Principles of Flight (Teoria de Voo)
Principles of flight explain why and how an airplane flies. You must understand the four forces (lift, weight, thrust, drag), the generation of lift via the airfoil and angle of attack, and the lift equation's dependence on airspeed, air density, and wing area. Know the types of drag - parasite (form and skin friction) and induced (from lift) - and that total drag is minimized at L/D max. Study the stall: it occurs at the critical angle of attack regardless of airspeed, weight, or attitude, and the airplane can stall at any speed. Understand load factor and how it raises stall speed, plus stability (static and dynamic, longitudinal/lateral/directional) and the effects of flaps and CG.
Traps revolve around the stall and angle of attack. A frequent error is believing an airplane cannot stall at high speed or in a descent - it can, if the critical angle of attack is exceeded. Another is confusing induced drag (high at low speed, high angle of attack) with parasite drag (high at high speed). Load-factor questions expect you to know that stall speed increases with the square root of load factor, so at 2 g the stall speed rises about 41%. Also watch for questions on the region of reversed command (behind the power curve) and on how flaps change the stall speed and approach angle.
Rule of thumb: "The wing stalls at the critical angle of attack, not at a particular airspeed." Worked example: a 60 kt stall speed at 1 g becomes about 85 kt at 2 g (60 × √2 ≈ 84.9).