Selecting a key on the left side of the MCD next to a hard waypoint will display which page?

When you select a key on the left side of the Multi-Function Control Display (MCD) next to a hard waypoint, it is designed to display the LAT FPLN AT page. This page provides information on lateral flight planning specifics, including waypoints, routes, and other navigation-related data that are critical for flight path management.

The LAT FPLN AT page is essential for understanding how the aircraft will navigate to different waypoints along its route, allowing pilots to make necessary adjustments to their flight plan in real-time. It emphasizes the lateral aspects of the flight plan, highlighting what is essential for navigation and situational awareness during flight operations.

In contrast, the SEC FLT PLAN page typically offers a more alternative or secondary flight plan view, while the MC APPROACH page is utilized for managing and viewing approach procedures during the transition to landing. The ACT ROUTE DATA page provides information about the active route's data but does not serve the same purpose as the LAT FPLN AT page when it comes to hard waypoints specifically.