Plain English Meaning

Flying the aircraft by what the cockpit gauges show, instead of by what the pilot can see out the window.

Full Definition

Flight conducted by reference to the cockpit instruments rather than by visual reference to the natural horizon or ground features, used when outside visual cues are unavailable or unreliable due to weather, darkness, or visibility conditions.

Context Anchor

Seen in discussions of flying in clouds, reduced visibility, night conditions, and upset prevention when the outside view may not give a reliable sense of which way the airplane is pointing.