RAPID CITY, S.D. (AP) — The U.S. Air Force's Powder River Training Complex is expanding the air space where flight crews will be allowed to train over the Northern Plains.

The 35,000-square-mile (90,650-square-kilometer) training complex is increasing its maximum altitude limit over the Dakotas, Montana and Wyoming, the Rapid City Journal reported . The Powder River complex is the largest air training complex in the continental U.S.

The altitude threshold increase will allow detection-evading stealth aircraft to fly at altitudes of 52,000 feet (15,850 meters), double the current 26,000-foot (7,925-meter) limit.

"What we want to practice is using our stealth aircraft to avoid the most powerful and capable radars systems," Sen. Mike Rounds said Thursday. "The way you do that is by practicing in an area that not only you can fly at the height you normally would, you can also coordinate with (non-stealth) aircraft, because they have to work together."

The complex's officials will only allow aircrafts to reach the maximum altitudes for training exercises over a 10- to 15-day period each year, Rounds said. Commercial passenger air traffic, which generally operates at altitudes between 28,000 and 35,000 feet, would be restricted during the training held for a couple of hours each day.

"It should mean minimal impact to commercial air traffic," Rounds said.

The altitude threshold will be necessary once the U.S. Air Force and Ellsworth Air Force Base begin transitioning to a new bomber called the B-21 Raider in 2023, he said. The bomber is expected to replace the current B-1B Lancer and B-2.

The altitude increase will make the Powder River complex more vital and help Ellsworth increase its value to the military more than a dozen years after a Pentagon Base Realignment and Closure commission considered shuttering the base, Rounds said.

"This is a game-changer for Ellsworth in terms of its stability," he said. "This basically ensures that Ellsworth isn't going to go any place for at least another 50 to 75 years."

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Information from: Rapid City Journal, http://www.rapidcityjournal.com