7 ms·

As I understand it, engine sourcing has been one of Boom's challenges. Rolls Royce was originally working on an engine for them, but cancelled it in '22. Boom a

by pnw 3y ago

As I understand it, engine sourcing has been one of Boom's challenges. Rolls Royce was originally working on an engine for them, but cancelled it in '22. Boom announced their own engine design last year but I'm assuming that's not ready. Apparently newer engines aren't designed for supersonic flight so I'm guessing options are limited for testing this airframe.

JumpCrisscross 3y ago
> Boom announced their own engine design last year but I'm assuming that's not ready The complexity of designing an engine is comparable to that of designing an airframe.
- smachiz 3y ago
  maybe more so.
  - mrguyorama 3y ago
    If China is anything to go by, immensely more so, and you are not significantly helped even if you had all the documents and industry secrets required to design and build a modern engine!
- dmurray 3y ago
  But supersonic engines already exist, and aircraft manufacturers almost universally buy instead of build when it comes to choosing an engine.
  - jlmorton 3y ago
    One of the key features of Overture is its planned use of e-fuels. I think this is almost crucial. Airlines are not going to line up to buy non-renewable, fuel-guzzling, net CO2-gushing supersonic jets for use over the next couple decades.
    - dhash 3y ago
      They will if its cheaper
      - resolutebat 3y ago
        Not if they're banned, which will almost certainly be the case by the time Boom is commercially available.
        willmadden 3y ago
        We're banning engines now?
        mlyle 3y ago
        Airlines are almost certain to face significant carbon regulation or carbon taxes in the next couple of decades. In turn, lots of engines will be effectively banned. Of course, this is nothing new: noise abatement effectively banned a whole lot of engines, too.
        nemo44x 3y ago
        [flagged]
        mlyle 3y ago
        I don't think it requires giving up on "affordable global flight". It might be a bit more expensive -- getting aircraft to be tens of decibels quieter cost something, too. Externalities -- whether they're noise imposed on a community or climate impacts -- aren't generally addressed by the market on its own. Indeed, we have a new regulatory regime coming into play for airplane emissions slowly-- with first effects in 2028.
        jlmorton 3y ago
        I mean, it's already happening all over the world. It's not just Germany. The UK already taxes carbon in aviation fuel. It's about to implement a carbon pricing mechanism for jet fuel obtained in jurisdictions without it. The EU is implementing carbon taxes, and a mandate for Sustainable Aviation Fuel. In 25 years, it will be illegal across the EU27 to use aviation fuel that is not at least 70% Sustainable Aviation Fuel. China has the world's largest emissions trading program. Civil aviation will be included next year. Australia has a carbon tax, and will soon have mandates on civil aviation emissions. Brazil does not yet have a carbon tax, but in the past year there has been legislation proposed, and it looks likely to be coming sometime soon. The US EPA just announced regulations that will not force, but will certainly make it cost prohibitive to sell lots of gasoline cars ten years from now. Civil aviation is a likely next target.
  - notahacker 3y ago
    They announced they're building their own because the regular engine OEMs showed little interest. Even if required modifications to historic or military turbojets are minor, there's a lot of expense in certifying them for use for a new type of passenger aircraft, and modern economical turbofans were not designed for supersonic flight...
  - foldr 3y ago
    Only for military applications, which have much lower reliability and serviceability requirements.
  - sofixa 3y ago
    (Almost?) exclusively on military planes which have different return on investment needs than commercial aircraft that need to be efficient first and foremost (ask Convair and BAC/Sud Aviation how many airlines valued speed over efficiency).
- foxyv 3y ago
  I believe they are thinking that one is a solved problem (Jet Engine) and the other is a novel problem (Airframe with reduced supersonic noise). There has been some work done on the sonic boom problem, but not nearly as much as the jet engine problem. They will probably just iterate from an existing engine design rather than trying to re-invent one. Just because no one is manufacturing them doesn't mean the designs are not there to be used.
  - cherryteastain 3y ago
    Jet engine is a "solved" problem for like 4 Western companies (GE, Pratt-Whitney, Rolls-Royce, Safran) plus some Russian and Chinese state-owned enterprises that mostly do military work. These organizations guard their secret sauces vigorously. Designing a cutting edge jet engine from scratch (i.e. with competitive fuel efficiency) is NOT a trivial task.
    - phkahler 3y ago
      >> Jet engine is a "solved" problem for like 4 Western companies (GE, Pratt-Whitney, Rolls-Royce, Safran) plus some Russian and Chinese state-owned enterprises that mostly do military work. Time to mention Williams International https://en.wikipedia.org/wiki/Williams_International https://en.wikipedia.org/wiki/Williams_International They're on light jets from Cirrus and Cessna. Boom probably needs something a bit larger - seems like an opportunity for a development program.
      - throwup238 3y ago
        There's actually quite a few companies that make small turbojets especially for military purposes and up to a certain point, you can even DIY your own from spare parts (there are some Youtubers that have done that). That's the first tier and includes companies like Williams, usually producing <5,000 lbf engines. Then you have companies like Garrett/Honeywell that can make engines that output tens of thousands lbf like the TFE731 for mid-range jets and fighter jets. These can power big jets but not very fuel efficiently; that's the second tier. The next tier up is the high bypass turbofans producing tens of thousands lbf used for commercial aviation and afterburner engines for last gen fighter aircraft are a completely different story. The GP is right there are only a few players in the game. Due to scaling laws, at this point it becomes less about the design and more about the metallurgy and material science. Magic like single crystal alloys are critical here and are very closely guarded secrets because the knowledge unlocks everything from ICBMs to gaseous centrifuges to nuclear reactors.
mc32 3y ago
Do they have the metallurgical expertise to manufacture their own engines? That would seem like a stretch… but who knows…
- nothercastle 3y ago
  Agreed I’m sure GE development very special material systems
  - jasonwatkinspdx 3y ago
    From what I've read GE spent roughly 10 years and 10 billion dollars to develop their monocrystalline turbine blade manufacturing materials and process.
spxneo 3y ago
my spider sense is already tingling from reading this! do we know the reason for why rolls royce pulled out???
- UberFly 3y ago
  "After careful consideration, Rolls-Royce has determined that the commercial aviation supersonic market is not currently a priority for us and, therefore, will not pursue further work on the program at this time. It has been a pleasure to work with the Boom team and we wish them every success in the future." Guess it was a cost thing. Wasn't worth their time. Not enough customers probably.
  - musiciangames 3y ago
    Not sure of the relative timing, but the new CEO is super focused on profitability/cash flow. In comparison to what he described as a ‘burning platform’ when he took over. So supersonic would have needed a brilliant business case to have survived his strategy. https://www.reuters.com/business/aerospace-defense/rolls-royce-track-new-ceo-finds-savings-2023-05-11/ https://www.reuters.com/business/aerospace-defense/rolls-roy...
trebligdivad 3y ago
Yeh, although on https://boomsupersonic.com/flyby/inaugural-first-flight-xb1-supersonic-demonstrator https://boomsupersonic.com/flyby/inaugural-first-flight-xb1-... they say 'Supersonic intakes: XB-1’s engine intakes slow supersonic air to subsonic speeds, efficiently converting kinetic energy into pressure energy, allowing conventional jet engines to power XB-1 from takeoff through supersonic flight.' - so perhaps the engine design problem is not as tricky as it would otherwise be.
- numpad0 3y ago
  All current supersonic aircrafts do that. The only kind of jet engine that can take supersonic intake air is scramjet(supersonic combustion ramjet), which is more like a space age gas torch, not a turbine engine. Shockwaves are going to blow off turbine blades if not done or something along that.

by pnw 3y ago

JumpCrisscross 3y ago

> Boom announced their own engine design last year but I'm assuming that's not ready The complexity of designing an engine is comparable to that of designing an airframe.

smachiz 3y ago
maybe more so.
- mrguyorama 3y ago
  If China is anything to go by, immensely more so, and you are not significantly helped even if you had all the documents and industry secrets required to design and build a modern engine!
dmurray 3y ago
But supersonic engines already exist, and aircraft manufacturers almost universally buy instead of build when it comes to choosing an engine.
- jlmorton 3y ago
  One of the key features of Overture is its planned use of e-fuels. I think this is almost crucial. Airlines are not going to line up to buy non-renewable, fuel-guzzling, net CO2-gushing supersonic jets for use over the next couple decades.
  - dhash 3y ago
    They will if its cheaper
    - resolutebat 3y ago
      Not if they're banned, which will almost certainly be the case by the time Boom is commercially available.
      - willmadden 3y ago
        We're banning engines now?
        mlyle 3y ago
        Airlines are almost certain to face significant carbon regulation or carbon taxes in the next couple of decades. In turn, lots of engines will be effectively banned. Of course, this is nothing new: noise abatement effectively banned a whole lot of engines, too.
        nemo44x 3y ago
        [flagged]
        mlyle 3y ago
        I don't think it requires giving up on "affordable global flight". It might be a bit more expensive -- getting aircraft to be tens of decibels quieter cost something, too. Externalities -- whether they're noise imposed on a community or climate impacts -- aren't generally addressed by the market on its own. Indeed, we have a new regulatory regime coming into play for airplane emissions slowly-- with first effects in 2028.
        jlmorton 3y ago
        I mean, it's already happening all over the world. It's not just Germany. The UK already taxes carbon in aviation fuel. It's about to implement a carbon pricing mechanism for jet fuel obtained in jurisdictions without it. The EU is implementing carbon taxes, and a mandate for Sustainable Aviation Fuel. In 25 years, it will be illegal across the EU27 to use aviation fuel that is not at least 70% Sustainable Aviation Fuel. China has the world's largest emissions trading program. Civil aviation will be included next year. Australia has a carbon tax, and will soon have mandates on civil aviation emissions. Brazil does not yet have a carbon tax, but in the past year there has been legislation proposed, and it looks likely to be coming sometime soon. The US EPA just announced regulations that will not force, but will certainly make it cost prohibitive to sell lots of gasoline cars ten years from now. Civil aviation is a likely next target.
- notahacker 3y ago
  They announced they're building their own because the regular engine OEMs showed little interest. Even if required modifications to historic or military turbojets are minor, there's a lot of expense in certifying them for use for a new type of passenger aircraft, and modern economical turbofans were not designed for supersonic flight...
- foldr 3y ago
  Only for military applications, which have much lower reliability and serviceability requirements.
- sofixa 3y ago
  (Almost?) exclusively on military planes which have different return on investment needs than commercial aircraft that need to be efficient first and foremost (ask Convair and BAC/Sud Aviation how many airlines valued speed over efficiency).
foxyv 3y ago
I believe they are thinking that one is a solved problem (Jet Engine) and the other is a novel problem (Airframe with reduced supersonic noise). There has been some work done on the sonic boom problem, but not nearly as much as the jet engine problem. They will probably just iterate from an existing engine design rather than trying to re-invent one. Just because no one is manufacturing them doesn't mean the designs are not there to be used.
- cherryteastain 3y ago
  Jet engine is a "solved" problem for like 4 Western companies (GE, Pratt-Whitney, Rolls-Royce, Safran) plus some Russian and Chinese state-owned enterprises that mostly do military work. These organizations guard their secret sauces vigorously. Designing a cutting edge jet engine from scratch (i.e. with competitive fuel efficiency) is NOT a trivial task.
  - phkahler 3y ago
    >> Jet engine is a "solved" problem for like 4 Western companies (GE, Pratt-Whitney, Rolls-Royce, Safran) plus some Russian and Chinese state-owned enterprises that mostly do military work. Time to mention Williams International https://en.wikipedia.org/wiki/Williams_International https://en.wikipedia.org/wiki/Williams_International They're on light jets from Cirrus and Cessna. Boom probably needs something a bit larger - seems like an opportunity for a development program.
    - throwup238 3y ago
      There's actually quite a few companies that make small turbojets especially for military purposes and up to a certain point, you can even DIY your own from spare parts (there are some Youtubers that have done that). That's the first tier and includes companies like Williams, usually producing <5,000 lbf engines. Then you have companies like Garrett/Honeywell that can make engines that output tens of thousands lbf like the TFE731 for mid-range jets and fighter jets. These can power big jets but not very fuel efficiently; that's the second tier. The next tier up is the high bypass turbofans producing tens of thousands lbf used for commercial aviation and afterburner engines for last gen fighter aircraft are a completely different story. The GP is right there are only a few players in the game. Due to scaling laws, at this point it becomes less about the design and more about the metallurgy and material science. Magic like single crystal alloys are critical here and are very closely guarded secrets because the knowledge unlocks everything from ICBMs to gaseous centrifuges to nuclear reactors.

mc32 3y ago

Do they have the metallurgical expertise to manufacture their own engines? That would seem like a stretch… but who knows…

nothercastle 3y ago
Agreed I’m sure GE development very special material systems
- jasonwatkinspdx 3y ago
  From what I've read GE spent roughly 10 years and 10 billion dollars to develop their monocrystalline turbine blade manufacturing materials and process.

spxneo 3y ago

my spider sense is already tingling from reading this! do we know the reason for why rolls royce pulled out???

UberFly 3y ago
"After careful consideration, Rolls-Royce has determined that the commercial aviation supersonic market is not currently a priority for us and, therefore, will not pursue further work on the program at this time. It has been a pleasure to work with the Boom team and we wish them every success in the future." Guess it was a cost thing. Wasn't worth their time. Not enough customers probably.
- musiciangames 3y ago
  Not sure of the relative timing, but the new CEO is super focused on profitability/cash flow. In comparison to what he described as a ‘burning platform’ when he took over. So supersonic would have needed a brilliant business case to have survived his strategy. https://www.reuters.com/business/aerospace-defense/rolls-royce-track-new-ceo-finds-savings-2023-05-11/ https://www.reuters.com/business/aerospace-defense/rolls-roy...

trebligdivad 3y ago

Yeh, although on https://boomsupersonic.com/flyby/inaugural-first-flight-xb1-supersonic-demonstrator https://boomsupersonic.com/flyby/inaugural-first-flight-xb1-... they say 'Supersonic intakes: XB-1’s engine intakes slow supersonic air to subsonic speeds, efficiently converting kinetic energy into pressure energy, allowing conventional jet engines to power XB-1 from takeoff through supersonic flight.' - so perhaps the engine design problem is not as tricky as it would otherwise be.

numpad0 3y ago
All current supersonic aircrafts do that. The only kind of jet engine that can take supersonic intake air is scramjet(supersonic combustion ramjet), which is more like a space age gas torch, not a turbine engine. Shockwaves are going to blow off turbine blades if not done or something along that.