Final answer:
The correct answer is c. When gear is down and NAV master mode is selected.The HUD landing display in an aircraft will be presented when the landing gear is down and the NAV master mode is selected.
Step-by-step explanation:
Regarding the question on when the HUD landing display (which includes an elongated horizon bar, AOA bracket, waterline symbol, steering display) will be presented, the answer is that it will be shown when gear is down and the NAV master mode is selected. This requirement is commonly implemented in modern aircraft systems to aid pilots during the landing phase. The HUD landing display provides critical information about the aircraft's attitude, flight path, and angle of approach, which assists in a safe touchdown.
Options such as those presented on HUD control panels or right DDI typically allow for different configurations or views based on the flight phase or pilot's preference but are not solely responsible for the activation of the HUD landing display. The activation of this specific mode is usually linked to the gear being deployed and the selection of a particular master mode, often the NAV mode for navigation. This ensures that the display aligns with the current phase of the flight—specifically, landing.