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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

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

introduction to flight
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

introduction to flight3
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

introduction to flight4
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

introduction to flight5
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

introduction to flight6
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

introduction to flight7
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

introduction to flight8
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

introduction to flight9
Introduction to Flight
  • Airplane Components:

Dr. R.A. Bartholomew - Civil Air Patrol, New Jersey Wing

introduction to flight10
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

introduction to flight11
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

to fly by the lifting power of rising air
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

to fly by the lifting power of rising air13
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

to fly by the lifting power of rising air14
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

balloons they create their own thermals
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

balloons they create their own thermals16
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

balloons they create their own thermals17
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

balloons they create their own thermals18
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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