Periodic control for minimum-fuel aircraft trajectories

The problem of minimizing fuel consumption of an aircraft is formulated as an optimal control problem with periodic boundary conditions. Two problems are considered: one with constant aircraft weight and one with variable weight. Numerical solutions are computed via a multiple-shooting method and consist of bang-bang control actions for power setting. In comparison to the steady-state solutions, savings in fuel consumption for an F-4-type aircraft are approximately 2%. The solution obtained is shown to satisfy the second-order sufficiency conditions for a weak local optimum.