The UAV’s engine performance is transformed into constraints in order to plan route, which reduces the route
tracking error. The relationships between the engine performances and the route planning constraints are analyzed. The
transfer formulae between the engine power and the maximum chlimbing angle, the maximum turing angle, the range or the
endurance are given. The mathematical connection between the maximum turing angle and the minimum route route length
is established. The simulation results show that the UAV’s 3-D route can be planned according to the different constraints
which are transformed from the engine performances.