Mach cutoff
The technical aerospace term for the boomless cruise technique.
First Mentioned
9/28/2026, 4:28:23 AM
Last Updated
9/28/2026, 4:32:24 AM
Research Retrieved
9/28/2026, 4:32:24 AM
Summary
Mach cutoff is a phenomenon in high-altitude supersonic flight where the sonic boom generated at speeds slightly above Mach 1 does not reach the ground. This principle is also referred to as "Boomless cruise" by aerospace engineers and has been implemented by Boom Supersonic in their XB-1 aircraft. Boom Supersonic's founder and CEO, Blake Scholl, discussed this technology, explaining that it directs the sound waves upward, preventing them from reaching the ground, which was a key factor in the demise of the Concorde. This innovation has contributed to regulatory changes, including an executive order by the Biden Administration to end the ban on civilian supersonic flight, and the unanimous passage of the Supersonic Legalization Act in the House of Representatives.
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View on WikipediaMach cutoff
Mach cutoff is a phenomenon of high-altitude supersonic flight in which the sonic boom generated at speeds not too far above Mach 1 never reaches the ground.
Web Search Results
- Mach cutoff
Mach cutoff is a phenomenon of high-altitude supersonic flight in which the sonic boom generated at speeds not too far above Mach 1 never reaches the ground.
- Acoustical Model of Mach Cut-off (COMPLETE)
Mach cut-off is a regime of supersonic flight where an aircraft flies just slightly supersonic, perhaps Mach 1.0 to 1.15, at altitudes where the sonic boom
- A brief guide: Supersonic flight without the boom
## How can Mach cutoff prevent the boom? Mach cutoff is a physical phenomenon that causes sound waves to refract and bend back up into the atmosphere, away from the ground. This means a supersonic aircraft emitting sound waves in flight that would normally be audible as a boom on the ground can pass overhead without any noticeable effect for humans. To do this, the aircraft must adapt precisely to the prevailing conditions of the area it is overflying. Blake Scholl, CEO of Boom Supersonic, explains: “Just as a beam of light refracts when passing through a glass filled with water, sound waves will also change direction depending on which layers of air they’re traveling through and how the speed of sound varies there.” [...] “It will always work, provided you have the exact weather data, precise ground contours, an exact calculation of the maximum possible flight speed, and precise flight control,” Liebhardt says. “Today’s technologies make the combination of these capabilities achievable at reasonable effort.” The maximum possible airspeed for Mach cutoff is Mach 1.3, but depending on the weather conditions it will usually lie in a range between Mach 1.1 and 1.2 (1,358 and 1,481 km/h). Hover over the image for a bigger view ©Boom Supersonic ©Boom Supersonic xb-1-ft13_hero_2048px ©Boom Supersonic A small sensation occurred here on January 28, 2025: the Boom XB-1 single-seater test aircraft managed to break the sound barrier several times, reaching a top speed of Mach 1.18. [...] ## Can Boomless Cruise work for supersonic passenger jets? The XB-1, Boom Supersonic’s test aircraft, proved for the first time in January 2025 during test flights over the Mojave Desert that Mach cutoff, and thus Boomless Cruise, works. So far, however, this has been shown only for shorter flights over land, where the capacity for boomless flight is also crucial. The only way speeds can be increased from today’s Mach 0.94 to anywhere up to Mach 1.3 in the future is if there is no boom. “But in this speed range, air resistance and hence fuel consumption are at their highest,” Liebhardt points out.
- Perceptual characterization of Mach cut-off sonic booms
Mach cut-off refers to a set of flight conditions wherein the direct sound of a sonic boom does not reach the ground.
- What factors contribute to Mach cutoff?
Mach cutoff is a phenomenon where a shockwave bends midair, never reaching the ground. This effect is intentionally utilized with the Boom Supersonic