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Boom supersonic jet readies for rollout
- DomenicoMazza 6y agoIf I recall correctly the Concorde used about 2 tonnes of fuel rolling on the ground alone.. I wonder how this new aircraft fares for fuel consumption? I believe the Concorde is a marvel. You could travel faster than the rotation of the earth in it! However I don’t think we need more environmentally unsustainable travel.
- catalogia 6y agoIt's hard to say how efficient this plane will be before it's built (or more details made public) but from what I've read sofar the big version, 'Boom Overture', is meant to use turbofan engines. That alone should provide significant fuel savings over the Concorde, which used turbojet engines with afterburners on takeoff. Even so, supersonic flight is less efficient than getting there a bit slower. Unfortunately, air resistance is nonlinear like that.
- ggm 6y agoRecent discussion of Concorde-2 discusses the fuel improvements which would have come with adding spools and turbofan to the motor, and wing changes, and larger fueltanks. Concorde didn't get to move beyond its first model. This boom jet is leveraging decades and decades of post-concorde engineering.
- gardenfelder 6y agoSeems to me that everything is nonlinear in the domain of aircraft, particularly when concerned with "efficiency". There is an equation [1] which makes it clear that the power required to maintain flight is a function of air density, drag coefficient, lift coefficient, wing area, and -- velocity cubed. All things being equal (which they never are), double the speed and you need 8 times the power. So in the most simplistic analysis (which is wrong, but instructive), consider that energy is a function of both power and time applied; if you double the speed to fly from say London to NY, would you cut the time to fly to less than 1/8th what it would otherwise be? To be clear, that's wrong, because of other factors; when you go faster in a given airplane, you can be more efficient at higher altitudes - mindful that wing size is dictated more by landing speeds than just how fast you want to go - if anything, you want smaller wings for weight, cost, and other considerations, but landing speed gets in the way. So, if you took the time to solve that equation for an airplane at, say, 30k feet, and for say 50k feet altitude, would you still get efficiencies over say, one of the modern , slower jumbo jets? [1] https://web.mit.edu/16.unified/www/SPRING/systems/Lab_Notes/airpower.pdf https://web.mit.edu/16.unified/www/SPRING/systems/Lab_Notes/... (edited for line spacing)
- Moto7451 6y ago> Seems to me that everything is nonlinear in the domain of aircraft, particularly when concerned with "efficiency". The same physics applies to fast trains and other modes of transit. Fast electric trains have the advantage of not having to lug their fuel along with them at speed. > consider that energy is a function of both power and time applied; if you double the speed to fly from say London to NY, would you cut the time to fly to less than 1/8th what it would otherwise be? I think I understand what you’re trying to say, but note that by definition going twice as fast will get you there in half the time. Work and Energy are in alignment here because of the various efficiency losses you’re talking about. The Concorde did have some reprieve in that it flew 20k feet higher than the usual cruising altitude. https://aviation.stackexchange.com/questions/21881/at-what-altitude-did-concorde-go-supersonic https://aviation.stackexchange.com/questions/21881/at-what-a... Ultimately high speed transport is not about conservation of energy. It’s about conservation of human time. Weighing that against the environment and other factors are important but few people weigh their total use of energy in a given day.
- ClumsyPilot 6y agoFast electric trains are also, well, electric already. Powering planes in a sustainable marrer is not a solved problem.
- Robotbeat 6y agoSo I think that’s not really true. Even existing battery chemistry could do 1000km per stop (although it still needs certification for aircraft) and at comparable speed as HSR. That’s much longer than the California HSR project that was canceled, plus you just need a recharge (or swap) to continue on your way. With further efficiency improvements and battery chemistries in development right now like Li-S, we could potentially do 4000km flights (enough to reach Hawaii... and anywhere else using multiple hops, as Boom is planning). And shorter flights at higher than HSR speeds. HSR has its own unsolved problems. Like not being able to work over deep ocean... and insane infrastructure costs.
- JKCalhoun 6y agoYeah, much more excited if there were talk of high-speed rail criss-crossing the U.S.
- Robotbeat 6y agoElectric aircraft like the Eviation Alice could do similar speeds and 1000km miles between stops. Comparable to HSR (early routes in CA were about 500km).
- TylerE 6y agoHigh-speed rail isn't high speed enough. Even with way faster than current tech and NO stops you'd still be looking at taking 12+ hours for what a plane can do in 5. That's ignoring the trillions it would cost. The US does not have the population density to make HSR viable.
- axaxs 6y agoI'm still hoping for rail. It's much more carbon friendly, and has the opportunity to be way less stressful. I'd do 18 hours on a NY to LA if I could walk around, eat, talk, sleep, etc over a 5 hour misery ride in an airplane any day.
- TylerE 6y agoA single NY-LA route alone would cost over $500 billion. High speed rail is well $100m/mile, just for the track.
- axaxs 6y agoI'd like to see it thoroughly planned out, and a real cost estimate. Most of the trip is plainsland...simple. Getting through the Rockies, way more complicated. I've tried to read on the subject but estimates are an order of magnitude off between projects. All that said, of course, figuring out how to lower costs safely would be a great thing.
- mrfusion 6y agoNice concise dismissal.
- na85 6y agoI think the real problem is that the Concorde wasn't fast enough to justify the cost. Whether you can fly JFK-CDG in 8 hours or 4 hours, when you factor in how irritating airports are, parking, security line ups, waiting for baggage, etc, it still takes all day to make the trip. Might as well save several thousand dollars and take a longer flight. I believe they would have to cut the flight time down to about an hour to justify Concorde pricing.
- projektfu 6y agoThey could have their own special terminals and all passengers pre-cleared.
- eloff 6y agoOr fly it out of a private airport without as much irritating stuff, much like private jets do today.
- clintonb 6y ago> Whether you can fly JFK-CDG in 8 hours or 4 hours, when you factor in how irritating airports are, parking, security line ups, waiting for baggage, etc, it still takes all day to make the trip. Security lines weren't a thing until 2001. The Concorde operated from 1976 to 2003. The retirement was due to low passenger count due to a crash in 2000 and 9/11 in 2001.
- robotresearcher 6y agoSecurity lines were absolutely a thing in the UK and France, where the Concordes flew from, due to terrorist campaigns.
- grkvlt 6y agoim guessing if you really need, and can afford, supersonic travel then either it'll be like flying business/first or you'll have top tier ff status with the airline, and queues etc are much less of, or even a non issue.
- 6y ago
- dreamcompiler 6y ago> You could travel faster than the rotation of the earth in it! You can do that in a conventional jet at latitudes far from the equator. You can walk faster than the earth rotates if you're very close to a pole (very very close).
- catalogia 6y ago> (very very close). Eh, within 15 miles or so. 4MPH * 24h = 96 mile circumference circle, 96 miles / 2pi ~= 15 miles.
- speedgoose 6y ago~24km.
- iso947 6y agoYou are going to struggle to walk at 4mph in Antarctica
- alfalfasprout 6y agoThe reason for that is that the concorde used afterburners (basically, pump fuel into the high speed exhaust for extra thrust) which are incredibly inefficient. Great for a fighter jet where you need a sudden burst of extreme thrust, but not something you want a long-haul airliner to use. Boom uses turbofan engines to reach supersonic speeds which are much, much more efficient. In fact, many airliners could theoretically go past mach 1. The reason they don't is that the airframe itself doesn't have the correct shape to deal with transonic and supersonic speeds. I'd expect fuel consumption to be higher than a typical passenger jet but nowhere near concorde levels. Fuel consumption would also depend on the climb profiles of the plane, ideal cruise altitudes, etc. Since the more time you spend in subsonic flight and at lower altitudes the more fuel you burn (more friction and the aerodynamics and engines will be optimized for supersonic flight).
- NickNameNick 6y agoConcorde had afterburners, but only used them for take-off and breaking through Mach 1. And they were optional for both.
- paulmd 6y agoConcorde itself could have been much more efficient, there were plans for a "Concorde B" with high-bypass engines that would have carried a larger payload with additional range at higher efficiency. https://www.heritageconcorde.com/concorde-b https://www.heritageconcorde.com/concorde-b
- dotancohen 6y agoWarning: That page contains a background animation that cannot be disabled, even when disabling page styles. I had to open it in W3M, which I'm glad I did as it was very informative.
- mkl 6y agoRunning this in the browser console worked for me: $('video').remove() (There aren't any other video elements.)
- phunctional 6y agoThey are also working on a deal to use carbon neutral fuel from a company called Prometheus https://www.prometheusfuels.com/ https://www.prometheusfuels.com/
- chrisco255 6y agoTried to read their FAQ but it is sort of handwavy. Do you have any links on the research behind this tech? I understand it uses CO2 from the atmosphere and solar + wind to build hydrocarbons? But what are the technical details there? How is this being done and why wasn't this done sooner?
- D_Alex 6y agoHeaps of links in these comments: https://news.ycombinator.com/item?id=19842240 https://news.ycombinator.com/item?id=19842240
- jabl 6y agoKerosene from fossil fuels is a lot cheaper than synthetic fuels.
- beambot 6y agoArticle about Prometheus in Science: https://www.sciencemag.org/news/2019/07/former-playwright-aims-turn-solar-and-wind-power-gasoline https://www.sciencemag.org/news/2019/07/former-playwright-ai...
- rvense 6y agoPropeller planes used about half as much fuel per mile as early jets. Jets have caught up, but it took half a century to get back to earlier levels of fuel efficiency. Slowing down in general is an easy way to bring down energy usage, but it's often a hard sell.
- nopzor 6y agobasically true, but speed isn't the only reason why jets have dominated; being able to fly above the weather, noise, and (perceived) safety are factors too.
- agurk 6y agoLooking at the Concorde's fuel usage taxing is only part of the picture. All turbine engines are very inefficient at low power outputs due to the need to use energy to create sufficient compression for them to function. On top of this the Olympus engines generated a lot of thrust at idle, so much so that only two were used for taxing and it was still apparently tricky to control. While cruising at supersonic speeds the engines were actually the most efficient machines of their time achieving 43% thermal efficiency [0]. Despite being very efficient they still had high fuel consumption rates as the total amount of energy required to sustain those speeds is a lot higher than subsonic. Modern jet are in the 50%s thermally efficient [1] but despite airframe improvements there has been no way to improve fundamental aerodynamics so that supersonic energy costs aren't high. The Concorde did use reheat to take off and break the supersonic barrier which is very fuel inefficient. Using a modern airframes and engines that also don't need reheat will reduce fuel consumption but not to a level anywhere similar to a modern jetliner. [0] https://en.wikipedia.org/wiki/Rolls-Royce/Snecma_Olympus_593 https://en.wikipedia.org/wiki/Rolls-Royce/Snecma_Olympus_593 [1] https://www.nap.edu/read/23490/chapter/6#38 https://www.nap.edu/read/23490/chapter/6#38
- deleted 6y ago[deleted]
- throwaway_pdp09 6y agoI'm a bit suspicious of the qualification 'thermal' in 'thermal efficiency' which sounds like it's hiding something. From the wiki article on thermal efficiency https://en.wikipedia.org/wiki/Thermal_efficiency https://en.wikipedia.org/wiki/Thermal_efficiency, and I'm no wiser for reading it: "For a heat engine, thermal efficiency is the fraction of the energy added by heat (primary energy) that is converted to net work output (secondary energy)." Does thermal efficiency = actual efficiency in the case of jet engines? I find that difficult to believe.
- Neil44 6y agoYes thermal efficiency is a common rating for engines that work by burning fuel to make heat then turn that into useful power. You take the theoretical energy in a litre of fuel and work out how much of that the engine can convert into useful work.
- iso1631 6y agoI wonder what the fuel usage of a spacex starship doing a sub-orbital flight from say NY to Tokyo would compare with a 787 or a concorde doing the same journey.
- credit_guy 6y ago> I don’t think we need more environmentally unsustainable travel. Why do you think Boom is environmentally unsustainable? Boom is working with fellow YCombinator startup Prometheus to use synthetically produced fuels that are net zero emissions.
- makerofspoons 6y agoPlease don't let COVID-19 kill this thing. They're going to need a lot of money to build the full-size plane and it's going to be hard to get it if airlines are cancelling orders and not placing any new ones for planes: https://dsm.forecastinternational.com/wordpress/2020/05/19/airbus-and-boeing-report-april-2020-commercial-aircraft-orders-and-deliveries/ https://dsm.forecastinternational.com/wordpress/2020/05/19/a...
- jazzyjackson 6y agoOTOH if flying becomes more rare, then the only demand left will be from people with deep pockets. Maybe the only way there is a market for supersonic jets is if all the other long haul routes go bankrupt.
- JKCalhoun 6y agoAnd the people with really deep pockets already have a jet. ;-)
- jazzyjackson 6y agoEven then, the Cessna might not have the juice to get to Tokyo nonstop.
- na85 6y agoA Gulfstream does
- ghaff 6y agoI know you're half-joking but it is still often missed in these discussions that private flight (whether owning a jet or something like NetJets) is an existing competitor. And I assume that many wealthier people would rather fly private (for a variety of reasons) than commercial, even if the commercial jet is faster and/or has longer range.
- redis_mlc 6y ago
- galacticaactual 6y agoAs a (pre-Covid) extreme frequent flyer, supersonic and other rapid point to point initiatives are thoroughly unenticing. Part of the reason I loved long flights was the ability to put away the laptop and zone out to a book or movie with some wine before landing, dealing with immigration, hotels, Ubers, and days of frenetic, high stress meetings afterward. The prospect of trying to optimize how fast we can jump from one business trip to another is uninspiring.
- ghaff 6y agoI don’t especially get the supersonic flight love especially from people who will never pay the $10k or whatever to take a transatlantic supersonic flight. I don’t love long economy flights. But honestly there’s not a lot wrong with modern lie flat business. A few hours of my time is not that big a deal.
- shermozle 6y agoYou sound like someone who doesn't live that far away from your destination. I live in Australia. Bring the boom boom flights! If I can get to London or New York in less than 20 hours, I will be very happy.
- ghaff 6y agoFlying trans-Pacific or the equivalent without refueling requires a whole different class of aircraft and seems very unlikely.
- mastazi 6y agoBut parent didn't say they wanted that without any refueling. A London - Sydney or London - Melbourne flight would have several eligible refueling locations in Asia and Middle East. Australia - West Coast of the US would be more challenging I guess, but probably not impossible, perhaps some of the diversion airports in the Pacific would be able to support refueling operations https://en.wikipedia.org/wiki/Diversion_airport https://en.wikipedia.org/wiki/Diversion_airport
- abeppu 6y agoCan anyone here comment on the kinds of things you can and can't learn accurately from a scaled prototype? I'd guess that for something that flies, changing the surface area/volume ratio makes a big difference.
- redis_mlc 6y agoI study aerodynamics, and haven't heard of problems from scaling down the models. The main problem with supersonic wind tunnels is ensuring there's no interference from shock waves bouncing off the sides of the tunnel, which is why the X-plane program used actual airplanes. So wind tunnels are rated to a certain Mach, and above that, like for hypersonic, actual airplanes are still used. FYI: I believe the DC-3 was the first passenger airplane designed with a wind tunnel, and as a result was efficient enough to be the first twin-engine commercial passenger airplane to fly over the Rockies with a safety margin to fly single-engine, and adequate to be the first proposed Shuttle wing design.
- starpilot 6y agohttps://i2.cdn.turner.com/money/dam/assets/170324152006-boom-aerospace-supersonic-xb-1-780x439.jpg https://i2.cdn.turner.com/money/dam/assets/170324152006-boom... This is a tech demonstrator and not quite a "scaled prototype." Two occupants vs ~40 makes it pretty much a completely different aircraft. What it's probably demonstrating is some key design aspects like inlet/engine interactions, sonic boom mitigation, thermal resistance on various points, and overall validating simulation data. It won't show anything about extrinsic performance like range or takeoff distance of the final passenger jet, at least not directly.
- jazzyjackson 6y agoWell you can use the same materials and manufacturing process that you intend to use for the full scale model, and know that your carbon composite body holds up as good as the simulations.
- na85 6y agoIn aerodynamics we have several "similarity" quantities such as the Reynolds Number which is a dimensionless coefficient that characterizes (in a nutshell) the ratio of inertial to viscous forces in a flow. Much research has gone into the applicability of scale models to real world conditions and the validity of a model is contingent on maintaining similarity coefficients. So for example you want your model to be flying at the same Reynolds Number as your full size aircraft will. If you can achieve those conditions then you can expect good predictive results from your model. In general you can learn a great deal about your aircraft from a model including handling and stability characteristics but you're limited by the tunnel and the test apparatus. Post stall behavior comes to mind as something I would imagine to be very difficult to investigate with a scale model in a tunnel.
- everybodyknows 6y ago>scaled prototype
- ItsDeathball 6y agoIt's still a supersonic jet, just not the one you want. What is essentially a privately-built supersonic fighter jet is still impressive, but how much more investment will they need for the full size passenger version?
- Alupis 6y agoI trust Boom has smart people working on these things, but... model aviation doesn't scale up[1]. It's interesting they're going with a scaled-down model instead of a full-scale testbed. The article seems to incidate they're wanting to go from the scaled-down model as a PoC, then onto an actual airline that JAL want's to fly. I'd think they'd need a full-sized PoC first... > “They want to enjoy a first-mover advantage in supersonic and have invested 10 million dollars.” That's chump change for an airline. Doesn't really signal strong support or anything - more of a curiosity I think. A Boeing 737-800 costs around $100 million, for comparison. [1] https://aviation.stackexchange.com/questions/3300/why-havent-quadcopters-been-scaled-up-yet https://aviation.stackexchange.com/questions/3300/why-havent...
- starpilot 6y agoQuadcopters don't scale up. Flyable scale models have used extensively in other aviation research: https://www.youtube.com/watch?v=pgDRkNseNxU https://www.youtube.com/watch?v=pgDRkNseNxU
- deleted 6y ago[deleted]
- avmich 6y ago>the development of the first privately built supersonic airliner and the second ever after Concorde Sad that in a rather specialized article author isn't familiar with such basic facts.
- mhandley 6y agoFrom the fact that you've been modded down, it seems the author wasn't the only one to forget the TU144.
- vikramkr 6y agoI'd imagine that had more to do with the tone of the comment. Would be more helpful to readers if it said "actually, the first supersonic aircraft for commercial use was the tu144 made by tupolev from the Soviet union"
- orbital-decay 6y ago"Privately built", so it's technically accurate, even if there's still an elephant in the room. Similar to that amusing SpaceX marketing speak with the Falcon Heavy being "the most powerful orbital rocket since Saturn V", which was also technically true because both Energia flights were payload-assisted. (they changed that line since then)
- ceejayoz 6y agoThat's not the issue. It's the third supersonic airliner, not the second; the Soviet Union had the Tu-144.
- mauvehaus 6y agoI think anybody would be hard-pressed to argue that the Tu-144 saw meaningful commercial passenger service. Neither has Boom yet, to be fair, but it at least isn’t provably a failure at this point.
- 6y ago
- paulcole 6y agoWhat a great time to get into the small confined shared space industry!
- xiphias2 6y ago,,The timeline for the planned entry into airline service has now also slipped from the previously envisaged 2023-24 to between 2025 and 2027.'' I think COVID-19 won't be a problem in 2025 anymore.
- deleted 6y ago[deleted]
- kohtatsu 6y agoIsn't one of the main drawbacks of supersonic flight the noise?
- idoh 6y agoFrom their website: Overture flights will focus on 500+ primarily transoceanic routes that benefit from supersonic speeds—such as New York to London or San Francisco to Tokyo. Overture won't generate a sonic boom over land cruising at subsonic speeds. Its passengers won't even notice breaking through the "sound barrier," which will be inaudible and uneventful.
- eikenberry 6y agoThe traditional solution was to only allow supersonic flights on the coasts where the jet could fly out over the ocean for the boom.
- repiret 6y agoThere is a common misconception that the boom happens once while accelerating through the speed of sound. In fact it happens continuously while traveling supersonic. The Concord mostly (only?) flew transatlantic mostly for that reason. The US military hasn’t always been shy about continental supersonic flight. I grew up near Beale AFB where the SR71 was stationed and hearing a sonic boom was not an uncommon occourance in the 80s.
- russellbeattie 6y agoHuh. As soon as I read what you wrote, I thought, "that actually makes sense", but then I wondered how it worked. Happily, Wikipedia's entry on Sonic Boom is detailed, with animations and specifics - including altitude and temperature, which affect if the boom is heard or not at ground level. Very interesting. https://en.m.wikipedia.org/wiki/Sonic_boom https://en.m.wikipedia.org/wiki/Sonic_boom
- eikenberry 6y agoThanks for pointing that out. Didn't even think to look it up as I had just assumed it was that way forever.
- latchkey 6y agoTheir parallax website is pretty entertaining... https://boomsupersonic.com/xb-1/build https://boomsupersonic.com/xb-1/build
- dmix 6y agoThat pilot interface looks really nice. Not used to seeing a single seat like that for commercial planes. Although I'm guessing the real one will be scaled up.
- Jaruzel 6y agoI think there's FAA laws etc, that state that commercial flights must have a pilot and a co-pilot.
- jonplackett 6y agoNice, anyone have some suggestions for quick ways to build parallax sites like this? Like themes, frameworks etc
- jcun4128 6y agoscrolling "mechanism" that you can hook into probably scrollmagic
- stareatgoats 6y agoWappalyzer says they use GSAP (https://greensock.com/ https://greensock.com/)
- jcun4128 6y agooh man the back view to the engine exhaust at the bottom of the page wow haha
- jacquesm 6y agoThat's beautiful, thank you for linking.
- ortusdux 6y ago
- nimbius 6y agoReal question: have we solved the radiation problem yet? The concord's solution was to sample exposure with a cockpit Geiger counter and descend to 40kft if things got too hot.
- sneak 6y agoThis is an issue of altitude, not speed. If the Concorde’s solution was to fly at a lower altitude, I know of no reason that wouldn’t be possible for other supersonic craft.
- regularfry 6y agoYou fly lower, you fly slower. When your main selling point is "damn that's quick" anything that gets in the way of that is a problem.
- ars 6y agoSome discussion on this topic: http://health.phys.iit.edu/extended_archive/0407/msg00074.html http://health.phys.iit.edu/extended_archive/0407/msg00074.ht...
- Balgair 6y agoWhere in the heck did you dig that up? What a jewel of a site!
- jazzyjackson 6y agoI expect with radiation it's really just the pilots having to deal with it day in and day out that are over their exposure limits right? If so, maybe automating it so the only people on the plane are the passengers would be a good move.
- SkyMarshal 6y agoThis would be a super cool project to work on. Their website has a fun tour of all the engineering components of it: https://boomsupersonic.com/xb-1/build https://boomsupersonic.com/xb-1/build
- mmmBacon 6y agoI too would love to be able to work on something like this.
- graycat 6y agoTheir engines are a version of the General Electric J85 that dates from the 1950s. It's been very widely used in both military and commercial aircraft. One version was used in the Dassault DA-20 executive aircraft used at the start of FedEx after FedEx cargo door, etc. modifications.
- new_realist 6y agoThe biggest time sink when traveling between continents is the jet lag. A faster jet doesn’t fix that, it only costs more and pollutes more.
- jjeaff 6y agoThe new 787 has made her lag a lot better with better air quality, timed, dimming cabin lights and a few other comfort trucks, it definitely takes the edge off.
- the_duke 6y agoOne of the biggest factors is cabin altitude. Both the Boeing 787 and the Airbus A350 XWB have a lower (than previous airliners) cabin altitude of 1,800 m. Note that some private jets do quite a bit better again: the Gulfstream G650 has ~1480 meters.
- mshook 6y agoConcorde cabine altitude was set to 1,700 metres or 5,500ft...
- the_duke 6y agoAccording to Wikipedia it was also 1,800m. [1] 1: https://en.wikipedia.org/wiki/Concorde#Cabin_pressurisation https://en.wikipedia.org/wiki/Concorde#Cabin_pressurisation
- mshook 6y agoWell different sources: https://www.heritageconcorde.com/concorde-pressurization-system https://www.heritageconcorde.com/concorde-pressurization-sys... Airliner cabins are usually pressurised to 6-8,000 ft (1,800-2,400 m) elevation while the aircraft flies much higher. Concorde’s pressurisation was set to an altitude at the lower end of this range, 6000 feet. https://museedelta.wixsite.com/musee-delta/single-post/2020/05/02/Technical-flight-report-Concorde-Thursday-April-3-1986 https://museedelta.wixsite.com/musee-delta/single-post/2020/... The two independent and fully automatic air conditioning units provide a cabin altitude of 5,500 ft (1,600m) at flight level 590. https://books.google.fr/books?id=aekGAgAAQBAJ&pg=PA506&lpg=PA506&dq=concorde+cabin+pressure+%226000%22&source=bl&ots=a-64-w7OGu&sig=ACfU3U2ulKUAIO0-lhxpbStDb4EVLSFwFw&hl=en&sa=X&ved=2ahUKEwjn_crogMvqAhVDQBoKHcUjCKoQ6AEwDXoECAkQAQ#v=onepage&q=concorde%20cabin%20pressure%20%226000%22&f=false https://books.google.fr/books?id=aekGAgAAQBAJ&pg=PA506&lpg=P... Concorde's pressurisation was set to an altitude at the lower end of this range, 6,000 feet (1,800 m). Bottom line is 1700 or 1800m, Concorde did that 50 years ago...
- epberry 6y agoThese guys followed the "Design Wins" pattern from Crossing the Chasm where the gtm is a series of technical evaluation meant to land one or two large customers. Same thing happens in Silicon startups.
- sarim 6y agoWhat is this?! Aircraft for ants?!!!
- rootusrootus 6y agoThe one in the picture is a reduced scale prototype. Then they hope to build a full scale plane. And then roll that out five years from now. Given how many years we've been hearing about this, I wouldn't hold my breath. I personally give it less than a 50/50 shot at even getting the prototype into the air.
- dreamcompiler 6y agoThis is cool, but despite what the company implies, it's never going to be anything but a toy for rich people. In no conceivable scenario are flights on this jet ever going to sell for less than $10k per seat. That might make Boom a viable business, but most of us will never get a ride on one.
- jeswin 6y ago> The timeline for the planned entry into airline service has now also slipped from the previously envisaged 2023-24 to between 2025 and 2027. A jet which has not even been flown once might enter airline service in 5-7 years? The whole article is a PR insert.
- _-___________-_ 6y ago> A jet which has not even been flown once might enter airline service in 5-7 years? Considering that flight testing will begin soon, it doesn't seem that unrealistic. Have you got some actual evidence to the contrary? > The whole article is a PR insert. Yes, clearly, but that doesn't seem related to your first point.
- barbegal 6y agoFlight testing of a one third scale prototype will likely begin next year. Given they haven't even started manufacturing the full scale prototype it seems unlikely that they can get into service in 7 years. To give a recent example the A400M took 7 years from the start of the prototype build in 2007 to entering service in 2014.
- jeswin 6y agoAnd besides, we're talking about a supersonic aircraft with no prior platform to build this out of. Given the safety profile that will need to be proven, the schedule can't be taken seriously. It's harder than making a rocket.
- efnx 6y agoI can already tell what the headline will be when this company incurs its first crash...
- dmos62 6y agoHaha, that was my first thought when I heard of this startup too. Wouldn't be surprised to see a rebranding in its later years.
- sxcurry 6y agoBut it doesn't - isn't this a prototype? The article talks about 2027 for the actual aircraft.
- random3 6y agoFunny how, by the middle of the video, they all start wearing masks.
- dmix 6y agoFrom my understanding a big problem with Concorde was the sonic boom which happened near takeoff and bothered urban residents. I've always wondered why they can't fly at normal airline speeds until over a rural area or an ocean before accelerating to sound barrier speeds.
- masklinn 6y ago> I've always wondered why they can't fly at normal airline speeds until over a rural area or an ocean before accelerating to sound barrier speeds. Because geometry and engines which are efficient at very high speed are extremely inefficient at low speeds, so you want to avoid subsonic flight as much as possible. Variable geometry (mostly variable-sweep wings) bridge that issue, but they're weak points, and significantly increase the weight and complexity of the machine, to the extent that Boeing's competitor SST (the 2707) abandoned variable-geometry mid-project as way too heavy and still not efficient enough, reverting to a more classic fixed delta.
- paulmd 6y agofuel burn is unacceptably high at subsonic speeds, decreasing the range from about 4500 miles to 2000 miles or less. good supersonic performance and high subsonic efficiency are essentially opposing goals - a big wing that generates lots of lift is more efficient at slower speeds, but obviously becomes problematic at supersonic speeds. Also, drag is highest near the transsonic regime, and fuel burn is nonlinear, it's partially a function of time, so "getting there faster" can actually burn less fuel than having to run the engines for longer.
- poma88 6y agoNot commercial with very few exceptions. The toilet operations seem uncertain for passengers for the aircraft size visible in the video..
- gorgoiler 6y agoIs there an intuitive everyday explanation as to why the sound barrier is so hard to break? I know that the forces in an airframe change a lot as you go faster, and that the controls invert for some reason, but I’ve never really had a good feel as to why. Perhaps something related to swimming?
- Jabbles 6y agoThe speed of sound is vaguely the speed at which air can get out of the way. If you try travelling faster than that the air bunches up into a shockwave, which causes all kinds of problems and is generally different to travelling through air slowly.
- jasin 6y agoIn simplistic terms, at supersonic speeds the air particles do not have sufficient time to "get out of the way" of the body moving in the air. This causes the air particles to be compressed into a dense "shock wave", which can cause separation of the air flow from the surface of the airfoil, leading to a stall. The properties of a wing that handles supersonic airflow well are often at odds with a subsonic wing.
- kolinko 6y agoHm, imagine your ship made really big waves when swimming. Below the speed of waves you don’t really need to worry about them because you don’t really experience them - they just run ahead of you. If your speed is close to the speed of waves, the waves that you produce get stuck on top of one another, so you have this huge wave ahead of you. If you want to break through that barrier, you need a really strong ship to plow through that huge wave, but once you’re through it, it gets smoother - you don’t encounter your own waves any more. But now the problem is: the moment you slow down, or make a turn, all the waves you produced will hit you from the back. We don’t get that with water due to various reasons, but we get that with air and sound.
- dotancohen 6y ago> Boom’s first major airline partner in the development of the > first privately built supersonic airliner and the second ever > after Concorde, retired in 2003, is Japan Airlines with an > option for 20 aircraft. How could any reporter, especially one writing for a publication called "airlineratings", not research the topic at hand? It is widely known in the aviation community that the Soviet union flew the supersonic TU-144 even before the Concorde flew.
- kmlx 6y agothat faded away from memory mostly because of this: https://en.wikipedia.org/wiki/1973_Paris_Air_Show_Tu-144_crash https://en.wikipedia.org/wiki/1973_Paris_Air_Show_Tu-144_cra... "During the show, there was a "fierce competition between the Anglo-French Concorde and the Russian Tu-144".[6] The Soviet pilot, Mikhail Kozlov, had bragged that he would outperform the Concorde.[6] "Just wait until you see us fly," he was quoted as saying. "Then you'll see something."[12] On the final day of the show, the Concorde, which was not yet in production, performed its demonstration flight first.[6] Its performance was later described as being unexciting, and it has been theorized that Kozlov was determined to show how much better his aircraft was.[12] Once in flight, the aircraft made what appeared to be a landing approach, with the landing gear out and the "moustache" canards extended, but then with all four engines full power, climbed rapidly. Possibly stalling below 2,000 ft (610 m), the aircraft pitched over and went into a steep dive.[6] Trying to pull out of the subsequent dive with the engines again at full power, the Tu-144 broke up in mid-air, possibly due to overstressing the airframe. The left wing came away first, and then the aircraft disintegrated and crashed,[6][8][10] destroying 15 houses,[13] and killing all six people on board the Tu-144 and eight more on the ground.[8] Three children were among those killed, and 60 people received severe injuries.[14]" i mean bragging about how good it was and then crashing is a trademark of the USSR.
- dwd 6y agoI thought the Cobra maneuver was a Russian trademark, just not something you should try in a Tu-144.
- new_realist 6y agoWill Zoom kill Boom?
- coopernewby 6y agoI am amazed at the, apparently almost exclusive, use of formed composites for the entire skin of the aircraft. This was an aircraft skin design no no for a long time because of the susceptibility of graphite filled epoxy composites to failure under shock and/or point loading even though the specific strength/rigidity was better than any metal. I wonder what the composition of the composites used now are comprised of. Anyone know?
- fluffy87 6y agoWhy are they using three engines instead of just one? Looks like a maintenance nightmare.