Principles of Flight
Core concepts
Understand lift generation, angle of attack, the lift coefficient curve, induced and parasite drag, the drag curve and L/D maximum, stability about three axes, control effectiveness, and the stall. Know how load factor, mass, CG position and configuration change performance, and why the critical angle of attack governs the stall regardless of speed or attitude.
Traps
Examiners test the misconception that a stall depends on speed. It depends on angle of attack. Also watch for the relationship between induced drag and speed (inversely), parasite drag and speed (squared), and the effect of aft CG on stability. Questions on the four forces in a climb and on the effect of flaps on the stall speed and approach attitude are common.
Worked example
An aircraft stalls at 50 kt at 1 g. In a 60-degree bank, load factor is 2 g, so stall speed rises by the square root of 2, about 1.41, giving roughly 71 kt. Rule of thumb: stall speed increases with the square root of load factor, so steep turns and pull-ups demand more speed margin.
Exam technique
Ask "what happens to angle of attack?" before answering any performance question. If an option contradicts the lift curve, eliminate it.