Denver-based Boom Technology's XB-1 demonstrator plane hit Mach 1.122 — 750 mph. It's the first independently developed ...

However, the jet was criticized for its inefficiency. Compared to a Boeing 747, the delta-wing Concorde guzzled four times as much fuel and carried only one-fifth as many passengers — around 100.

While the prospect of commercial supersonic flights is probably at least a decade from becoming a reality due to Boom ...

The groundbreaking jet made its final flight on Nov. 26, 2003. However, the jet was criticized for its inefficiency. Compared to a Boeing 747, the delta-wing Concorde guzzled four times as much fuel ...