Final answer:
The reversionary switch panel allows pilots to switch essential flight information to a backup display in case of primary display failure, ensuring continued access to critical data for safe flight operations.
Step-by-step explanation:
The reversionary switch panel is a crucial component in the cockpit of modern aircraft. It is designed to allow pilots to switch the display of critical flight information from one screen to another, typically in the event of a primary display failure. These panels are part of the aircraft's avionic systems, which include a variety of electronics used for communication, navigation, and display of various flight parameters.
Operationally, if the primary flight display (PFD) fails, the reversionary mode can be activated via the reversionary switch panel. When this happens, the multifunction display (MFD), which usually shows other information like maps or engine parameters, will display the critical flight information instead. As such, the pilot can maintain access to essential data required for safe flight operations, such as artificial horizon, altitude, speed, and navigational data.
Furthermore, the reversionary mode can sometimes offer redundancy for other systems as well. For instance, if navigation computers fail, the reversionary system may allow for the continuation of using GPS data or other navigational aids through the secondary display. This highlights the importance of such systems in modern aviation, where redundancies are critical for dealing with unexpected technical problems during flight.