The bottom half of the PFD consists of ______.

• A. The attitude indicator, AOA, airspeed, altitude, vertical speed indicators
• B. A compass rose or arc that includes a map, glideslope or lateral deviation indicators, and active FMS waypoint information
• C. Aircraft and engine system information and CAS messages
• D. The horizontal situation indicator and provides primary heading, navigation display, course selection, indication, NAV source, and localizer

Answer: (D)

The bottom portion of a modern PFD is dominated by the Horizontal Situation Indicator. This instrument combines your current heading with navigation guidance to keep you oriented laterally as you fly. It shows the primary heading, the active navigation display, the course you’ve selected, which navigation source is feeding the CDI (for example GPS or VOR/LOC), and the localizer indication when you’re aligned with an ILS. In short, it provides your directional reference and how you’re tracking against the chosen course and nav source.

The other options describe things that belong on different displays or in different parts of the cockpit. The top instruments—attitude, airspeed, altitude, vertical speed, and sometimes AOA—are the primary flight instruments. A moving-map style display with map, glideslope or lateral deviation indicators, and FMS waypoint information fits the navigation/ND context, not the bottom half of the PFD. Engine and systems information with CAS messages belong to engine/EICAS/ECAM displays, not the PFD’s bottom section.