A vertical take off and landing (VTOL) aircraft has a pair of fixed wings fore and aft, straddling a pair of tiltable propulsors, such as ducted fans. The aircraft includes a modular crew cabin or freight payload and a dynamic counterbalance positioning system which can shift the location of an integral aircraft segment which may contain operational components such as fuel tanks, batteries, avionics equipment etc. in order to move the aircraft center of gravity closer to the center of lift and/or vertical thrust.