A Primary Flight Display or PFD, found in an aircraft equipped with an Electronic Flight Instrument System, is the pilot's primary reference for flight information. The unit combines the information traditionally displayed on several electromechanical instruments onto a single electronic display reducing pilot workload and enhancing Situational Awareness.
The layout and information displayed on the PFD varies depending upon manufacturer and installation. However, most Primary Flight Displays are configured with a central attitude indicator (AI) and flight director surrounded by other flight parameters. Convention normally places the airspeed tape on the left side of the AI and the altitude and vertical speed references on the right. Vertical deviation for ILS glideslope or VNAV (vertical navigation) is displayed to the right of the AI while lateral deviation from the ILS, VOR or FMS track is displayed below the AI. A compass reference is provided at the bottom of the instrument while, in most cases, flight director, approach, autopilot and auto-throttle modes are annunciated across the top of the instrument.