BOOM’s XB-1 passed Mach 1.122-what we learned and what we didn’t HEAR
Everybody HEARD from the media about the noteworthy flight of the Boom Supersonic’s XB-1 flight on January 28, 2025, over the Mojave Desert. What was not reported in most of these stories was the ground noise/sonic impact of the plane nicknamed “Baby Boom,” blasting through Mach 1 son the ground. Research on the internet did not find specific dBA (decibel) data or detailed reports on the shock wave impact measurements.
The first commercial flight of an SST aircraft was 1976 and sadly its last trip was 2003. The aerodynamics of these aircraft has been proven; the BOOM flight showed that its design could sustain flight above Mach 1 for several minutes of the test. Boom changed one element of the well-known Concorde’s “droop snoot”; the newer aircraft relies on video cameras in its nose to guide the pilot during take-off and landing.
An expert’s comment sets this development in context:
Bob van der Linden, curator of air transportation and special purpose aircraft at the Smithsonian’s National Air and Space Museum, said Tuesday’s successful test flight bodes well for Boom, one of the few companies competing in the supersonic passenger jet space. But he cautions that the company will face the same challenges that the Concorde encountered.
“There’s a long, long, long way to go between this test flight and building that supersonic passenger jet,” he said. “And then the other question about the supersonic transport is: Is there a market for it? Have they solved the problems that the Concorde couldn’t? That’s still up in the air.”
Still, van der Linden said, the idea endures, in part because when it comes to travel, “everyone wants to go faster, faster, faster.”
BOOM, NASA and FAA (the latter two with Congressional direction [1]) are very resolutely studying the sonic boom’s impact on the people under such flights. The two federal agencies are also involved in extensive study of how/whether regulations could be crafted to minimize/eliminate the annoyance. The library of information that they have provided is immense. Here is a very small sample of their work:
At the same time, some Members [2] have aggressively argued that FAA’s regulation of all noise should seek to protect their very active constituents.
Sonic booms here tested above Mojave are loud and explosive sounds caused by shock waves created when an aircraft exceeds the speed of sound, The data collected will help Boom Supersonic understand and mitigate the impact of sonic booms, which is crucial for the future of commercial supersonic travel.
Given that these numbers constitute highly proprietary property of BOOM, the results were not widely distributed. THOSE RESULTS DEFINE THE LIKELIHOOD OF OVERATURE’S FUTURE.
Boom Supersonic’s XB-1 Testbed Plane Breaks the Sound Barrier
Story by Rob Pegoraro
The single-seat, triple-engine testbed plane took off from California’s Mojave Air & Space Port at 8:21 a.m. Pacific and climbed above 35,000 feet before one of Boom’s flight controllers instructed test pilot TRISTAN BRANDENBURG: “You are go for acceleration to Mach 1.1.”
Brandenburg lit the afterburners of XB-1’s three GE J-85 engines and exceeded Mach 1 at 8:33 a.m. Boom’s livestream—featuring video relayed by a Starlink Mini system on a T-38 chase plane—showed the needle-nosed jet smoothly flying above the sandy valley floors and snowcapped mountains of California’s high desert.
XB-1 then slowed below Mach 1 and sped past that threshold two more times, reaching a top speed over the flight that Boom later reported as Mach 1.122. Brandenburg then concluded this 35-minute flight with a smooth landing back at Mojave.
Minutes after XB-1’s landing, CEO BLAKE SCHOLL posted his own reaction on X:
This was the first time a civil aircraft had broken the sound barrier in level flight since the final flight of the Aérospatiale/British Aerospace Concorde in 2003. (A test version of a Bombardier business jet briefly broke Mach 1 in shallow dives in 2021.)
Scholl regularly cites the failure of existing aircraft manufacturers to develop a successor to the Concorde—a money-losing supersonic airliner that operated from 1971 to 2003 by Air France and British Airways on transatlantic routes—as a reason for his founding Boom.
WGHP-TV Greensboro Boom Supersonic attempts to break the sound barrier
Boom has also found that supersonic aircraft development is harder than it might look. XB-1’s breakthrough flight was originally booked for the previous decade; back in 2016, Boom said it planned to fly XB-1 starting in 2017. Instead, this compact jet did not take off until March 2024, with Tuesday’s flight marking its 12th.
Boom has used these missions both to verify the XB-1’s airworthiness and to test subsystems like the cameras that provide a full view of runways at the XB-1’s high landing angles. That’s how Boom avoids the need for a nose cone that must hinge downward like the Concorde’s “droop snoot” to allow an unobstructed airport approach view.
XB-1 and its tests of such components as that synthetic-vision system represent an opening act for Boom’s Overture, a four-engined, delta-winged airliner that will accommodate from 64 to 80 business-class passengers at speeds up to Mach 1.7. While Denver-based Boom bought existing engines for XB-1, it has teamed up with a consortium of suppliers to develop a clean-sheet engine design for Overture that won’t require noisy, fuel-guzzling afterburners and will be able to operate on 100% sustainable aviation fuel.
UNITED AIRLINES signed an order for 15 of these jets in 2021, followed by a 20-airframe order from AMERICAN AIRLINES in 2022. JAPAN AIRLINES also inked options for 20 Overtures in 2017 that it has yet to convert into firm orders; no other airlines have placed Overture orders so far.
However, Boom has now ADVANCED MUCH FARTHER than other startups vying to build the first supersonic passenger jet since Concorde. For example, one named Aerion never advanced to the point of bending metal for its planned supersonic business jet, and a proposed joint venture between Gulfstream and the Russian manufacturer Sukhoi also went nowhere.
Building and flying a civil supersonic jet, however small, sets Boom apart from those other aspirants; whatever else the company accomplishes, it’s earned that spot in the record books.
[1] The legislation directing the FAA and NASA to advance supersonic transport (SST) is the FAA Reauthorization Act of 2024 (Public Law 118-63). Signed into law on May 16, 2024, this act reauthorizes and improves the Federal Aviation Administration (FAA) and other civil aviation programs](https://www.congress.gov/bill/118th-congress/house-bill/3935/text). It includes provisions to support the development and integration of new aviation technologies, including supersonic transport.
[2] The **National Quiet Skies Coalition (NQSC)** is actively involved in advocating for noise regulation beyond supersonic transport (SST). Their efforts focus on addressing aircraft noise pollution caused by the Federal Aviation Administration’s (FAA) NextGen program. Here are some key initiatives and proposals by the NQSC:
1. **Community Engagement**: NQSC advocates for a robust community engagement process, including public hearings for all new flight paths or changes to existing flight paths. They emphasize the importance of meaningful, two-way communication between the FAA and affected communities.
2. **Environmental Reviews**: NQSC calls for the reform of Section 213(c)(2) of the FAA Modernization and Reform Act of 2012 to reinstate environmental reviews for all new flight paths or changes to existing flight paths. They believe that bypassing environmental reviews can be materially harmful.
3. **Noise Impact Metrics**: NQSC proposes that the FAA lower the significant impact Day-Night Average Sound Level (DNL) threshold and use other variables and supplemental metrics when considering the impact of aviation noise on communities. They argue that the current 65 DNL standard is arbitrary and does not align with current health research.
