What does IFR stand for in aviation?

In aviation, IFR stands for Instrument Flight Rules. This set of regulations governs how aircraft operate under instrument meteorological conditions, meaning when visibility is limited due to weather, such as clouds or heavy precipitation. Under IFR, pilots must rely predominantly on their instruments for navigation and control of the aircraft, as opposed to visual references outside the cockpit.

IFR is essential for ensuring safety in poor visibility conditions, as it provides guidelines for the operation of aircraft when pilots cannot safely navigate or control the aircraft solely using visual cues. Pilots flying under IFR must follow specific air traffic control instructions, file flight plans, and adhere to procedures that help maintain separation from other aircraft.

The other options describe terms that either do not exist in aviation or do not accurately encapsulate the concept of IFR as understood within the context of aviation regulations and procedures. For instance, although "Instrument Flight Regulations" might sound plausible, the correct terminology specifically uses "Rules" rather than "Regulations."