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. Jeppesen Private Pilot Manual (for pictures)

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 FLIGHT

Objective: 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

Oral evaluation/quiz and discussion questions: (3 minutes)
Q: How do ailerons and elevator work?
Q: When lift is produced, something else is produced. What?
Q: How does the answer to the first question apply to turning an airplane?