The boom-less supersonic jet race is on, following Boom Supersonic’s completion of testing earlier this year of its XB-1 test aircraft. The first successful U.S. commercial supersonic jet proved that breaking the sound barrier at Mach 1.122 (about 750 mph), was possible and the next step for the Colorado startup will be to demonstrate that its much larger commercial airliner, the Overture, can reach an even more blistering Mach 1.7 (about 1,304 mph), with a mitigated sonic boom that will never reach land.
Competitor Spike Aerospace has the same goal for its S-512 Diplomat, which has reached a new milestone in its development according to the company. The 18-passenger jet, which has a theoretical top end of Mach 1.6 (1,100 mph), is also designed to minimize the sonic boom for overland travel.
The S-512 Diplomat is designed to fly at Mach 1.6 or 1,100 mph.
Spike Aerospace
Spike said it is now completing a study that will redefine the Diplomat’s (so named because its target audience is senior government officials and UHNWI fliers) aerodynamics, cabin space, and performance. “The S-512 Diplomat is being engineered to connect cities like New York and Paris in under four hours—quietly and sustainably,” said Vik Kachoria, president and CEO of Spike Aerospace, in a statement.
Beyond being able to travel from Paris to New York in four hours, compared to eight in a conventional commercial jet, the S-512 is developing its sonic boom to allow overland flight. In 2017, Spike said that it had flown its SX1.2 demonstrator aircraft, which was a scaled version of the Diplomat to help validate the aerodynamics. Testing with a third high-speed aircraft will be completed by the end of the year. “We’ll be moving towards a supersonic demonstrator towards the end of next year,” Kachoria told Robb Report.
Spike claims its aircraft will have a much lower, more localized sonic boom than conventional supersonic jets.
Spike Aerospace
“One of the things that the media is surprised by is how long it takes to build an aircraft that we announced years ago,” said Kachoria. “It’s the nature of how complex it is to build. It needs to be fuel-efficient, have a low-sounding boom, and low environmental impact. It takes time to get everything just right.”
The announcement is well timed, coming just weeks after the White House announced a new executive order to “re-establish the United States as the undisputed leader in high-speed aviation.” President Trump ordered the FAA to take the necessary steps to repeal the prohibition of overland supersonic flight within 180 days of the June 6 order.
The world’s only commercial supersonic jet, the needle-nosed Concorde, which flew between 1976 and 2003 with over 2.5 million passengers, had prompted the supersonic overland ban in the first place. Its boom traveled for miles, breaking windows in cities and causing havoc in rural areas. The resultant supersonic ban, which slowed the Concorde to subsonic speeds, negated its edge over conventional jets. The Diplomat will cut flight time by half on some routes, while its “quiet” boom’s decibel levels will only be heard as a quiet clap from the ground.
The interior of the Ambassador will have video screens that offer soundproofing, instead of windows.
Spike Aerospace
The cabin will also be subdued, with noise levels of about 60 dBa, about the same as a dishwasher or office. Windows are being replaced with digital screens that allow exterior views through cameras, or the ability to watch movies while soaring over the Atlantic.
The S-512 Ambassador will continue to experience “ongoing changes as we pass through different iterations of the aircraft,” says Kachoria, noting that it is expected to enter service in 2031. “Our goal is to redefine long-distance travel, offering the speed of supersonic with the comfort and discretion of a private jet.”
