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Boom Tries Again To Fly Overland
The aircraft maker is behind a bill in Congress to allow for supersonic flying overland
Alon Futter
May 16, 2025
In today’s issue: Boom backs a bill to allow overland supersonic flying and Scott Kirby really really really wants to get into JFK
Overland Supersonic Flights?
🔵Legislation was introduced yesterday in Congress to allow supersonic air travel overland in the US. The Supersonic Aviation Modernization (SAM) Act, nicknamed the Boom bill, would overturn a 1973 FAA rule which bans overland supersonic flights due to concerns over sonic booms.
The bill would require the FAA to revise current regulations within 1 year of the bill passing, to allow overland supersonic flight “so long as the aircraft is operated in such a manner that no sonic boom reaches the ground in the United States.”
🔵This bill comes on the heels of Boom’s test flight earlier this year in January, when their test aircraft, the XB-1, broke the sound barrier without producing an audible boom on the ground using their Boomless Cruise technology.
However, as Dan Rutherford, a Senior Director of Research at the independent non-partisan International Council on Clean Transportation think tank points out, the results of the XB-1 test flight might be a bit misleading:
[Boomless Cruise is] based on Mach cutoff, a theory which says that under the right atmospheric conditions a slow supersonic aircraft—typically flying between 110% and 130% the speed of sound—might 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.
Given the novelty of the claim—Boom made no mention of a goal to achieve Boomless Cruise before the flight, and the company is literally named after the atmospheric disturbance—some 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.
Penn State researchers found that for certain wind speeds 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’s because a precise combination of speed, aerodynamics, aircraft mass, and atmospheric conditions 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, ‘boomless’ aircraft might prove to be anything but.
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 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.
Additionally, as flagged by the market intelligence firm Space Insider, even if the Boomless Cruise feature works as intended, it comes with trade-offs. The technology limits the aircraft’s speed to between Mach 1.1 and Mach 1.2 which would increase fuel consumption and potentially reduce the aircraft’s range (though Boom claims it won’t):
Fuel efficiency remains a tradeoff. While Overture is optimized for cruising at Mach 0.94 and Mach 1.7, flying at low supersonic speeds (Mach 1.1 to 1.2) incurs a modest drag penalty, increasing fuel consumption. However, Boom Supersonic indicates that Overture will still have sufficient range for long-haul routes, such as Vancouver to Miami.
🔵Note that Boom's efforts to get rid of the overland supersonic rule goes back to at least 2017, so this isn’t their first go round.
Given that they now have a plane that flew supersonic without producing a boom that they can point to could help. Also likely to be helpful for Boom is having President Trump in the Oval Office with Elon by his side. Of course, broader questions remain about the commercial viability of the Boom Overture—though that topic could easily warrant its own newsletter.
United Really Wants Back Into JFK
🔵Meanwhile, over in Chicago, Scott Kirby is doing everything he possibly can to get back into JFK. After seemingly buttering up President Trump (to try and head off potential future regulatory scrutiny) by publicly supporting tariffs, Kirby is now turning his attention to JetBlue. According to Aviation Week, Kirby recently reiterated his interest in getting back into JFK, stating on the sidelines of the recent Polaris reveal event that “JFK is important to us. One way or another, we need to be back in JFK. I wish United had not pulled out of JFK back in the day.”
He didn’t stop there and went on to say that JetBlue and United apparently have quite a bit in common:
I have a lot of respect for JetBlue, because they have the same core customer DNA that we have… We want lifelong customers who believe in United, who love the brand. JetBlue comes from a similar culture and DNA.
That wasn’t all though, Kirby went on to detail how JetBlue introducing TVs was something he didn’t get at first but apparently was a transformational moment in his career or something like that:
I originally thought that’s a gimmick. And then I went and flew it, and I watched people—that was a transformational moment for me. They got it right. I was wrong. They got it right. Part of my journey to being the airline CEO really started with watching how successful JetBlue was for customers.
For starters, while United has certainly been investing heavily in the customer experience under Scott Kirby, I don’t think most United customers have ever loved the United brand the same way that some JetBlue customers love the JetBlue brand. It’s just apples and oranges in my opinion,
Beyond that though, in an interview with the Airline Observer last year, Kirby was asked about his emphasis on service and product at United. One Mile At A Time had a great recap of the entire interview including Kirby’s response to that question, where he insisted he’s always been a product guy and didn’t mention JetBlue:
Kirby first worked at America West, then US Airways, and then American Airlines, before becoming CEO of United Airlines. He has historically been known for being a spreadsheet guy who is all about costs, rather than a product guy. So, what has changed?
According to Kirby, the network has changed. United’s network is so big that the airline can actually compete for everyone’s business. Meanwhile, when he worked for the smaller airlines, that wasn’t an option. He explains that throughout the mergers, the goal all along was to get bigger, so that you could then start competing on product and service.
So Is it possible that JetBlue first inspired him to care more about the customer experience and product? Sure.
But it seems more likely that Scott Kirby really wants whatever he has in the pipeline with JetBlue to go through and is doing whatever he can to get it done. I definitely can’t say I blame him. Though this could be an indicator of how tenuous this whole situation is between getting the deal done with JetBlue and then getting regulatory approval.
🎧️ THINGS I’M LISTENING TO
🔵The Air Show podcast breaks down the ultra premium arms race among the big 3 US carriers
📺️ THINGS I’M Watching
🔵Patrick Shea’s reviews Global Airline’s much hyped first flight from Glasgow to JFK
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