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Cadet Phase I & II Aerospace Dimensions Introduction to Flight (Module 1)

Cadet Phase I & II Aerospace Dimensions Introduction to Flight (Module 1). Session 1: Chapter 1 ‘Introduction to Flight’ (For all Cadets that have not yet passed corresponding test, and Cadet Mentors) Activity Additional material for Cadet Officers only Session 2:

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Cadet Phase I & II Aerospace Dimensions Introduction to Flight (Module 1)

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  1. Cadet Phase I & IIAerospace DimensionsIntroduction to Flight (Module 1) Session 1: Chapter 1 ‘Introduction to Flight’ (For all Cadets that have not yet passed corresponding test, and Cadet Mentors) Activity Additional material for Cadet Officers only Session 2: Chapter 2 ‘To Fly by the lifting power of rising air’ Chapter 3 ‘Balloons - They create their own thermals’ (For all Cadets that have not yet passed corresponding test, and Cadet Mentors) Activity Additional material for Cadet Officers only Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing

  2. Introduction to Flight • Important Terms (your new ‘language’) (Quiz): • Aero • Aerodynamics • Aeronautics • Aerospace • AGL • Air • Aircraft • Airplane • Airfoil • Airport • Altitude • Aviation • Aviator • Camber • Chord • Drag • Dynamic • Leading Edge • Lift • Relative Wind • Static • Supersonic • Thrust • Trailing Edge • Wind • Aerospace Education: ‘the branch of general education concerned with communicating knowledge, skills and attitudes about aerospace activities and the total impact of air and space vehicles upon society’ Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing

  3. Introduction to Flight • Daedalus & Icarus • Greek mythology: Father and son escaped imprisonment by fashioning wings from feathers and beeswax, and flying away • Icarus was said to have flown too close to the sun, which melted the beeswax, and his wings fell apart • Marco Polo • Reported seeing Chinese sailors strapped under huge kites, and used as aerial observers • Montgolfier Brothers • Designed first confirmed manned balloon to actually fly (burner = power) • Flown by d’Rozier and d’Arlandes in Paris France Nov 21st 1783 (Note: just 7 years after US declaration of Independence!) Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing

  4. Introduction to Flight • Daniel Bernoulli (1700-1782, Dutch) • When air is accelerated, its pressure drops • Sir Isaac Newton (1643-1727, English) • An object at rest will remain at rest unless acted upon by some outside force • THRUST (Propeller or Jet) needed for the plane to move • A force acting upon a body causes it to accelerate in the direction of the force. Acceleration is directly proportional to the mass of the body being accelerated • Prop or Jet causes acceleration, more power = more speed(what would happen if you strapped a jet to a Cessna 172?) • For every action, there is an equal and opposite reaction • Jet points backwards, but plane goes forward • And air impacting under the wing causes the wing to rise Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing

  5. Introduction to Flight • Bernoulli in action: The Airfoil • Because it has to travel further, the air over the top of the wing ‘travels’ faster, and so is at lowerpressure than the air under the wing, and that = LIFT! • This ‘traveling’ air (airflow) is called the Relative Wind • LIFT = CL x R x ½V² x A • CL - Coefficient of lift ~ defined by angle of attack and airfoil design • R - Density of air (mass/volume) ~ more dense = more lift • ½V² - ½(Velocity of air)² ~ air speed x2 = lift x4 • A - Area of Wing ~ average chord x wing span Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing

  6. Introduction to Flight • How do the theories of Bernoulli and Newton apply to a bird? • Birds create ‘thrust’ by flapping and controlling the angle of their wings (Dynamic Lift) • They control their feathers to trap air on the downbeat, but allow it through on the upbeat (Newton 1 AND 2) • Also, by tilting the wing upward, Newton’s3rd law provides additional lift • A bird’s wing has an airfoil like cross-section, so air MUST move faster over than under, which created lower pressure on top = Bernoullian Lift (Induced) Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing

  7. Introduction to Flight • Four Main Forces acting on an Airplane in Flight: • To stay aloft, Lift MUST = Weight (Mass x Gravity) • To accelerate, Thrust MUST be GREATER than Drag Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing

  8. Introduction to Flight • How can you get MORE lift from a wing? • Make a Bigger Wing (Area increases {remember lift equation}) • (Flaps can do this temporarily) • Increase the Curve of the upper camber (CL increases) • (Flaps also do this temporarily. They provide additional lift at the lower speeds of Take off and Landing) • Increase Speed (½V² increases) • Increase the Angle of Attack (CL increases) • Like when the pilot pulls back on the stick at takeoff • BUT, go too far (over about 17°)and the wing will ‘stall’i.e. airflow over top of wing separates. A wing stalls at its Critical Angle of Attack Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing

  9. Introduction to Flight • Airplane Components: Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing

  10. Introduction to Flight • The Three Axes of an Airplane: • Movement around Lateral Axis = Pitch • caused by Elevatormovements • Movement around Vertical Axis = Yaw • caused by Rudder movements • Movement around Longitudinal Axis = Roll • caused by Aileron movements Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing

  11. Introduction to Flight • So what does a Propeller do, and how? • A Propeller creates thrust that causes the airplane to move forward • It is a wing, on its edge, moving in a fixed circle, creating its own relative wind • Because of its airfoil shape, it creates lower pressure on the forward edge, which results in forward lift, which pulls it (and the attached airplane forward) • Question - how can the propeller create more thrust (lift)? • Aerodynamics of a Propeller (why the funny shape?): • Design tries to equalize the thrust (lift) along the blade • 1 = Hub (attachment point, no lift) • 2,3,4 = Main Blade (each is faster, so blade gets progressively flatter) • 5 = Tip (fastest point, so lowest curve) Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing

  12. To Fly by the lifting power of rising air • Important Terms: • Soaring • staying up on natural energy • Span • distance between wingtips • Spoilers • wing lift reducers (Dive Brakes) • Stability • atmosphere resistance to vertical motion • Thermal • rising column of air • Tow Plane • plane providing initial thrust and altitude ‘gift’ for a glider • Wave • up and down air currents from air flow over mountains • Altitude • AGL or MSL • Aspect Ratio • Wing Span : Chord • Convection • Fluid motion due to temp differences • Density • Mass/Volume • Glide Ratio • How far forward per unit of descent • Lapse Rate • temp decrease / altitude increase • Lift-to drag Ratio • gliding efficiency Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing

  13. To Fly by the lifting power of rising air • How rising air provides LIFT for flight: • Heat from the sun (93 Million Miles away!), causes air to warm up and rise • Heated air rises because it becomes less dense (molecules move more, and push each other further apart), and so this air is now lighter than surrounding air • The upper atmosphere is quite cold, so eventually this rising air cools, and falls again • The rising and falling motion is called convection • When the atmosphere resists convection, it is said to be stable • Cooling with altitude is called the Lapse Rate, which is about 3½°F for every 1000ft up Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing

  14. To Fly by the lifting power of rising air • Gliders and Sailplanes • Sailplanes can ride the columns of warm rising air, and stay aloft by soaring on the free solar energy • Gliders do not soar, but they do have a higher glide ratiothan conventional powered airplanes • Both Gliders and Sailplanes mustfirst be towed to altitude Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing

  15. Balloons - They create their own thermals • Important Terms: • Balloon - Aircraft lifted by lighter than air gas, with no means of horizontal control • Burner - Device which heats air(hot air is lighter than surrounding air) • Buoyancy - Rising or Floating in a fluid (such as air or water) • Crown - Top of a Balloon’s ‘Envelope’ • Envelope - The main body of a balloon (usually nylon) • Gore - The vertical panels that make up the envelope • Montgolfier - French brothers who created first successful manned balloon • Parachute Panel - Device inside top of envelope, allows hot air to escape when required • Propane - Lightweight fuel for burner • Thermistor - Device which measures temp inside envelope • Variometer - Vertical Velocity Indicator (Rate of Climb/Descent) • Wicker - Woven wood used to make the basket (Gondola) Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing

  16. Balloons - They create their own thermals • How a Balloon flies: • Buoyancy - Hot Air is Lighter than Cold air, so it rises above it • Trap enough hot air inside the envelope, and the buoyancy can lift both the air itself, and the balloon and passengers too • To Rise - The envelope’s air is heated by the Propane Burner • To Descend - Hot air can be ‘let out’ through a vent at the top of the envelope by partially collapsing the Parachute • Directional control comes from natural wind, which moves in different directions at different altitudes - So the pilot must climb/descend to find a wind going in the required direction • The Math of a Balloon’s Lift: • Hydrogen balloon (like the Hindenburg) ~ 60lb LIFT per 1,000 cu ft • Hot Air balloon ~ 17 - 20lb LIFT per 1,000 cu ft • 77,000 cu ft balloon LIFT = 17 x 77 = 1309lb ( minus about 600lb for envelope + basket, burner and propane = 709lb payload ) Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing

  17. Balloons - They create their own thermals • Balloon Components (6 - 18 feet wide) Load Tapes support the envelope, and maintain its shape (ideally spherical) Typical Instruments are Thermistor, Variometer (Vertical Velocity Indicator), and Altimeter Typical materials are Nylon & Dacron, with a Polyurethane coating Several MILLION BTU’s per Hour(1 BTU = raise 1 lb water by 1°F) Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing

  18. Balloons - They create their own thermals • Hydrogen balloon example (not for test) • Hindenburg the Largest Aircraft EVER to Fly • Gas volume 7,062,000 cubic feet!! • LIFT = 60 x 7062 = 423,720lb (212 TONS!! Actually quoted as 242 Tons) • Minus about 260,000lb for structure and fuel = 112 Tons useful payload!! • That’s the Gross Weight of a Boeing 757-200! • Only 9% shorter than the Titanic! • She was destroyed by firewhile arriving at NAS Lakehurst NJ, May 6, 1937 • Now known that fire was due to flammable skin NOT Hydrogen Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing

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