Aerodynamics and Principles of Flight
Lift, drag and the four fundamentals
Understand how angle of attack, airspeed and wing shape produce lift, and that lift rises with the square of airspeed. Know the four drag types: parasite (form, skin friction, interference), induced (from lift, greatest at low speed/high AoA), profile, and total drag. The power curve and thrust curve cross at specific speeds; best glide occurs near minimum total drag, best climb rate near maximum excess power.
Stability and control
Learn static versus dynamic stability, longitudinal (pitch), lateral (roll) and directional (yaw) stability, and how dihedral, sweep and fin area affect them. Understand the stall as exceeding the critical angle of attack, independent of airspeed, and that load factor raises stall speed by the square root of the load factor. Know adverse yaw, aileron drag, and why coordinated flight uses rudder.
Traps in questions
- Believing a stall is caused by low airspeed alone; it is an AoA phenomenon.
- Confusing best glide speed with minimum sink speed.
- Assuming induced drag falls with speed without checking total drag.
- Mixing up static and dynamic stability.
Worked example: stall speed under load
Clean stall speed 50 kt at 1 g. At 60° bank, load factor is 2 g. New stall speed = 50 × √2 ≈ 70.7 kt. Rule of thumb: stall speed rises by about 41% at 2 g and doubles at 4 g. This explains why steep turns and turbulence demand higher approach speeds.