sometimes worked as an engineer or military architect. He produced designs for a variety of war machines, among them tanks, machine guns, and movable bridges. World Book Encyclopedia
Italian artist and scientist Leonardo da Vinci ( ) gathered data on the flight of birds and developed concepts of the propeller, the parachute, and heavier-than-air craft.

4. The Quest for Flight
By 17th Century, ancient ideas inspired scientific theories and experiments
Characteristics of the atmosphere and the discovery of gasses and properties led to lighter-than-air balloon experiments
Airships needed power and direction control
Glider flying increased the understanding of flight forces, wing geometry & controls

5. Definition: Aerodynamics
Aerodynamics is a branch of fluid mechanics that deals with the motion of air and other gaseous fluids, and with the forces acting on bodies in motion relative to such fluids

6. Bernoulli’s Principle
According to Bernoulli’s Principle, as the velocity of a fluid increases the pressure exerted by the fluid decreases.

7. Air Flow Past a Wing
The air speed is greater over the upper surface, as indicated by the closer streamlines, the air pressure is lower there and the wing is lifted
When the wing is angled upward, air deflected from its lower surface provides additional lift.
If the angle is too great, turbulence reduces lift and increases drag.

8. Powered Flight Breakthrough
Experiments showed basic ingredients of flight are: sufficient power, lift , control
Wright’s successfully applied theories of lift and drag to practical use in powered gliders
Progress (and a conventional designs) came with lighter materials and drag reduction
1853 Yorkshire, England
George Cayley is, by some, considered to be the father of heavier than air flight. In 1799 he demonstrated his grasp of fundamental aerodynamics when he engraved on a silver disk a sketch of the physical forces acting on an aeroplane. The aeroplane was complete with mainplane, fuselage, tail elevator and rudder. Cayley was not only interested in theory but also the more practical aspects of flight. He developed simple experimental techniques of measuring the lift force acting on bodies by a simple rotating arm device. He also put theory into practice by constructing his flying machine and launching it across the valley near his home at Brompton Hall. The unfortunate coachman who was instructed to be the pilot survived the flight but promptly resigned his post saying that he was hired to drive, not to fly. Cayley lost interest in flight after this and not until later in his life did he investigate flight further. Source: Strickland
1896 Berlin
Otto Lillienthal died in hospital from injuries incurred from a flying accident. Lillienthal can be considered to be the first heavier than air pilot. His research into the aerodynamics of gliding flight plus the piloting of them will always hold a place in history. He was one of the first to realise that for success he not only had to theorise but had to construct the aircraft themselves and then fly them in order to further his research. His gliders would be familiar to most people today as they closely resembled the modern hang glider and utilised the movement of the body to alter the cg for control. Unfortunately while piloting one of his gliders he was caught by a gust of wind and crashed from about 50 ft.
1904 There was doubt in Europe the Wright’s claim to have mastered powered flight were true. This may have been due in some part to the refusal of the Wright’s to demonstrate their machine in public because of their fear that their construction methods would be stolen.

9. Breakthrough Sir Hiram Maxim Wright brothers Glen Curtiss
The Main Events
Sir Hiram Maxim
power, lift, control
Wright brothers
Glen Curtiss
Improved designs, promoted aviation
1894 Sir Hiram Maxim built huge steam powered flying machines but never successfully flew them. Experimenters were learning there are three main requirements for powered flight: sufficient power and lift, and control. Source, Jepperson Sanderson
10:35 a.m. December 17th The Wright machine Flyer took to the air from a 40 ft wood rail under its own power for a flight of 120 ft in 12 seconds. They made four flights before noon; the longest covered 852 ft in 59 seconds. The Flyer was then damaged by a gust of wind before the fifth flight could be made. The Wright’s no-risk, methodical approach to flying had paid off. The success of this powered flight was in no small way aided by the light petrol engine the brothers had developed over the previous winter. Source: Strickland
December 17, 1903, near Kitty Hawk, North Carolina, Wilbur and Orville Wright made the world's first successful powered, free, controlled, sustained flights in a heavier-than-air craft.

10. World War I War speeds up technology development
The Main Events
War speeds up technology development
Airplane speed, loads increased
Large manufacturing base developed
Congressional medal of Honor winner Captain Eddie Rickenbacker went on to be a pioneer in civil aviation, too

11. After the War Veteran pilots kept interest alive
Commercial aviation catches on
Dramatic design advances
Beginning of rocket flight
Invention of the jet engine
1926 Auburn Massachusetts, USA
Robert Goddard fired a liquid fuelled rocket to an altitude of 41 ft for 184 ft at a speed of 70 mph, paving the way for further developments in liquid fueled rocketry. Strickland
1927 Paris, France.
Charles Lindbergh made the first solo crossing of the Atlantic in his custom built Ryan NYP Spirit of St Louis and in doing so pocketed the $25,000 Orteig prize. The flight took 33 hrs 30 minutes and covered in excess of 4,000 miles. Strickland
1933 Seattle, USA.
Airline service with the first truly modern airliner commenced with the first scheduled flights of the Boeing model 247. The 247, a development of the B9 bomber was the first all metal streamlined monoplane transport. It had fully retractable undercarriage, trim tabs, automatic pilot, wing and tail de-icing. Powered by Pratt and Whitney Wasp 550 hp supercharged radial engines it had a cruising speed of 155 mph a range of 485 miles. It was also equipped with toilets and reading lights in the soundproof cabin.
1936 Marienehe, Germany.
Hans Pabst von Ohain started to develop a turbojet at the Heinkel plant. His first engines were powered by hydrogen in order to simplify combustion.
1937 Warwickshire, England
Frank Whittle ran his gas turbine for the first time much to the surprise of onlookers who fled the test stand as the engine spooled up and then ran away in a frightening scream. Von Ohain's engine ran for the first time less than a month later.
1939
Following Hitler's refusal to withdraw from Poland the Second World War commenced and with it began one of the most rapid periods of development in the fields of aerodynamics, structures and propulsion in the history of aviation.

12. Four Forces of Flight Lift Weight Thrust Drag
Source NASA Glen Research Center Learning Technologies
A force may be thought of as a push or pull in a specific direction. This slide shows the forces that act on an airplane in flight.
The motion of the airplane through the air depends on the relative strength and direction of the forces shown above. If the forces are balanced, the aircraft cruises at constant velocity. If the forces are unbalanced, the aircraft accelerates in the direction of the largest force.
Source: NASA Glen Research Center

13. Two of the four forces on an airplane
Standards in this lesson: Physics-motion and forces-Newton’s laws
When forces are balanced no acceleration occurs; thus an object continues to move at a constant speed or stays at rest (Newton's 1st Law).
When one object exerts a force on a second object, the second object always exerts a force of equal magnitude and opposite direction (Newton's 3rd Law).
The relationship between the universal law of gravitation and the effect of gravity on an object at the surface of the earth
Lift and Drag
Two of the four forces on an airplane
General Concept:
Just like in the first page of this manual, an airplane flies by balancing forces. If the trust of the airplane’s engines is greater than the force of the wind (drag force), the plane will go forward. Likewise, if the lifting force of the wings is greater than the weight of the plane (the force of gravity), the plane will rise in the air. Therefore, to make the airplane work, one must have sufficiently powerful engines to push the plane through the air, and have designed wings to lift the plane in the air. Once in the air, airplanes maneuver by moving control surfaces which provide torques about the center of mass of the airplane. These torques will rotate the aircraft in the
appropriate direction.

14. Lift Lift is an aerodynamic force Lift must exceed weight for flight
Generated by motion of aircraft through air
Created by the effects of airflow past wing
The top of an airplane wing is curved, so that air has to travel further to reach the trailing end of the wing.
Therefore, the air on the underside of the plane is exerting more pressure, causing the plane to lift.

15. Weight Weight is not constant
varies with passengers, cargo, fuel load
decreases as fuel is consumed or payload off-loaded
Direction is constant toward earth’s center
May be assumed concentrated at the center of gravity

16. Drag An aerodynamic force Drag is also called air resistance.
the force that pulls the plane backward.
Two broad drag classifications
Parasite drag: drag created by airplane design
Induced drag: by-product of lift generation
Acts through the center of pressure

17. Thrust Forward-acting force opposes drag
Direction of thrust depends on design
Propulsion systems produce thrust
Equal to drag in straight, constant speed flight

18. Stability Center of Gravity Center of Pressure Longitudinal Stability
Lateral Stability
Directional Stability

19. Definition: Aeronautics
Aeronautics is the design and construction of
aircraft and
The theory and practice of aircraft navigation

20. Definition: Aerospace Engineering
Aerospace engineering is closely allied to aeronautics and aeronautical engineering but
Includes the study and development of rocket engines, satellites, and spacecraft

21. Activities and Exercises
Build gliders for flight control experiments
Worksheets