Boom Supersonic is Finally Supersonic
On Tuesday, January 29th, 2025, thirty-five thousand feet above the Mojave Desert, Boom Supersonic broke the sound barrier. Boom is an aviation startup seeking to revive supersonic commercial air travel. January’s flight, in Boom’s XB-1 demonstrator — a one-third scale aircraft of Boom’s ultimate commercial airliner the “Overture” — is proof Boom has the technical knowhow and manufacturing ability to break the sound barrier.
Founder and CEO Blake Scholl began his career as a software developer at Amazon, before eventually cofounding ecommerce app Kima Labs, which was sold to Groupon in 2012. After two years at Groupon, Scholl founded Boom in 2014. Since then, Boom’s mission is “to make the world dramatically more accessible through flights that are faster, more affordable, more convenient, and more sustainable.”
January’s flight demonstration brings Boom closer to reviving supersonic travel. Whether that progress is one small step, or a giant leap, remains to be seen. Boom faces economic, technical, and regulatory headwinds.
First, and arguably most significantly, the engines Boom needs to propel the Overture to Mach 1.7 do not yet exist. Boom advertises that the Symphony will be capable of flying at Mach 1.7, with no afterburners, and be capable of burning 100% sustainable aviation fuel (SAF). While advanced jet engine design is far beyond the scope of this article, simply put, these three goals, particularly in tandem, are an incredible challenge.
Flight above the speed of sound, without the use of afterburners, is called supercruise. The Concorde could achieve supercruise, but still relied on afterburners for takeoff. Similarly, the F-22 Raptor, the only aircraft currently in the US Military’s roster capable of supercruise, also uses afterburners for certain portions of flight. Supersonic flight exerts far greater drag on an aircraft than subsonic flight. Greater drag means greater fuel burn. The Concorde, Boom’s only real point of comparison in the industry, saw a fuel burn rate of approximately 16.7 liters per 100 kilometers, per passenger (16.7 L/100 km/passenger). Modern passenger planes such as the Boeing 787 or Airbus A350 achieve less than 3 L/100km/passenger.
Further, the goal of using SAF is an additional obstacle: to address the lack of fuel efficiency compared to contemporary airliners, Boom will use SAF, which is sustainably produced, leading to an arguably neutral carbon footprint despite emitting the same level of greenhouse gas as standard fossil fuel. The argument against this, however, asks why, when SAF is still a scarce and expensive resource, should it be used to shuttle 65 Boom passengers across the Atlantic, if the same amount of fuel could carry 260 in conventional aircraft?
Finally, Boom faces two major regulatory hurdles: first, FAA certification of a new commercial aircraft is lengthy and expensive, particularly for “clean sheet” designs such as the Overture. Following Boeing’s 737 Max crashes, FAA certification will likely be even more rigorous, as a 2023 notice of proposed rulemaking suggests. Second, supersonic flight over land has been banned in the US since 1973. Boom knows this, and advertises supersonic routes only over the ocean, much like the Concorde did. Over land, Boom advertises itself as faster than the rest, but still not supersonic. Supersonic flight over land would drastically shorten travel from coast to coast, and open a new, potentially large, market to Boom and its airline partners.
January’s flight demonstration brings Boom closer to reviving supersonic travel. Whether that progress is one small step, or a giant leap, remains to be seen.
The impetus for the supersonic ban was a series of tests in the 1960s to gauge the public’s appetite for sonic booms. The government was eagerly pursuing supersonic flight, and needed to understand the potential impact to populated areas. As a point of trivia, Boeing was the recipient of federal funds to develop a supersonic transport aircraft in the 1960s. Such excitement surrounded the project that Seattle’s new basketball team took inspiration, becoming the Seattle SuperSonics. Faced with economic and technological challenges that may not be unfamiliar to Boom, plus the overland boom ban, Boeing never completed its supersonic airliner.
Fortunately for Boom and any passengers eager to travel faster than sound, NASA and Lockheed Martin are working to develop an aircraft design that results in a sonic “thump” instead of a boom — hopefully resulting in far less disruption to the public under the jet’s path at as it crosses the sounds barrier. NASA and Lockheed, with the X-59 aircraft, aim to demonstrate that the sound barrier can be crossed in a far less disruptive manner through cutting edge aircraft design. NASA’s goal is to provide data to the FAA that over land sonic booms can be reduced to a far gentler “thump” and that therefore the half-century old ban should be overturned. To Boom, this regulatory revision would be a boon. If NASA is successful, Boom, or other entrants to the supersonic transport space, can adopt the new aerodynamic designs into future aircraft, opening up new routes for a new generation of supersonic aircraft.
While Boom faces hurdles from the FAA, economy, and laws of physics, this author remains hopeful, if not optimistic. The New York Times famously, and improvidently, predicted man wouldn’t fly for another “one million to ten million years” just two months before the Wright Brothers first took to the sky in December of 1903. Hopefully, with Boom, we are on the cusp of another great leap forward aviation.
Benjamin D. Spain
Ben is an aviation and technology enthusiast. Prior to law school, Ben worked in the software industry, and holds a (now expired) private pilot’s license. Ben is a second-year student at UNC School of Law. He holds a BS in business from Tulane University.