AUG 16, 2022American Airlines Announces Agreement to Purchase Boom Supersonic Overture Aircraft, Places Deposit on 20 OverturesAmerican, the world’s largest airline, poised to have the world’s largest supersonic fleet with new Boom Supersonic aircraft FORT WORTH, Texas, and DENVER, Aug. 16, 2022 — American Airlines and Boom Supersonic today announced the airline’s agreement to purchase up to 20 Overture aircraft, with an option for an additional 40. American has paid a non-refundable deposit on the initial 20 aircraft. Overture is expected to carry passengers at twice the speed of today’s fastest commercial aircraft.
The Overture is about the same size and has nearly the same range as Concorde, but without the sonic boom and ear splitting engine noise on take-off.
Quote from: sghill on 08/16/2022 02:39 pmThe Overture is about the same size and has nearly the same range as Concorde, but without the sonic boom and ear splitting engine noise on take-off.Overture is essentially a 75% scale model of Concorde with three medium-bypass Rolls-Royce engines that don't exist yet. The engines will not have afterburners and should be significantly quieter on takeoff than Concorde. However, it's the only supersonic transport project of this new generation that is NOT pursuing low-boom solutions. The first flight of the XB-1 demonstrator in Mojave is apparently any month now.
United and American are both in contract talks with their pilots. United put their Contract vote on hold after American released a better proposal to their pilots during the voting period, and after outrage from the pilot group over the contract proposal. Boom is a combination of 3 things: incentivizing the pilots over a new toy (see also: Shiny Jet Syndrome), PR to the general public, and hiding money to not pay employees a better wage. I doubt any pilots currently employed by either United or American will ever fly these planes.
Quote from: JAFO on 08/16/2022 07:52 pmUnited and American are both in contract talks with their pilots. United put their Contract vote on hold after American released a better proposal to their pilots during the voting period, and after outrage from the pilot group over the contract proposal. Boom is a combination of 3 things: incentivizing the pilots over a new toy (see also: Shiny Jet Syndrome), PR to the general public, and hiding money to not pay employees a better wage. I doubt any pilots currently employed by either United or American will ever fly these planes.Pan Am used this strategy for quite a while. They were the first (and I think only?) US airline to place a non-binding order for Concorde, and they told their pilots that they would be the first airline pilots in America to break the sound barrier. This was the order that frakked off JFK and prompted the phone call to Juan Trippe that led to the ill-fated US SST effort.
There are so many different pumped rocket engine startups and many companies were able to make their own engines for their own launch vehicles. That enabled the proliferation of launch vehicles were have today (half of which have launched and half are set to launch in the next 24 months).I wonder if… there just needs to be an in-house developed jet engine for this to happen.
It would seem that Boom is going to have to put hard currency on the table to get the engine development going if this report is correct:https://theaircurrent.com/engine-development/boom-supersonic-rolls-royce-engine-business-model/The article suggests that Rolls Royce wont develop the engine without Boom putting in the cash.
Can't remember the exact name of the FAA takeoff noise regulation of the early 1970's (FAR-36 ?) but it was a huge PITA for SST engine designers. Rockets have no such worries.
Rolls-Royce has officially terminated their relationship with Boom, declining to develop engines for the aircraft:https://www.ainonline.com/aviation-news/air-transport/2022-09-06/boom-seeks-engine-airlines-mull-supersonic-use-caseWe here at NSF understand that it's hard for an aerospace transportation provider to innovate and to control their own destiny when they rely on other companies enmeshed in existing business models to supply appropriate engines.
A smaller concord might’ve survived longer than the original concord due to higher flightrate.That change alone could’ve made a big difference.
But also, global real GDP is more than 4 times what it was in 1969 when Concord debuted. Worldwide airline passenger volume is up like 20 times since 1969.The original Concord was unchanged in any significant degree from 1969 debut until 2003, an extremely long run. No transatlantic passenger aircraft built in 1969 would be commercially viable today.
So with upgrading the efficiency to in line with modern standards (obvious differences due to supersonic regime!!!), upgrading avionics and safety and passenger comforts… I can definitely see it doing far better than the original Concord did. The same exact concord but with 20 times the demand for flights debuting in 1969 would’ve made the original Concord a success, with probably lots of follow-on aircraft and upgrades.
I think Boom has a chance of success. The wrinkle I think is the fact that making ANY largeish cleansheet passenger jet is incredibly hard nowadays, costing billions in development money, even ignoring subsonic vs supersonic. Propulsion is still a huge questionmark for Overture.If they can avoid being gobbled up by Boeing or Airbus (or some Chinese firm) while keeping above water financially, it’ll be a huge boon to the stagnant passenger aviation industry (and it’d be interesting to see them branch out to efficient subsonic as well). But let’s not burn that bridge before it hatches or whatever.
During the heyday of Concorde, there was a stampede to the bank of payphones in the terminal after deboarding. A lot of the reason why they were paying a premium was to minimize the amount of time they were out of contact with their organizations. Today it's a different world, and with Starlink coming to commercial aviation, the loss of productivity associated with time spent on the airliner is becoming even smaller.
There is a minimum practical size involved, because a delta-winged twinjet isn't going to cut it for transoceanic flights. I was astonished when Boom announced their original plan because it was a twinjet, and with a low aspect supersonic wing, it's not very nice to lose half your thrust over the middle of the Atlantic. They pretty quickly pivoted to a trijet for this reason.
It was a modification of the Pratt & Whitney J52 turbojet engine which powered the US Navy A-6 Intruder attack aircraft.The Volvo RM8 is an afterburning version that was license-built in Sweden for the Saab 37 Viggen fighter.
Concorde Olympus engine was created and funded two major ways - British side: Vulcan and TSR-2 military legacies - French side (also British, make no mistake): government big vanity project, just like Apollo. - In June 1963 PanAm ordered 6 Concordes, triggering another JFK Apollo moment: the SST mostly forgotten history... So the engine existed (thanks the British military wallet for that) and then two governments paid for the "polishing" to civilian standards. Boom can do the same for the first part (borrow an engine from the military, who paid for the development cost) but for the next step... they are not obviously a deep pocket government. Or TWO deep pocket governments. To pay for the engine "polishing" to civilian, FAA / EASA draconian noise and pollution certification process. That's the big problem I think. The case and story of Dassault SSBJ (1997-2001) is quite interesting. I often mentions it, not because I'm French but rather because Dassault is a big and experimented player in both fronts - supersonic (for the military) and civilian (Falcon bizjets).
In the wake of Rolls-Royce’s departure from Boom Supersonic’s Overture programme, three additional propulsion specialists have indicated they have no interest in developing powerplants for supersonic civilian aircraft, leaving fresh questions about who will supply the jet’s engines.Boom is developing Overture, a four-engined airliner it says will carry 65-80 passengers, fly at Mach 1.7 and have range of 4,250nm (7,871km). First delivery is scheduled for 2029.However, as yet, there is no engine supplier. That issue was brought into focus last week when Rolls-Royce announced it was exiting the project having completed contracted engineering studies.Now GE Aviation, Honeywell and Safran Aircraft Engines tell FlightGlobal they also have no interest in developing engines for civil supersonic aircraft.GE Aviation had been tipped to step in to the Overture programme using a version of the Affinity engine it had been working on to power a supersonic business jet being developed by now-defunct Aerion, a US company that failed in May 2021 amid financial difficulties.But the engine manufacturer rules itself out: “Civil supersonic is not a segment that we are currently pursuing,” GE Aviation says. Another of the relatively few companies capable of developing such a powerplant – Pratt & Whitney – declines to comment on the Overture programme. But a top P&W executive stresses that the company remains focused on subsonic engines.“We haven’t added [civil supersonic] into our overall business strategy,” P&W chief sustainability officer Graham Webb says. He calls supersonic civil aircraft “tangential” to P&W’s core market, and cites efficiency concerns. Indeed, a 2022 report from The International Council on Clean Transportation found that supersonic passenger aircraft would use 7-9 times more fuel per passenger, per kilometre, than subsonic jets burning fossil fuel. ICAO cited the study in its 2022 Environmental Report.For those reasons, P&W is dumping resources into boosting the efficiency of its geared turbofan. It aims to have an improved powerplant available for the narrowbody jets Airbus and Boeing are expected to field in the mid-2030s, Webb says. “There’s a bit of risk – in terms of distracting your resources, your engineering team – on something that is kind of in a different sector.”Boom insists Overture will be environmentally sustainable, offsetting its carbon output by burning sustainable aviation fuel (SAF).“This is the first airplane that is… capable of meeting net-zero carbon,” Boom chief executive Blake Scholl says. “We care deeply about making this not just good for passengers, not just good for airlines, but also good for the planet.”ICAO’s report calls supersonic jets a “poor use of scarce SAF supplies”, saying their fuel burn largely negates SAF benefits in relation to subsonic jets burning fossil fuel.Aerospace analysts say few other engine manufacturers could take on the Overture project. “Nobody else can do an engine in this class, realistically, although Honeywell and Safran aren’t inconceivable,” says Richard Aboulafia with AeroDynamic Advisory.But those companies are also apparently out. “Honeywell has no plans right now to develop a supersonic engine for civilian aircraft,” it says. Honeywell makes turbofans for business jets and Leonardo’s M-346 light-attack/trainer aircraft.“Supersonic is not part of Safran Aircraft Engines commercial propulsion strategy,” adds the French engine maker.Safran holds a massive chunk of the civil turbofan market via its CFM International joint venture with GE, which produces Leap engines for Airbus and Boeing narrowbodies.Safran remains “strongly focused on the RISE initiative to develop the technologies for the next generation of narrowbody aircraft engines,” Safran says.RISE – Revolutionary Innovation for Sustainable Engines – is a joint Safran-GE effort to develop an open-rotor powerplant, delivering a 20% fuel-burn saving at service entry, likely in the mid-2030s. RISE aligns with a broad push by the aerospace industry to reduce emissions. Michael Merluzeau, aerospace consultant with AIR, says International Aero Engines (IAE) could “theoretically” have an engine for Boom. A consortium including P&W, MTU Aero Engines and Japanese Aero Engines, IAE makes V2500s, which power aircraft including first-generation A320s and the Embraer C-390.“That does not, however, mean the engine can be adapted for the Overture [and] can deliver maintenance, fuel burn and performance required, Merluzeau says.Overture needs “more firm [order] commitments and a firmer industrial roadmap” to attract an engine supplier, he adds. “Without an effective propulsion system, this is a programme that is not going anywhere any time soon.”R-R on 8 September said it was departing the Boom programme. “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 programme at this time,” it said.In response, Boom said: “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”.Despite many questions, Scholl insists Overture development is on track, reiterating the company will soon announce an engine partner. He points to order commitments from customers including American Airlines and United Airlines.“We would not have the customer relationships we have if the airplane that we’re building was not one that the airlines wanted, and so, I think… that speaks for itself,” Scholl says.In June 2021, United said it had signed a “commercial agreement” – that included a deposit for an undisclosed amount – to buy 15 Overtures contingent on “demanding safety, operating and sustainability requirements”.Then in August, American said it too had paid a “non-refundable deposit” – it also did not say how much – as part of an agreement to buy up to 20 of the jets.Boom’s other partners include Safran Landing Systems, Collins Aerospace, fuel-system company Eaton and Northrop Grumman, which is helping with a military variant.”I feel really good about this – very, very confident we are going to have a great answer. We are looking at multiple offers,” Scholl says.Story updated on 16 September to note that GE’s engine is called Affinity and that The International Council on Clean Transportation completed the research cited in ICAO’s study.
Seems no one is interested in developing an engine for Boom.
Well, that doesn't really leave many options does it. If they want a US military variant of Overture, then russian engines aren't happening, and no chinese engines either. Who else does that leave?
Ukraine…
They did a bunch of rocket engine work, too. Point is they could make engines for probably an unbeatably cheap price if they weren’t currently being invaded. Aerospace labor costs there are less than a tenth those of the US, IIRC.
Option 3: Develop engine internally.
Similar claims of impossible complexity were made for rocket engines, but reality has proven otherwise. Boom also do not need the most bleeding-edgiest high-bypass turbofans on the planet, nor do they need an elaborate hypersonic engine. What they need is the state of the art as of the mid 1950s, and their problem is the market has moved away from servicing that need. RR did not claim they could not make the engine (they've even manufactured engines of the required specifications in the past), they just don't want to shoulder the economic risk of doing so.
Boom also do not need the most bleeding-edgiest high-bypass turbofans on the planet,
What they need is the state of the art as of the mid 1950s, and their problem is the market has moved away from servicing that need.
RR did not claim they could not make the engine (they've even manufactured engines of the required specifications in the past), they just don't want to shoulder the economic risk of doing so.
. That was good enough for Concorde, back when oil was $3/barrel.
Quote. That was good enough for Concorde, back when oil was $3/barrel. Not even close. PanAm cancelled their orders in January 1973, not 1974 - that is months BEFORE the first oil shock
Quote from: edzieba on 09/20/2022 08:47 pmOption 3: Develop engine internally.Okay, we can stop even mentioning that option right now. It is impossible, period.
This reminds me of when making pumpfed rocket engines was only considered possible for a handful of aerospace primes, now you have everyone and their mom building them. Even amateurs are building turbopumps and some of these small space companies like Ursa Major (and Launcher) are building oxygen-rich staged combustion engines, which literally no US company had done 20 years ago (and was thought practically impossible before the fall of the Iron Curtain).
Quote from: ZuluLima on 09/21/2022 07:12 amQuote from: edzieba on 09/20/2022 08:47 pmOption 3: Develop engine internally.Okay, we can stop even mentioning that option right now. It is impossible, period. I don’t think Boom will do that, and they’d almost certainly go bust if they tried, but that’s poppycock.Jet engines are very complicated, but they are not magical.This reminds me of when making pumpfed rocket engines was only considered possible for a handful of aerospace primes, now you have everyone and their mom building them. Even amateurs are building turbopumps and some of these small space companies like Ursa Major (and Launcher) are building oxygen-rich staged combustion engines, which literally no US company had done 20 years ago (and was thought practically impossible before the fall of the Iron Curtain).An axial flow jet engine is more mechanically complicated than the typical centrifugal turbopump, but the same “impossible for the little guys” mindset that was common 20-30 years ago for pumpfed engines that people have for jet engines today is just as magical-thinking as anything else.It’s not magic, it’s just physics and engineering.People who talk like this demonstrate their own ignorance (on the one hand) or hubris (on the other).
Jet engines are very complicated, but they are not magical.An axial flow jet engine is more mechanically complicated than the typical centrifugal turbopump, but the same “impossible for the little guys” mindset that was common 20-30 years ago for pumpfed engines that people have for jet engines today is just as magical-thinking as anything else.It’s not magic, it’s just physics and engineering.People who talk like this demonstrate their own ignorance (on the one hand) or hubris (on the other).
Quote from: Robotbeat on 09/21/2022 02:15 pmQuote from: ZuluLima on 09/21/2022 07:12 amQuote from: edzieba on 09/20/2022 08:47 pmOption 3: Develop engine internally.Okay, we can stop even mentioning that option right now. It is impossible, period. I don’t think Boom will do that, and they’d almost certainly go bust if they tried, but that’s poppycock.Jet engines are very complicated, but they are not magical.This reminds me of when making pumpfed rocket engines was only considered possible for a handful of aerospace primes, now you have everyone and their mom building them. Even amateurs are building turbopumps and some of these small space companies like Ursa Major (and Launcher) are building oxygen-rich staged combustion engines, which literally no US company had done 20 years ago (and was thought practically impossible before the fall of the Iron Curtain).An axial flow jet engine is more mechanically complicated than the typical centrifugal turbopump, but the same “impossible for the little guys” mindset that was common 20-30 years ago for pumpfed engines that people have for jet engines today is just as magical-thinking as anything else.It’s not magic, it’s just physics and engineering.People who talk like this demonstrate their own ignorance (on the one hand) or hubris (on the other).The biggest difference between the jet and rocket engine industry is that if your jet engine is 10% less efficient than the market leader, nobody will take your calls....
Quote from: Robotbeat on 09/21/2022 02:15 pmJet engines are very complicated, but they are not magical.An axial flow jet engine is more mechanically complicated than the typical centrifugal turbopump, but the same “impossible for the little guys” mindset that was common 20-30 years ago for pumpfed engines that people have for jet engines today is just as magical-thinking as anything else.It’s not magic, it’s just physics and engineering.People who talk like this demonstrate their own ignorance (on the one hand) or hubris (on the other).People who hand-wave away knowledgeable criticisms demonstrate their own ignorance, too. ...
Quote from: Robotbeat on 09/21/2022 02:15 pmJet engines are very complicated, but they are not magical.An axial flow jet engine is more mechanically complicated than the typical centrifugal turbopump, but the same “impossible for the little guys” mindset that was common 20-30 years ago for pumpfed engines that people have for jet engines today is just as magical-thinking as anything else.It’s not magic, it’s just physics and engineering.People who talk like this demonstrate their own ignorance (on the one hand) or hubris (on the other).People who hand-wave away knowledgeable criticisms demonstrate their own ignorance, too. Try to grasp what is being proposed; name ONE current engine that is capable of what Boom needs. Must be:1. Certified as safe for commercial use and for emissions in post-2030 western world.2. Efficient enough to support range requirements (ocean-crossing) and economics of airline industry.3. Capable of supercruise (supersonic without afterburner) at M1.7.4. Capable of all-day flight-cadence at over 99.8% dispatch reliability, roughly the current standard, and high Mean Time Between Overhauls.5. Sized to fit in a smallish nacelle with all fittings.6. MANY more technical and practical issues that suffuse the aviation industry.I'm sure a startup with modest funding and 0 track record can easily design, manufacture, test, certify, deliver, and support such an engine with never-before-seen performance while simultaneously doing the same for the vehicle, which no one else is also even attempting. Because, "it's not magic".
People who hand-wave away knowledgeable criticisms demonstrate their own ignorance, too. Try to grasp what is being proposed; name ONE current engine that is capable of what Boom needs. Must be:1. Certified as safe for commercial use and for emissions in post-2030 western world.2. Efficient enough to support range requirements (ocean-crossing) and economics of airline industry.3. Capable of supercruise (supersonic without afterburner) at M1.7.4. Capable of all-day flight-cadence at over 99.8% dispatch reliability, roughly the current standard, and high Mean Time Between Overhauls.5. Sized to fit in a smallish nacelle with all fittings.6. MANY more technical and practical issues that suffuse the aviation industry.
Balooney. That's true for rocket engines, too. If you have a hydrolox upper stage engine with just 410s vacuum Isp (vs 450-460s), good luck getting anyone to pick up the phone.And if just accepting 90% of their desired efficiency initially was all they'd have to do to get an engine, Boom would be happy to do it.
Really don't care for people who over-fit on the status quo of the existing, stifled ("mature") industry as the only way things can be done trying to speak authoritatively on what a new effort can and cannot "possibly" do for a new kind of aircraft (supersonic passenger jet) not represented at all in the current status quo fleet.
Bottom line: whoever develop that peculiar engine has to find some billion dollars in development costs. Then - who pays for that ? That's the HUUUUGE issue with supersonic civilian, be it SSBJ or SST.
Plus the sonic boom. Flying overwater is a bit restrictive although acceptable.
There seems to be a new, larger issue. Flying supersonic - basic physics - can only be fuel intensive. With the accelerating global warming and the growing anger at commercial aviation, it is perhaps not a good time to fly supersonic, civilian. Aviation already has hard times trying to find a viable kerosene substitute: ammonia, hydrogen, mix of the two (my favorite solution) SAF, batteries... none is a panacea. And this is for subsonic civilian travel.
With 20 000Km going M5
One idea I don't think anyone has considered is to power the compressor with batteries. Someone has acutally built such a jet engine (for a bench test) using an electric motor to drive the compressor. I've literally no idea if the mass numbers work out, but it would ditch all the heavy high temperature turbine section and greatly simplify the hardware.
I would rather go suborbital with a rocket in the tail, rather than hypersonic inside the atmosphere with any scramjet.
A specific impulse of 345 and a prop mass fraction of 0.80 could get 6500 m/s of delta-v,transportation. But we are disgressing away from Boom... (or bust, which I don't wish them: I love their design).
A specific impulse of 345 and a prop mass fraction of 0.80 could get 6500 m/s of delta-v, and with that ballistic range could be 7000 km to 12 000 km - depends whether or not the trajectory is flattened to not hit the lower van Allen belts.
OTOH air breathing gets you Isp of several 1000s, allowing wings, landing gear that can handl full GTOW etc.
All of which applies for a commercial product that's designed to be sold to other customers, which is probably why RR turned them down from going any further. But if they are doing it on their own then the engine becomes a part of the package
That made no sense. It's ALL commercial. The engine, the plane, the operators, the regulatory jurisdiction. Doesn't matter who designs it and whether they're vertically integrated. How does being part of a "package" change any of the requirements and physics involved?
Maybe they've looked at it an figured out that it's just not feasible?
I think it’s lame that none of the engine makers care to partner on this. Shortsighted and sad.
Quote from: Robotbeat on 10/26/2022 01:22 pmI think it’s lame that none of the engine makers care to partner on this. Shortsighted and sad.Why risk spending $100Ms if not $Bs developing engine which may never find a market. If Boom and their investors are so sure of market they can pay for development and own engine rights.
I’d like to think capital-intensive projects that aren’t mere evolutionary improvements on the status quo don’t require billionaire backers (or war) to happen, but the evidence points the other way.
Also, it wouldn’t be in the duopoly’s (Boeing’s or Airbus’s) interest for Boom to succeed.
Quote from: Robotbeat on 10/26/2022 10:59 pmAlso, it wouldn’t be in the duopoly’s (Boeing’s or Airbus’s) interest for Boom to succeed.This is nonsense. No conspiracy please. There is a very looooong way before Boom present any threat to Boeing and Airbus - or supersonic flight, to classic subsonic flight.
Have they really found an engine supplier? Guess we'll see tomorrow.https://onemileatatime.com/news/boom-supersonic-engine/
Boom has partnered with Kratos Defense & Security Solutions, which acquired a small turbojet supplier called in Technical Directions Inc. in 2020. They make engines for low-cost cruise missiles and drones, with up to 200 pounds of thrust. It's quite a jump in scale from that to an 80-passenger airliner, but they say that have engineers that have worked on supersonic military engines, so maybe they have what it takes.
Or they could, you know, build it with sufficient margin for a longer lifetime.
It is not the critic who counts; not the man who points out how the strong man stumbles, or where the doer of deeds could have done them better. The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood; who strives valiantly; who errs, who comes short again and again, because there is no effort without error and shortcoming; but who does actually strive to do the deeds; who knows great enthusiasms, the great devotions; who spends himself in a worthy cause; who at the best knows in the end the triumph of high achievement, and who at the worst, if he fails, at least fails while daring greatly, so that his place shall never be with those cold and timid souls who neither know victory nor defeat.
Kratos is involved with USAF unmanned fighter loyal wingman drone work, the XQ-58, but that's a high subsonic drone using a low-lifetime turbine as an attritable drone.They seem to be confident in low cost design and production of turbines for attritable drones (reusable, but cheap enough to be expendable), based on their various military turbine contracts. I wonder if the math works out for a low lifetime turbine being replaced more often on a commercial vehicle?
The joker in all this is is the involvement of GE Additive, bringing 3D printing to the table. For example, 3D printing a near-net blisk for the engine could reduce machining costs and lost material costs from machining. 3D printed monolithic aerospace parts are a thing now.There's also some wacky engine design choices that could help with materials choices as well, such as the proposed D-16 turbocompound, which utilizes a reciprocating engine core in a diamond 16 piston arrangement to drive the high pressure compressor coupled with a conventional single spool low pressure turbine/compressor. Seeing a deltic take on the ICE core of such an engine would be fun.https://www.flightglobal.com/systems-and-interiors/hybrid-geared-fan-and-piston-concept-could-slash-fuel-burn/127860.articlehttps://web.archive.org/web/20180826030208/http://www.ultimate.aero/page/media_items/composite-cycle-engine-28cce2928.phphttps://www.researchgate.net/publication/327601208_A_Composite_Cycle_Engine_Concept_for_Year_2050
Quote from: Asteroza on 12/15/2022 03:42 amThe joker in all this is is the involvement of GE Additive, bringing 3D printing to the table. For example, 3D printing a near-net blisk for the engine could reduce machining costs and lost material costs from machining. 3D printed monolithic aerospace parts are a thing now.There's also some wacky engine design choices that could help with materials choices as well, such as the proposed D-16 turbocompound, which utilizes a reciprocating engine core in a diamond 16 piston arrangement to drive the high pressure compressor coupled with a conventional single spool low pressure turbine/compressor. Seeing a deltic take on the ICE core of such an engine would be fun.https://www.flightglobal.com/systems-and-interiors/hybrid-geared-fan-and-piston-concept-could-slash-fuel-burn/127860.articlehttps://web.archive.org/web/20180826030208/http://www.ultimate.aero/page/media_items/composite-cycle-engine-28cce2928.phphttps://www.researchgate.net/publication/327601208_A_Composite_Cycle_Engine_Concept_for_Year_20503D printing is partially what enabled the proliferation of all the new pumpfed rocket engines (and therefore smallsat launchers) of late.Rocketlab, Relativity, Astra, SpaceX, ABL, etc all use either 3D printed engines or major components of their engines are 3D printed.So I agree that this could end up being part of what enables a novel jet engine to be developed quickly.(Still don't expect them to meet their schedule, of course.)
One unique aspect of supercruise engines is that the compressors operate in high-temperature working fluid for hours on end, not just the turbines. Concorde's Olympus engines, for example, had a 10,000-hour life for both the compressor and turbine blades, whereas the rest of the engine was certified for 25,000 hours. Kratos will certainly need to use nickel-based superalloys and/or ceramic matrix composites in the turbomachinery. Titanium won't cut it for the later stages of the compressor. It's a whole different ballgame than subsonic.
So being a two spool with fan engine design, the Symphony at first glance appears to slap on a fan in front of a regular tubojet core. Doesn't seem to be one of the fancier variable bypass 3 stream type engines that are increasingly popular.
Compare this with Hermeus, which just announced they are going to use a Pratt and Whitney F100 turbine as the core of their engine (which if I remember correctly is a precooled turboramjet TBCC). CotS, and possibly available used.https://www.hermeus.com/press-release-f100-engine
So being a two spool with fan engine design, the Symphony at first glance appears to slap on a fan in front of a regular tubojet core. Doesn't seem to be one of the fancier variable bypass 3 stream type engines that are increasingly popular.Compare this with Hermeus, which just announced they are going to use a Pratt and Whitney F100 turbine as the core of their engine (which if I remember correctly is a precooled turboramjet TBCC). CotS, and possibly available used.https://www.hermeus.com/press-release-f100-engine
Overture Superfactory is going up here in Greensboro! Taken July 12
If I could go back in time 5 years, I'd poach propulsion engineers coming out Blue and SpaceX, along with some industry vets from GE or the like, and create a jet engine start-up. You'd have to do a study to figure out what the best direction to take that company in would be, but between little engines for drones, the many different sizes of commercial jet engine, and a super cruise engine for Boom and Air Force One, there'd be a lot of routes to success.
Quote from: JEF_300 on 01/05/2023 07:30 pmIf I could go back in time 5 years, I'd poach propulsion engineers coming out Blue and SpaceX, along with some industry vets from GE or the like, and create a jet engine start-up. You'd have to do a study to figure out what the best direction to take that company in would be, but between little engines for drones, the many different sizes of commercial jet engine, and a super cruise engine for Boom and Air Force One, there'd be a lot of routes to success.I think high end jet engines are one of the more difficult things humans make, in the sense that they’ve been pushed *really hard* to get them as good as we can make them. So better ones are incredibly difficult. Arguably harder to advance than the state of art in rocket engines was pre Raptor, just because so much more money and effort has been invested in to jet engines.Witness how most of the startups have tried to get an established player to do their engine.
Quote from: Redclaws on 07/20/2023 12:11 amQuote from: JEF_300 on 01/05/2023 07:30 pmIf I could go back in time 5 years, I'd poach propulsion engineers coming out Blue and SpaceX, along with some industry vets from GE or the like, and create a jet engine start-up. You'd have to do a study to figure out what the best direction to take that company in would be, but between little engines for drones, the many different sizes of commercial jet engine, and a super cruise engine for Boom and Air Force One, there'd be a lot of routes to success.I think high end jet engines are one of the more difficult things humans make, in the sense that they’ve been pushed *really hard* to get them as good as we can make them. So better ones are incredibly difficult. Arguably harder to advance than the state of art in rocket engines was pre Raptor, just because so much more money and effort has been invested in to jet engines.Witness how most of the startups have tried to get an established player to do their engine.IMHO there’s actually a lot of room for disrupting the jet engine manufacturers like GE, actually. They’re companies that operate like Boeing does.
Is it just me, or does that building look a little small for an SST factory? Maybe the size of Boeing/Airbus facilities has permanently distorted my perception of the "correct" size for such a factory.
Construction of the Greensboro, North Carolina, production site where Boom Supersonic plans to assemble the Mach 1.7 Overture airliner remains on schedule for completion in 2024 following the raising of the final beam into place to finish the frame of the main building.The "topping out" ceremony at the 62-acre Boom site at Greensboro's Piedmont Triad International Airport comes nine months after the start of construction on what is intended to be the final assembly line building. Boom has sized the facility to produce up to 33 Overture aircraft per year. There is space to add a second line which would boost capacity up to 66 Overtures per year. The Overture facility, which Boom announced in 2022, is roughly 150,000 ft2 with an additional 24,000 ft2 of office space. The Denver-based company expects to begin installing tooling in 2024. Assembly of the first aircraft would start later that year and roll out is targeted for 2026. Certification and entry-into-service is planned for the end of the decade.
XB-1 is currently at the Mojave Air & Space Port in Mojave, California, continuing preparations for first flight. The aircraft has undergone extensive ground testing since arriving, including medium-speed taxi test events reaching 90 knots (104 mph). In preparation for flight, Boom’s test pilots, including Tristan ‘Geppetto’ Brandenburg and Chief Test Pilot Bill “Doc” Shoemaker, have completed hundreds of hours in the simulator for aircraft evaluation, operations development, training, and human factors assessments. The test pilots also maintain flight proficiency in a T-38 trainer aircraft, the same aircraft that will be used as a chase plane for all flight tests of XB-1. In August, XB-1 received its experimental airworthiness certificate from the Federal Aviation Administration (FAA), following a detailed aircraft inspection. Boom has also secured letters of authorization to allow Chief Test Pilot Bill “Doc” Shoemaker and test pilot Tristan “Geppetto” Brandenburg to fly XB-1.
Aviation startup Boom Supersonic took a major step today toward its goal of returning commercial supersonic aviation to the skies, after the company’s prototype aircraft, the XB-1, left the ground for the first time this week. The short, subsonic flight over the Mojave Desert came years later than expected, but it shows that Boom is at least still making progress.The XB-1 took off Thursday at 7:28AM PT, reached a maximum altitude of 7,120 feet, and a top speed of 246 knots (283 mph). It landed 12 minutes later at 7:40AM.
Taxi tests before flight tests is completely normal and expected.
Mar 31, 2024The race to supersonic flight was one of the most enthralling stories of the 20th century. In this episode, we take a look at how it all started, how the American's betrayed the British and the current state of supersonic flight.
FARNBOROUGH—Boom Supersonic is accelerating development of the Symphony engine for its Mach 1.7 Overture airliner and has expanded its partnership with Standard Aero to include production of the powerplant at the maintenance provider's site in San Antonio.Announcing details of the 35,000-lb.-thrust engine development plan, Boom founder and CEO Blake Scholl says the intent is to begin full-scale core tests in 18 months. “Our plan is to get to hardware quickly, and let’s learn and iterate," Scholl says. "Eighteen months ago, the Symphony was a sketch on a napkin. Now the conceptual design is complete, and we’ve said, ‘Great, let’s go.’”Aware of the central importance of the engine design to the success of Boom’s supersonic airliner concept and broader industry confidence in the overall project, Scholl says the plan is to put the propulsion system through a rapid test and development cycle. “The core is the hardest part, so let's go build the first one as quickly as we can, and let's go put it on a test stand. We are 18 months out from that.”“As we go into next year, the full-scale core of the Symphony should be running on a test stand in prototype form. We'll iterate from there, and that should put us in a place where the rest of the program is more attainable,” Scholl says.Boom Supersonic has begun rig tests of the combustor section in collaboration with its design partner Florida Turbine Technologies (FTT), a business unit of Kratos. Tests are being conducted at FTT’s design and test facility in Jupiter, Florida, using an additively manufactured one-eighth section of the combustor module. Colibrium Additive, a supplier owned by GE Aerospace, has meanwhile produced the first 3D-printed parts for Symphony, including fuel nozzles and turbine center frames.The two-spool, medium-bypass turbofan engine will be equipped with a single-stage 72-in.-dia. fan and be optimized for prolonged supersonic operation with an air-cooled, single-stage high-pressure turbine and three-stage low-pressure turbine. The Symphony’s compressor will be made up of a six-stage high-pressure unit and a three-stage low-pressure section, while the engine’s mixed compression supersonic inlet, diffuser and exhaust design is devised to meet Chapter 14 noise levels.The agreement with StandardAero also marks a key move to industrialize production of the engine for both Overture and, according to Scholl, other potential unidentified high-speed platforms. “There's over 100,000 ft.2 in that facility there that will be dedicated to Symphony and to test cells. That's sufficient to get us to 330 engines a year, which is about where we need to be for full rate on Overture with two final assembly lines—plus we need spares,” Scholl says.Russ Ford, chairman and CEO of Standard Aero, says: “We began working with the Boom team several years ago, initially to introduce the ideas of maintainability and a sustainable supersonic aircraft engine. Over the last couple of years, we're now pleased to announce that we've expanded that partnership, and we have dedicated a portion of one of our facilities to not only the assembly and test of engines but also full-scale production to really try to be a part of this program.”
BREAKING: XB-1 has completed its second flight at the Mojave Air & Space Port in CA. XB-1 retracted and extended its landing gear for the first time and successfully demonstrated a new digital stability augmentation system. We continue to target year-end for supersonic flight. https://boomsupersonic.com/flyby/xb-1-completes-second-flight
XB-1 executed its 2nd flight today–flight objectives achieved:Landing gear retracted and extended in flightNew digital stability augmentation system activatedTufting applied to the right wing to verify aerodynamic characteristics
Shoutout to all of the plane spotters in Mojave for XB-1’s second flight–here’s an amazing shot of XB-1 taking off, accompanied by its chase plane.
Can you spot XB-1? Our supersonic demonstrator aircraft might look small, but it’s doing big things.Learn more about XB-1’s second flight: https://boomsupersonic.com/flyby/xb-1-completes-second-flight
The first ever look into Boom Supersonic, captured during last Friday's XB-1 flight 3 on S3. Get an up close look at XB-1, the moments before takeoff, and test pilot "Geppetto" re-opening the cockpit and sharing his unfiltered thoughts with Blake right after flight.
BREAKING: XB-1 successfully completed its sixth test flight and continues to gain altitude, approaching supersonic flight later this year.✅New max altitude: 20,000 ft✅Flutter excitation system (FES) test at Mach 0.65✅Demonstrated successful FES operation in flight
On October 25, 2024, XB-1 successfully completed its sixth test flight and continues to make progress in expanding the envelope for supersonic flight.Flight six primarily targeted flutter and handling qualities testing at a higher altitude than previous flights. The FES, or Flutter Excitement System, is crucial in testing new aircraft to ensure there are no undesirable interactions between the airflow around the vehicle and the structure of the aircraft. Flutter is a phenomenon where the energy from the airflow can interact with the airframe vibration modes and cause structural failure. Modern aircraft design uses tools and predictions to develop aircraft that should not be susceptible to flutter, which we verify with testing. In this flight, XB-1 made significant progress towards validating a fully functional FES system.Unfortunately, we did experience a degradation in GPS signal strength which impacted our ability to accomplish more in this flight. The team is currently troubleshooting this issue and as soon as the source of interference is identified and corrected, we will be on to Flight 7.
We recently had the opportunity to visit Boom Supersonic, where we spoke with their founder and CEO, Blake Scholl, and got an up-close look at their XB-1 supersonic jet.
Unless there's some technical glitch or weather problem, the first privately developed supersonic aircraft will go supersonic in about 4 hours.
Boom is supersonic. On Jan. 28, 2025 at 8:31am PST / 16:31 GMT, XB-1 broke the sound barrier.✅New top speed: Mach 1.122 (652 KTAS)✅New max altitude: 35,290 ft.✅Flight time: 34 minutes
Boom Supersonic XB-1 jet breaks sound barrier on historic test flight - 1/28/2025Boom Supersonic made history today (Jan. 28) when its XB-1 jet broke the sound barrier for the first time.Boom Supersonic's chief test pilot Tristan "Geppetto" Brandenburg took off in the company's XB-1 jet from the storied Mojave Air & Space Port in California this morning under mostly clear skies. Some 11.5 minutes into the flight — the 12th overall for the XB-1 — at an altitude of around 35,000 feet (10,668 meters), the test plane exceeded Mach 1, the speed of sound, marking the first time a civil aircraft has gone supersonic over the continental United States.
[Boom Supersonic's chief test pilot Tristan "Geppetto" Brandenburg took off in the company's XB-1 jet from the storied Mojave Air & Space Port in California this morning under mostly clear skies. Some 11.5 minutes into the flight — the 12th overall for the XB-1 — at an altitude of around 35,000 feet (10,668 meters), the test plane exceeded Mach 1, the speed of sound, marking the first time a civil aircraft has gone supersonic over the continental United States.
Quote from: cohberg on 01/28/2025 05:22 pm[Boom Supersonic's chief test pilot Tristan "Geppetto" Brandenburg took off in the company's XB-1 jet from the storied Mojave Air & Space Port in California this morning under mostly clear skies. Some 11.5 minutes into the flight — the 12th overall for the XB-1 — at an altitude of around 35,000 feet (10,668 meters), the test plane exceeded Mach 1, the speed of sound, marking the first time a civil aircraft has gone supersonic over the continental United States.That has me wondering: over what other countries have civilian aircraft exceeded Mach 1? Surely the Soviets' Tu-144 did so over the Soviet Union. Did Concorde ever fly supersonically over France or the UK?
That has me wondering: over what other countries have civilian aircraft exceeded Mach 1?
Decision to do our own engines was probably the single most important one in Boom history. Company most likely would have died waiting for the big guys to get stuff done. Also being in control of powertrain means we can make it do what we want. Including something pretty cool…7:00 AM · Feb 3, 2025
https://twitter.com/bscholl/status/1886429521571942640QuoteDecision to do our own engines was probably the single most important one in Boom history. Company most likely would have died waiting for the big guys to get stuff done. Also being in control of powertrain means we can make it do what we want. Including something pretty cool…7:00 AM · Feb 3, 2025
Feb 8, 2025This is the starting gun in the race to high speed passenger travel. Humanity is ready to go fast again.Read the field notes here: https://jasoncarman.com/Supersonic+Fl...0:00 An early Mojave morning02:17 A few months ago...04:12 The big day06:54 Supersonic11:01 What's next
Feb 9, 2025Boom made aviation history on the morning of January 28, 2025, with the first supersonic flight of our demonstrator aircraft, XB-1. After taking off from the Mojave Air & Space Port in California, XB-1 safely and successfully reached an altitude of 35,290 ft. before accelerating to Mach 1.122 (652 KTAS or 750 mph)—and breaking the sound barrier.With over 1,000 years of combined aerospace experience, the XB-1 team has devoted nearly two years to ground and flight testing. Each team member is driven by a deep passion for aviation and a singular mission: to make commercial supersonic flight a reality.During XB-1’s first supersonic flight, Chief Test Pilot Tristan “Geppetto” Brandenburg broke the sound barrier not just once, but three times.Here’s a closer look at each of XB-1’s test flights, documenting its progression up to the sound barrier and beyond: https://boomsupersonic.com/flyby/xb-1-live-blog-flight-test-program
11:35 AM · Feb 10, 2025 @boomaero XB-1 demonstrator completes 13th and last landing - wrapping up test campaign for first privately developed civil supersonic aircraft - exceeded Mach 1 - 6 times in total - Stratolaunch Roc in background