Principles of Flight
Lift, drag and the four forces
Know how lift is generated - circulation, angle of attack, and the pressure distribution - and the lift equation: lift depends on density, velocity squared, wing area and lift coefficient. Understand the drag curve: parasite drag rises with the square of speed, induced drag falls as speed rises, and total drag is minimum at the speed for best glide or maximum endurance. Know the four forces in climb, descent and turn.
Stalls, stability and control
A stall occurs at the critical angle of attack, independent of speed, mass or attitude. Know the factors affecting stall speed (mass, load factor, configuration, CG) and the difference between a stall and a spin. Understand static and dynamic stability, dihedral effect, and the secondary effects of controls. Traps include believing a stall requires low speed, or that a heavier aircraft stalls at the same angle of attack - it does, but at a higher speed.
Worked example / rule of thumb
Rule of thumb: stall speed increases with the square root of load factor - at 2 g the stall speed is about 41 % higher (√2 ≈ 1.41). In a 60° bank level turn the load factor is 2. For best glide, fly the speed that gives minimum total drag, and remember that wind affects glide range over the ground, not the glide ratio through the air.
Study strategy
Sketch the drag curve and mark the speeds for minimum drag, best glide and best endurance; most performance questions resolve on that sketch.