Metropolitan Tower Complex – Two (2) or more airport traffic control terminals that provide traffic advisories, spacing, sequencing, and separation services to VFR and IFR aircraft operating in Class B airspace within the vicinity of the airport using a combination of radar and direct observations. These airport traffic control terminals must serve separate Large Hub Airports located in a major metropolitan area and independently be within one (1) facility pay level of each other. Additionally, each airport must be located within fifteen (15) nautical miles (center of airport to center of airport), and have traffic flows that have to be closely coordinated between facilities such that the operational configuration of one (1) airport affects the operational configuration of the other(s).
Traffic Count Index (TCI) – A combined measure of the complexity of the air traffic and the sustained traffic index at each facility. It is the measure used to set facility pay levels. For a Metropolitan Tower Complex, the Traffic Count Index for each airport traffic control terminal facility is calculated independently, and the pay level of the Complex is set based on the highest independently calculated TCI.