PRINCIPLES OF FLIGHT

 Objective: Understanding of aerodynamics

Content: Four forces of flight; Stability, Maneuverability, Controllability; Stalls and spins; Weight and balance considerations; Left-turning tendencies; Lift-to-drag ratio and best glide; Turning flight; Airspeed limits

Equipment:
White board. Gleim Pilot Handbook Page 25

Schedule:
Ground lesson: 50 minutes

Completion Standards:
Understanding of aerodynamics: how lift is produced, and the aspects of maneuvering in flight

GROUND LESSON:
PRINCIPLES OF FLIGHTObjective: Aerodynamics and terminology of flight
Materials: Jeppesen book, Chapter 3 for pictures

INTRODUCTION: Attention/motivation: (1 minute)
How does an airplane fly? It all has to do with unbalanced air pressure, and this has some effects not only putting the plane into the air, but on some other aspects of flight as well.

DEVELOPMENT: Overview and explanation: (45 minutes)
Aerodynamics:
I. Four forces: lift, thrust, weight, drag
LIFT:
Bernoulli Principle (Venturi effect)
Airfoils: chord, aspect ratio, camber, planform, sweep
Flaps and their effect on lift and drag
Angle of incidence
Angle of attack
Critical angle of attack and stalling
DRAG:
Parasite drag: form, interference, skin friction
Induced drag: downwash, wingtip vortices
II. Stability, Maneuverability, Controllability
Longitudinal stability along lateral axis
Location of CG vs. center of pressure on wing
Prop and wing downwash on horizontal stabilizer
Thrustline effect
Lateral stability along longitudinal axis
Dihedral
Sweepback
Directional stability along vertical axis
Weathervaning
Dutch Roll and spiral instability
III. Stalls and spins:
Stalls caused by exceeding critical angle of attack
Spins caused by stalling in uncoordinated flight
IV. Weight and balance considerations
V. Left-turning tendencies:
Torque
P-factor (asymmetrical thrust)
Spiraling slipstream
Gyroscopic precession (when lifting the tail of a taildragger)
VI. Lift-to-drag ratio and best glide
VII. Turning flight
Turns a result of the horizontal component of lift
Adverse yaw vs. Overbanking tendency
Rate and radius of turn vs. airspeed
Load factor, Load factor and stall speed
VIII. Airspeed limits