What altitude must all operations comply with under IFR conditions?

Under IFR (Instrument Flight Rules) conditions, all operations must comply with the minimum enroute altitude. This altitude is critical because it ensures that an aircraft remains clear of terrain and obstacles along its intended route. The minimum enroute altitude is determined by the highest terrain or obstacle within a designated area plus an appropriate buffer, thus maintaining a safe margin for flight.

This requirement enhances safety during flight, particularly in cases where pilots may be reliant on instruments due to low visibility or other adverse conditions, as it provides a guaranteed clearance above the terrain that could otherwise pose a risk. Ensuring that all operations comply with this altitude allows for effective navigation and adherence to air traffic control guidelines while minimizing the chances of in-flight incidents due to terrain conflicts.