No business case
No engine
No Mach 2
No regulation (until at least 2028)
No societal support

I am an aviation nerd, and I wish the best for all the people involved. But this endeavour has zero percent chance of succeeding.
XB-1 prototype will be interesting to see however, and the production of a single civilian, supersonic aircraft is already a beautiful engineering feat.

cpd wrote:

MohawkWeekend wrote:

Well i guess if the availability of the Boom meant 6 or 7 Gulfstreams or BBJ's didn't make the trip over the pond, then maybe it's not so bad for the environment.

Which begs the question - might they be better off with a smaller design that carried fewer passengers and could get by with 2 engines?

And what state will the plane be in with one engine remaining, how will it fly, will it have adequate thrust to be able to safely divert elsewhere?

We are not talking about subsonic planes with hefty big engines here with massive thrust.

Four engines seems a better bet for this kind of plane.

If the Concorde lost an engine at cruise, it would descend and slow down to a subsonic speed.
Why wouldn't a twin engine supersonic jet have the same option?

RJMAZ wrote:

cpd wrote:

On afterburners, even Concorde was to get rid of those with the follow on B model, so we can probably say those won’t be necessary for any SST going forward these days.

Maybe. Afterburners need unburnt oxygen to provide extra thrust. Pure turbojets only have a small percentage gain from using afterburners. The Concorde engines only went from 140kn to 169kn when adding afterburner. Only a small 20% gain.

The proposal for the B model engines was said to have quite significant power improvements despite going without the afterburners. We can say that it was just propaganda from manufacturers or internet fan-base (just to cover off that angle), but maybe it might have worked. Alongside those engine changes were to be wing changes. Wonder if some of those proposed changes for aero could benefit Boom as well?

The sources:
https://www.heritageconcorde.com/concorde-b
http://www.concordesst.com/concordeb.html

They are not my sites and I do not endorse them or claim the accuracy of them or not. Any issues with them should be addressed to the site owners.

Mohawk: If Concorde lost an engine, it still had three others. If a twin-engine SST lost an engine, it has just one and will it be able to fly acceptably on that remaining engine? What power is necessary to make that so, even considering a smaller/lighter plane.

Edit: this is getting into technical type discussion which is off-topic.

Roll Royce pulls out of the project:

https://www.flightglobal.com/airframers ... 11.article

"Rolls-Royce has ended its involvement in a project by Boom Supersonic to develop a faster-than-sound passenger airliner, leaving unclear the powerplant options available to Boom.

“We are appreciative of Rolls-Royce’s work over the last few years, but it became clear that Rolls’ proposed engine design and legacy business model is not the best option for Overture’s future airline operators or passengers,” Boom said on 7 September."

MPadhi wrote:

...legacy business model..."

Let me translate that: We are a cool start up that don't need to uphold to realities provided by partners who are the experts and can VC our way to a solution...

JonesNL wrote:

MPadhi wrote:

...legacy business model..."

Let me translate that: We are a cool start up that don't need to uphold to realities provided by partners who are the experts and can VC our way to a solution...

Legacy business model would have been 'power by the hour' and profits going to RR and not Boom?

"Legacy business model" = "They expect us to pay for an engine, how old fashioned!"

Seems the Boom has become the first supersonic glider as per this (behind paywall)

https://aviationweek.com/air-transport/aircraft-propulsion/rolls-royce-withdraws-boom-supersonic-project

GE was offering what they called the Affinity (based on a CFM56 core) for the proposed Aerion supersonic transport. Maybe Boom can go to them and that engine?

From Boom to Bust....

Pretty hard to get a project of this scope anywhere serious without a powerplant. Good luck...

I would have suspected this from the power plant company that once powered the Concorde. I think they are saving their expertise for a new European version! And to Boom's credit, perhaps where others have failed since the Concorde, they are really trying to establish a framework by which to solicit ideas. With rejection, it's one step closer to progress made!

This whole project is a joke.

airtran737 wrote:

This whole project is a joke.

It is just another scheme to squeeze out stupid VC money from the market. Similar to Theranos…

TYWoolman wrote:

I would have suspected this from the power plant company that once powered the Concorde. I think they are saving their expertise for a new European version! And to Boom's credit, perhaps where others have failed since the Concorde, they are really trying to establish a framework by which to solicit ideas. With rejection, it's one step closer to progress made!

What????

Who on Earth is going to build an SST in the current climate change crisis, in Europe (or anywhere else for that matter). The only suspect would be Airbus and they have already stated they have no interest. It would not be a good look environmentally, and there would be no money in it to show a return on the massive investment required.
Some of Airbus' ancestors did once build an SST, with massive amounts of state aid, and a fine beast she was too! Concorde was the only SST that anybody could realistically buy a commercial ticket to fly in, and so they literally had the World market to themselves. They sold or gave away... fourteen aircraft.
I don't think Rolls-Royce see any vast profits to be made from SSTs anytime soon!

With American and United orders this is 100% done deal. So this is RR loss. There is no way this would not get delivered in time. These airlines doesn't play childs games.
And if FAA makes a fuss of this, United can just threaten to withdraw from the states, and issue would resolve immediately.

Metchalus wrote:

Boom supersonic unveil new configuration. Gone from a trijet to 4 engines

... to no engine

miegapele wrote:

With American and United orders this is 100% done deal. So this is RR loss. There is no way this would not get delivered in time. These airlines doesn't play childs games.
And if FAA makes a fuss of this, United can just threaten to withdraw from the states, and issue would resolve immediately.

Please tell us you forgot the "/s" at the end...

miegapele wrote:

With American and United orders this is 100% done deal. So this is RR loss. There is no way this would not get delivered in time. These airlines doesn't play childs games.
And if FAA makes a fuss of this, United can just threaten to withdraw from the states, and issue would resolve immediately.

Back in the day Concorde had orders from Pan-Am and TWA... how many did they actually buy (I'll give you a clue, it's a round number)?

aviatorcraig wrote:

TYWoolman wrote:

I would have suspected this from the power plant company that once powered the Concorde. I think they are saving their expertise for a new European version! And to Boom's credit, perhaps where others have failed since the Concorde, they are really trying to establish a framework by which to solicit ideas. With rejection, it's one step closer to progress made!

What????

Who on Earth is going to build an SST in the current climate change crisis, in Europe (or anywhere else for that matter). The only suspect would be Airbus and they have already stated they have no interest. It would not be a good look environmentally, and there would be no money in it to show a return on the massive investment required.
Some of Airbus' ancestors did once build an SST, with massive amounts of state aid, and a fine beast she was too! Concorde was the only SST that anybody could realistically buy a commercial ticket to fly in, and so they literally had the World market to themselves. They sold or gave away... fourteen aircraft.
I don't think Rolls-Royce see any vast profits to be made from SSTs anytime soon!

I am just trying to be optimistic. Anything for a U.S.-led endeavor is great in my book. I mean the Wright Brothers were probably thought as crazy!

miegapele wrote:

With American and United orders this is 100% done deal. So this is RR loss. There is no way this would not get delivered in time. These airlines doesn't play childs games.
And if FAA makes a fuss of this, United can just threaten to withdraw from the states, and issue would resolve immediately.

That gave me a chuckle.

With the orders by major airlines, this impasse is more doom than boom. No engine no achievable timeline commitments, eventually airline interest will be lost and not plane will be built. What other engine options are there for Boom to work with? What new redesigns and timeline will look like. Disappointing

TYWoolman wrote:

I am just trying to be optimistic. Anything for a U.S.-led endeavor is great in my book. I mean the Wright Brothers were probably thought as crazy!

Daffy Duck was thought of as crazy too. That's not really aa argument.

Come on, engines. That’s just a tiny technical detail…

Seriously, I hope this „project“ will be stopped as soon as possible. No person on this planet is so important that they have to develop a new aircraft.. oh well, and these fast spinning things underneath the wings.. just to save some three to four hours per business trip.

What's funny is the airlines 'investing' and 'ordering' aircraft from Boom, knowing full well it will always be a paper airplane. What a waste of valuable dollars by AA and UA..

If this effort does go bust fast, and AA/UA did in fact commit hard cash to this, I do wonder if both company's boards will take a serious look at the decision making here.

JonesNL wrote:

MPadhi wrote:

...legacy business model..."

Let me translate that: We are a cool start up that don't need to uphold to realities provided by partners who are the experts and can VC our way to a solution...

I would translate it a little more generously as: Boom doesn't have the capital to fund engine development themselves at this stage, and Rolls Royce isn't willing to put their money at risk without far better assurances this aircraft will not only come to fruition, but also prove out enough of a market top pay back the engine development costs.

Rolls Royce will risk share with Boeing and Airbus because they keep developing aircraft that address a proven market. That doesn't apply to Boom. They need a lot more investors willing to take a big risk.

While I like to be optimistic about this endeavor, I always recognized this was one of Boom's big risks.

I have generally maintained that getting the XB-1 flying and validating their models is an important step for convincing potential investors the project is technically viable. But even that doesn't guarantee they will get necessary level of funding. It is possible that the XB-1 performs as well or even better than expected, but investors still deem the market too uncertain.

JonesNL wrote:

It is just another scheme to squeeze out stupid VC money from the market. Similar to Theranos…

Theranos committed outright fraud by claiming to have a revolutionary technology nearly ready for FDA approval when in reality it was not even capable of being approved.

Boom is proposing to develop a product based on existing technology. Investors know there is not a product yet, and that the market is not guaranteed.

ILS28ORD wrote:

What's funny is the airlines 'investing' and 'ordering' aircraft from Boom, knowing full well it will always be a paper airplane. What a waste of valuable dollars by AA and UA..

Business executives don't typically consciously throw money away. Either they see some prospect of success, or they have an alternative motive like the marketing value of the publicity their involvement can generate.

miegapele wrote:

With American and United orders this is 100% done deal. So this is RR loss. There is no way this would not get delivered in time. These airlines doesn't play childs games.
And if FAA makes a fuss of this, United can just threaten to withdraw from the states, and issue would resolve immediately.

I’ll take delusional for $1,000 please, Alex.

TWFlyGuy wrote:

If this effort does go bust fast, and AA/UA did in fact commit hard cash to this, I do wonder if both company's boards will take a serious look at the decision making here.

We don't know how much money (probably not very much) and under what terms they can get it back (probably a lot).

They're not spending this money on airplanes, they're spending it on marketing hype and the small bet that if things work out, they're front of the pack.

I don't see a large enough market for this thing to even make if feasible to build. How many units would have to be sold to even break even? Somebody's pockets will be fat when this ponzi scheme goes belly up.

lxman1 wrote:

I don't see a large enough market for this thing to even make if feasible to build. How many units would have to be sold to even break even? Somebody's pockets will be fat when this ponzi scheme goes belly up.

I think most expect that if Boom is able to fly their prototype and then continue developing the Overture, they will be bought out by a bigger/established manufacturer to carry the project to completion. The inability to partner with an engine manufacturer is a huge blow to their prospects.

Well if Boom just went bust, United doubles down in the other direction with their $ -

"United Airlines raises bet on electric air taxis with 200 aircraft from upstart Eve"
https://www.cnbc.com/2022/09/08/united- ... t-eve.html
"he carrier has options for 200 additional aircraft, and said it will invest $15 million. The investment follows a deposit of $10 million on Archer’s electric aircraft."

$25 million for electric helicopters that carry 4 people. And they can't make 50 seaters work.

I’d feel more confident investing in the Carreidas 160 over this thing.

United’s investment in these projects seems like paying for marketing to me. Any time Business Insider or CNN run a future of aviation clickbait article, or there is an update on the development of Boom (or the air taxi) United will get a mention as being part of the program or the “future”. Major companies often spend hundreds of millions per year on advertising. Throwing $20M or so on these projects seems to have generated quite a bit of free press already. I personally assume that was the plan all along.

FGITD wrote:

I’d feel more confident investing in the Carreidas 160 over this thing.

Love the reference!

Btw, as a general point to those commenting on orders in this thread, those orders were not really orders in the conventional sense of the word. In most cases, United and others were lending their brand to give upstart companies credibility by association, in exchange for extremely favorable terms and often some equity in the company. If the project fails or succeeds, United are unaffected and stand to lose nothing. If the project succeeds, hey cool new airplane and a valuable stake in the company. They even milked some publicity out of the order, which the average Joe Public won't even remember next year.

That being said, it was easy to see the writing on the wall when Aerion folded, and they had a partnership with Airbus IIRC. VC money is drying up. Boom, and several of the e-VTOL companies, will run aground as the tide recedes.

Look ya'all...The Emperor really is neked!! And it runs on soybean oil!!

I dunno - $25 million is still a lot of money for electric helicopters and I forgot how much went to Boom .

Unless they think they can now say to Congress - "See we're trying to be green"

Unless Boom can pivot and use an existing jet engine, this project is DOA. And even then, such an engine might not be ideal.

TWFlyGuy wrote:

If this effort does go bust fast, and AA/UA did in fact commit hard cash to this, I do wonder if both company's boards will take a serious look at the decision making here.

Notably the size of the 'deposit' which with Airbus/ Boeing was never mentioned by Boom.

I suspect they got AA and UA to 'commit' by striking off lots of zeroes. And there will be an absolute ton of outs.

MPadhi wrote:

Rolls’ proposed engine design and legacy business model is not the best option

We will see who will still be there in 2 years between the old, legacy Rolls-Royce and the young, vibrant, dynamic Boom start-up.
This situation was totally expected. It's sad for the employees but I am sure they will find fulfilling employment somewhere else.

TWFlyGuy wrote:

If this effort does go bust fast, and AA/UA did in fact commit hard cash to this, I do wonder if both company's boards will take a serious look at the decision making here.

1. Any "hard cash" commitment is a rounding error to a company of AA/UA's size.
2. A "nonrefundable" deposit for an aircraft purchase still has all sorts of requirements that have to be met to make it actually nonrefundable (and unless the lawyers were completely asleep, Boom providing an airplane certified for pax transport is probably at the top of this list)
3. Even if hard cash did go to Boom, never to be seen again, the press splash was worth the spend.
4. AA and UA's board of directors have much bigger things to worry about.

LaunchDetected wrote:

MPadhi wrote:

Rolls’ proposed engine design and legacy business model is not the best option

We will see who will still be there in 2 years between the old, legacy Rolls-Royce and the young, vibrant, dynamic Boom start-up.
This situation was totally expected. It's sad for the employees but I am sure they will find fulfilling employment somewhere else.

Boom hasn't gone bust (yet), but I sure hope those employees are getting paid in cash, not Boom stock options.

The first red flag for me was when they dropped the vaunted "Concorde-beating" cruise speed from mach 2.2 to 1.7. Second was/is the massive delays in getting the XB-1 airborne. Third was completely changing the aircraft configuration ala Aerion.

Now Overture is featured fairly prominently on the Northrop-Grumman web site, including co-branding:

https://www.northropgrumman.com/supersonic-aircraft/

If NG steps in big time with the full weight of its engineering resources, Overture exits the 100% vaporware status, but then the question becomes why is NG involved? I don't know what NG can learn from Boom that it doesn't already know (my guess: nothing).

ReverseFlow wrote:

JonesNL wrote:

MPadhi wrote:

...legacy business model..."

Let me translate that: We are a cool start up that don't need to uphold to realities provided by partners who are the experts and can VC our way to a solution...

Legacy business model would have been 'power by the hour' and profits going to RR and not Boom?

It's not about profit but about investment, IMHO. RR doesn't believe in the project enough to invest the billion(s) needed to develop an engine. Power by the hour isn't legacy, on the contrary I'd say it's modern, but it comes into play only when you have already an engine to provide.

IADFCO wrote:

Now Overture is featured fairly prominently on the Northrop-Grumman web site, including co-branding:

https://www.northropgrumman.com/supersonic-aircraft/

If NG steps in big time with the full weight of its engineering resources, Overture exits the 100% vaporware status, but then the question becomes why is NG involved? I don't know what NG can learn from Boom that it doesn't already know (my guess: nothing).

Seems like it would be something to sell to the US government, basically.

TangoandCash wrote:

3. Even if hard cash did go to Boom, never to be seen again, the press splash was worth the spend.

This.
They spent money on PR, not on a future aircraft they knew they had a 0.1% chance of ever getting.

Then again, maybe Kuznetsov or Saturn could cut them a good deal on a new engine after the war is over... Thinking out of the box is what these startups are supposed to be good at, right?

United ordering Boom is like O'Leary saying he's going to charge pax to use the lavs....cheap/free publicity. I'd be shocked if UA spent more than $100k on the deposit.

IADFCO wrote:

Now Overture is featured fairly prominently on the Northrop-Grumman web site, including co-branding:

https://www.northropgrumman.com/supersonic-aircraft/

If NG steps in big time with the full weight of its engineering resources, Overture exits the 100% vaporware status, but then the question becomes why is NG involved? I don't know what NG can learn from Boom that it doesn't already know (my guess: nothing).

Unless of course Boom has got some interesting patents that NG could use?

sturmovik wrote:

FGITD wrote:

I’d feel more confident investing in the Carreidas 160 over this thing.

Love the reference!

Btw, as a general point to those commenting on orders in this thread, those orders were not really orders in the conventional sense of the word. In most cases, United and others were lending their brand to give upstart companies credibility by association, in exchange for extremely favorable terms and often some equity in the company. If the project fails or succeeds, United are unaffected and stand to lose nothing. If the project succeeds, hey cool new airplane and a valuable stake in the company. They even milked some publicity out of the order, which the average Joe Public won't even remember next year.

That being said, it was easy to see the writing on the wall when Aerion folded, and they had a partnership with Airbus IIRC. VC money is drying up. Boom, and several of the e-VTOL companies, will run aground as the tide recedes.

As far as I'd understood, Aerion was paying Airbus for their support and it wasn't Airbus paying Aerion.

https://www.flyingmag.com/aircraft-jets ... ic-bizjet/