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Comment by sharpercoder | Hacker News Reader

I wonder about noise concerns. The concorde only reached supersonic flight on the ocean, not on land because of the sonic boom.

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Supersonic flight doesn't have to be as noisy as the Concorde was. Remember, Concorde was designed in the mid 1960s (over 50 years ago) with minimal use of computer modeling. We've had decades of advances in computer modeling and processing power so it's now possible to design planes with much quieter sonic booms. On the order of 100x to 1000x quieter.

Here's one plane being developed by Lockheed Martin, "designed to create a sonic boom only 1% as strong as that generated by the Concorde." Though, this plane is smaller than the Concorde so it's boom should naturally be smaller, however the idea still applies to other supersonic planes.

https://en.wikipedia.org/wiki/SAI_Quiet_Supersonic_Transport

Lockheed Martin claims their design only generates 60 A-weighted decibels of noise. This is compared to the Concorde’s sound at cruising altitude of about 90 A-weighted decibels. 60 decibels would put it at about the sound of a normal conversation. That would make it quiet and non-intrusive enough for overland flights.

http://lockheedmartin.com/us/innovations/072016-webt-superso...

In USA, all supersonic flight over land by civil aircraft has been prohibited by regulation introduced in March 1973. [0] Without changes in the legislation, airlines can only offer supersonic flights over the ocean.

[0] https://www.faa.gov/about/office_org/headquarters_offices/ap...

Not necessarily a dealbreaker. Concorde did ok with British airways flying out of NY. Assuming the rules don’t change there are plenty of viable routes out of Houston, NY, and SFO.

I never said it's a deal breaker, just that it's not possible to fly supersonic over the land.

I do hope that the Boom team will be able to deliver a viable service for benefit us all. Would love nothing more than to travel faster.

Concorde was a British-French aircaft, so it was allowed to fly over the UK. If it had been American, it would have been banned instantly. It was horrifically noisy.

> It was horrifically noisy.

I saw it land/take off a handful of times as a kid. The noise was unlike anything else I've ever experienced - you could hear it many kilometers away and up close (on the airport boundary) you'd feel every internal cavity vibrating when it departed. As a child it was marvellous!

Boom (and others) are working to get those rules changed to limit maximum noise rather than maximum speed. If they can figure out how to make Mach 2.0 as quiet as Mach 0.85 to people in the flight path, go for it:

http://aviationweek.com/bca/legislation-open-door-us-superso...

It's pretty much a solved problem for the last two decades. You can use the shape of the wing and fuselage to broaden sound wave, and go supersonic at an angle of attack that sends the brunt of the transition sonic boom above the horizon or at least on a long trajectory to the ground.

And a lot of the push back was NIH because boing bailed on its SST it would be interesting to find out who bankrolled the anti concord activits.

And Boom is a US company :-)

Presumably they’d only do trans-oceanic flights.

Their FAQ says:

> Boom's airliner is designed to maximize efficiency while producing a “boom” at least 30 times quieter than Concorde's.

So I don't think they have that presumption.

Dubai or Singapore to Heathrow or CDG are over land and still have plenty of potential.

Trans-Pacific routes could also use supersonic planes, since longer distances mean even more time savings (Tokyo to Los Angeles in 5 hours instead of 10) and there's virtually nobody underneath to complain about the noise.

The look like they’re doing ocean only flights. At 3:15 in the video they show a map with about 500 routes.

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