TABLE OF CONTENTS An airplane is a flying machine. Like any other machine, it is judged by its performance. Some of the questions that usually come to mind are How fast can it fly? How high can it fly? How fast and how steep can it climb? How far can it go with a tank-load of fuel? What length of runway does it need for takeoff and landing? How sharp and how fast can it turn? Answers to these and many other questions form the subject matter of aircraft performance.
Performance characteristics depend on the weight of the airplane, aerodynamic characteristics of the airframe, and the thrust or the power developed by the powerplant. For a given airplane configuration, aerodynamic characteristics depend on angle of attack/sideslip, Mach number, and Reynolds number. The thrust/power characteristics of the powerplant depend on altitude, flight velocity, and engine operating conditions. Therefore, in general, it is not possible to analytically estimate airplane performance considering the arbitrary variations of aerodynamic and propulsive characteristics. Prior to the arrival of modern digital computers, it was common practice to use graphical methods for performance evaluations. Using high-speed computers, these calculations, which once took several hours or days, can now be performed in a matter of a few minutes with much more precision and accuracy. However, we are not going to discuss these computational methods of performance estimation. Instead, we will introduce some simplifying assumptions so that performance calculations become amenable to the methods of ordinary calculus.
We assume that...
