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Hmmm. Augmented reality display, Carbon fiber frame, supersonic intakes... And 3 J85-15 jet engines designed in the 1950s (?) I remember reading about these J
by LarsDu88 3y ago
Hmmm.
Augmented reality display, Carbon fiber frame, supersonic intakes...
And 3 J85-15 jet engines designed in the 1950s (?)
I remember reading about these J85 engines in an issue of Popular Mechanics roughly 20 years ago. This engine was designed to be cheap and small enough to fit in a carry-on suitcase circa 1955. They are best known for powering the F5 "low-budget fighter" from 1959.
Crazy that a new aircraft is launching with such new tech, but still rocking engines that were fundamentally designed around 10 years after the dawn of jet aircraft.
- TotempaaltJ 3y agoIf it ain't broke...
- madmask 3y agoIt warms my heart seeing old designs still working just fine.
- KolmogorovComp 3y agoThey are not testing the engines here (which they will not be manufacturing anyway), but the aerodynamics and the systems.
- zitterbewegung 3y agoWell since Rolls-Royce abandoned the project that might be why? This seems like more of a proof of concept of the airframe itself.
- phonon 3y agohttps://en.wikipedia.org/wiki/Boom_Symphony https://en.wikipedia.org/wiki/Boom_Symphony aren't ready yet.
- rbanffy 3y agoMeh... I'll take whatever supersonic passenger transport is offered, but Mach 1.7 is disappointing.
- jameshart 3y agoWhy did they design it to fit in a carry on suitcase?
- kube-system 3y agoBecause you have to be able to take them on the plane, obviously. /s But seriously I think 'fitting in a suitcase' wasn't the design goal, per se, but an approximate description of the design goals. The engine was designed to go in a missile.
- jameshart 3y agoThat’s interesting actually - and a lot of 1950s era ‘small enough to fit in a suitcase’ descriptions (computers, nuclear warheads, jet engines…) make more sense if you realize they are a euphemism for ‘small enough to fit in a missile’. Makes me wonder what ‘small enough to fit in a cigar box’ was a euphemism for.
- dsr_ 3y agoThat's a euphemism for cigar boxes; smuggled cigars get through borders with a little rake-off at each inspection. The fact that they are actual cigars on the top layers allows all the boxes to get past slightly bent but nonetheless patriotic guards.
- kube-system 3y agoEh, maybe. The suitcase itself is also, more simply, literally just something designed to be a reasonable amount of stuff that a human could carry. Many early portable PCs (e.g. Osborne) targeted a suitcase form factor just because it was a reasonable form factor for people to carry around. And the comparison is something colloquially convenient. "The device was the size of a suitcase" is just more illustrative than "the device was 50 liters in volume"
- jameshart 3y agoLike I’m going to take advice from someone called ‘kube-system’ about container sizes :D
- pnw 3y agoAs 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 agomaybe more so.
- mrguyorama 3y agoIf 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 agoBut supersonic engines already exist, and aircraft manufacturers almost universally buy instead of build when it comes to choosing an engine.
- jlmorton 3y agoOne 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.
- 3y ago
- JumpCrisscross 3y agoHermeus is starting with the engine [1]. [1] https://www.hermeus.com/ https://www.hermeus.com/
- rbanffy 3y agoSmart - if you fail to develop an airframe, you can still sell engines. The other way around is much more difficult.
- pandemicsyn 3y agohttps://www.youtube.com/watch?v=UyKtxsdI0z8 https://www.youtube.com/watch?v=UyKtxsdI0z8 but even they're using relatively old engines as the starting point. Because they're simple and well understood.
- kilroy123 3y agoPersonally, I'm far more bullish on hermeus than I am Boom.
- notahacker 3y agoThey have a bigger addressable market
- dralley 3y agoAnd military payloads don't complain about cramped seats, nor is the sticker price as much of a concern.
- llsf 3y agoYet still based on GE J85 turbojet https://www.hermeus.com/chimera https://www.hermeus.com/chimera
- brcmthrowaway 3y agoCan we get LLMs to design the engine?
- rbanffy 3y ago> Crazy that a new aircraft is launching with such new tech, but still rocking engines that were fundamentally designed around 10 years after the dawn of jet aircraft. Their goal is to prove the design's aerodynamics WRT sonic boom, not the engines.
- bell-cot 3y agoThis is their 1/3-scale test/demo airplane. Spending big on engines for it would not make sense. https://en.wikipedia.org/wiki/Boom_XB-1 https://en.wikipedia.org/wiki/Boom_XB-1
- 1letterunixname 3y agoExactly. The real thing™ will have their custom Symphony jets. The XB-1 is a tech and systems demonstrator platform cheaper than big design upfront and costs (and risks) all at once.
- sandworm101 3y ago>> Augmented reality vision system: Two nose-mounted cameras, digitally augmented with attitude and flight path indications, feed a high resolution pilot display enabling excellent runway visibility. This system enables improved aerodynamic efficiency without the weight and complexity of a movable nose. (Cough) Don't tell the passengers it is all because the pilot literally cannot see the runway during landing.
- JumpCrisscross 3y ago> because the pilot literally cannot see the runway during landing ILS solved this problem for airline transport pilots [1]. [1] https://en.wikipedia.org/wiki/Instrument_landing_system https://en.wikipedia.org/wiki/Instrument_landing_system
- Gare 3y agoTo be fair, they do need an alternate with a better visibility. But if the computers are not working, you're not in for a good time in a modern airliner anyway.
- 9659 3y agoMaybe not a 'good time', but a safe one. Commercial airliners have standby instruments and a VHF radio that works on a battery. Which is all you need to get it on the ground in one piece.
- Gare 3y agoYou cannot operate fly-by-wire aircraft without computers, that's what I meant. Redundancy is name of the game, I see no problem in using cameras if they're made redundant.
- potatolicious 3y agoILS generally still requires manual visual approaches from the minimum altitude to the ground. Only ILS Cat III-C is a true autoland that can take the aircraft down all the way to the ground. Even then, aircraft certification requirements even for Cat III-C capable aircraft requires that pilots be able to conduct a visual approach because the ILS system can fail. An aircraft that has literally no recourse when ILS Cat III-C capability goes down (either on the aircraft side or the airfield side) does not seem like a good idea, especially because in this case large categories of emergencies are positively correlated with avionics failure. For example an engine failure may cause power loss to avionics, so your fancy AR webcam feed is more likely to go down in that situation just when you need to make an emergency landing. Not impossible to overcome of course - you certainly can ensure your avionics have its own isolated (and multiply redundant) power source so that it does stay up in the event of many kinds of emergencies, but personally I'd need to really see the homework on that before I'd feel safe flying in that kind of setup.
- NegativeLatency 3y agoProbably a good engine choice because it's plentiful, and used on other similar aircraft, for example their T-38 chase plane uses the same engine.
- B4CKlash 3y agoHigh tech manufacturing at scale is often equally as challenging as development work. Starting with a proven design let's teams focus on leveling up their manufacturing capabilities prior to introducing the double complexity of manufacturing a part that just made it out of CDR. A bit of a tangent, but this is the genius of Musk's Merlin engine. Simple design utilizing RP9 allows the manufacturing staff to hit their stride before introducing the raptor (methalox).
- api 3y agoFalcon 9's Merlin engine is really just based on a NASA reference design for a simpler low cost rocket engine. Raptor is new tech, but that was long after SpaceX had proven itself and had the capital and talent to invest in building something like that. It makes total sense to use flight proven engines like this off the shelf at first.
- HumblyTossed 3y agoIf they work, I don't understand the issue. Not everything has to be modern to be useful.
- FrustratedMonky 3y agoI don't think people here understand how old a lot of the designs are that they use everyday. Old Design + New Materials can still be cutting edge
- fnord77 3y ago> This engine was designed to be cheap and small enough to fit in a carry-on suitcase circa 1955. Not quite... " a jet engine that’s all of 18 inches wide and 45 inches long."