The B-21 Raider is the first new American bomber in more than 30 years. The Air Force unveiled the first new US stealth bomber in decades on Friday, following years of covert development.

The U.S. Air Force’s latest B-52 variant just reached another milestone. According to the service, the bomber’s F130 engines have passed their critical design review.

Now, as the Commander of the 509th Bomb Wing at Whiteman Air Force Base in Missouri, home of the world’s only B-2 Spirit stealth bomber unit, Butler oversees the very operations that make such ...