Aircraft performance optimization.

Using the calculus of variations, the solutions to various fixed end point flight-path optimization problems are developed. These include the minimum fuel-fixed range problem, the minimum time-fixed range problem, and the minimum fuel-fixed range-fixed time problem. Altitude profiles and throttle control laws are presented. A variety of aircraft mathematical models is initially examined, and the existence of a classically optimal controller is verified for a simple model. For this model, the first integral condition is used to eliminate the requirement of integrating the Euler Lagrange adjoint differential equations. The resulting computational algorithms are attractive for both laboratory investigations and airborne implementations.