Boom has orders for 76 of its future supersonic passenger jets

Is there a big difference in practicality between 6 hours and 10 hours? Feels like you still lose the day to travel for the most part.

As you say, one major problem was that the aircraft skin got really hot from friction - hot enough that they had to build it out of a special titanium alloy, and paint it with heat resistant paint - but that was inadequate. Due to the heating and cooling that occurred each cycle the entire airframe would expand and contract very substantially - over repeat cycles this lead to metal fatigue, and would lead to failure but not for incessant expensive maintenance. For an idea of how much the thing expands, on the final flight of the model now at RNAS Yeovilton, the flight engineer stuck his cap between the engineering console and the bulkhead, where it remains sandwiched by pressure today.

Apart from the thermal issues, the entire craft suffered from “so cutting edge it barely works” all over, from special tyre compounds to window seals to the famous drop nose. It was an engineering marvel and nightmare, in one improbable package. It’s frankly surprising it even ever existed.

I think the major difference will be that Concorde was a space age plane built with 60’s tech, and these will Be space age planes built with space age tech.

> 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.

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

The Concord had 12-15uSv/hr [1] (2-3x a long haul flight). The lower bound and best case, workers are fine. Upper bound and European (which are stricter than American, but we're talking international flights) standards are 1mSv (whole body) or 50mSv (effective to skin) [2]. So we're between 4166hrs/yr and 66.6hrs/yr working that would be allowed.

Because it is international they'd probably go with the lowest common denominator, at 1mSv/yr dosage allowed (50mSv/yr for American radiation workers, 150 for Astronauts). And we're just talking flight, not adding the nominal background radiation, which is going to reduce the number of hours even more.

So in short, no, the extra radiation exposure at those altitudes is not minor. It has to be considered if you are going to hire people to fly your plane and attend to your passengers. Airlines already consider radiation exposure. No one wants to do massive medical payouts 30 years from now.

[1] http://aviationknowledge.wikidot.com/aviation:in-flight-heal...

[2] http://www.radioactivity.eu.com/site/pages/Doses_Limits.htm

Addendum: 1Sv in a year is a 5.5% increase of cancer over your entire lifetime. 1Sv in an hour will probably kill you.

Partial payments like that are an investment in the chance that Boom will deliver something exceptional; they avoid not being in the first wave if Boom succeeds.

It doesn't mean they think the chances of Boom producing a worthwhile product are > 50%.

The supersonic wing is also terrible at subsonic speeds, meaning it takes a terrifying amount of fuel to push it up to altitude and supersonic. Military supersonics deal with this by getting a drink from a tanker after takeoff.

What? I don't think that has anything to do with it at all, and the distinction between types of engineering seems irrelevant. I think he's pointing out that they're trying to make a profitable business without understanding the necessary costs. Given the nature of startups to overpromise and underdeliver (as that's a common tactic to help raise money), his skepticism seems reasonable to me. I see just as many criticisms of software businesses on this site (actually many more, since there are far more articles about software companies here than hardware companies).

I have very little aerospace experience so I do not claim to be an expert, and while like to see people tackling big problems eventually succeed, his points seem salient to me.

I'm also an "aerospace veteran" and have seen more projects cancelled than succeed (most recently the Lear 85). Designing a new plane is capital "H" Hard. That goes doubly so for planes that are big departures from the previous experience of the company. Cessna makes great light business jets. They are currently trying to design a line of bigger jets and are finding it very hard. Lear can't figure out how to make anything without mechanical flight controls. It takes a couple generations of design to figure things out. So a bunch of engineers from Scaled and Boeing aren't going to help. How many ex-Concorde engineers have they hired?

We should remain skeptical whenever someone says they will do great things that hasn't been done before, but immediately going to the conclusion of "it's impossible because I can't imagine how to make it work" is just plain arrogance - a true skeptic should be skeptical of his/her own judgement.

There was some computational modeling, but mostly it was old fashioned engineering: slide rules, models, and as someone else remarked, some over-engineering. The same way people built bridges 150 years ago when that was a black art.

There's a wonderful/sad picture at the Hiller museum on 101 in San Carlos. It shows the day the Boeing SST program† was shut down. In front of the mockup (which is also at the museum) are wooden workbenches with vices attached.

It made me realize that not only were they designing everything with slide rules, but people then built all the parts by hand from drawings a draftsman (not draftsperson in those days unfortunately) also produced by hand from hand-sketches and notes by and engineer. Honestly this blew my mind when I realized that the ME-262, SR-71 and LEM were produced in the same way.

And I should have known: at MIT I took Unified the last year (1983) that the practical work was done entirely on old WW II surplus machine tools. In the next room, not yet unpacked, were early CAD systems.

† I still wonder if Boeing was every really serious about passenger SST.

You make some good points, but BA received their Concordes for free. It's easy to turn a profit with a 150 million pound gift. Air France did not have it as easy. Boom's customers will not be getting their planes for free. And a 50% efficiency saving does not translate into 75% cheaper tickets. And my experience is that claimed maintenance savings are never as good as promised, and that goes doubly so for the "A" variant of any plane.

FWIW Concorde ticket prices were so high because they were expected to be so high. By clients. BA raised their prices significantly in the early 80s to match what customers perceived the prices would be:

> Market research had revealed that many of Concorde's existing business customers had their tickets purchased by their employers, and thought the cost of a journey on Concorde was more expensive than it actually was; thus ticket prices were progressively raised to match these perceptions.

London is introducing a new "T-charge" today whereby owners of older and more polluting vehicles have to pay an extra fee to enter central London.

I suspect that 'a jet that generates double the pollution so that rich people can get to their destination faster' is dead on arrival.

https://en.wikipedia.org/wiki/Scandinavian_Airlines_Flight_7...

Automation has made flying safer, as pointed out in the article you link, but we have entered a new era where humans can no longer trust computers nor fully take over control.