An aircraft having omnidirectional ground maneuver capabilities. The aircraft includes an airframe and a plurality of propulsion assemblies attached to the airframe. Each of the propulsion assemblies includes a nacelle having a mast axis, a rotor assembly having a tilting degree of freedom relative to the mast axis and a tail assembly rotatable about the mast axis. The tail assembly includes at least one wheel having a rotational axis. A flight control system is operable to independently control each of the propulsion assemblies including tilting each rotor assembly and rotating each tail assembly. For each propulsion assembly, the rotor assembly and the tail assembly have complementary configurations in which a thrust vector generated by the rotor assembly has a horizontal component that is generally perpendicular to the rotational axis of the wheel, thereby enabling omnidirectional ground maneuvers.