What does "Fence [In/Out]" refer to in a flight operation?

The term "Fence [In/Out]" specifically refers to setting the appropriate cockpit switches and systems prior to entering or exiting a combat area during flight operations. This is a critical step to ensure that the aircraft is properly configured for the environment it is about to enter or leave. When pilots say "Fence In," they are typically preparing their aircraft for combat operations. This involves confirming the status of various systems, weapons, and defensive measures, ensuring everything is ready for action.

On the other hand, "Fence Out" denotes a return to a safe configuration, which may involve disabling weapons systems and adjusting the aircraft back to a non-combat mode. This ensures safety and compliance with operational protocols when transitioning between combat and non-combat environments.