Boom Supersonic's XB-1 demonstrator completes second test flight

> safely achieving an altitude of 7,120 feet (2,100 meters) and speeds up to 238 knots (273 mph)

Mach 0.4 and less than cruising altitude. That said, its J85 engines are big-boy military turbojets. Given Boom plans “a total of 10-20 flights…before reaching supersonic speeds” [1] that puts earliest supersonic flight around early 2025 [a].

[1] https://boomsupersonic.com/flyby/xb1-prepares-for-first-supe...

[a] 5 months between 1 and 2 and half the time between each succeeding flight until 2x a week steady to 10