Definition
Flight operations conducted by reference to cockpit instruments rather than by visual reference to the ground or horizon, performed under Instrument Flight Rules (IFR) and using procedures, navigation aids, and air traffic control services designed for flight in instrument meteorological conditions or controlled airspace.
Plain English
Flying that relies on the aircraft's instruments to navigate and control the airplane, instead of looking outside at the ground, horizon, or other landmarks.
Context Anchor
Seen in instrument procedure and NextGen discussions about newer ways to fly precise routes, arrivals, and approaches using aircraft equipment and published procedures.
Derivation
Instrument comes from a Latin word meaning a tool or piece of equipment. In aviation, the word points to the aircraft’s gauges, displays, and navigation equipment—the tools the pilot uses when outside visual cues are not enough.
Why Pilots Care
Allows continued flight and approaches when weather reduces visibility below visual flight minimums.
Grounding Statement
If clouds block the outside view, instrument-based operations let the pilot keep flying the planned path by using cockpit information instead of visual cues.
Intuition Check
Do not read this as simply “using instruments sometimes.” In this context, the instruments and approved procedure are the main basis for how the operation is flown.
Example Sentence 1
NextGen improvements such as Performance Based Navigation are designed to make instrument-based operations more efficient in busy terminal areas.
Example Sentence 2
NextGen upgrades improve the accuracy of instrument-based operations during arrival.