We study an important class of tracking problems for unmanned air vehicles (UAVs) with input constraints. The states give the position with respect to an inertial coordinate system, the heading angle, and the inertial velocity. The controls are the commanded heading angle and inertial velocity. We design controllers that give global tracking control. Two key features are the bounds on our controllers and our proof that the tracking is input-to-state stable with respect to additive actuator errors on the velocity controller, under a restriction on the perturbation that respects airspeed constraints. We allow a wide class of reference trajectories that satisfy a nondegeneracy condition on a weighted sum of the reference velocity and reference acceleration. We illustrate our work in simulations.