BOOM’s XB-1’s sonic impact good, but a Trump EO’s shortcut may delay overseas sales
On January 29, 2025 it was reported here that BOOM’s XB-1 passed Mach 1.122-what we learned and what we didn’t HEAR – JDA Journal. The flight was praised as a historic repeat of the first supersonic flight on October 14, 1947. U.S. Air Force Captain Chuck Yeager piloted the Bell X-1 aircraft, nicknamed “Glamorous Glennis.” What was exceptional about the BOOM flight was its
promise to fly supersonic without the sonic boom that negatively impacts those on the ground. This early report did not include the results of the measurements of the effect on the folks under the flight path.
The article below announces that the flight generated no audible measurements. The Fox News broadcast also included a thorough explanation of what scientists know and have known to be “MACH CUTOFF.” Basically, under a combination of altitude, speed, and other atmospheric conditions, the waves generated by breaking the sound barrier are deflected or dissipated by the atmosphere.
The Concorde SSTs did not have the onboard technologies to avail themselves of this atmospheric refraction. The sonic booms associated with their max speeds created strong opposition from the public. The regulators placed limitations on the SSTs only allowing them to exceed MACH 1 only over water. These restrictions and some high operating costs led to the demise of the Concordes in October 24, 2003.
With his announcement of the XB-1’s successful demonstration of the MACH CUTOFF, Boom Supersonics’ founder and CEO Blake Scholl asked via X “THAT THE PRESIDENT COULD ISSUE AN EXECUTIVE ORDER DIRECTING THE FAA TO ALLOW FOR SUPERSONIC FLIGHT OVER LAND AS LONG AS THERE IS NOT AN AUDIBLE SONIC BOOM.”
SURPRISE on 02/11/2025 :
In response to an X post by Boom Supersonic founder Blake Scholl, the SpaceX founder said that Trump’s new administration plans to “get rid of all regulations that make no sense, like this one,” referring to 14CFR 91.817, which states that “no person may operate a civil aircraft in the United States at a true flight Mach number greater than 1.”
A Presidential Executive Order may get the result sought by Mr. Scholl, but it will diminish the ability of the Administrator to perform the safety duties of the office. It seems as though the data which BOOM developed on 01/29/2025 and again on 02/11/2025 would provide the proof needed for the FAA to quickly amend 14 CFR § 91.817. More significantly for the US aviation safety organization to convince other CAAs that the BOOM technology meets international safety and environmental standards. Without such proof BOOM’s global market aspirations will be delayed.
Boom Supersonic says XB-1 aircraft flew over Mach 1 with no audible sonic boom on the ground below
02/10/2025
BOOM SUPERSONIC, a company working to develop passenger aircraft capable of traveling faster than the speed of sound, announced that its planes will be able to fly at supersonic speeds WITHOUT THE SONIC BOOM BEING AUDIBLE ON THE GROUND BELOW. The company says that it accomplished the feat during a test flight of its XB-1 aircraft late last month.
“During its historic first supersonic flight on January 28, 2025, Boom’s demonstrator aircraft, XB-1, broke the sound barrier three times without generating a sonic boom that reached the ground, demonstrating that quiet supersonic travel is possible,” the aviation company noted in a press release on Monday. “Specialized microphone arrays placed in strategic locations under the flight path confirmed that sonic booms did not reach the ground as XB-1 flew at a top speed of Mach 1.12.
Fast flights sans the sonic boom sound on the ground are possible due to the concept known as “MACH CUTOFF,” Boom Supersonic’s founder and CEO Blake Scholl explained.
In a thread on X, Scholl said, “It’s actually well-known physics called MACH CUTOFF. When an aircraft breaks the sound barrier at a sufficiently high altitude, the boom refracts in the atmosphere and curls upward without reaching the ground. It makes a U-turn before anyone can hear it.”
“Just as a light ray bends as it goes through a glass of water, sound rays bend as they go through media with varying speeds of sound. Speed of sound varies with temperature… and temperature varies with altitude. With colder temperatures aloft, sonic booms bend upward,” he noted.
“This means that sonic booms can make a U-turn in the atmosphere without ever touching the ground. The height of the U varies—with the aircraft speed, with atmospheric temperature gradient, and with winds. So making this work requires tech not available in Concorde’s era,” he indicated on X.
Scholl suggested that this could be possible with speeds as fast as Mach 1.3.“Top speed for Boomless Cruise varies with weather and can be as high as Mach 1.3—but will usually be between Mach 1.1 and Mach 1.2. At higher speeds, the geometry doesn’t work, and a boom will still reach the ground,” he tweeted. Scholl told Fox News Digital during an interview on Monday that the ability to consistently avoid audible sonic booms will be “very reliable.”
While supersonic flight over land is not currently permitted, Scholl hopes that will change.
“Currently, all civil aircraft flights are prohibited from operating above Mach one speeds over land in the United States. Aircraft companies seeking to advance the testing of civil supersonic aircraft require a special flight authorization,” according to the Federal Aviation Administration.
Scholl said that the president could issue an executive order directing the FAA to allow for supersonic flight over land as long as there is not an audible sonic boom.
Though frequent fliers may find the prospect of dramatically slashing their travel times exciting, they will have to keep waiting as the company works to develop its Overture passenger aircraft.
Scholl said the company will begin building the first Overture aircraft at its factory in North Carolina in around 18 months and the first one will “roll off the line” in around three years, with the goal for passengers to be able to buy tickets aboard the supersonic planes by the end of 2029.
“Overture’s order book stands at 130 aircraft, including orders and pre-orders from American Airlines, United Airlines, and Japan Airlines. Boom is working with Northrop Grumman for government and defense applications of Overture,” the company noted in its press release.
The company’s XB-1 aircraft is conducting its second supersonic test flight today.
