Boom stated that XB-1 achieved \u201cBoomless Cruise\u201d and claims that its Overture aircraft, which it says it\u2019ll bring into service in 2029, will do this, as well. Boomless Cruise was originally the goal of Aerion, a different supersonic startup that went bankrupt in 2021. It\u2019s based on Mach cutoff<\/span><\/a>, a theory which says that under the right atmospheric conditions a slow supersonic aircraft\u2014typically flying between 110% and 130% the speed of sound\u2014might not generate a sonic boom that propagates to the ground. Mach cutoff occurs when the sonic boom is reflected away from the ground due to a density difference in a warmer layer of air below the aircraft.<\/p>\n Given the novelty of the claim\u2014Boom made no mention of a goal to achieve Boomless Cruise before the flight, and the company is literally named<\/i><\/b> after the atmospheric disturbance<\/i><\/b>\u2014some scrutiny is in order. Modeling suggests that achieving Mach cutoff, which is sensitive to speed, altitude, temperature, humidity, and winds, will be tricky under real-world flight conditions.<\/p>\n Penn State researchers<\/a><\/span> found that for certain windspeeds and headings, a 1% change in cruise speed can disrupt Mach cutoff and lead to a focused boom being concentrated down on the ground. That\u2019s because a precise combination of speed, aerodynamics, aircraft mass, and atmospheric conditions<\/span><\/a> is needed to produce Mach cutoff, and that needs to be supported by precise avionics and accurate atmospheric tracking. So, without first being demonstrated under a variety of flight conditions, \u201cboomless\u201d aircraft might prove to be anything but.<\/p>\n Boom did not release any observational data about the XB-1 test flight and such data is needed to help understand how representative the conditions were that XB-1 was operating under. For example, Georgia Tech research<\/span><\/a> found that conditions of low humidity and low temperature lead to lower perceived boom on the ground. XB-1 was flown over the Mojave Desert in late January, which might be ideal for Mach cutoff.<\/p>\n To understand why Scholl may be interested in raising this issue, you need to know a bit about how the economics of supersonic flight intersect with the challenge of sonic boom. How large the market will be for Overture is hotly debated. Boom estimates that it can sell more than 1,000 aircraft to service routes over water. It’s a bold claim given that only 14 Concorde\u2014which had famously bad economics<\/span><\/a>\u2014ever entered commercial service.<\/p>\n How likely are those 1,000 planes? Well, back in 2022, we analyzed<\/span><\/a> the potential market for supersonic aircraft in 2035 using a model that MIT\u2019s Laboratory for Aviation and the Environment developed for NASA<\/span><\/a>. The model used consumer\u2019s willingness to pay for time savings to project the potential supersonic market. We estimated that there could be a market for about 235 Overture-sized supersonic aircraft in 2035, with about 70% of the potential demand in the Middle East and North America (map).<\/p>\n[\/et_pb_text][et_pb_text _builder_version=”4.27.4″ _module_preset=”default” text_text_color=”#36424A” global_colors_info=”{}”]Figure<\/strong>. Geographic breakdown of large supersonic transport operations by market, unconstrained case[\/et_pb_text][et_pb_image src=”https:\/\/theicct.org\/wp-content\/uploads\/2025\/03\/ID-336-Fig01-e1743101471203.jpg” title_text=”ID 336 Fig01″ _builder_version=”4.27.4″ _module_preset=”default” global_colors_info=”{}”][\/et_pb_image][et_pb_text _builder_version=”4.27.4″ _module_preset=”default” text_text_color=”#36424A” global_colors_info=”{}”]Source<\/em>: Rutherford et al. (2022)<\/a>[\/et_pb_text][et_pb_text _builder_version=”4.27.4″ _module_preset=”default” text_text_color=”#36424A” text_line_height=”1.8em” global_colors_info=”{}”]\n But there’s a catch. That’s an unconstrained forecast that assumes no overland flight ban. If supersonic aircraft can only operate over water, the modeled market falls by 95% to around 12 aircraft. So, right back to Concorde levels\u2014and Concorde was tried on a variety of routes before settling into its core, profitable markets of Paris to New York and London to New York.<\/p>\n This result suggests that there just aren\u2019t enough profitable routes over water to justify the more than $20 billion<\/span><\/a> needed to build a new supersonic aircraft. That\u2019s a problem for a cash-strapped startup that has raised about 4% of that capital<\/span><\/a> to date. Prior to the test flight, Boom said it had identified 600 to-be-announced routes<\/span><\/a> over water on which Overture could operate profitably. Now, Scholl is arguing that Overture will be so quiet that the United States should repeal its ban<\/span><\/a> on overland supersonic flight outright. Conveniently, that would translate to a much larger market for Overture, assuming that the public can handle any sonic boom.<\/p>\n Due to the powerful engines needed to achieve sustained supersonic flight, supersonic aircraft will always be noisier than subsonic designs. According to an upcoming UN report, supersonic aircraft are, on average, expected to emit 25% more noise per flight and about 6 times more noise per seat during takeoff and landing. Still, the Achilles\u2019 heel of supersonic aircraft is sonic boom: An aircraft operating supersonically propagates a shock wave continuously along its flight path. Sonic boom has been found to be deeply unpopular with the public<\/span><\/a> and supersonic flight is banned overland not just in the United States but in most countries. The current ban on overland supersonic flight is enforced via\u00a0a speed limit for aircraft.<\/p>\n Back to Boomless Cruise. If achieved, this would increase the market for Overture but wouldn’t be a panacea. Flying at 110% the speed of sound will save some time but also increase fuel burn, thereby increasing both fuel costs and greenhouse gas emissions. The German Aerospace Center estimated that achieving Mach cutoff speeds by a commercial supersonic airliner would increase fuel burn about 25%<\/span><\/a> compared with operating at Mach 0.95.<\/p>\n Unfortunately, with XB-1\u2019s retirement, we\u2019re unlikely to get additional data on Boomless Cruise until at least 2028, the target date for Overture\u2019s first flight. To complicate things, we won\u2019t know if Overture\u2019s full-scale, four engine turbofan design, which bears little resemblance to the smaller turbojet XB-1, can achieve Boomless Cruise until after it\u2019s built.<\/p>\n What\u2019s a careful regulator to do? A prudent approach would be to continue to support an international standard for sonic boom intensity, which the UN is aiming to deliver in 2031\u2014not much later than Overture\u2019s target entry-into-service date of 2029. That would supplant the overland speed limit with a robust and objective noise standard for supersonic aircraft. A bit of patience here to project the American public from unwanted noise pollution is preferable to hasty regulatory changes to support a product that may or may not be built, and that may or may not boom.<\/p>\n[\/et_pb_text][\/et_pb_column_inner][\/et_pb_row_inner][\/et_pb_column][et_pb_column type=”1_4″ _builder_version=”4.16″ custom_padding=”|||” global_colors_info=”{}” custom_padding__hover=”|||”][et_pb_text admin_label=”Title” module_id=”policedepartment” _builder_version=”4.22.1″ _module_preset=”680e9250-5983-47d2-b125-d1c0a97feb17″ text_text_color=”#007A94″ header_text_color=”#007A94″ custom_margin=”||||false|false” global_colors_info=”{}”]\n Dan Rutherford<\/strong><\/span> This study investigates the market potential and atmospheric impacts of two potential supersonic transport (SST) aircraft: a small jet (\u201cSmall SST\u201d) seating 15 passengers and designed for 140% the speed of sound (MN 1.4), and a larger airliner (\u201cLarge SST\u201d) seating 75 and operating at MN 1.7.[\/et_pb_text][et_pb_divider color=”#36424A” divider_weight=”2px” _builder_version=”4.21.0″ _module_preset=”default” custom_margin=”-50px|||||” global_colors_info=”{}”][\/et_pb_divider][et_pb_code admin_label=”blog post meta shortcode” _builder_version=”4.22.2″ _module_preset=”default” custom_margin=”-30px||||false|false” custom_margin_tablet=”||||false|false” custom_margin_phone=”||||false|false” custom_margin_last_edited=”on|phone” global_module=”27472″ global_colors_info=”{}”]Author<\/strong><\/span><\/h6>\n[\/et_pb_text][et_pb_text admin_label=”Author” _builder_version=”4.27.4″ _module_preset=”default” text_text_color=”#36424A” header_text_color=”#36424A” custom_margin=”||||false|false” custom_padding=”||14px||false|false” global_colors_info=”{}”]
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<\/strong><\/span><\/a><\/p>\n
\nSenior Director of Research<\/em><\/span>[\/et_pb_text][et_pb_divider color=”#36424A” divider_weight=”2px” _builder_version=”4.21.0″ _module_preset=”default” custom_margin=”-50px|||||” custom_padding=”23px|||||” global_colors_info=”{}”][\/et_pb_divider][et_pb_text admin_label=”Title” module_id=”policedepartment” _builder_version=”4.27.4″ _module_preset=”680e9250-5983-47d2-b125-d1c0a97feb17″ text_text_color=”#007A94″ header_text_color=”#007A94″ custom_margin=”-15px||||false|false” global_colors_info=”{}”]\nRelated Reading<\/strong><\/span><\/h6>\n[\/et_pb_text][et_pb_image src=”https:\/\/theicct.org\/wp-content\/uploads\/2025\/03\/Environmental-limits-on-supersonic-aircraft-in-2035-working-paper-cover.png” title_text=”Environmental limits on supersonic aircraft in 2035 working paper cover” _builder_version=”4.27.4″ _module_preset=”default” custom_padding=”|90px||||” border_width_all=”0.5px” border_color_all=”#737373″ global_colors_info=”{}”][\/et_pb_image][et_pb_text _builder_version=”4.27.4″ _module_preset=”default” text_text_color=”#36424A” custom_padding=”||71px|||” global_colors_info=”{}”]Environmental limits on supersonic aircraft in 2035<\/strong><\/a><\/p>\n