The FAA says planes flying around Dallas will save 4.1 million gallons of fuel a year and reduce carbon emissions. (Susan Biddle/The Washington Post)

The Federal Aviation Administration took another step in the rollout of its massive new aviation control system Wednesday, announcing that planes flying the busy skies around Dallas will save 4.1 million gallons of fuel a year and reduce carbon emissions as key features of the system known as NextGen come online.

The announcement that descent procedures and more direct routing allowed by NextGen were in place at the Dallas hub airports came a day after the aviation agency was blasted in absentia on Capital Hill by members of Congress frustrated with the pace of progress on the $40 billion project.

“We flipped the switch on 80 new NextGen procedures here in North Texas,” FAA Administrator Michael P. Huerta said at a news conference in Dallas. “Overnight we saw significant benefits in this complex airspace. Planes are flying fewer miles and burning less fuel. Flights are arriving a little earlier than before, and departures are able to get on their way even faster.”

Though they were modest steps in the context of extraordinarily complex transformation from a radar- to a GPS-based aviation control system, they came a day after House Transportation Committee Chairman Bill Shuster (R.-Pa.) said the FAA was “moving at a snail’s pace” on NextGen.

Another committee member, Del. Eleanor Holmes Norton (D-D.C.), called a 2020 target date for implementing much of the new system “fiction.”

The FAA has implemented elements of the NextGen system at several airports, including Reagan National Airport, while working on technology and procedures that may not come on line for a decade.

One of the fuel- and time-saving NextGen procedures now in use at Dallas/Fort Worth International Airport and Dallas Love Field allows planes to glide smoothly toward the runway. With the radar-based system, planes use a step-down process as they descend.

“It will allow aircraft to descend from cruise altitudes almost at idle,” Huerta said. “That saves a lot of fuel because that glide-line profile is a lot like sliding down a banister rather than going down the stairs.”

He said the use of GPS-based arrival and departure paths meant that airliners would fly 1 million fewer miles in North Texas.

“Using satellite-based NextGen technology, we’ve changed some of the most complicated airspace in the country into some of the most efficient,” he said. “Flights taking off and landing at both airports are flying in much more precise paths.”

Huerta was joined by Paul Rinaldi, president of the National Air Traffic Controllers Association, who was among those who testified before Shuster’s committee Tuesday.

“We’re often asked when is NextGen going to happen,” Rinaldi said. “It’s actually happening today.”

The NextGen system is designed to allow planes to safely travel packed skies closer to other planes. They would be able to fly direct routes, unlike in the current system, which relies on flying to waypoints before turning to a final destination.

NextGen is expected to cut flight delays, eliminate time spent on the runway waiting to take off and shorten flight times once planes are airborne.