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Aerion SBJ

TomcatViP

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There is however a favorable factor for them: aside of the pandemic effect that can only be seen as favorable IMOHO, the growth in size of the average business jet and their bigger engines.

Flying at Mach 2, engine wise, will not be seen as anachronism as it was before. Also, the increased rotations ratio will help the economic downside when crew cost are factored in.

Remember that Boom is not a business jets, but an airliner with high paying passengers as a target.
The pandemic will results in the segregation of first class with economy class. And that's a market Boom will grab.
 

Archibald

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There is however a favorable factor for them: aside of the pandemic effect that can only be seen as favorable IMOHO, the growth in size of the average business jet and their bigger engines.

Flying at Mach 2, engine wise, will not be seen as anachronism as it was before. Also, the increased rotations ratio will help the economic downside when crew cost are factored in.

Remember that Boom is not a business jets, but an airliner with high paying passengers as a target.
The pandemic will results in the segregation of first class with economy class. And that's a market Boom will grab.

I had forgotten Boom wasn't working on a SSBJ but on a larger, 55-passengers machine.
That's a daring and unexpected move, perhaps they grasped that SS bizjets would go nowhere but a 250 pax Concorde successor would bust any private funding atempt. So they are trying their luck at an intermediate size.
I know, studies from the 60's or even the 50's - deep in the prehistory of commercial aviation BUT... I'm not sure Boom picks of an "intermediate capacity" seating is a good idea.
Concorde sat 100 to 140 and was an economic disaster. Others studies from the same era repeatdly showed that SST paid only above 200 PAX. (That's the reason why the US SST looked the way it looked - it needed to pack 200 to 250 pax into a supersonic narrow fuselage, and ended nearly 300 feet long as result; Concorde seating only 140 max, was as long as a 747 at 200 feet).

Related to subsonic airliners in the same 20 - 90 passenger range: while ATR is in passable shape, Embraer and Bombardier... well you know.

In a few words: I'm not sure a supersonic ERJ or CRJ is a good idea.
 

TomcatViP

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Boom intents to have a range of 4500NM for its supersonic airliner. This kind of distance is beyond regional flight. But I fully understood that your meaning was related to cabin size and seating which are fairly comparable (except notably pitch seating ;))
 

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Fair enough. 4500 miles at least in a good range, plenty enough to shuttle between America and Europe. Can't help thinking (typing this) that very ironically, the two engine options explored by Aerion (JT8D and Affinity: the supersonic CFM56 core returning to its F101 B-1A engine roots) would be even better for Boom larger aircraft.
I mean, even heavily modified a JT8D or a F101 core are clearly oversize and overkill for a 10 seat bizjet. But less for a 55-seat small airliner... Boom should really takeover the now cancelled Affinity for their own larger bird.
 

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Boom should really takeover the now cancelled Affinity for their own larger bird.

Rolls Royce is already working on propulsion for the Boom Overture aircraft. Right now, it seems to be mainly at the level of figuring out what actual characteristics are needed for the engine and whether there is anything existing that can do the job. But I'd expect RR to get first crack at an actual engine design (if the money is there).

 

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Fair enough. 4500 miles at least in a good range, plenty enough to shuttle between America and Europe. Can't help thinking (typing this) that very ironically, the two engine options explored by Aerion (JT8D and Affinity: the supersonic CFM56 core returning to its F101 B-1A engine roots) would be even better for Boom larger aircraft.
I mean, even heavily modified a JT8D or a F101 core are clearly oversize and overkill for a 10 seat bizjet. But less for a 55-seat small airliner... Boom should really takeover the now cancelled Affinity for their own larger bird.
Boom needs a much larger engine than the Affinity. Maximum takeoff weight is very sensitive to payload and range for supersonic aircraft. Aerion was publishing 8 pax and 4200nm. If Boom is at 55 pax and 4500nm it will be on the order of double the MTOW (~300k+ lbs vs ~150k+ lbs). The SST does not need as high a thrust loading as the SSBJ because of a less challenging takeoff field length performance requirement, but there is still a very large mismatch in thrust required. Boom would need five Affinity engines which would be prohibitively expensive (both acquisition and maintenance). They are also at a higher Mach number and hence need a lower compressor pressure ratio to limit the temperature at the last stage of the compressor.
 

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Thank you. So RR once again starts from a clean sheet of paper... we shall see.
 

lowboom

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For those interested in commercial supersonic flight, I recommend reading "Supersonic (Airliner) Non-Sense" by R.E.G. Davies. It is a very short read, but has some very good points. I think there are some significant flaws as well, but it is a worthwhile read. I believe there is a market for the 'right' supersonic airplane.
 

NUSNA_Moebius

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For those interested in commercial supersonic flight, I recommend reading "Supersonic (Airliner) Non-Sense" by R.E.G. Davies. It is a very short read, but has some very good points. I think there are some significant flaws as well, but it is a worthwhile read. I believe there is a market for the 'right' supersonic airplane.
Boom definitely seems like they could fill that "right" gap focusing on proven aerodynamics, configuration, market and routes where Mach 2 flight really has its merits over typical cruise speeds like the Pacific. There is good reason why JAL has sent funds their way.

Boom's real challenge is the engine. If a clean sheet design is really necessary then perhaps they can reduce the three engine configuration down to two.
 

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For those interested in commercial supersonic flight, I recommend reading "Supersonic (Airliner) Non-Sense" by R.E.G. Davies. It is a very short read, but has some very good points. I think there are some significant flaws as well, but it is a worthwhile read. I believe there is a market for the 'right' supersonic airplane.
Boom definitely seems like they could fill that "right" gap focusing on proven aerodynamics, configuration, market and routes where Mach 2 flight really has its merits over typical cruise speeds like the Pacific. There is good reason why JAL has sent funds their way.

Boom's real challenge is the engine. If a clean sheet design is really necessary then perhaps they can reduce the three engine configuration down to two.
Boom has a few challenges:
1) They have committed to flying the XB1 demonstrator. I believe they originally claimed it would fly in 2017. Recently, they have stated early 2022. XB1 will consume a large amount of their capital. What technology is it demonstrating? It was originally claimed to be a M2.2 aircraft, but I now read that it is M1.3. Why is that?
2) It is difficult to design one supersonic aircraft with a relatively inexperienced team. Boom is trying design two concurrently. This is a major error in judgment and will likely adversely impact both aircraft.
3) There has been a massive amount of turn-over in their leadership team; much more than is typical, even for a start-up. It has occurred in both the technical and non-technical roles. This makes a difficult task even more so.
4) The ICAO Chapter 14 community noise rule is exceptionally difficult for a supersonic aircraft to achieve. This is the most difficult design challenge. The impact is to dramatically increase the maximum takeoff weight of the aircraft. This then reduces the number of routes in which it can operate profitably. This reduces the market size which increases the per aircraft non-recurring cost. In order to achieve a positive profit margin the selling price must be increased. The increase is selling price increases the overall operating costs which further reduces the market size for the aircraft.
5) There is a big difference in the performance of a new versus a derivative engine. An engine OEM will not commit to an all new engine program unless there is a large capturable market size. Because of 3) above there is not a large enough market to compel an engine OEM to develop a new core. So the newest propulsion technology cannot be utilized to improve the efficiency of the aircraft. This actually is most impactful in the weight of the propulsion system. This further limits the performance and hence market size for the aircraft.
6) Boom’s large valuation is based on becoming an independent OEM with entry into service in 2029. If Boom tries to commercialize this independently it will take at least five years longer. This blows up the already fictitious economics.

In summary, there is a lot of stupid VC money out there in the $10M to $200M range. Boeing’s investment in Aerion was at least $200M. Is Boeing “stupid”? Well, companies aren’t stupid. But the decision to invest in Aerion was made out of Chicago without vetting by the technical experts in Seattle. So, “stupid” decisions can be made by arrogant leaders. I imagine Boom will be able to continue to raise stupid money, but at some point they need an engine commitment. That will require a much higher burden of proof that the business case closes. Don’t believe that GE was ready to commit to the Affinity engine. GE and RR both have strict gating processes for good reason. They will take the money from companies like Aerion and Boom when they are being very well compensated, but a go-ahead commitment will require either a huge investment by the airframe OEM or a very strong business case. As Aerion found out, the serious ‘smart’ money requires a different level of confidence. Aerion, Boom, Spike, Exosonic, Virgin Galactic, and Hermeus can print all the claims they want, but they are just claims. I can show you plenty of ‘printed’ claims that the earth is flat. Do you believe that?

Lastly, if you don’t have a viable concept, spending a lot of money on it is just ‘good money after bad’.
 

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4) The ICAO Chapter 14 community noise rule is exceptionally difficult for a supersonic aircraft to achieve. This is the most difficult design challenge. The impact is to dramatically increase the maximum takeoff weight of the aircraft. This then reduces the number of routes in which it can operate profitably. This reduces the market size which increases the per aircraft non-recurring cost. In order to achieve a positive profit margin the selling price must be increased. The increase is selling price increases the overall operating costs which further reduces the market size for the aircraft.

- this excellent point
+ low-boom being speed-limited to mach 1.2 to mach 1.6
+ the alternative being "flight over oceans only"
+ supersonic flight remaining a major energy-hog since 1947 (the laws of physics haven't changed by an inch)

I've mostly given up on supersonic / airbreathing civilian aircraft, be it bizjet, intermediate, or 250 pax.

It is just hopeless.

Seriously, Musk is right developing suborbital P2P as a secondary mission for Starship. While ballistics can be irritating (polite word and understatement here), going suborbital through boost-glide eventually extended by skip-glide to me is the last chance of fast intercontinental transportation.

Introducing a conventional rocket engine at airports is NOT a major issue provided
- ordinary jets assume takeoff, the rocket starts only at altitude
- kerosene is used as fuel
- a begnin oxidizer like N2O or nytrox is used (LOX is too deep a cryogen, H2O2 has a bad rep... and all the others are atrocious)

But that's out of topic for this thread.
 
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lowboom

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There is a path to a successful series of civil supersonic aircraft. But it requires a comprehensive conceptual design before throwing a bunch of money at it. And ithe commercialization should be done in partnership with an existing OEM to leverage the immense infrastructure and experience required in fabricating, certifying, and servicing such an aircraft. Certifying a supersonic commercial aircraft is difficult; just ask Mitsubishi. Innovate upfront and leverage the execution; that is the path to success.
 

lowboom

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Oh, and M1.6 is not a hard stop on low boom. Check out Lockheed Martin’s N+2 NASA CR. One of the investigators was John Morgenstern, who recently join Exosonic.
 

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Boeing CEO Dave Calhoun answered questions about the company’s investment in the AS2, and why it had decided to withdraw support for the supersonic aircraft developer. Speaking at the June 3 Alliance Bernstein 37th Annual Strategic Decisions Conference, Calhoun cited the strategic question asked internally among Boeing management, “Is it going to be big enough and meaningful enough to Boeing? And maybe not just in terms of share of market and service market but also in terms of return on capital? And does it bring any technology to our existing core business? And if it doesn’t, then it’s got to really stand on its own … And our decision on supersonic was that it didn’t.
 
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