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2016 CBA Tentati ve Agreement Page 159 of 217 • Terrain features; and • Oceanic and domestic - over - water traffic. These factors tend to be present in different centers in various combinations and with varying degrees of intensity. All these factors, whethe r separately measured or not, take on increasing significance and importance with substantial increases in the congestion of air traffic. The influence of complexity factors for CCF radar approach control positions is the same as described above for Appro ach Control, and for CCF center control positions, as described above for En Route, as practical in consideration of counting methodologies and, where applicable, for CCF tower positions, the same as described above for Towers. The difference in air traff ic congestion and other complexity factors is recognized in the complexity criteria discussed in the section s titled, "Weighting and Modifying the Traffic Count to Reflect Complexity." THE INFLUENCE OF TRAFFIC CONGESTION ON COMPLEXITY It is the level of sustained congestion of air traffic that is significant, rather than the total annual volume of air traffic handled by a facility. Therefore, it is not the total annual volume of control operations that primarily influences the level of complexity. It is t he level of congestion of air traffic which controllers must handle on a sustained basis that has the most significant influence on the complexity of these positions. The specific methods used to measure level of air traffic congestion at the various faci lities are described in detail in the section titled "Complexity Formula – Sustained Traffic Index." COMPLEXITY FORMULA – SUSTAINED TRAFFIC INDEX Most facilities experience their busiest air traffic during the day and evening hours with operations declin ing sharply during the very late evening and early morning hours. Operations at individual facilities also vary from day - to - day and during different seasons of the year. The formula below addresses these daily and seasonal variances in air traffic by put ting them in proper perspective in developing the sustained traffic index. It measures the busiest air traffic periods while also recognizing the influence of sustained levels of air traffic within the facility. The segment of the work year measured is th e busiest 1,830 hours and the next busiest 1,830 hours in terms of total aircraft handled in a consecutive 365 - day period. The use of 1,830 hours is based on the realization that at most facilities the greatest concentrations of air traffic occur during 10 hours, rather than 12 hours, 16 hours, or the full period a facility is open over a 24 - hour day. Half the days in a year (183) are multiplied by the 10 hours to derive 1,830 hours. In those facilities where there is very little decline in air traffic le vels between the busiest 1,830 hours and the second busiest 1,830 hours, the count is adjusted to reflect the sustained level of air traffic. In those facilities where there is a substantial difference between the peak and the next level of air traffic (i. e. the second busiest 1,830 hours) the count is adjusted to reflect that the high level of air traffic is not sustained.

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