Final answer:
When the FCC determines conditions are correct for a pilot-selected flight director mode, it provides an indication through the flight director display, showing the desired flight path and providing guidance cues to the pilot. For example, if the pilot selects VNAV mode, the display may show a vertical path indicator or altitude target.
Step-by-step explanation:
When the FCC (Flight Control Computer) determines that conditions are correct for a pilot-selected flight director mode, it provides an indication through the flight director display on the primary flight display (PFD) or the navigation display (ND). The flight director mode indicates the desired aircraft flight path and provides guidance cues to the pilot for maintaining or achieving that flight path.
For example, if the pilot selects a vertical navigation (VNAV) flight director mode, the flight director display may show a vertical path indicator or an altitude target. This indicates to the pilot that the conditions are correct for the selected VNAV mode and the aircraft should follow the displayed vertical path or altitude target.
Other flight director modes that the FCC may support include heading select (HDG SEL), track select (TRS SEL), altitude hold (ALT HLD), and vertical speed select (V/S SEL), among others.