When is the term "heavy" required by an En Route controller?

The term "heavy" is required for communications regarding heavy jet operations. This designation is crucial because it informs air traffic controllers and other pilots that a specific aircraft has a maximum takeoff weight of 255,000 pounds or more. The designation impacts wake turbulence separation criteria, as heavy aircraft generate significant wake turbulence that can affect following aircraft, especially smaller ones.

Using the term "heavy" helps in maintaining safety and providing appropriate separation between aircraft. It ensures that all controllers in the airspace are aware of the operational characteristics of the aircraft, which is particularly important during arrival and departure operations, but it specifically applies to communications related to heavy jet operations rather than all aircraft or in general traffic advisories. Understanding when to use this term helps ensure safety and efficiency in managing air traffic.