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Comment by pixl97 | Hacker News Reader

No one is flying supersonic over land at least in the US. Going over the oceans is where it would happen.

That's because there was a dumb ban in place, with an executive order [1] and bill that just cleared to lift it [2]. The ban was "dumb" because it's indirect, trying to control loudness by limiting speed, which is an incorrect [3] assumption based on old tech of the time.

[1] https://www.whitehouse.gov/presidential-actions/2025/06/lead...

[2] https://www.govtech.com/transportation/bill-authorizing-supe...

[3] https://boomsupersonic.com/boomless-cruise

The ban was specifically to hinder the Concorde, so it made sense to base it on supersonic flight rather than noise in case the Concorde would have managed to mitigate its noise level one way or another.

Reference? There was an "Anti-Cordorde Project" [1] but its purpose was to ban all supersonic flight, for environmental reasons. Concorde being the only in regular service, thus the targeted name.

[1] https://en.wikipedia.org/wiki/Anti-Concorde_Project

I don't trust it. They will get approval and then when sonic booms disrupt nature from coast to coast they will say "it's just because the weather/it only affects a small number of people/the 3rd party contractor who supplied the data was wrong, they are gone now/the benefits outweigh the downside/think of all the jobs". Basically they'll say anything other than "oopsie we were wrong, no transonic flight for you".

Bear in mind that despite carefully worded PR, "Boomless cruise" is 1) not guaranteed to be "boomless" 2) is much slower than would make all the rigmarole of supersonic flight worth it even when it is "boomless".

I'm not sure how that matters. A sonic boom in a phenomenon not an SPL reading. The goal should be to have a direct metric for how loud/how much it disturbs things is. "boomless" and "speed" aren't a direct metric. If someone makes a sonic boom that's quiet enough, that's fine too.

I'm not sure how to respond to this because it's really just ignoring what I said entirely (maybe due to a lack of context?) and instead responding to things that I didn't say. "Supersonic for supersonic's sake" makes no sense.

Wasn't that just an act of spite because Europeans were the first to deliver commercial supersonic flight? I'm sure it will be reversed if the US becomes the leader.

The author of this slop seems to believe Boom's pitch deck that they can use AI to only boom into space and thus do supersonic overland. The only thing his article suggests though is that you could do it under certain atmospheric conditions, and more likely this is just cover for "do it all the time and blame the computer when we rattle peoples' windows".

Saying it requires or uses AI seems to be just... modern marketing bullshit. But the technique itself seems sound enough. NASA studied the phenomenon already: https://ntrs.nasa.gov/api/citations/20160007348/downloads/20...

But if you actually, you know, read that NASA study, it mentions that the maximum practical speed (from theory) for “boomless” flights is less than Mach 1.3, and they only demonstrated “boomless” flights at Mach 1.1.

That would result in far, far less time savings that what is posited by the commentary on HN. Compared to Cessna Citation X, for example, that would reduce time in the air by just 15%.

Total travel time savings would be even less… so a private Citation X at M0.95 would still be beat a commercial M1.1 flight in door to door travel time.

Right but Mach 1.0-1.3 is all that "Boom Supersonic" is claiming to hit, though, so the paper is in line with the marketing pitch. The speed advantage of "up to Mach 1.3" might not be worthwhile, no, but that's orthogonal to the claims of "boomless" supersonic.

Now the article randomly pulls Mach 1.7 out of seemingly nowhere, and I have no idea where that came from or how that is justified. But the company isn't making that claim as far as I can tell ( https://boomsupersonic.com/boomless-cruise the "FAQ" section even specifically says: "Boomless Cruise is possible at speeds up to Mach 1.3, with typical speed between Mach 1.1 and 1.2.")

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