Boom Supersonic might have snatched aviation’s holy grail after announcing on Monday that its XB-1 test plane had completed its maiden supersonic flight two weeks ago without producing a sonic boom audible on the ground. The dreaded boom smothered early commercial supersonic flight in the crib. The FAA’s 1973 ban on overland supersonic flights severely discouraged any American airliner from purchasing the canceled Boeing 2707 or Concorde.
Boom quietly placed several microphone arrays along the XB-1’s flight path. Despite the one-third-scale demonstrator hitting a top speed of Mach 1.12, the startup claims the microphone didn’t record an audible sonic boom. Boom utilized the Mach cutoff, a studied physics phenomenon where sound waves refract off the atmosphere. The manufacturer refers to the increased speed envelope created by Mach cutoff as “Boomless Cruise.” Boom Supersonic CEO Blake Scholl said in a release:
“XB-1 broke the sound barrier three times during its first supersonic flight—without an audible boom. This confirms what we’ve long believed: supersonic travel can be affordable, sustainable, and friendly to those onboard and on the ground. With this success, we’re bringing Boomless Cruise to Overture, unlocking faster travel on even more routes.”
The Boom Overture theoretically could offer 90-minute flights between New York and Los Angeles, but the airliner has to overcome a ban imposed for good reason. In 1964, the Federal Aviation Administration used U.S. Air Force jets to bombard Oklahoma City with over 1,250 sonic booms to study the impact on the population. After shattering hundreds of windows, the FAA tried to ignore most of the public complaints and issued paltry payouts. However, a class-action lawsuit was filed against the agency, which the government lost.
A few years ago, American Airlines and United Airlines placed orders for 35 Boom Overture planes. The major carriers were seemingly hedging their bets on whether Boom could deliver on its ambitious promises. “Boomless Cruise” still needs to be proven on a full-size plane. Boom estimated that Overture will receive type certification in 2029.