Is it really a huge leap in aerodynamics over, say, the F-105 that went supersonic on its maiden flight in 1955?
Yes. Because configuration wise, it's representative of what we were doing in the eighties which was much better aerodynamically than an F-105. Where it improves on the eighties tech is in terms of materials, propulsion, and being able to use cameras/spatial computing for the cockpit so one doesn't need the windshield and/or the lowering nose for vision cockpit vision, allowing for much better cockpit integration and lower weight. I'm sure there are other areas I'm missing, but the key is in getting the costs down compared to what was done before.
 
Is it really a huge leap in aerodynamics over, say, the F-105 that went supersonic on its maiden flight in 1955?
Yes.

for example, in the 1970s, Nasa developed a supersonic supercritical wing, which greatly improves efficiency (lower drag, lower fuel burn).

The whole idea of shaping to reduce boom effects is something that wasn't even realized as possible until the late 1990s!
 
Yes.

for example, in the 1970s, Nasa developed a supersonic supercritical wing, which greatly improves efficiency (lower drag, lower fuel burn).

The whole idea of shaping to reduce boom effects is something that wasn't even realized as possible until the late 1990s!

Remember that Boom is not doing shaping for sonic boom reduction. Their scheme is to take off and fly subsonic at partial thrust over land and only go supersonic outside the 12-mile limit.

The goal of Boom's current test flights is mainly to validate their simulation and design tools. They want to see how closely the demonstrator flies compared to their computer models, which will tell them whether the tools are good enough or not.
 

As guessed earlier the lateral stability and AoA were problematic. It is then understandable that adding the SAS for the next flight takes them time. I am only wondering why it wasn´t part of the first flight configuration.
The aircraft had a SAS system on board for first flight. It just wasn't active.
 
I thought they were? That super long nose looks like it's for boom reduction, for example.
They may be doing some minor boom shaping efforts but it's not a significant part of the design now.

From their website FAQ:

How is Boom dealing with the sonic boom?
When flying over land, Overture can fly significantly faster than subsonic commercial jets—about Mach 0.94, without breaking the sound barrier. This is about 20% faster than subsonic flight.

Globally, there are more than 600 mostly transoceanic routes on which Overture offers a compelling speedup without changes to today’s overland flight regulations.
 
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They may be doing some minor boom shaping efforts but it's not a significant part of the design now.

From their website FAQ:
Makes sense, the X59 needs to establish what the acceptable boom limits are before it's worth spending a lot of design time/$$ shaping to minimize boom.
 
Boom opens a "Giga factory*" (the size of regular boutique hangar shop**) that will start producing next year a plane that hasn´t been completed, flown, tested or certified (but get State support):

https://www.wral.com/story/boom-sup...sboro-bringing-2-400-jobs-to-region/21486650/

Humm, what´s your delusional level Tars?

iu

Not fair, I can´t really gawk at it, Cooper.


*Notice that AW reports 200k sqft when it´s 25% less with 150k only dedicated to manufacturing. In case G. Norris reads these lines, I advise him to revisit the chapter on rounding numbers in his mathematics textbook.
**As an example, the giant production line of the A380 is rated at 1,6M sqft


Edit:
The video featuring the surrealistic CEO speech seems to have been deleted in no times.
 
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Boom opens a "Giga factory*" (the size of regular boutique hangar shop**) that will start producing next year a plane that hasn´t been completed, flown, tested or certified (but get State support):

https://www.wral.com/story/boom-sup...sboro-bringing-2-400-jobs-to-region/21486650/

Humm, what´s your delusional level Tars?

iu

Not fair, I can´t really gawk at it, Cooper.


*Notice that AW reports 200k sqft when it´s 25% less with 150k only dedicated to manufacturing. In case G. Norris reads these lines, I advise him to revisit the chapter on rounding numbers in his mathematics textbook.
**As an example, the giant production line of the A380 is rated at 1,6M sqft


Edit:
The video featuring the surrealistic CEO speech seems to have been deleted in no times.
Did Boom hire some of the former Aerion folks? Aerion provided nothing from the outset but I guess they were consistent? Depending how this plays out, we are Boom Supersonic, then I'll have the soup.
 
All joking aside (until next time), I would really like Boom to succeed, they flew their XB-1 and they need to complete their flight test program. I think we are at the cusp of a reasonable supersonic platform. Put the giga factory on-hold and finish testing at Mojave, really crunch the data and progress properly. Boom needs to seriously work with an engine maker and do not make the mistake of prematurely unveiling grandiose plans for the future, that will sink them just like Aerion.
 
All joking aside (until next time), I would really like Boom to succeed, they flew their XB-1 and they need to complete their flight test program. I think we are at the cusp of a reasonable supersonic platform. Put the giga factory on-hold and finish testing at Mojave, really crunch the data and progress properly.
Yes, their flight testing allows them to verify the computer model they developed, and that is a HUGE step forward.


Boom needs to seriously work with an engine maker and do not make the mistake of prematurely unveiling grandiose plans for the future, that will sink them just like Aerion.
The problem is, they really need something like F101s. A CFM56 with a 2-stage or 3-stage fan some 55" in diameter, with an afterburner.

And those are LOUD.

Passing modern aircraft noise requirements is going to be difficult.
 
Completely agree with you guys. I was flabbergasted yesterday by the surging "evidences" of a potential crumbling scenario (that had traces rooted as far back as a couple of year; if I do remind well we commented on it then).

If they do not have really a Super factory (seems there is some semantic gymnastics here - see also the absence of tools (an open hangar is not a factory)), still they have a beautiful airplane that we all want to see for real:

View: https://youtu.be/-befoZ6nDpM


@Scott Kenny : many airplane started their life with subpar engines, not fully adapted to their innovative design philosophy. I would tend to think that rationally nobody could care much that F101 engines are fitted to the earliest model. Customer will adapt to the exceptional abilities of the plane that would be a market breaker, leaving room for aggravated user constraints and overpriced seating.
 
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@Scott Kenny : many airplane started their life with subpar engines, not fully adapted to their innovative design philosophy. I would tend to think that rationally nobody could care much that F101 engines are fitted to the earliest model. Customer will adapt to the exceptional abilities of the plane that would be a market breaker, leaving room for aggravated user constraints and overpriced seating.
The problem is that the F101s would be entirely too loud to operate from most airports. Any operators would either need a waiver, pay whatever fines there are per flight if that is an option, or figure out a way to quiet the engines if paying a fine per flight is not an option.

The 2707 had a big muffler section on the engines, as did the 727 Hush Kit engines.
 
Yes. Pay fines, make special arrangements, fly secondary destinations with dedicated connection flights, use gliding approaches, takeoff at minimum Gross weight and stopover for hot-refueling on a private airfield etc...

Early operations won´t see multiple flights per day with fast turnaround, as pricing will narrow the clientele. Transatlantic flights would be also de-facto offset in departures for example as crossing time will be halved. Hence, more opportunity to takeoff at less disturbing hours for the public.
Marketing will also help turning away from the today meat-cargo image back to the Jet-set spirit that bloomed with the 707, creating an esprit de corp that will make passengers more compliant with the small disagreements of trimmed and tuned destinations and services.

Obviously all those are temporarily measures and perennial solutions would have to be incorporated in the airframe as you mention (muffler as suggested?)
 
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Remember that Boom's operating concept is to take off and cruise subsonic at partial power before accelerating to supersonic speeds over water. That's one way they propose to mitigate noise.

And also that they do have their own plans for a new engine that is not an F101 and does not involve an afterburner. From this time last year:


Now, I'm also skeptical about whether they can actually pull off this engine but let's critique their actual plans, not ones we make up.
 
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Yes, their flight testing allows them to verify the computer model they developed, and that is a HUGE step forward.

They've made one test flight which achieved 238 knots. Given the completely different configuration proposed for Overture, I don't know how much validation that can provide.
 
They've made one test flight which achieved 238 knots. Given the completely different configuration proposed for Overture, I don't know how much validation that can provide.

The question is how far off those results were from what the model predicted they would be. If it's close, that validates the modeling tools to some degree, at least for lower speeds. Supersonic of course is a different kettle of fish, since aerodynamic models that work fine for subsonic flight can completely flake at transonic or supersonic regimes.
 
You are too kind with them and... Science. Nobody with its right mind would consider one single test flight as being a blank check to validate anything. Especially the one we were given to see. Especially with a startup that has produced nothing.
 
They've made one test flight which achieved 238 knots. Given the completely different configuration proposed for Overture, I don't know how much validation that can provide.
They still have the predictions the computer made for the test article. If flight tests show that the predictions are lining up with the actual results, then it's likely to be accurate for the Overture as well.


You are too kind with them and... Science. Nobody with its right mind would consider one single test flight as being a blank check to validate anything. Especially the one we were given to see. Especially with a startup that has produced nothing.
Who said one flight test would validate the model? No, it's going to take a lot of flights to validate the model, all the way into supersonic speeds.

And note that Boom has produced SOMETHING, their demo plane. Which flies. You're thinking of Aerion(sp?), another company that talked a lot of stuff for a supersonic transport and didn't even make a demo plane before running out of other people's money.
 
And also that they do have their own plans for a new engine that is not an F101 and does not involve an afterburner. From this time last year:


Now, I'm also skeptical about whether they can actually pull off this engine but let's critique their actual plans, not ones we make up.
Must have missed that!

Interesting. Looks like a moderate bypass turbofan (~3:1 or so BPR) with 1 fan stage, 3 stage LP compressor, 6 stage HP compressor, and 4-5 turbine stages however they're split (looks like 1 HP, 3 LP, and maybe one for the fan). Aiming for 35,000lb thrust with no afterburner. Has a fairly complex mixing stage between the fan bypass and the core exhaust, which will help reduce core exhaust velocity and noise while increasing fan exhaust velocity. And written descriptions on Wiki suggest that the engine will have a plug nozzle for the converging-diverging back pressure control.

Gross layout is actually quite similar to a CFM56, which has 1 fan, 3stg LP, 9stg HP, 1 HPT, 4 LPT. I suspect that the fewer stages in the HP compressor compared to the CFM56 is to lower overall pressure ratio to improve performance at supersonic speeds. Downside is that lower OPR increases fuel consumption pretty significantly. I'd want to juggle max speed versus fuel burned, I suspect that at Mach 2.7 you get close to equal fuel burn compared to a jet at Mach 0.9, but Boom doesn't seem to be chasing that high a speed.
 
And note that Boom has produced SOMETHING, their demo plane. Which flies. You're thinking of Aerion(sp?), another company that talked a lot of stuff for a supersonic transport and didn't even make a demo plane before running out of other people's money.
There is indeed a difference that I have myself been alerting on in the debate. Still, I would expect we understand that Producing an airplane is something different from manufacturing a single experimental airframe.

Garage build are not industrial products.
 
There is indeed a difference that I have myself been alerting on in the debate. Still, I would expect we understand that Producing an airplane is something different from manufacturing a single experimental airframe.

Garage build are not industrial products.
I'm still willing to give Boom a lot more credit than any of the other modern SST companies, because they built a demonstrator to validate their computer model.

I'm also oddly amused at how much their current proposed airframe looks like a 2707.
 
I'm also oddly amused at how much their current proposed airframe looks like a 2707.
Interestingly it looked like Concorde (except the third engine) whilst they used the services of the wonderful ex Concorde engineer/regular genius Ted Talbot. A while after Ted pass away it went all Boeing 2707-esk. My guess is an old fellow from that project replaced him.

Four engines is two to many, and don’t they know of B58’s woes if an outboard engine surge…. It swapped ends while flying at M2…. Engine surge is just a matter of time for an SST. Ted once told me that the key to any commercially successful SST was to make the surge of any engine benign to the pilots.

He once told the story of Concords first FAA demo flights;- When at M2 Trubshaw called for a deliberate surge on number 4, the FAA and former B58 pilot, turned white. He really thought Trubshaw was joking because such a test in the B58 was very high risk, indeed had killed quite a few test and service pilots. He didn’t know Concorde had been designed to be surge benign right from the get go…. And indeed it was.
 
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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.”
 
103876_anthemflightdeck_63100.jpg


Boom Overture flight deck mockup

Interestingly, the seating position gives only the pilots a very low profile regarding to forward visibility
Remarkable also, are the force feedback side sticks and the newly* announced HMD with see-through camera view (probably another expensive gadget).

*if my mem stands right
 
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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.
Those two sentences do not agree. The second sentence implies ~6 months to the full scale core on a test stand, roughly start of 2025. The first one says 18 months, so start of 2026.
 
Oddly enough, it seems as if he still does not catch that Business jet owners will be the ones justifying the CO2 footprint: instead of dozens of private jet crossing the Atlantic each days, there will be one or a couple of Boom supersonic airliners, filling their extra capacity with Business and premiums economy seats. Carbon emission will be de-facto reduced.
This will also reinvent the spirit of the Jetset from the 1960s, with a snowballing economic model hard to predict at this stage but positively driven by a popular upstage for speed, driving us undeniably toward the early massification of supersonics. (everyone would want to be part of it). Traveling will become again an event with Billionaires seating aside Millionaire around a fine glass of Champagne (bourbon for me, please); you get the picture.

Boom is re-inventing the Lockheed Vega or Boeing 247 with a slight touch of 707. Not the eco-friendly electrified railway. Burdening their design with the high cost and, mostly delays, of a new engine design is a strategic error*. And I fear, a near fatal one.

interior-asientos-de-pasajeros-de-un-avion-boeing-247-jgyb62.jpg


*I have already expressed how getting around the engine design with a modded J-79 or a more modern alias would do as well for teh early years.
 
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I agree with the “just build the damn thing” sentiment. Everyone else liked to talk a big talk, suck up venture capital, and run endless simulations. XB-1 actually taking to the air did much to boost their credibility and a prototype is within reach. It would be fantastic to have their engine ready for a prototype airframe but I sincerely hope they have an interim backup to get a prototype in the air sooner than later.
 
The excellent book on the Boeing 787 written by Guy Norris and Mark Wagner has a chapter that discusses why the Sonic Cruiser failed. Boeing was genuinely committed to the project but airline reactions were mixed. Early on potential airlines that Boeing was targeting raised issues such as environmental concerns, high fuel consumption, economic and operational issues. Even though the aircraft could shave as much as 2.5 hours off a typical transpacific flight such as Singapore to Los Angeles, carriers were concerned about the logistical challenges of fitting such an aircraft into their hub and spoke systems due to the timing of arriving much earlier. In late 2002 Boeing asked several key carriers at a conference what they preferred and they all were unanimous in their preference that they preferred efficiency over speed and were more interested in the reference model that Boeing was using to showcase all the advanced tech the Sonic Cruiser would bring to the table. That was when Boeing shifted its resources the 7E7 project and formally cancelled the Sonic Cruiser in December 2002. Years later a Boeing executive admitted that had the company built the Sonic Cruiser its high fuel consumption would have rendered it a failure.

Now granted the global airline industry was in the worst crisis in its history at the time so it can be understandable why carriers did not want to roll the dice with such an innovate design, but I would argue that even today, efficiency trumps speed every time.
So wouldn't this SST have the exact same difficulties as the Sonic Cruiser or the Concorde ? How realistically big is the market for this aircraft ?
 
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The excellent book on the Boeing 787 written by Guy Norris and Mark Wagner has a chapter that discusses why the Sonic Cruiser failed. Boeing was genuinely committed to the project but airline reactions were mixed. Early on potential airlines that Boeing was targeting raised issues such as environmental concerns, high fuel consumption, economic and operational issues. Even though the aircraft could shave as much as 2.5 hours off a typical transpacific flight such as Singapore to Los Angeles, carriers were concerned about the logistical challenges of fitting such an aircraft into their hub and spoke systems due to the timing of arriving much earlier. In late 2002 Boeing asked several key carriers at a conference what they preferred and they all were unanimous in their preference that they preferred efficiency over speed and were more interested in the reference model that Boeing was using to showcase all the advanced tech the Sonic Cruiser would bring to the table. That was when Boeing shifted its resources the 7E7 project and formally cancelled the Sonic Cruiser in December 2002. Years later a Boeing executive admitted that had the company built the Sonic Cruiser its high fuel consumption would have rendered it a failure.

Now granted the global airline industry was in the worst crisis in its history at the time so it can be understandable why carriers did not want to roll the dice with such an innovate design, but I would argue that even today, efficiency trumps speed every time.
So wouldn't this SST have the exact same difficulties as the Sonic Cruiser or the Concorde ? How realistically big is the market for this aircraft ?
I'm also very curious about how this project will work, especially in terms of economics. There are simply too many different individual factors to dive into, but I find it hard to believe that there is going to be a significant market to offset the inefficiencies of the proposed operating strategy and possible FAA noise-fine extravaganza. Additionally, they are quite limited in which routes this aircraft can operate, and if they are flying subsonic above land to reduce noise then they are taking a hit both in fuel consumption and their goal to save people's time.

I think the technology for supersonic flight is going to need more time to mature before it will work for the masses. Good luck to these guys in trying to get something done though. Cool looking prototype (why the XB designation? are they going to be dropping munitions in addition to validating their simulations??)
 
I'm also very curious about how this project will work, especially in terms of economics. There are simply too many different individual factors to dive into, but I find it hard to believe that there is going to be a significant market to offset the inefficiencies of the proposed operating strategy and possible FAA noise-fine extravaganza. Additionally, they are quite limited in which routes this aircraft can operate, and if they are flying subsonic above land to reduce noise then they are taking a hit both in fuel consumption and their goal to save people's time.

I think the technology for supersonic flight is going to need more time to mature before it will work for the masses. Good luck to these guys in trying to get something done though. Cool looking prototype (why the XB designation? are they going to be dropping munitions in addition to validating their simulations??)
I reluctantly concur - I have come to believe that until I depart this particular plane of existence (and quite possibly way beyond that) airplane travelers will remain firmly stuck in the subsonic muck flight envelope established first by the Boeing 707 over six decades ago, due to primarily fuel/block time efficiency and associated cost considerations as well as environmental reasons. But a man can always dream...
 
Glad you agree Martin. The future is definitely going to lie in efficiency, or rather the cheaper operating costs and tickets that will come with it. The average Joe doesn't care about getting to London 2 hours faster when he'd rather pay half the price of the ticket to get there on a super-efficient passenger jet and spend that extra money doing things with his family on vacation.

The idea that "faster is better" doesn't really stand on its own, just becuase the only market for extremely fast planes for the foreseeable future is probably a select few affluent people who would rather pay "waste" time. Efficiency is likely going to be king forever, so it's just a matter of waiting until supersonic can be quiet enough and efficient enough to get fares that are somewhat comparable to a traditional subsonic design.
 
The only way to go (much) faster would be suborbital - rocketplanes. With a kerosene rocket, hence burning the same fuel as the jets. Main issue is the oxidizer, too few of them. My favorite one is nytrox : part N2O, part LOX. Suborbital would have no sonic booms, unlike hypersonics. Or only reduced sonic booms when going up and down.
 

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