What does pressing the MEM special function switch do?

Pressing the MEM special function switch sets the last used preset channel in standby, allowing the pilot to quickly access the previously selected frequency. This feature is particularly useful in flight as it provides ease of frequency management without needing to manually search for a channel. The memory function enhances operational efficiency and ensures the pilot can swiftly return to the last communications channel, which can be critical in dynamic flying conditions where quick communication changes may be necessary.

In contrast, options such as enabling emergency mode or displaying memory storage capacity do not relate to the immediate functionality of the MEM switch, as its primary role centers around managing and retrieving preset channels efficiently. Clearing all preset channels is also not a function of the MEM switch, making it essential to understand that the primary purpose is to enhance the pilot’s access to communication frequencies they have used previously.