Patent US 5,457,634

An onboard flight management system produces cost-effective trajectory target signals in response to an input desired time of arrival. Aircraft monitoring systems produce signals corresponding to real-time aircraft parameters including fuel flow rate, airspeed, windspeed, thrust, drag and mass. Stored in memory are aircraft characteristics including time cost, fuel cost, and acceleration due to gravity. A flight computer responds to an input desired time-of-arrival and the real-time parameters and stored characteristics signals and produces cost-effective trajectory target signals. The computer employs multiply regressed drag and fuel flow models which avoid trajectory discontinuities and the trajectory targets are produced using a Fibonacci search technique, which is computationally very efficient.