What conditions require a pilot to use an IFR flight plan?

The requirement for a pilot to use an IFR flight plan primarily arises under specific operational conditions dictated by air traffic regulations and safety considerations. One of the central circumstances is when operating in controlled airspace under Instrument Meteorological Conditions (IMC). In such scenarios, pilots must adhere to IFR to ensure proper separation and control while navigating in potentially hazardous weather conditions.

Furthermore, ATC may request a flight plan to enhance the safety and efficiency of air traffic management. This is crucial in busy airspace where coordination between multiple aircraft is essential to prevent mid-air collisions and ensure that all aircraft operate on safe and predictable routes.

Using an IFR flight plan in controlled airspace under IMC or when requested by ATC ensures that the pilot adheres to established procedures that facilitate the safe movement of aircraft in varying conditions and environments. These rules are in place to bolster safety for both the pilot and passengers, as well as for other airspace users.