Arapahoe County has sent a scathing letter to the Federal Aviation Administration criticizing the draft plan to revamp flight paths at five Colorado airports.

“It is an understatement to say that we are disappointed by the fact that the FAA has completely ignored most comments … while proceeding unabated with pushing the DEN-Metroplex without any regard for the health, welfare, safety and quality of life of residents living underneath the proposed flight paths,” Centennial Airport CEO Robert P. Olislagers wrote in a letter dated Dec. 18.

Nationwide, the FAA’s “metroplex” efforts are to accommodate the Next Generation Air Transportation System, which optimizes air traffic control procedures. The analyses from region to region examine “congestion, airports in close geographical proximity, and other limiting factors that reduce efficiency in busy metroplex airspace,” according to the FAA.

The Denver Metroplex Project will improve the efficiency of airspace by recalibrating arrivals and departures at five airports, including Denver International Airport, Centennial and three northern Colorado facilities. The FAA formed a study area over a large swath of the Front Range and Eastern Plains to evaluate the environmental impacts of aircraft routing changes.

The project could affect flight paths and altitudes, but would not by itself increase the number of flights.

In his letter, sent during the public comment period on a draft environmental impact report, Olislagers wrote that the FAA “consistently misapplies, misinterprets or ignores” the potential increases in noise and pollution that can be expected with growth at Denver International Airport.

“It is our well-founded belief that the FAA has not adequately demonstrated the cumulative impacts of the proposed Metroplex in this rapidly growing area despite knowing and having documented the annual increases in flight operations in and out of the Denver metropolitan area,” he explained.

Olislagers took issue with the FAA’s planned finding of no significant environmental impact of the Metroplex plan. He also criticized the FAA for not examining the noise impacts on children, “ostensibly because it lacks a standard.”

The letter, which identifies Centennial Airport as the second busiest general aviation airport in the nation, asks for a more comprehensive environmental impact study from the FAA.