 The first being the basic "communications" mini airliner, the next having two nav crates and an astrodome fitted, and the last, the "signals" version, sporting two radio crates for student AEOps to practice their airborne duties.While the aircraft could be operated by a single pilot, Flying Flight of NATS also had four signallers on its establishment and these grand masters of the morse key were essential equipment when the little twin pistons headed off into the cold and icy South Pacific for three hours at a time in the middle of winter.They also gave moral support to the pilot who found himself navigating in the dark on a knee pad to ensure the student passing navigational information forward was not taking him towards the South Pole instead of Wigram airfield.