What is one requirement for flying an aircraft under IFR?

Flying an aircraft under Instrument Flight Rules (IFR) involves operating in conditions where visual reference to the ground or horizon is limited, such as in poor weather or at night. One key requirement for IFR flight is maintaining a certain minimum level of visibility, which is typically specified in terms of nautical miles.

Clear visibility of 2 nautical miles is a typical requirement in certain airspace classifications or specific weather conditions. Under IFR, pilots must rely on their instruments primarily for navigation and control, and maintaining this minimum visibility helps ensure safety during approach and landing phases, particularly when dealing with low cloud cover or adverse weather.

The other considerations, while important, do not directly relate to the fundamental requirement for IFR operations. Authorization from the control tower pertains to air traffic control protocols rather than an inherent flight operation requirement. Correct navigation instruments are necessary for safe operation but do not represent a regulatory visibility requirement. Likewise, having a specified amount of fuel is crucial for safe flight but is not specifically tied to the procedures or regulations for flying under IFR conditions.