Plain English Meaning

Before flying on instruments, the pilot goes through each system on the aircraft — radios, navigation receivers, flight instruments, autopilot, and so on — to make sure each one is working properly and is legal to use for the planned flight.

Full Definition

The set of checks a pilot performs before an instrument flight to confirm that all required navigation, communication, and flight instrument systems on board the aircraft are present, powered, current, and functioning correctly for the type of operation planned.

Context Anchor

Seen during instrument-flight preflight planning, cockpit setup, and .