CLINTON — Sandy Carstensen never used to watch NBC’s “America’s Got Talent,” but she has a reason to do so this season.

Carstensen, who was born and raised in Clinton, tunes in on Tuesdays and Wednesdays to see her grandson, Zach Hevel, perform with the United States Air Force Academy’s all-male a cappella group “In The Stairwell.” Hevel is a senior in the group, which will be among the 33 acts competing Tuesday in the first live episode of season 12 of the reality competition series.

“They are a fine group of young men,” Carstensen said.

Hevel is a second lieutenant in the Air Force and will begin training to be a pilot in October, according to Carstensen. Watching “In The Stairwell” perform on “America’s Got Talent” and in their many YouTube videos is a source of pride and inspiration for Hevel’s family less than a year after they suffered a loss. Carstensen’s mom died in October 2016 at the age of 100.

Debbie Hevel, Zach’s mom, said that when he went off to the Air Force Academy in 2013, his squad group said he was the best beat boxer they had ever seen. They told Zach about “In The Stairwell” and he has been involved ever since.

Debbie says “In The Stairwell” was entered in a Varsity Vocals International Championship of Collegiate A Cappella competition in Salt Lake City this past spring. The group did not progress into the semi-finals, but Zach called her a few weeks later to say that someone from “America’s Got Talent” was at the competition and “In The Stairwell” would soon compete in the series.

According to the “In The Stairwell” Facebook page, the group was originally formed in 2004. Mercer Martin is currently the Cadet in Charge. The cadets practice on a weekly basis and perform contemporary hits as well as the national anthem. The group performs at various entertainment and official functions on base and in communities.