Embodiments of a flight deck display system deployed onboard an aircraft are provided, as are embodiments of a method carried-out by a flight deck display system. In one embodiment, the flight deck display system includes a cockpit display device and a controller. The controller is configured to: (i) establish the speed trend of the aircraft over a predetermined time period; (ii) generate a primary flight display on the cockpit display device including a speed trend vector graphic representative of the established speed trend; and (iii) alter the appearance of the speed trend vector graphic in a first predetermined manner if a low speed change condition is detected during at least one of aircraft takeoff and landing.