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dredgy
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Re: Will Boom Supersonic's overture be cancelled?

Sun Sep 18, 2022 10:55 am

Doubt it will be shelved too soon, though medium to long term all depends on if they can find an engine.
They should have enough money to putter along for a while until it’s clear either way on the technical viability of bringing the product to market.
 
aeropix
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Re: Will Boom Supersonic's overture be cancelled?

Sun Sep 18, 2022 11:22 am

I don't understand all the hubbub about the engines. We have currently in-production military supersonic engines. Surely one of those, especially the ones installed on existing long-range supersonic bombers - could be adapted to commercial use. It's like they're looking for an excuse to wind down this project gracefully.

On a side note whatever happened to their fighter-jet looking supersonic demonstrator? Nobody talks about that any more.
 
sibibom
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Re: Will Boom Supersonic's overture be cancelled?

Sun Sep 18, 2022 11:43 am

The sad truth is a project of such scale are fraught with risks and uncertainities, a governmental bank rolling will be required. I doubt a private company will ever succeed let alone a startup.
 
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Boeing757100
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Re: Will Boom Supersonic's overture be cancelled?

Sun Sep 18, 2022 12:04 pm

aeropix wrote:
I don't understand all the hubbub about the engines. We have currently in-production military supersonic engines. Surely one of those, especially the ones installed on existing long-range supersonic bombers - could be adapted to commercial use. It's like they're looking for an excuse to wind down this project gracefully.

On a side note whatever happened to their fighter-jet looking supersonic demonstrator? Nobody talks about that any more.

I am no economist, but that for sure has gotta be hella expensive to adapt fighter jet engines for commercial use. Don't know if Boom will be willing and able to pay that.
 
GDB
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Re: Will Boom Supersonic's overture be cancelled?

Sun Sep 18, 2022 12:05 pm

aeropix wrote:
I don't understand all the hubbub about the engines. We have currently in-production military supersonic engines. Surely one of those, especially the ones installed on existing long-range supersonic bombers - could be adapted to commercial use. It's like they're looking for an excuse to wind down this project gracefully.

On a side note whatever happened to their fighter-jet looking supersonic demonstrator? Nobody talks about that any more.


'Existing military engines', or rather an extremely heavily developed version of one, was used in the only technically successful SST.
And at 50,000 ft+ and Mach 2, it was very efficient, our RR rep in BA Concorde Tech reckoned for that it could not be beaten today, (speaking in the late 1990’s).
Problem is/was the rest of the flight envelope, the acceptability of today's noise and emission requirements, fuel consumption at lower speeds.
Until a powerplant that can combine the efficiency of the Olympus 593 at cruising speed/altitude and the features of high bypass ration turbofan for the rest of the envelope, you are frankly stuffed. It won’t fly politically, therefore economically, so certainly not technically.
And Boom's silence/refusal to answer this aside from vague babbling about 'sustainable' fuels speaks volumes.
Which RR and GE (who would have powered the B2707) have heard.

No one has tried to develop such an engine, while a smaller, slower, SST on the face of it eases those problems, actually, it doesn’t.
RR pulling out should be a red flag, after all they, with at the time Snecma, are/were the only ones to have successfully powered long term, a SST.
Last edited by GDB on Sun Sep 18, 2022 12:18 pm, edited 1 time in total.
 
m66
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Re: Will Boom Supersonic's overture be cancelled?

Sun Sep 18, 2022 12:15 pm

GDB wrote:
aeropix wrote:
I don't understand all the hubbub about the engines. We have currently in-production military supersonic engines. Surely one of those, especially the ones installed on existing long-range supersonic bombers - could be adapted to commercial use. It's like they're looking for an excuse to wind down this project gracefully.

On a side note whatever happened to their fighter-jet looking supersonic demonstrator? Nobody talks about that any more.


'Existing military engines', or rather an extremely heavily developed version of one, was used in the only technically successful SST.
And at 50,000 ft+ and Mach 2, it was very efficient, our RR rep in BA Concorde Tech reckoned for that it could not be beaten.
Problem is/was the rest of the flight envelope, the acceptability of today's noise and emission requirements.
Until a powerplant that can combine the efficiency of the Olympus 593 at cruising speed/altitude and the features of high bypass ration turbofan for the rest of the envelope, you are frankly stuffed.
And Boom's silence/refusal to answer this aside from vague babbling about 'sustainable' fuels speaks volumes.
Which RR and GE (who would have powered the B2707) have heard.

https://www.concordesst.com/powerplant.html


But even then it basically ruined the project financially.
 
GDB
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Re: Will Boom Supersonic's overture be cancelled?

Sun Sep 18, 2022 12:25 pm

m66 wrote:
GDB wrote:
aeropix wrote:
I don't understand all the hubbub about the engines. We have currently in-production military supersonic engines. Surely one of those, especially the ones installed on existing long-range supersonic bombers - could be adapted to commercial use. It's like they're looking for an excuse to wind down this project gracefully.

On a side note whatever happened to their fighter-jet looking supersonic demonstrator? Nobody talks about that any more.


'Existing military engines', or rather an extremely heavily developed version of one, was used in the only technically successful SST.
And at 50,000 ft+ and Mach 2, it was very efficient, our RR rep in BA Concorde Tech reckoned for that it could not be beaten.
Problem is/was the rest of the flight envelope, the acceptability of today's noise and emission requirements.
Until a powerplant that can combine the efficiency of the Olympus 593 at cruising speed/altitude and the features of high bypass ration turbofan for the rest of the envelope, you are frankly stuffed.
And Boom's silence/refusal to answer this aside from vague babbling about 'sustainable' fuels speaks volumes.
Which RR and GE (who would have powered the B2707) have heard.

https://www.concordesst.com/powerplant.html


But even then it basically ruined the project financially.


While they wanted to sell as many as possible naturally, it was a bi national high tech program, which in turn spurred the US to do the same, especially after the USSR were building one too.
What ruined it financially was in part the issue of the boom but mostly the massive hikes in the price of oil after the 1973 Arab/Israeli war, which battered the whole sector, including Boeing, (this was two years after Congress pulled the plug on the US SST program).
That change, alongside the noise and general environmental issues reshaped the industry, to this day.
Computer graphics and VC money won’t change that.
 
Noshow
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Re: Will Boom Supersonic's overture be cancelled?

Sun Sep 18, 2022 12:35 pm

If the engine selection would be easy they would have picked one and announced one. But they don't have after so many years. It makes you wonder what those performance figures are based on and why basic stuff like cruise speed and number of engines keeps changing at this late point in time?
 
2175301
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Re: Will Boom Supersonic's overture be cancelled?

Sun Sep 18, 2022 6:50 pm

SYD330 wrote:
Anyone have any useful information regarding this supersonic project whether it will still proceed ahead or shelved soon?


I believe it will be kept alive for now; but, unless they are willing to put some real money into engine development it's going nowhere.

My understanding is that the original 3 engine concept was based on a variant of the Prat & Whitney (P&W) F119 engine developed for the F22 Raptor. It has super-cruise to sustain supersonic flight without afterburners.

The Boom Engine Program Manager had worked on the F119 program prior to moving to Boom.

I heard from a P&W insider some months ago that Boom had been negotiating with P&W for a civilized version based on the F119 (remove the variable thrust nozzles, etc) which broke down when P&W essentially said that we will develop and certify the proposed engine if you pay us up front to do it (I heard that was about $1 Billion). Boom continued talks but that eventually died out.

Since then we have a new 4 engine concept based on other company engines, and now RR has pulled out for what I believe is essentially the same reason: They did not want to invest the development and certification money for an engine with likely limited sales opportunities (which would pay back the R&D cost).

I suspect GE's and anyone else's answer will be about the same: Provide the money to develop and certify the engine...and we will build what you want.

So Boom is facing a decision point. If you are going to make a real attempt at this - you need to raise in the range of $1 Billion (or more) to provide to any of several engine manufacturers to develop and certify the needed engine based on an existing engine core.

I note that the new hot Military engines are all developed under a process where the mfr is guaranteeing payment of the R&D of those engines. Boom (or anyone else trying to enter the SSJ market) will in my opinion have to do that same.

Balls in Boom's court. Lets see what they do.
 
Noshow
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Re: Boom Supersonic new configuration.

Sun Sep 18, 2022 6:58 pm

They must have known before how this works? Especially with the F119 specialist in the team.
I heard they originally had hoped for some specific military engine that cannot be made available to commercial use ever for security or military funding legal reasons or similar.
 
Metchalus
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Re: Will Boom Supersonic's overture be cancelled?

Mon Sep 19, 2022 9:18 am

SYD330 wrote:
Anyone have any useful information regarding this supersonic project whether it will still proceed ahead or shelved soon?


Officially it's proceeding.

Unofficially it's not looking good.
 
Sancho99504
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Re: Boom Supersonic new configuration.

Mon Sep 19, 2022 4:52 pm

Supersonic jet startup Boom's future is in doubt after every major jet-engine maker refuses to help

https://www.businessinsider.com/engine- ... 2022-9?amp
 
ReverseFlow
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Re: Boom Supersonic new configuration.

Mon Sep 19, 2022 5:50 pm

Sancho99504 wrote:
Supersonic jet startup Boom's future is in doubt after every major jet-engine maker refuses to help

https://www.businessinsider.com/engine- ... 2022-9?amp
"Boom Supersonic may be forced to make its own engine for its ultra-fast Overture jet."

We've got Lightsaber saying how hard it is/will be for Russia/China to build efficient engines in the Russia threads and here a company without any experience is wanting to build their own?
How many billions more would they need??
 
bluecrew
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Re: Boom Supersonic new configuration.

Mon Sep 19, 2022 7:06 pm

ReverseFlow wrote:
Sancho99504 wrote:
Supersonic jet startup Boom's future is in doubt after every major jet-engine maker refuses to help

https://www.businessinsider.com/engine- ... 2022-9?amp
"Boom Supersonic may be forced to make its own engine for its ultra-fast Overture jet."

We've got Lightsaber saying how hard it is/will be for Russia/China to build efficient engines in the Russia threads and here a company without any experience is wanting to build their own?
How many billions more would they need??

That's just not viable. If they wanna engineer what they're looking for, from scratch, and in-house and all they have today is the one expert from the F119 program? They'll run out of cash years before it even does a static runup test.

http://www.youtube.com/watch?v=u_aLESDql1U

I'm not sure how much money they have, but I'd really doubt they could hang on for 10 years while they try developing their first engine. It would also make spare parts expensive, with RR/PW/GE/CFM, you're relying on economy of scale and part commonality to make the engine viable long-term. With the hypothetical "Engine go BOOM!" they'd also now be an engine manufacturer. That's gonna be a whole new ecosystem of production lines.

If I had any money in this I'd be urging them to scrap the whole thing for parts, and sell the IP to someone stupid enough to pay. It's a rough, but unsurprising, ending.
 
Canuck600
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Re: Boom Supersonic new configuration.

Mon Sep 19, 2022 8:03 pm

I think there is a better chance that my spinal cord will regenerate after 53 years of paralysis than there is of Boom being able to build a certified functioning aircraft.
 
iamlucky13
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Re: Boom Supersonic new configuration.

Mon Sep 19, 2022 11:53 pm

Sancho99504 wrote:
Supersonic jet startup Boom's future is in doubt after every major jet-engine maker refuses to help

https://www.businessinsider.com/engine- ... 2022-9?amp


"Refuses to help" isn't remotely close to what Rolls Royce is quoted as saying in that article:

linked article wrote:
"We've completed our contract with Boom and delivered various engineering studies for their Overture supersonic program," Rolls-Royce said.

"After careful consideration, Rolls-Royce has determined that the commercial aviation supersonic market is not currently a priority for us and, therefore, will not pursue further work on the program at this time," the company continued. "It has been a pleasure to work with the Boom team and we wish them every success in the future."


This is a money problem. If Boom had the money to fund the development themselves, Rolls Royce would no doubt be happy to sign additional contracts to continue the work. They're not interested in risk sharing, however.

Boom needs to find the money to fund the engine development, in addition to the rest of the development costs, or the project won't happen.

ReverseFlow wrote:
"Boom Supersonic may be forced to make its own engine for its ultra-fast Overture jet."

We've got Lightsaber saying how hard it is/will be for Russia/China to build efficient engines in the Russia threads and here a company without any experience is wanting to build their own?


No. Please check the source for that statement. It is not Boom.

It is an uninvolved 3rd party speculating in response to a journalist looking for quotes. His stated specialty is market analysis for the travel industry. I might be interested in his views on what percentage of business class passengers would pay how much of a premium for a faster flight, but I see no indications he has any insight into aircraft manufacturing or especially the aircraft engine business.
 
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Aesma
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Re: Boom Supersonic new configuration.

Tue Sep 20, 2022 6:21 am

This thing is for billionaires, so one could fund it. Of course they might as well buy the company with it.
 
Noshow
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Re: Boom Supersonic new configuration.

Tue Sep 20, 2022 7:12 am

Supersonic will have a business again when transpacific nonstop ranges become possible.
 
N757ST
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Re: Boom Supersonic new configuration.

Tue Sep 20, 2022 10:51 am

Noshow wrote:
Supersonic will have a business again when transpacific nonstop ranges become possible.


It’ll happen when a company with actual pedigree in airframe manufacturing decides there is an economic case to design and build it. Building an aviation company in todays highly technical age from scratch is highly improbable, building an SST without that technical background is laughable.
 
Noshow
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Re: Boom Supersonic new configuration.

Tue Sep 20, 2022 10:53 am

And wanting to do all this without an engine is impossible.
 
muralir
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Re: Boom Supersonic new configuration.

Tue Sep 20, 2022 5:05 pm

The lack of an engine at this stage of the company screams that these guys don't know what they're doing. My understanding of modern aircraft design is that it's the opposite: you start with an engine, nail down its expected performance characteristics and development timeline, and then design the rest of the aircraft around it. I imagine with supersonic travel, this is even more important as the aerodynamics are well understood at this point, and it's mainly a question of engine tech to get you there at an acceptable cost and reliability.

Noshow wrote:
Supersonic will have a business again when transpacific nonstop ranges become possible.


I'm not so sure. My take on Concorde was that it was so successful (such as it was...) on the transatlantic market because it enabled people to avoid overnighting on a flight. The average flight from NY to LHR/CDG was about 3.5 hours, vs 7-8 hours in a regular flight. (Note that probably at least 1 hour of that time savings was due to concorde getting priority clearance at those airports and avoiding the routine congestion delays in those airports). With Concorde's schedule, you could fly out of LHR in the morning and be in NY in the morning for a full day of work. Similarly, you could fly out of NY in the afternoon (maybe leaving work just a few hours early), and arrive in London by the evening. And then check in to a hotel for a good night's sleep before the next day's meetings.

This was valuable at a time when even first class on a flight didn't have lay-flat seats, and overnight flights were called redeyes for a reason. So you had two options for regular flight: leave NYC in the morning to get to LHR in the evening, thereby losing a day's work in NYC. Or leave NYC on a redeye and arrive in LHR bleary and tired and not your best for meetings. Concorde allowed you to essentially save a day while still avoiding a redeye.

But this advantage no longer is needed; first class and even business class on modern airlines gives you a very comfortable sleep, and most people feel refreshed enough that they can work a full day immediately after without issue. So If you can take an afternoon flight out of NYC on Boom (cutting a few hours out of your workday to do it) and arrive in the evening and head straight to your hotel, or take a regular flight later in the evening (maybe even have dinner with your family first) and arrive in London in the morning feeling equally refreshed as sleeping in a hotel, what's the advantage?

This goes doubly in the Pacific. Even at supersonic speeds, flights will be long. Concorde's seats, as expensive as they were, look like they're equivalent to United's economy+, i.e. basically economy seats with some more legroom. And the only picture of seats I see on Boom's site makes them look like angled flatbeds at best (notice how the seat is somewhat higher than the footwell; only way to convert to flatbed would be to angle the bed). This makes sense, because the fuselage is so narrow, there's no way to rotate the seats into something like a reverse herringbone in there. So the real question is, assuming you will need to sleep on both flights, and lose a day of travel regardless, would you rather travel in a spacious lie-flat business / first class seat with all the bells and whistles like doors, big bathrooms, perhaps showers, etc. Or would you prefer to do it in a cramped angled flatbed, and save 6 hours that don't really change your travel schedule all that much anyway?
 
cpd
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Re: Boom Supersonic new configuration.

Wed Sep 21, 2022 12:10 am

Noshow wrote:
Supersonic will have a business again when transpacific nonstop ranges become possible.


But that range won't be possible until someone builds an engine. The engine shouldn't be that difficult - it just needs money to do it. So with that blocker, it just won't happen.

If people can put huge amounts of money on enormous superyachts, surely an SST engine is possible.

muralir wrote:
(Note that probably at least 1 hour of that time savings was due to concorde getting priority clearance at those airports and avoiding the routine congestion delays in those airports).


Compare the beginning of take-off roll to landing times, Concorde is still much faster than a conventional plane and that's nothing to do with priority clearances.

muralir wrote:
But this advantage no longer is needed; first class and even business class on modern airlines gives you a very comfortable sleep, and most people feel refreshed enough that they can work a full day immediately after without issue. So If you can take an afternoon flight out of NYC on Boom (cutting a few hours out of your workday to do it) and arrive in the evening and head straight to your hotel, or take a regular flight later in the evening (maybe even have dinner with your family first) and arrive in London in the morning feeling equally refreshed as sleeping in a hotel, what's the advantage?


Flat business class seats and first class suite (using Emirates for example) are nice but I still arrive in Europe from Sydney absolutely exhausted. So I need an extra day or two to be fresh enough to be riding at a high level. It's not the same as sleeping in a hotel. Because of this I deliberately choose the flights that give me a stopover in Dubai so I can sleep in a comfortable hotel, can walk around and stretch out, etc. It helps a little bit because from Dubai to Europe then is just about 6 hours and a day time flight, plus it arrives in the afternoon so I'm ready to sleep that night.

On the way back from Europe to Sydney I'm usually wrecked for a few days, and I'm flying very comfortable business class or first class. I would take a flight at M2.0 any day if it were available.
 
strfyr51
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Re: Boom Supersonic new configuration.

Wed Sep 21, 2022 12:21 am

gadFly wrote:
[quote="
even if Boom could cruise at .96-.98M they would be miles ahead of most anybody else across the Pacific westbound. and thet could average M+ coming eastbound with the Prevailing Westerly winds on their tail. .


Boeing tried that. It was called the Sonic Liner, and every lease company and armchair SST guy (like me :D ) Could point out that this was the worst configuration for fuel consumption. Fuel prices will not go down, so the story ends here.[/quote]
But? if Boom can get thereon what they have on Board? then there are people who would pay whatever it costs. they Paid for the Concorde didn't they?
Had it not been for the Concorde crashing out of Paris? they doggone thing might still be flying today in some Version.
 
GalaxyFlyer
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Re: Boom Supersonic new configuration.

Wed Sep 21, 2022 12:24 am

I would guess an SST engine is very expensive and an engineering marvel considering it’s only been done once before. Not happening, especially with this team.

There’s a minuscule number of passengers willing to pay the fares necessary to fund an SST, even business travelers. Super yachts are very simple and well understood engineering, even at $500 million.
 
strfyr51
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Re: Will Boom Supersonic's overture be cancelled?

Wed Sep 21, 2022 12:42 am

Boeing757100 wrote:
aeropix wrote:
I don't understand all the hubbub about the engines. We have currently in-production military supersonic engines. Surely one of those, especially the ones installed on existing long-range supersonic bombers - could be adapted to commercial use. It's like they're looking for an excuse to wind down this project gracefully.

On a side note whatever happened to their fighter-jet looking supersonic demonstrator? Nobody talks about that any more.

I am no economist, but that for sure has gotta be hella expensive to adapt fighter jet engines for commercial use. Don't know if Boom will be willing and able to pay that.

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
OK? So tell me how fighter engines Can't be adapted for commercial use? The JT8-D? WAS developed from the J52 and powered the Boeining 727. 737.DC9 and the French Caravelle, there are more versions that powered other commercial airplanes but I don't remember them off the top of my head though I can look them up. I'f I'm not mistaken? a version of the J79 was used to power the Convair 880 and 990 wasn't it? Matter of Fact? the CJ610 that powered the Lear23 was the military J85 used on the T-38 and the Lockheed Jetstar was powered by the Pratt J-60 used on the Navy T-2 Buckeye. So? It has been done, and Can be done.
You just might not have seen anybody do it recently.
 
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Boeing757100
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Re: Will Boom Supersonic's overture be cancelled?

Wed Sep 21, 2022 12:53 am

strfyr51 wrote:
Boeing757100 wrote:
aeropix wrote:
I don't understand all the hubbub about the engines. We have currently in-production military supersonic engines. Surely one of those, especially the ones installed on existing long-range supersonic bombers - could be adapted to commercial use. It's like they're looking for an excuse to wind down this project gracefully.

On a side note whatever happened to their fighter-jet looking supersonic demonstrator? Nobody talks about that any more.

I am no economist, but that for sure has gotta be hella expensive to adapt fighter jet engines for commercial use. Don't know if Boom will be willing and able to pay that.

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
OK? So tell me how fighter engines Can't be adapted for commercial use? The JT8-D? WAS developed from the J52 and powered the Boeining 727. 737.DC9 and the French Caravelle, there are more versions that powered other commercial airplanes but I don't remember them off the top of my head though I can look them up. I'f I'm not mistaken? a version of the J79 was used to power the Convair 880 and 990 wasn't it? Matter of Fact? the CJ610 that powered the Lear23 was the military J85 used on the T-38 and the Lockheed Jetstar was powered by the Pratt J-60 used on the Navy T-2 Buckeye. So? It has been done, and Can be done.
You just might not have seen anybody do it recently.

Wow, I really do learn something new everyday! Those planes and engines were developed nearly 5 decades before I was born, so no wonder. Sorry for my ignorance.
 
muralir
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Re: Will Boom Supersonic's overture be cancelled?

Wed Sep 21, 2022 5:14 am

strfyr51 wrote:
OK? So tell me how fighter engines Can't be adapted for commercial use? The JT8-D? WAS developed from the J52 and powered the Boeining 727. 737.DC9 and the French Caravelle, there are more versions that powered other commercial airplanes but I don't remember them off the top of my head though I can look them up. I'f I'm not mistaken? a version of the J79 was used to power the Convair 880 and 990 wasn't it? Matter of Fact? the CJ610 that powered the Lear23 was the military J85 used on the T-38 and the Lockheed Jetstar was powered by the Pratt J-60 used on the Navy T-2 Buckeye. So? It has been done, and Can be done.
You just might not have seen anybody do it recently.


Anything can be adapted for anything. The question is always cost. Here, there are 3 big issues:
1) Fighter jet engines are designed to get a *fighter jet* to supersonic speed. Most fighter jets house 1-2 pilots and some bombs. Commercial aircraft are much bigger and need correspondingly bigger engines, which is not what fighter jet engines are designed for. For example, the F135 engine, which powers the F35 fighter, generates 40k lbs of thrust. In contrast, a single GE9x (powering the 777x) generates >100k lbs of thrust. A fighter jet engine is optimized for the weight and performance requirements of fighter jets, of which supersonic speed is only one requirement. Adapting it to civilian use with a much different performance specification will be very expensive. Just saying that since they both need to go supersonic, the engines can be largely the same is wrong because it assumes speed is the main factor in designing an engine.

2) Fighter jet engines are rated for markedly fewer hours of use than commercial engines. Here's an article about the service life of F18 Hornets:
https://www.globalsecurity.org/military ... e-life.htm

tl;dr the original service life of a hornet was 8,000 hours, which is now being extended through extensive refurbishment to about 10,000 hours. And Hornets have been taking 30 years and more to reach those 10,000 hours of service life. In contrast, a 777 is expected to last for 160,000 flight hours over the same 30 year lifespan. Unfortunately I don't have lifetime ratings for the engines (which usually last for much less than the airframes), but you get the idea: fighter jets are not expected to be running 12-18 hour flights every day and racking up thousands of hours with minimal maintenance in between. As a result, military engines tend to be optimized for pushing the edge of performance at the expense of worse maintenance and reliability issues.

3) Volume. Issues 1 and 2 can be solved with a massive upfront development effort, and that can be justified only with a large number of engines to amortize that development cost over. It's getting to the point where even regular subsonic engines -- including ones which are revisions of pre-existing engines -- are just barely having enough volume to justify their development costs (why most new planes only have a single engine vendor). Take the massive development costs to adapt a military engine to commercial use, and spread it over a much smaller number of aircraft, and you have a recipe for bankruptcy.

Bottomline is that adapting military engines for civilian use is not that easy. They're designed with vastly different goals and performance requirements, of which speed is only one consideration. I suspect that unless you can spread that development cost over several thousand engines, the economics just won't work out.
 
ReverseFlow
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Re: Boom Supersonic new configuration.

Wed Sep 21, 2022 6:12 am

iamlucky13 wrote:
Sancho99504 wrote:
Supersonic jet startup Boom's future is in doubt after every major jet-engine maker refuses to help

https://www.businessinsider.com/engine- ... 2022-9?amp


"Refuses to help" isn't remotely close to what Rolls Royce is quoted as saying in that article:

linked article wrote:
"We've completed our contract with Boom and delivered various engineering studies for their Overture supersonic program," Rolls-Royce said.

"After careful consideration, Rolls-Royce has determined that the commercial aviation supersonic market is not currently a priority for us and, therefore, will not pursue further work on the program at this time," the company continued. "It has been a pleasure to work with the Boom team and we wish them every success in the future."


This is a money problem. If Boom had the money to fund the development themselves, Rolls Royce would no doubt be happy to sign additional contracts to continue the work. They're not interested in risk sharing, however.

Boom needs to find the money to fund the engine development, in addition to the rest of the development costs, or the project won't happen.

ReverseFlow wrote:
"Boom Supersonic may be forced to make its own engine for its ultra-fast Overture jet."

We've got Lightsaber saying how hard it is/will be for Russia/China to build efficient engines in the Russia threads and here a company without any experience is wanting to build their own?


No. Please check the source for that statement. It is not Boom.

It is an uninvolved 3rd party speculating in response to a journalist looking for quotes. His stated specialty is market analysis for the travel industry. I might be interested in his views on what percentage of business class passengers would pay how much of a premium for a faster flight, but I see no indications he has any insight into aircraft manufacturing or especially the aircraft engine business.
I realise that, but it was just as easy to dispute the message that they'll somehow be able to build an engine, as it was to attack the messenger.
 
Avatar2go
Posts: 2090
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Re: Will Boom Supersonic's overture be cancelled?

Wed Sep 21, 2022 6:39 am

strfyr51 wrote:

OK? So tell me how fighter engines Can't be adapted for commercial use? The JT8-D? WAS developed from the J52 and powered the Boeining 727. 737.DC9 and the French Caravelle, there are more versions that powered other commercial airplanes but I don't remember them off the top of my head though I can look them up. I'f I'm not mistaken? a version of the J79 was used to power the Convair 880 and 990 wasn't it? Matter of Fact? the CJ610 that powered the Lear23 was the military J85 used on the T-38 and the Lockheed Jetstar was powered by the Pratt J-60 used on the Navy T-2 Buckeye. So? It has been done, and Can be done.
You just might not have seen anybody do it recently.


Important to note that in the early jet era, there were only turbojet engines, and thus there was significant crossover between military and commercial applications. The two markets began to diverge with the introduction of the turbofan, where the ever increasing fan diameter is a major contributor to their increased efficiency.

Thus the turbofans became too large for most military applications, and further were optimized for subsonic cruise conditions to reduce fuel burn. While the much smaller turbojets were optimized for supersonic military performance, and therefore too inefficient for commercial use.

Even the most recent military engines like the F-135, are only mild turbofans, they are still primarily turbojets, especially when afterburner is considered.

The F-35B is an interesting application, because the lift fan essentially converts the engine into a full turbofan. However the fan is perpendicular, to create lift rather than propulsion.

The new AETP engines integrate a third airstream, that allows the engine to adjust from turbojet-like, to turbofan-like, in flight, thus bringing some of the benefits of both. But as a new technology, probably is not nearly mature enough to pursue civilian adaptation & certification. Something like that might one day be suitable for something like the Boom Overture.
 
GDB
Posts: 16242
Joined: Wed May 23, 2001 6:25 pm

Re: Boom Supersonic new configuration.

Wed Sep 21, 2022 10:16 am

strfyr51 wrote:
gadFly wrote:
[quote="
even if Boom could cruise at .96-.98M they would be miles ahead of most anybody else across the Pacific westbound. and thet could average .


Boeing tried that. It was called the Sonic Liner, and every lease company and armchair SST guy (like me :D ) Could point out that this was the worst configuration for fuel consumption. Fuel prices will not go down, so the story ends here.

But? if Boom can get thereon what they have on Board? then there are people who would pay whatever it costs. they Paid for the Concorde didn't they?
Had it not been for the Concorde crashing out of Paris? they doggone thing might still be flying today in some Version.


No, really had Paris and more damagingly for commercial reasons, 9/11, not happened it would have gone on until, well a date was never given as doing that too far ahead would have made maintaining the vendor support all the more difficult.
And there was only ever one version, nice as the proposed B model of the late 1970’s would have been, at least for our operation.

But most likely, at the most, the 2009-11 period. Certainly not beyond that, the actual answer being ‘when support costs overtake profit’ closely linked with if one operator retires it, meaning the other shoulders the full burden, instantly bringing that to pass. All happened in a short space of time, with the major external factor having two buildings where a lot of your regular customers were based, being destroyed one morning in September.
Though the 2008 financial crisis would have likely forced early retirement too.
External factors, from the 1973/74 oil crisis onwards were the major issues.

As for using modified military engines for civilian airliners, the past is another country, the noise and increasingly emissions are the key drivers, what was fine in the 50’s and 60’s is not now, hasn’t been for decades.
The fact that the only engine vendor to actually make a technically viable SST engine, another heavily modified military originated design, has walked away should inform.
The money won’t be there to build this thing if investors, companies think it won’t be acceptable from an environmental background, Concorde wasn’t, however the collapse of its market meant the production run was so small a dispensation was given, too few to make a negative impact.
Boom won’t be using that slogan to attract investment.
But it will be a very major issue and no dispensations for a decent sized production run.

Agree about the Sonic Cruiser, even avoiding the major pitfalls of SST’s, they couldn’t sell it as a design.
 
phlswaflyer
Posts: 143
Joined: Sat Oct 19, 2013 9:02 pm

Re: Boom Supersonic new configuration.

Wed Sep 21, 2022 11:21 am

THis will never see the light of day.
 
N757ST
Posts: 1246
Joined: Sat Feb 16, 2002 6:00 am

Re: Boom Supersonic new configuration.

Wed Sep 21, 2022 4:16 pm

GalaxyFlyer wrote:
I would guess an SST engine is very expensive and an engineering marvel considering it’s only been done once before. Not happening, especially with this team.

There’s a minuscule number of passengers willing to pay the fares necessary to fund an SST, even business travelers. Super yachts are very simple and well understood engineering, even at $500 million.


The only, only manufacturer that could announce a supersonic product in the near to medium term without me immediately questioning its viability is gulfstream.
 
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AA777223
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Re: Boom Supersonic new configuration.

Wed Sep 21, 2022 4:46 pm

WayexTDI wrote:
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...

I completely agree with you that this should be complete an utter sarcasm, but for the life of me, I cannot understand how Boom got, not one, but two US legacies behind this pipe-dream, paper project.
 
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Francoflier
Posts: 6392
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Re: Boom Supersonic new configuration.

Wed Sep 21, 2022 5:28 pm

N757ST wrote:
GalaxyFlyer wrote:
I would guess an SST engine is very expensive and an engineering marvel considering it’s only been done once before. Not happening, especially with this team.

There’s a minuscule number of passengers willing to pay the fares necessary to fund an SST, even business travelers. Super yachts are very simple and well understood engineering, even at $500 million.


The only, only manufacturer that could announce a supersonic product in the near to medium term without me immediately questioning its viability is gulfstream.



True, but without an adequate engine, they'll go no farther than Boom...

It's the catch 22 that meant this project was doomed from the start. A new civilian supersonic design needs a new engine, which would take billions to develop, but which will never be profitable because the supersonic market is not large enough.

That Gulfstream and, especially, Dassault (who know a thing or two about supersonic airplanes) haven't dared put a foot in that market despite having a large part of their customer base who would buy a supersonic jet is indeed very telling.
 
af773atmsp
Posts: 2586
Joined: Mon Aug 28, 2006 1:37 am

Re: Boom Supersonic new configuration.

Wed Sep 21, 2022 10:45 pm

AA777223 wrote:
WayexTDI wrote:
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...

I completely agree with you that this should be complete an utter sarcasm, but for the life of me, I cannot understand how Boom got, not one, but two US legacies behind this pipe-dream, paper project.


Marketing and publicity, that's why.
 
GalaxyFlyer
Posts: 10021
Joined: Fri Jan 01, 2016 4:44 am

Re: Boom Supersonic new configuration.

Wed Sep 21, 2022 11:30 pm

N757ST wrote:
GalaxyFlyer wrote:
I would guess an SST engine is very expensive and an engineering marvel considering it’s only been done once before. Not happening, especially with this team.

There’s a minuscule number of passengers willing to pay the fares necessary to fund an SST, even business travelers. Super yachts are very simple and well understood engineering, even at $500 million.


The only, only manufacturer that could announce a supersonic product in the near to medium term without me immediately questioning its viability is gulfstream.


Funnily enough, it was Bombardier that actually broke, for not long, the sound barrier as part of a certification test. G8000.
 
744SPX
Posts: 809
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Re: Boom Supersonic new configuration.

Thu Sep 22, 2022 1:30 am

The next step for bizav is to take Boeing's sonic cruiser and shrink it to large business jet size; .98 mach cruise with 9000-10,000 nmi range (and possibly mach 1.2-1.3 over the ocean)
 
strfyr51
Posts: 5587
Joined: Tue Apr 10, 2012 5:04 pm

Re: Will Boom Supersonic's overture be cancelled?

Thu Sep 22, 2022 4:11 am

muralir wrote:
strfyr51 wrote:
OK? So tell me how fighter engines Can't be adapted for commercial use? The JT8-D? WAS developed from the J52 and powered the Boeining 727. 737.DC9 and the French Caravelle, there are more versions that powered other commercial airplanes but I don't remember them off the top of my head though I can look them up. I'f I'm not mistaken? a version of the J79 was used to power the Convair 880 and 990 wasn't it? Matter of Fact? the CJ610 that powered the Lear23 was the military J85 used on the T-38 and the Lockheed Jetstar was powered by the Pratt J-60 used on the Navy T-2 Buckeye. So? It has been done, and Can be done.
You just might not have seen anybody do it recently.


Anything can be adapted for anything. The question is always cost. Here, there are 3 big issues:
1) Fighter jet engines are designed to get a *fighter jet* to supersonic speed. Most fighter jets house 1-2 pilots and some bombs. Commercial aircraft are much bigger and need correspondingly bigger engines, which is not what fighter jet engines are designed for. For example, the F135 engine, which powers the F35 fighter, generates 40k lbs of thrust. In contrast, a single GE9x (powering the 777x) generates >100k lbs of thrust. A fighter jet engine is optimized for the weight and performance requirements of fighter jets, of which supersonic speed is only one requirement. Adapting it to civilian use with a much different performance specification will be very expensive. Just saying that since they both need to go supersonic, the engines can be largely the same is wrong because it assumes speed is the main factor in designing an engine.

2) Fighter jet engines are rated for markedly fewer hours of use than commercial engines. Here's an article about the service life of F18 Hornets:
https://www.globalsecurity.org/military ... e-life.htm

tl;dr the original service life of a hornet was 8,000 hours, which is now being extended through extensive refurbishment to about 10,000 hours. And Hornets have been taking 30 years and more to reach those 10,000 hours of service life. In contrast, a 777 is expected to last for 160,000 flight hours over the same 30 year lifespan. Unfortunately I don't have lifetime ratings for the engines (which usually last for much less than the airframes), but you get the idea: fighter jets are not expected to be running 12-18 hour flights every day and racking up thousands of hours with minimal maintenance in between. As a result, military engines tend to be optimized for pushing the edge of performance at the expense of worse maintenance and reliability issues.

3) Volume. Issues 1 and 2 can be solved with a massive upfront development effort, and that can be justified only with a large number of engines to amortize that development cost over. It's getting to the point where even regular subsonic engines -- including ones which are revisions of pre-existing engines -- are just barely having enough volume to justify their development costs (why most new planes only have a single engine vendor). Take the massive development costs to adapt a military engine to commercial use, and spread it over a much smaller number of aircraft, and you have a recipe for bankruptcy.

Bottomline is that adapting military engines for civilian use is not that easy. They're designed with vastly different goals and performance requirements, of which speed is only one consideration. I suspect that unless you can spread that development cost over several thousand engines, the economics just won't work out.

fighter Engines are built for rapid power changes as the need for Speed develops. Commercial engines are based for long range cruise. A commercial jet or Turbo-fan engine goes to takeoff power for 5-7 minutes max, Climb power is between 75-80% power until the airplane gets to its assigned cruise altitude as the engines are operated for longevity rather than quick power changes that would be in Combat flying. I.ve seen engines that stayed on the wing for more than 10,000 flight hours before having to be removed for an inspection that required a complete teardown, and many engines go 4,000 to ^,000 hours as a matter of Course. the issue with Commercial engine is NOT the max power but the longevity the engne can make Max Power. When Cruise power drops off or the fuel burn gets excessive? The Airliner Engine usually gets replaced.
 
muralir
Posts: 206
Joined: Mon May 27, 2013 3:44 pm

Re: Will Boom Supersonic's overture be cancelled?

Thu Sep 22, 2022 3:13 pm

strfyr51 wrote:
muralir wrote:
strfyr51 wrote:
OK? So tell me how fighter engines Can't be adapted for commercial use? The JT8-D? WAS developed from the J52 and powered the Boeining 727. 737.DC9 and the French Caravelle, there are more versions that powered other commercial airplanes but I don't remember them off the top of my head though I can look them up. I'f I'm not mistaken? a version of the J79 was used to power the Convair 880 and 990 wasn't it? Matter of Fact? the CJ610 that powered the Lear23 was the military J85 used on the T-38 and the Lockheed Jetstar was powered by the Pratt J-60 used on the Navy T-2 Buckeye. So? It has been done, and Can be done.
You just might not have seen anybody do it recently.


Anything can be adapted for anything. The question is always cost. Here, there are 3 big issues:
1) Fighter jet engines are designed to get a *fighter jet* to supersonic speed. Most fighter jets house 1-2 pilots and some bombs. Commercial aircraft are much bigger and need correspondingly bigger engines, which is not what fighter jet engines are designed for. For example, the F135 engine, which powers the F35 fighter, generates 40k lbs of thrust. In contrast, a single GE9x (powering the 777x) generates >100k lbs of thrust. A fighter jet engine is optimized for the weight and performance requirements of fighter jets, of which supersonic speed is only one requirement. Adapting it to civilian use with a much different performance specification will be very expensive. Just saying that since they both need to go supersonic, the engines can be largely the same is wrong because it assumes speed is the main factor in designing an engine.

2) Fighter jet engines are rated for markedly fewer hours of use than commercial engines. Here's an article about the service life of F18 Hornets:
https://www.globalsecurity.org/military ... e-life.htm

tl;dr the original service life of a hornet was 8,000 hours, which is now being extended through extensive refurbishment to about 10,000 hours. And Hornets have been taking 30 years and more to reach those 10,000 hours of service life. In contrast, a 777 is expected to last for 160,000 flight hours over the same 30 year lifespan. Unfortunately I don't have lifetime ratings for the engines (which usually last for much less than the airframes), but you get the idea: fighter jets are not expected to be running 12-18 hour flights every day and racking up thousands of hours with minimal maintenance in between. As a result, military engines tend to be optimized for pushing the edge of performance at the expense of worse maintenance and reliability issues.

3) Volume. Issues 1 and 2 can be solved with a massive upfront development effort, and that can be justified only with a large number of engines to amortize that development cost over. It's getting to the point where even regular subsonic engines -- including ones which are revisions of pre-existing engines -- are just barely having enough volume to justify their development costs (why most new planes only have a single engine vendor). Take the massive development costs to adapt a military engine to commercial use, and spread it over a much smaller number of aircraft, and you have a recipe for bankruptcy.

Bottomline is that adapting military engines for civilian use is not that easy. They're designed with vastly different goals and performance requirements, of which speed is only one consideration. I suspect that unless you can spread that development cost over several thousand engines, the economics just won't work out.

fighter Engines are built for rapid power changes as the need for Speed develops. Commercial engines are based for long range cruise. A commercial jet or Turbo-fan engine goes to takeoff power for 5-7 minutes max, Climb power is between 75-80% power until the airplane gets to its assigned cruise altitude as the engines are operated for longevity rather than quick power changes that would be in Combat flying. I.ve seen engines that stayed on the wing for more than 10,000 flight hours before having to be removed for an inspection that required a complete teardown, and many engines go 4,000 to ^,000 hours as a matter of Course. the issue with Commercial engine is NOT the max power but the longevity the engne can make Max Power. When Cruise power drops off or the fuel burn gets excessive? The Airliner Engine usually gets replaced.


Agreed. Military engines spend a lot more of their time on max thrust, with rapid changes in thrust, whereas civilian engines are stressed out much less.

I think the difference between yesteryear and today wrt adapting military engines is that back in the day, there was no real civilian research in jet engines, so civilian aircraft had to be built around military engines and deal with the limitations. And there was no competitive disadvantage to doing so, because no other alternatives existed. But once civilian jet engines became a real market, a real R&D effort was started focusing on civilian needs, and this led to the two markets diverging. The problem with Boom is that now, if Boom were to use a minimally modified military engine, their aircraft has to compete with the price/performance/reliability of aircraft that use civilian engines highly optimized for their purpose. Is supersonic speed enough to overcome all the other disadvantages and limitations that a military engine will impose? IMHO, no. Could you develop one of the military engines into something that could compete with civilian engines? Sure, for a few billion dollars.
 
Jdv
Posts: 5
Joined: Wed Apr 06, 2016 10:02 pm

Re: Boom Supersonic new configuration.

Thu Sep 22, 2022 7:33 pm

I just saw a headline in the Business Journal that BOOM hired a former Rolls Royce executive...
 
Dalmd88
Posts: 3299
Joined: Fri Jul 28, 2000 3:19 am

Re: Boom Supersonic new configuration.

Thu Sep 22, 2022 9:15 pm

You guys left out one big military engine cross overs. The F101 from the B1 program became the F110 (numerous fighters) and the F118 (B-2) all relate to the development of the civilian CFM 56 core.
 
GalaxyFlyer
Posts: 10021
Joined: Fri Jan 01, 2016 4:44 am

Re: Boom Supersonic new configuration.

Thu Sep 22, 2022 10:27 pm

744SPX wrote:
The next step for bizav is to take Boeing's sonic cruiser and shrink it to large business jet size; .98 mach cruise with 9000-10,000 nmi range (and possibly mach 1.2-1.3 over the ocean)


No business case right now anyway. Way too much investment for questionable return. Even billionaires have limits
 
cpd
Posts: 7491
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Re: Boom Supersonic new configuration.

Fri Sep 23, 2022 5:28 am

Jdv wrote:
I just saw a headline in the Business Journal that BOOM hired a former Rolls Royce executive...


I'm not sure what he is going to do, aside from hopefully get some money before Boom goes bust.

It will be very hard for them to do an engine themselves. Even the big engine manufacturers have dramas with their new engines and they've been doing engines for a long time.
 
iamlucky13
Posts: 1615
Joined: Wed Aug 08, 2007 12:35 pm

Re: Boom Supersonic new configuration.

Fri Sep 23, 2022 3:36 pm

cpd wrote:
Jdv wrote:
I just saw a headline in the Business Journal that BOOM hired a former Rolls Royce executive...


I'm not sure what he is going to do, aside from hopefully get some money before Boom goes bust.

It will be very hard for them to do an engine themselves. Even the big engine manufacturers have dramas with their new engines and they've been doing engines for a long time.


Boom lists Richard Park of Rolls Royce as being part of the company "advisory council." I'm guessing this is a part time consulting role, which likely is intended to help Boom understand how to work effectively with the engine manufacturers, manage engine integration with the airframe, etc..

There is no reason to think that Boom would try to develop an engine themselves, especially since they have all but said otherwise:

https://www.prnewswire.com/news-release ... 29409.html

"As we prepare to announce our engine partner and transformational new economic model for Overture later this Fall, Ric will continue to bring relevant and valuable insight to Boom," said Blake Scholl, Boom Founder and CEO.
 
DenverBrian
Posts: 24
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Re: Boom Supersonic new configuration.

Fri Sep 23, 2022 3:50 pm

strfyr51 wrote:
Had it not been for the Concorde crashing out of Paris? they doggone thing might still be flying today in some Version.
Probably not. They were already running out of spare parts by 2000.
 
User avatar
LAXintl
Posts: 26705
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Re: Boom Supersonic new configuration.

Fri Sep 23, 2022 9:49 pm

Blake Scholl had an audio interview this week and was asked about RR and engine selection.

His answer was:

"We knew earlier this year that Rolls Royce was not going to be the best option technically and from a business model perspective. They chose to go ahead and share that with the world, but we are on track to announce our engine partner later this year. I can't go into conversations that are private, but we are incredibly excited about what is in front of us. I cant steal my own thunder on this, but later this year we will be unveiling the engine for Overture, and then that question will be answered."

https://sustainabilityintheair.com/podcast/
 
strfyr51
Posts: 5587
Joined: Tue Apr 10, 2012 5:04 pm

Re: Will Boom Supersonic's overture be cancelled?

Fri Sep 23, 2022 10:15 pm

muralir wrote:
strfyr51 wrote:
muralir wrote:

Anything can be adapted for anything. The question is always cost. Here, there are 3 big issues:
1) Fighter jet engines are designed to get a *fighter jet* to supersonic speed. Most fighter jets house 1-2 pilots and some bombs. Commercial aircraft are much bigger and need correspondingly bigger engines, which is not what fighter jet engines are designed for. For example, the F135 engine, which powers the F35 fighter, generates 40k lbs of thrust. In contrast, a single GE9x (powering the 777x) generates >100k lbs of thrust. A fighter jet engine is optimized for the weight and performance requirements of fighter jets, of which supersonic speed is only one requirement. Adapting it to civilian use with a much different performance specification will be very expensive. Just saying that since they both need to go supersonic, the engines can be largely the same is wrong because it assumes speed is the main factor in designing an engine.

2) Fighter jet engines are rated for markedly fewer hours of use than commercial engines. Here's an article about the service life of F18 Hornets:
https://www.globalsecurity.org/military ... e-life.htm

tl;dr the original service life of a hornet was 8,000 hours, which is now being extended through extensive refurbishment to about 10,000 hours. And Hornets have been taking 30 years and more to reach those 10,000 hours of service life. In contrast, a 777 is expected to last for 160,000 flight hours over the same 30 year lifespan. Unfortunately I don't have lifetime ratings for the engines (which usually last for much less than the airframes), but you get the idea: fighter jets are not expected to be running 12-18 hour flights every day and racking up thousands of hours with minimal maintenance in between. As a result, military engines tend to be optimized for pushing the edge of performance at the expense of worse maintenance and reliability issues.

3) Volume. Issues 1 and 2 can be solved with a massive upfront development effort, and that can be justified only with a large number of engines to amortize that development cost over. It's getting to the point where even regular subsonic engines -- including ones which are revisions of pre-existing engines -- are just barely having enough volume to justify their development costs (why most new planes only have a single engine vendor). Take the massive development costs to adapt a military engine to commercial use, and spread it over a much smaller number of aircraft, and you have a recipe for bankruptcy.

Bottomline is that adapting military engines for civilian use is not that easy. They're designed with vastly different goals and performance requirements, of which speed is only one consideration. I suspect that unless you can spread that development cost over several thousand engines, the economics just won't work out.

fighter Engines are built for rapid power changes as the need for Speed develops. Commercial engines are based for long range cruise. A commercial jet or Turbo-fan engine goes to takeoff power for 5-7 minutes max, Climb power is between 75-80% power until the airplane gets to its assigned cruise altitude as the engines are operated for longevity rather than quick power changes that would be in Combat flying. I.ve seen engines that stayed on the wing for more than 10,000 flight hours before having to be removed for an inspection that required a complete teardown, and many engines go 4,000 to ^,000 hours as a matter of Course. the issue with Commercial engine is NOT the max power but the longevity the engne can make Max Power. When Cruise power drops off or the fuel burn gets excessive? The Airliner Engine usually gets replaced.


Agreed. Military engines spend a lot more of their time on max thrust, with rapid changes in thrust, whereas civilian engines are stressed out much less.

I think the difference between yesteryear and today wrt adapting military engines is that back in the day, there was no real civilian research in jet engines, so civilian aircraft had to be built around military engines and deal with the limitations. And there was no competitive disadvantage to doing so, because no other alternatives existed. But once civilian jet engines became a real market, a real R&D effort was started focusing on civilian needs, and this led to the two markets diverging. The problem with Boom is that now, if Boom were to use a minimally modified military engine, their aircraft has to compete with the price/performance/reliability of aircraft that use civilian engines highly optimized for their purpose. Is supersonic speed enough to overcome all the other disadvantages and limitations that a military engine will impose? IMHO, no. Could you develop one of the military engines into something that could compete with civilian engines? Sure, for a few billion dollars.

OK? So have you looked at the profile of the Boom aircraft? Since most if not ALL the civilian engine technology has gone into the Hi Bypass Turbofan engines. And the Boom fuselage seems to indicate they're looking at a low to medium Bypass engines? Just exactly whAT ENGINE WOULD you reccomend for their application except an adapted fighter engine design with a Low Bypass fan? And? an Afterburner? 1they might be able to get away with the modified Rolls engine powering the Gulfstream aircraft but Rolls pulled out of the running. So? GE, Pratt and Ratheon might be what they have to choose from. And as I know it? None of their as it would take commercial engines can support an afterburner as it would take an extra fuel control, Fuel Nozzle, and Exhaust nozzle to make that happen. Can it be done? it can be but it is NOT going to be a Bolt on and Go. And? It's going to cost them some SERIOUS cash for it to be commercially certified.
 
muralir
Posts: 206
Joined: Mon May 27, 2013 3:44 pm

Re: Will Boom Supersonic's overture be cancelled?

Tue Sep 27, 2022 3:02 am

strfyr51 wrote:
muralir wrote:
strfyr51 wrote:
fighter Engines are built for rapid power changes as the need for Speed develops. Commercial engines are based for long range cruise. A commercial jet or Turbo-fan engine goes to takeoff power for 5-7 minutes max, Climb power is between 75-80% power until the airplane gets to its assigned cruise altitude as the engines are operated for longevity rather than quick power changes that would be in Combat flying. I.ve seen engines that stayed on the wing for more than 10,000 flight hours before having to be removed for an inspection that required a complete teardown, and many engines go 4,000 to ^,000 hours as a matter of Course. the issue with Commercial engine is NOT the max power but the longevity the engne can make Max Power. When Cruise power drops off or the fuel burn gets excessive? The Airliner Engine usually gets replaced.


Agreed. Military engines spend a lot more of their time on max thrust, with rapid changes in thrust, whereas civilian engines are stressed out much less.

I think the difference between yesteryear and today wrt adapting military engines is that back in the day, there was no real civilian research in jet engines, so civilian aircraft had to be built around military engines and deal with the limitations. And there was no competitive disadvantage to doing so, because no other alternatives existed. But once civilian jet engines became a real market, a real R&D effort was started focusing on civilian needs, and this led to the two markets diverging. The problem with Boom is that now, if Boom were to use a minimally modified military engine, their aircraft has to compete with the price/performance/reliability of aircraft that use civilian engines highly optimized for their purpose. Is supersonic speed enough to overcome all the other disadvantages and limitations that a military engine will impose? IMHO, no. Could you develop one of the military engines into something that could compete with civilian engines? Sure, for a few billion dollars.

OK? So have you looked at the profile of the Boom aircraft? Since most if not ALL the civilian engine technology has gone into the Hi Bypass Turbofan engines. And the Boom fuselage seems to indicate they're looking at a low to medium Bypass engines? Just exactly whAT ENGINE WOULD you reccomend for their application except an adapted fighter engine design with a Low Bypass fan? And? an Afterburner? 1they might be able to get away with the modified Rolls engine powering the Gulfstream aircraft but Rolls pulled out of the running. So? GE, Pratt and Ratheon might be what they have to choose from. And as I know it? None of their as it would take commercial engines can support an afterburner as it would take an extra fuel control, Fuel Nozzle, and Exhaust nozzle to make that happen. Can it be done? it can be but it is NOT going to be a Bolt on and Go. And? It's going to cost them some SERIOUS cash for it to be commercially certified.


I think we're saying the same thing? There is no civilian supersonic engine today. The only one that used to exist is from the 70s. Yes, they'd have to adapt a military engine. No, they won't do it because it will cost too much. There is no bolt-on-and-go option. Which means they're dead in the water. Are you saying something different?

Frankly, they should have started their feasibility studies with the engine options, and nailed down an engine development program before doing anything else. They would have learned their answer (yes or no) much quicker and saved a lot of time and money. A supersonic airframe is a lot easier to design than a supersonic engine. As they're now learning...
 
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LaunchDetected
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Re: Boom Supersonic new configuration.

Tue Sep 27, 2022 4:05 am

N757ST wrote:
The only, only manufacturer that could announce a supersonic product in the near to medium term without me immediately questioning its viability is gulfstream.


What about Dassault?
They have an strong experience in supersonic flight and can produce serious jets, trijets included.
Give them a good engine and a business case and they will do it successfully. The fact is that there is no engine and no business case.
 
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Re: Boom Supersonic new configuration.

Tue Sep 27, 2022 8:37 am

Didn't Mr. Scholl announce to name his engine partner several times in different years before without ever doing it? Good if they finally found somebody.
I believe it when I see it.

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