[namirez]

Sadly Boom is doomed and it’s been a writing on the wall all along. They never had a good engine option. The military engines are not safe enough and developing a new civilian engine makes sense only if you make hundreds of them.

Their net-zero emission claim is also bogus. Their pricing model doesn’t make much sense either unless they’re willing to lose money for a decade or so. There is not much innovation in aerodynamics and shock wave shaping either. Their only innovation compared to Concorde is the use of composite materials which is just not enough to hit their targets.

[wahern]

More than hundreds, perhaps thousands, or at least hundreds in a much shorter time frame than in previous eras. Rolls Royce's firm rejection of requests to develop a new engine is the most immediate reason the A380 was canceled. IIRC, Emirates and Airbus decided to kill the A380 within days of the Rolls Royce announcement, and in any event Emirates was clear that it was Rolls Royce's decision that forced their hand. Emirates alone would have guaranteed to purchase hundreds of such engines, considering there were 4 on each plane, but in the end Rolls Royce simply had no appetite for new development of any kind, though presumably they were entertaining the idea for quite some time beforehand.

According to Emirates and some other analysts, and contrary to popular narrative, the A380's biggest competitive handicap was the generation of engines, not the mere fact they had 4 instead of 2. The engines were nearly a full generation behind when the A380 debuted, and the gap only grew over time. Engines on a 4-engine plane are smaller, meaning less drag; have narrower power bands, running more optimally at all stages of flight; and have lower maintenance costs, even at twice the number, as they're both less stressed and subject to longer MTBF requirements--losing 1 of 4 engines is much less of a problem than 1 of 2. All considered a 4-engine configuration might still be nominally less fuel efficient, but the difference was negligible given these countering dynamics and in the opinion of some more than made up by other factors favoring the A380. The hub vs point-to-point model disfavored larger planes, but the air travel market was growing and in absolute terms so too was the potential A380 market. But the efficiency gap between engine generations was simply too large to overcome.

[Melatonic]

Could be that they were hoping to get bought out and had made some actual improvements though no?

I would imagine that a plane using new advances in material sciences for the outer skin (maybe something like Quasi Crystals) might have significant advantages over an older design like the Concorde. Heat must be a big issue at those speeds.

[namirez]

I don’t know much about their long term business strategy but what bothers me is that they’re vague about how they intend to achieve the flight mission objectives. This is very different than SpaceX which focused on reusable rockets and landing them.

As for materials, the main advantage of composites is the strength to weight ratio but they’re more challenging to work with compared to aluminum and titanium. Heat is one aspect but there are many more challenges. It’s been done though for example B787 and A350 are mostly composite. So Boom has a genuine advance here over Concorde. But supersonic flight is inherently fuel inefficient due to wave drag so the economy doesn’t make sense.

[thetinguy]

>Their only innovation compared to Concorde is the use of composite materials which is just not enough to hit their targets.

There’s been 50 years of commercial aviation development since the Concorde. Composite materials is only one thing on a list of differences between Concorde and boom.

[phlipski]

Luckily for Boom there is a supersonic engine startup in the YC S22 batch!

https://www.ycombinator.com/companies/velontra

[namirez]

Good luck to them but it sounds like an expensive solution. I’d be super excited to see a scramjet startup but scramjet is always decades away like the fusion reactor.