Definition
A small bordered window on the Primary Flight Display (PFD) that temporarily shows information from a function the pilot has activated, such as the Nearest Airports list, while the main flight display continues to show normal flight data behind it.
Plain English
A pop-up box on the main flight screen that shows extra information the pilot has called up, without taking over the whole display.
Context Anchor
Seen on glass cockpit displays and radio displays when selecting a frequency, such as choosing an airport frequency from the GPS nearest airport page.
Derivation
From 'stand-by,' meaning 'ready and waiting nearby.' The box stands by on the display, holding requested information for the pilot to use, then closes when no longer needed.
Why Pilots Care
Lets the pilot review and select an alternate airport quickly without interrupting the current flight plan or navigation display.
Intuition Check
Stand-by does not mean the radio is off. It means the frequency is queued and ready, but not active yet.
Example Sentence 1
When the engine began running rough, the pilot pressed the NRST button and the stand-by box appeared on the PFD showing the closest airports.
Example Sentence 2
With the current waypoint active, the stand-by box displayed the next-closest airport for quick reference during the approach briefing.