This text describes the basic forces which dictate and decide the performance of an aircraft. It is aimed at pilots and flight-test engineers seeking answers to questions of flight mechanics. Referring to real-life situations, performance analysis is presented for most phases of flying, including takeoff, climb, cruise, turn, descent and landing. To improve confidence in dealing with these situations, a list of problems is provided at the end of each chapter to encourage trouble-shooting and theory comprehension. Charts, figures and references reinforce and complement the text throughout.