SALEM, Ore. -- Ryan Douglas, a Salem-native, is beginning to realize Tuesday night's "America's Got Talent" semifinals might be it for him.

"I’m maybe not going to be able to ever sing in a group like this again," the 2nd lieutenant said. "So that's always going to be running through my mind."

The Air Force Academy a capella group In The Stairwell, which he is a part of, will be performing in the live semifinal round of "America's Got Talent" on Sept. 12.

File: Salem man in 'America's Got Talent' with Air Force singing group

After this performance, whether the group advances or not, Douglas is done. He graduated from the academy in May and starts introductory flight training in Colorado on Sept. 20.

“I’ll just have to jump ship at this point in time," he said. “It’s kind of been a defining group for my time at the academy.”

In The Stairwell advanced to the semifinals in "America's Got Talent," to air Sept. 12. (Photo: NBC, Trae Patton/NBC)

Douglas, a 22-year-old baritone, attended West Salem High School, where he won the state competition with the concert choir his senior year. In 2013, he moved to Colorado to begin at the U.S. Air Force Academy. He joined In the Stairwell his first year there.

In The Stairwell advanced beyond the quarterfinals following an Aug. 15 performance of Fun.'s "Some Nights." It was the group's third performance for the show but the first that was judged by the audience. With the semifinals hanging in the balance, Douglas was worried his time might be done even then.

"I mean, I started tearing up just thinking about it. You make bonds with these people over four years, and singing is how you all connect for a lot of it," he said.

But Douglas is thankful for the time he's had. Especially considering that In The Stairwell wasn't expecting to get this far in the first place.