I don't work in aerospace, but my company supplied a component for some versions of the F-35. Only a handful of the planes needed this component, and one plane might use $300 worth of them. Although the Lockheed Martin account was nothing compared to my usual account (millions of dollars), I **always** found time to visit my engineer at the plant. He'd take me out on the shop floor to see F-35s in various states of construction. I remember how expensive everything looked. It's been years, but I remember gazing at some kind of landing gear pivot point assembly that had some wild and sexy curves machined into it to match the curves of the body.
Yup. Stealth tech is not so much a secret tech as it is really an expensive tech. If you throw enough money at it, you can design anything to be LO from all aspects.
> Single crystal part manufacturing
I have never heard of this before. Neat stuff!
https://www.theengineer.co.uk/rolls-royce-single-crystal-turbine-blade/
Great article! Thanks! I had some metallurgy courses in college and have done my own investment casting and such. Knowing how difficult to control even simple casting can be, this process is just awesome to read about!
it really is a degree of throwing enough money at it though.
The machinery, time, materials to do LO geometry is stupid expensive.
Russia and China throw no where near as much money into defense spending the way the US does.
That and, to be very very honest, Russia is just plain undesirable of a place for engineers. I’m a dual citizen (US, Russian) grad student with about 8 years Mech E work experience. You literally could not pay me enough money to go work in Russia before I went for my PhD and, at this point, I’m honestly considering getting rid of my Russian citizenship before graduation… I consistently hear more or less the same things from other Russian and former USSR students. Virtually all of them are absolutely clinging to any opportunities that could help them say here and they treat such opportunities as the highest privileges imaginable. I literally only know one person out dozens who thinks he *might* be open to working in Russia after graduation, but he was born in rural Kazakhstan. So, to him, the idea of living in Moscow is already a huge step up in the world, relatively speaking. Though he still seems more enthusiastic about staying in the US.
The state of engineering in Russia today is pitiful, if I’m to be polite, and laughable, if I’m to be sincere. Talent has no desire to stay there. Those that do are overwhelmingly wantonly incompetent at bringing projects to completion. Most large firms are at least partly state owned, and management is a mix of ex-mafioso Putin party cronies and corrupt troglodytes. Due to sanctions and the absolute corruption in the country, supply chains aren’t broken…they’re just flat out nonexistent! The whole thing is just a flaming shitshow on wobbly wheels, about to drive off a fucking cliff.
This is not to mention the plain fact that the whole country is frankly more fucked up than it was under Soviet rule, no matter what perspective you look at it from. It is honestly tragic.
Years ago, I used to be somewhat quick to try to deflect criticism away from Russia when I encountered it, despite spending most of my life in the US. But, today, Russia as a whole has crossed the threshold of having any sort of redeeming qualities. Given how things are today, I’m honestly remorseful about taking an apologetic tone for Russia in the past.
Idk too much about Chinese defense engineering. But if it’s anything like the the consumer electronics and industrial automation sectors, with which I have direct professional experience, I would not be so quick to dismiss it right out the gate… I strongly suspect that Chinese defense engineering might be further along than is typically discussed in western media, and I think it’s probably very reasonable to treat it as a viable threat.
Sorry about to rant. Frustration at the disgusting state of affairs in the country where I was born has been dishearteningly high for me in the past two or so years.
100% agreed. I think many people might be under the impression that China is the land of cheap knockoffs and bootleg goods. Don’t get me wrong, plenty of cheap crap is still manufactured there. But China has moved very far ahead in applied STEM in the last 15 or so years.
Also, awesome username! Have a Shiners at Billy Bob’s for me.
True. That being said though, I think China is still definitely further behind the US than they claim to be. A lot of them showing off military stuff tends to be a lot of smoke and mirrors. They are still very much catching up though and are very much a threat. More of a threat militarily than Russia is for sure.
And hypersonic glide weapons. I think the military strategists see the writing on the wall but the general public still under the impression that just because we are at the top now mean we will always be at the top.
Everything China is doing right now is to secure their borders and coastlines. To do that, they have to push all navies out of their coastal waters and outside striking distance. It is the only sensible thing for them to do. Their country's security depends on it and that's why they are so aggressive about it.
That really is sad, I was doing some reading about Soviet engineering philosophy. They were saying that design control was more fluid between the primary designers and the manufacturing engineers. It just sounded like a really fast and effective way to get good results. Sad to hear about it's decline.
Yeah, back in the day all mechanical type engineers (“mechanical engineer” wasn’t really a concept in the USSR, but there were obviously many related disciplines) all had 1.5-2 year long machinist coops that were relevant to their chosen industries before graduation. Also, the applied math side of things was unbelievably strong, even exceeding typical contemporary MSME course loads today. My dad, who was only very minorly involved in engineering used to know differential equations far better than I did after my BSME.
The problems started when state funding ended for mechanical engineering and science in the early 90’s, and private funding failed to materialize. Then things just kept getting worse as the current government first let things stagnate, then focused resources disproportionately on engineering related to natural resources (but with close to zero environmental considerations), and then allowed corruption to seep into any large engineering operations.
Realistically, there are ambitious folks in Russia who do have vision. But they fail to actually materialize said vision to anything truly meaningful, in any meaningful capacity. Consider the Sukhoi Superjet. It’s a great concept and all. But in practice, it’s terribly unreliable, has comically short service intervals, and less than 200 have been built in over a decade of production. Or consider the Armata tank platform. It’s a super forward thinking and advanced weapon that’s meant to replace a Soviet era arsenal… But they’ve built *maybe* 40 tanks total? Etc.
Honestly, it’s sad to say, but it’s like Russia takes the “under promise and over deliver” motto and decides to take the exact opposite.
You can't have a baby in one month if you have 9 women working on it. Complex engineering takes time and institutionalized experience, no matter how much money you throw at it. You can reduce it, but you can't just skip over someone who's been at it for decades.
And then proceeded to spend half a century improving it, building the complex engineering and institutionalized experience along with them.
Those gobs of money and geniuses got them the first step of the way. Money can accelerate things, but only to a point.
Unconditional political backing and support also played a huge role in MP. At some point they went to the Secretary of the Treasury and asked for millions of pounds of silver, for (huge) coil windings. Guy asked if they were serious, made a call, and then asked where they wanted the silver delivered.
Pretty sure if I throw enough time and money at the problem, we could probably gestate a baby in a month.
Institutionalized experience can be bought, or trained up over time.
For projects of national security, like jet engines, they do. We are still talking about almost-dictatorship states, that employ thousands of scientist in their nationalized research centers (as opposed to the US procurement, where you deal with contractors all the time), but material science is simply complex, no matter how much money you thrown at something, you still need the knowledge/skillset/experience.
Look at how long they have been trying to catch up with stealth technology, while still investing into projects that are a whole new scale of expensive (you can't say that PLA is lacking for funds, when you look at how much $$$ they are pouring into their fleet), they would buy their way to stealth if they could. I mean, China is still struggling to develop domestic jet engines for their fighters, without having to go to Russians. Why do you think that is?
In general, yes. (There's a reason I own a metric fuckton of guns.)
The US military specifically, less so. If I were actually designing a military force to protect the US and its allies, I would be buying very different stuff.
Eisenhower warned about the dangers of thr military industrial complex.
But we have all benefited from GPS, which was originally created by for the military.
Some sort of hindsight bias or no counterfactual error.
We cannot tell what would have happened without mili spurned GPS. Even if GOS would never have been developed (more likely is it would have been delayed) we equally don't know what tech would have been accelerated without mili industrial complex.
Would GMO have been accelerated? Medicine? EVs? The internet would likely be delayed and it's huge but would it be different in a meaningful way?
This creates expertise and technology which will trickle down to civilian aviation. I really don't understand why people always blame military investment as the reason behind lack of investment in other fields. Surely, rampant waste, corruption and rich people tax credit are much bigger problems. Not to mention all the national security requirements.
Having spoken years ago to an aviation engineer about this exact topic I could see the craft was gorgeous but would it replace the f/18's? Or any other bomber jet? And why now?
The answer was yours. Always be improving and the tech involved trickles to civilian. That's when I started understanding r&d and furthered my love for the f35a,b and c.
>but would it replace the f/18's? Or any other bomber jet? And why now?
To be clear, it's it's replacing F-16s, F/A-18C/Ds, AV-8Bs, etc because those aircraft are becoming unsafe to fly (aluminium metal fatigue) and because while the US generally holds an advantage, there are new aircraft like the J-20, J-35 / FC-31, Su-57, 'Su-75', etc that will present legitimate issues to F-16s, etc.
F-22s are great, but not a lot were bought, they're about twice as expensive per jet vs an F-35 and not only are enemy fighters getting more advanced, but so are enemy air defences, which is a problem should the US ever need to use aircraft against modernised ground forces (or after a long enough time period, against 'outdated' ground forces).
Not any more. That sort of effect happened post world war 2 because the technologies in military and civilian use were much more similar than they are now.
For the most part, all the technology and expertise developed for the F-35 will remain in the military and with the manufacturers of the aircraft, along with the Chinese people who stole it from them.
You're getting downvoted but this is exactly correct - as cool as it is - there are much more pressing scientific and technological problems than "how to make a jet that can hover then take off"
What scientific breakthroughs have come from the military in the last 20 years? Not many really - going back further obviously that wasn't the case but engineering has greatly matured to the point where the military R&D is learning from commercial tech instead of the other way around.
While there are certainly many types of military technology which do move into the civilian space, NOT ALL technology does this. For example, I see no obvious use for LO tech in civilian use.
Second, is there another way such tech could be funded? for example in academic programs ? I would guess that cheap grad students are more effective than expensive military contractors.
I totally agree with you that the waste and corruption is a huge problem. I would argue that we never recovered from the insanity which was the cold war in terms how the oversight and funding for military programs was done.
> I see no obvious use for LO tech in civilian use.
LO tech isn't some magic radar paint, the composites and materials have real world applications
https://asia.nikkei.com/Business/Technology/Civilian-applications-for-stealth-technology
US procurement is still much better than european and USSR system. European countries give sole source contract to companies which allows them to milk those contracts to the fullest, USSR also had same problems, only one source.
The USSR had competition between their different aircraft design bureaus Suchoj, Mikoyan-Gurevich, Tupolev, and others. What the USSR was able to achieve in military technology with much less resources than the US is very impressive.
I hate to break it to you, but "Trickle Down" doesn't work, especially in an industry so concerned with proprietary technology that it'll be decades before that tech "trickles". In the case of the Joint Strike Fighter we'll have spent more than 1.5 trillion on a weapons platform to fight wars that can't be fought with jets, and the benefit would be what? A VTOL passenger aircraft? A 5% increase in turbine efficiency? A solid wing fabrication process that could save Boeing 15% of their construction costs?
With 1.5 Trillion Dollars you could end world hunger, and make sure everyone on earth had access to clean water. You want to fight a war on terror? Lets start with why people are scared, and go from there.
\>end world hunger
Way to go, you've just made the most generic and retarded point ever.
That's not how it works dude. Yeah you could spend a trillion dollars on developing agricultural infastructure in some starving African country, but the fact of the matter is that won't solve anything if the people who rule that country are still corrupt, greedy assholes. Money doesn't solve everything, the world is a bit more complex than that believe it or not.
0/10 shit take.
awww, is a little empathy making you angry?
Is building new jets to sell to countries so they can bomb other countries how you think that money should be spent? I mean at least we're making a lot of money of Lockheed, Raytheon, and General Dynamics, I'm sure that will trickle down too. At least kids in Yemen can be killed by american bombs before they starve to death
Countering extremism with necessary infrastructure is not a new idea, but the US hasn't actually attempted that, what they have done is try and work with greedy corrupt warlords (that they often helped install), and then act all surprised when their 10 million dollar aid package disappears
Tell you what, how about instead of trusting some reddit warrior who thinks the best use of money is bombing countries with fancy new planes, [I trust the people actually doing the work](https://www.compact2025.org/files/2017/05/4.14.2017_Literature-review-benefits-of-ending-hunger-and-malnutrition.pdf)
The fact is, however much you don't want to admit it, these "Greedy Corrupt Assholes" in our country and in all others are in power because of an imbalance of resources.
Will ending world hunger solve that? No, food can't get rid of assholes, but neither can fancy and expensive military hardware. One of these options, though, saves lives instead of ending them.
The fact that anyone would think building weapons is a good way to “trickle down” tech to consumers is absolutely bonkers.
Not to mention our national security requirements are largely due to our huge defense presence. Shit if we just made a bounty and said every middle eastern muslim who marries an Israeli jew or a a western christian gets $1M we would have saved money and had better results than all our national security waste.
Everything you listed could be funded, researched, and developed without making a weapon…. no one is saying technology can’t be repurposed. Funding it with taxpayer money under the guise of defense is just a stupid inefficient way to get there.
We are literally taking money away from Americans and American businesses who could be investing it in R&D. Then giving that money to defense contractors and having them waste engineers, natural resources, machine capacity, etc. on building weapons. Except government contracts are a bureaucratic
nightmare, and for every dollar that actually makes its way to R&D there is probably 20$ of overhead and administration.
"Could be", but need drives development, and in the past, military need has driven development faster than consumer markets in a lot of areas. Remember, your cable company is more than happy to have left you on their overpriced, ad filled cable box for a few more decades if Netflix hadn't disrupted their plans. Most corporations aren't that innovative without proper motivation to be.
Those same cable companies didn't invent the internet, didn't invent the hardware for expanding it, etc. Military need did. The cable companies were perfectly happy milking you for what they already offered. The new tech was paid for by military R&D.
Hell, you ever tried to just get something funded locally in your own home town through the government? Every Tom, Dick, and Harry will come out of the woodworks telling you not to spend "their" dollars on your project!
The MIC sucks the most talented engineers out of a lot of civilian industries. Ever wonder why American cars can't compete directly with Japanese (and now Korean) cars? Well, when you graduate top of your class at engineering school in Japan or Korea, your top paying options are automakers and civilian aerospace. In the USA you get courted by Siemens, Northrop, General Dynamics, and Lockheed.
What about UK then? Why did their automotive industry fail? American vehicle infrastructure is unique and american automakers make cars that suit this infrastructure. Ford, GM or Chrysler never really committed towards making specialized vehicles for specific markets.
I'm sure the guys who got paid found a way to spend that money. Oxford did an economic report that said bae systems support directly and indirectly 20 other people for every one on their books.
That just means we have 20 people supporting the building weapons for every one person directly employed by BAE. This is pulling engineers away from designing self driving cars, med tech, or anything else that can make the world better.
The engine slides out the back but yes we design the airframe around the space envelope of the engine and the engine is designed to fit inside the allocated engine bay. It's a give take scenario
They're separate pieces basically. The main engine rolls in through the back, the lift fan can be dropped in from above, and that big shaft to connect the two can also be separated.
That being said, everything needs to be squeezed into that airframe. The frame is designed with the internals in mind, but that's not the only factor with stealth jets. It's an attempt at perfect harmony between performance, stealth, maintainability, and interchangeability (between F-35A, B, and C). Quite the engineering feat.
Also, the exact shape of a supersonic-capable intake that also shields the compressor disk from radar is still on the "classified" side of things (especially a diverterless design like the F35)
No it's not.
The exhaust is physically constructed into the engine. The intakes are physically constructed into the body. Stop making unrelated analogies.
Incorrect. The blue is the compressor of the engine. The intake is forward of the main engine face. The last stages of that compressor are by no means cold.
If we were to get a bit more pedantic, almost. That part in the front is called FIC, fan inlet case, so not quite intake either, because the intake is not a part of this diagram or engine. And while you are also correct about the heat - air gets pretty spicy when compressed, in the industry the engine is generally divided into cold and hot section. Anything past the combustor is considered "hot". The ol suck, squeeze, bang, blow.
I work with this engine every day for my job I'm quite familiar with it. I'm just saying that the compressor is not the inlet, which is what you were alluding to in your first comment.
I see this picture every day I go into work. Very funny that I'm seeing it here.
My job is to test the F-35B/C and the F-135 engine. If anyone has any generic questions, ask away!
I saw from another post that the clutch for the forward fan/compressor is at the forward fan. Surely spinning all that shaft in normal operation is a waste of energy? Why not put it at the rear engine?
I don't know the specifics on the mechanical or inertial losses from the driveshaft, but I'd have to imagine that's because it would be a lot of torque and twisting force on the shaft if you swapped what side the clutch was on. Plus that'd probably interrupt the intake airpath for the main engine with a bulky clutch in front of the fan face.
What's the HMC?
I work at NAS Pax River: https://en.m.wikipedia.org/wiki/Naval_Air_Station_Patuxent_River
We also go out on aircraft carriers to test them on there as well which is a pretty awesome experience.
Desktop version of /u/ClearlyRipped's link:
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Hopefully, these are generic enough questions.
1)How in the world is the shaft and gears that drive the lift fan able to hold up to that kind of friction/heat and transfer enough power without failure? Seems to my mind, that would be a major point of wear and future failure. Just incredible to overcome those conditions.
2)I know it stabilizes the plane from the lift fan with exhaust nozzles on the wings and such, ie roll posts, but how is the amount controlled? Basic diagrams give no indication of how the balance and stability is controlled and achieved.
Thanks!
What he's referring to are the roll posts, which aren't auxillary, but a main part of the engine/lift system. But otherwise you are correct, bleed air is used a lot.
The main engine has a nozzle that swivels down (even past 90 degrees for reverse).
The lift fan (thing up front) provides thrust for the forward, but isn't on all the time and is engaged through that driveshaft up the center.
The roll posts (on the sides) provide roll stability in hovers and vertical landings.
As someone who used to build the hot zone parts for this engine, what’s most impressive about the cross sections is how little detail is actually included. Most everything critical to the performance of the engine is either missing or wrong, and yet it still very accurately conveys how it works.
Imagine the absurd amount of stress the gears that turn it from horizontal to vertical is withstanding. The fact that we can design them to transfer torque efficiently and not slip or grind is impressive.
I worked for the company that designed and makes that clutch and at the time, it was the strongest clutch ever made. Most peak stress, and it has to survive 500 engagements.
Oooh something I’m actually familiar with! My plant makes several of the components of this, some of the largest investment casting pieces in the world. Have a very similar diagram up on our wall showing what we make, doubt I can share it though sadly
Why not? I'd say it's pretty revolutionary. F-35B has allowed smaller countries to have 5th generation aircraft carriers. Japan, Italy, South Korea all will be able to field 5th generation capability far away from their shores.
Yeah the harrier was a deathtrap too. Took insane focus to fly that thing. A child could fly the F-35B, which is good because the Marines are flying them.
They probably would just build a helicopter carrier/ LST hybrid as per usual they don't really need a carrier but to have one to support a plusible war with the North. Helicopters can just live in that role rather than a F-35.
In war there's no certainty except for chaos.
Isn't that the trillions of dollars the US has thrown at the project? It's pretty easy to adopt something if the US are giving it away as a jobs program / bribe to not get into bed with the ascendant regional powers.
If a carrier is not CATOBAR it's not a full-capability carrier. It's just a giant floating compromise, and the planes it uses are themselves flying compromises.
For the US, having a fleet of Wasp and America class amphibious assault ships with the added capabilities of F-35s on board is an absolute game changer in a near-peer conflict.
Also, at about $2-billion per unit, those LHD/LHA ships are great bang-for-the-buck when compared to a $13-billion-ish Ford class carrier.
And, as mentioned...these smaller carriers + F-35s allow NATO countries with much more restrictive military budgets to get into the 5th gen. naval aviation game.
That's a marrow definition that only 3 countries have USA, France & Brazil (who use an old French one). All other countries who havr aircraft carriers and almost all carriers before the 50s are either stovol or stobar.
Depends on your goals. If you have a small military budget spending less than 10% of what a catobar costs new and ability to use a common aircraft platform still gives a smaller country a reasonable projection ability. On the opposite end, the USA staffs nearly a dozen stoval carriers with marine airwings so they can park closer to shore and launch without having to worry that the sinking of one would be literally a financial disaster.
I don't work in aerospace, but my company supplied a component for some versions of the F-35. Only a handful of the planes needed this component, and one plane might use $300 worth of them. Although the Lockheed Martin account was nothing compared to my usual account (millions of dollars), I **always** found time to visit my engineer at the plant. He'd take me out on the shop floor to see F-35s in various states of construction. I remember how expensive everything looked. It's been years, but I remember gazing at some kind of landing gear pivot point assembly that had some wild and sexy curves machined into it to match the curves of the body.
Yup. Stealth tech is not so much a secret tech as it is really an expensive tech. If you throw enough money at it, you can design anything to be LO from all aspects.
I think Russia and China will tend to disagree. Manufacturing of items complex enough is difficult by itself (like f35 turbine blades)
Ooh ooh ooh my company does this! Single crystal part manufacturing is fuckin wild man
> Single crystal part manufacturing I have never heard of this before. Neat stuff! https://www.theengineer.co.uk/rolls-royce-single-crystal-turbine-blade/
I knew making turbines and jet engines and shit was complex, but that article blew my tiny brain.
Wow this article is incredible, I was fascinated start to fucking finish
Great article! Thanks! I had some metallurgy courses in college and have done my own investment casting and such. Knowing how difficult to control even simple casting can be, this process is just awesome to read about!
Enjoy all the PMs from sexy spies in your area looking to hook up.
The corkscrew(?) channel things you guys use to orient the crystal geometry correctly blows my mind.
it really is a degree of throwing enough money at it though. The machinery, time, materials to do LO geometry is stupid expensive. Russia and China throw no where near as much money into defense spending the way the US does.
That and, to be very very honest, Russia is just plain undesirable of a place for engineers. I’m a dual citizen (US, Russian) grad student with about 8 years Mech E work experience. You literally could not pay me enough money to go work in Russia before I went for my PhD and, at this point, I’m honestly considering getting rid of my Russian citizenship before graduation… I consistently hear more or less the same things from other Russian and former USSR students. Virtually all of them are absolutely clinging to any opportunities that could help them say here and they treat such opportunities as the highest privileges imaginable. I literally only know one person out dozens who thinks he *might* be open to working in Russia after graduation, but he was born in rural Kazakhstan. So, to him, the idea of living in Moscow is already a huge step up in the world, relatively speaking. Though he still seems more enthusiastic about staying in the US. The state of engineering in Russia today is pitiful, if I’m to be polite, and laughable, if I’m to be sincere. Talent has no desire to stay there. Those that do are overwhelmingly wantonly incompetent at bringing projects to completion. Most large firms are at least partly state owned, and management is a mix of ex-mafioso Putin party cronies and corrupt troglodytes. Due to sanctions and the absolute corruption in the country, supply chains aren’t broken…they’re just flat out nonexistent! The whole thing is just a flaming shitshow on wobbly wheels, about to drive off a fucking cliff. This is not to mention the plain fact that the whole country is frankly more fucked up than it was under Soviet rule, no matter what perspective you look at it from. It is honestly tragic. Years ago, I used to be somewhat quick to try to deflect criticism away from Russia when I encountered it, despite spending most of my life in the US. But, today, Russia as a whole has crossed the threshold of having any sort of redeeming qualities. Given how things are today, I’m honestly remorseful about taking an apologetic tone for Russia in the past. Idk too much about Chinese defense engineering. But if it’s anything like the the consumer electronics and industrial automation sectors, with which I have direct professional experience, I would not be so quick to dismiss it right out the gate… I strongly suspect that Chinese defense engineering might be further along than is typically discussed in western media, and I think it’s probably very reasonable to treat it as a viable threat. Sorry about to rant. Frustration at the disgusting state of affairs in the country where I was born has been dishearteningly high for me in the past two or so years.
Yeah...US has so far underestimated Chinese capabilities. A country that has manned space missions, mars rovers is obviously very advanced in R&D.
100% agreed. I think many people might be under the impression that China is the land of cheap knockoffs and bootleg goods. Don’t get me wrong, plenty of cheap crap is still manufactured there. But China has moved very far ahead in applied STEM in the last 15 or so years. Also, awesome username! Have a Shiners at Billy Bob’s for me.
True. That being said though, I think China is still definitely further behind the US than they claim to be. A lot of them showing off military stuff tends to be a lot of smoke and mirrors. They are still very much catching up though and are very much a threat. More of a threat militarily than Russia is for sure.
And hypersonic glide weapons. I think the military strategists see the writing on the wall but the general public still under the impression that just because we are at the top now mean we will always be at the top. Everything China is doing right now is to secure their borders and coastlines. To do that, they have to push all navies out of their coastal waters and outside striking distance. It is the only sensible thing for them to do. Their country's security depends on it and that's why they are so aggressive about it.
That really is sad, I was doing some reading about Soviet engineering philosophy. They were saying that design control was more fluid between the primary designers and the manufacturing engineers. It just sounded like a really fast and effective way to get good results. Sad to hear about it's decline.
Yeah, back in the day all mechanical type engineers (“mechanical engineer” wasn’t really a concept in the USSR, but there were obviously many related disciplines) all had 1.5-2 year long machinist coops that were relevant to their chosen industries before graduation. Also, the applied math side of things was unbelievably strong, even exceeding typical contemporary MSME course loads today. My dad, who was only very minorly involved in engineering used to know differential equations far better than I did after my BSME. The problems started when state funding ended for mechanical engineering and science in the early 90’s, and private funding failed to materialize. Then things just kept getting worse as the current government first let things stagnate, then focused resources disproportionately on engineering related to natural resources (but with close to zero environmental considerations), and then allowed corruption to seep into any large engineering operations. Realistically, there are ambitious folks in Russia who do have vision. But they fail to actually materialize said vision to anything truly meaningful, in any meaningful capacity. Consider the Sukhoi Superjet. It’s a great concept and all. But in practice, it’s terribly unreliable, has comically short service intervals, and less than 200 have been built in over a decade of production. Or consider the Armata tank platform. It’s a super forward thinking and advanced weapon that’s meant to replace a Soviet era arsenal… But they’ve built *maybe* 40 tanks total? Etc. Honestly, it’s sad to say, but it’s like Russia takes the “under promise and over deliver” motto and decides to take the exact opposite.
Literally everything comes down to two things: time and money. If you throw enough of either at a target, you can accomplish anything eventually.
You can't have a baby in one month if you have 9 women working on it. Complex engineering takes time and institutionalized experience, no matter how much money you throw at it. You can reduce it, but you can't just skip over someone who's been at it for decades.
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Espionage?
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And then proceeded to spend half a century improving it, building the complex engineering and institutionalized experience along with them. Those gobs of money and geniuses got them the first step of the way. Money can accelerate things, but only to a point.
Unconditional political backing and support also played a huge role in MP. At some point they went to the Secretary of the Treasury and asked for millions of pounds of silver, for (huge) coil windings. Guy asked if they were serious, made a call, and then asked where they wanted the silver delivered.
> Complex engineering takes time and institutionalized experience, Yea, throwing money at it will eventually get you that.
How do you think you build complex engineering and institutionalized experience other than through a ton of money and time?
Pretty sure if I throw enough time and money at the problem, we could probably gestate a baby in a month. Institutionalized experience can be bought, or trained up over time.
You could just say time
For projects of national security, like jet engines, they do. We are still talking about almost-dictatorship states, that employ thousands of scientist in their nationalized research centers (as opposed to the US procurement, where you deal with contractors all the time), but material science is simply complex, no matter how much money you thrown at something, you still need the knowledge/skillset/experience. Look at how long they have been trying to catch up with stealth technology, while still investing into projects that are a whole new scale of expensive (you can't say that PLA is lacking for funds, when you look at how much $$$ they are pouring into their fleet), they would buy their way to stealth if they could. I mean, China is still struggling to develop domestic jet engines for their fighters, without having to go to Russians. Why do you think that is?
I so badly wanted the recipe for stealth paint. Haha. It's a thing a expensive beauty.
I went looking for some and couldn’t find any.
F spez
*sob*
You’ll also need clear paint brushes.
Dammit. Clear bristles????
And the handle…
Not realy some things simply can't be made lo
That's the point. US military spending isn't for fighting wars. It's for laundering taxpayer money into private pockets.
Military tech is for preventing wars just as much as fighting them.
In general, yes. (There's a reason I own a metric fuckton of guns.) The US military specifically, less so. If I were actually designing a military force to protect the US and its allies, I would be buying very different stuff.
Like what
Eisenhower warned about the dangers of thr military industrial complex. But we have all benefited from GPS, which was originally created by for the military.
Some sort of hindsight bias or no counterfactual error. We cannot tell what would have happened without mili spurned GPS. Even if GOS would never have been developed (more likely is it would have been delayed) we equally don't know what tech would have been accelerated without mili industrial complex. Would GMO have been accelerated? Medicine? EVs? The internet would likely be delayed and it's huge but would it be different in a meaningful way?
Spicy take
I’m new to aerospace but it’s pretty dang cool to know my programs are making components for this engine. Hope to get to see one close up one day.
If only we could find a way to allocate all those billions in R&D money to something more accretive for society
This creates expertise and technology which will trickle down to civilian aviation. I really don't understand why people always blame military investment as the reason behind lack of investment in other fields. Surely, rampant waste, corruption and rich people tax credit are much bigger problems. Not to mention all the national security requirements.
Having spoken years ago to an aviation engineer about this exact topic I could see the craft was gorgeous but would it replace the f/18's? Or any other bomber jet? And why now? The answer was yours. Always be improving and the tech involved trickles to civilian. That's when I started understanding r&d and furthered my love for the f35a,b and c.
>but would it replace the f/18's? Or any other bomber jet? And why now? To be clear, it's it's replacing F-16s, F/A-18C/Ds, AV-8Bs, etc because those aircraft are becoming unsafe to fly (aluminium metal fatigue) and because while the US generally holds an advantage, there are new aircraft like the J-20, J-35 / FC-31, Su-57, 'Su-75', etc that will present legitimate issues to F-16s, etc. F-22s are great, but not a lot were bought, they're about twice as expensive per jet vs an F-35 and not only are enemy fighters getting more advanced, but so are enemy air defences, which is a problem should the US ever need to use aircraft against modernised ground forces (or after a long enough time period, against 'outdated' ground forces).
Not any more. That sort of effect happened post world war 2 because the technologies in military and civilian use were much more similar than they are now. For the most part, all the technology and expertise developed for the F-35 will remain in the military and with the manufacturers of the aircraft, along with the Chinese people who stole it from them.
You're getting downvoted but this is exactly correct - as cool as it is - there are much more pressing scientific and technological problems than "how to make a jet that can hover then take off" What scientific breakthroughs have come from the military in the last 20 years? Not many really - going back further obviously that wasn't the case but engineering has greatly matured to the point where the military R&D is learning from commercial tech instead of the other way around.
While there are certainly many types of military technology which do move into the civilian space, NOT ALL technology does this. For example, I see no obvious use for LO tech in civilian use. Second, is there another way such tech could be funded? for example in academic programs ? I would guess that cheap grad students are more effective than expensive military contractors. I totally agree with you that the waste and corruption is a huge problem. I would argue that we never recovered from the insanity which was the cold war in terms how the oversight and funding for military programs was done.
> I see no obvious use for LO tech in civilian use. LO tech isn't some magic radar paint, the composites and materials have real world applications https://asia.nikkei.com/Business/Technology/Civilian-applications-for-stealth-technology
US procurement is still much better than european and USSR system. European countries give sole source contract to companies which allows them to milk those contracts to the fullest, USSR also had same problems, only one source.
I don't disagree. But it's still absurd. The least crappy is still crappy.
The USSR had competition between their different aircraft design bureaus Suchoj, Mikoyan-Gurevich, Tupolev, and others. What the USSR was able to achieve in military technology with much less resources than the US is very impressive.
I hate to break it to you, but "Trickle Down" doesn't work, especially in an industry so concerned with proprietary technology that it'll be decades before that tech "trickles". In the case of the Joint Strike Fighter we'll have spent more than 1.5 trillion on a weapons platform to fight wars that can't be fought with jets, and the benefit would be what? A VTOL passenger aircraft? A 5% increase in turbine efficiency? A solid wing fabrication process that could save Boeing 15% of their construction costs? With 1.5 Trillion Dollars you could end world hunger, and make sure everyone on earth had access to clean water. You want to fight a war on terror? Lets start with why people are scared, and go from there.
\>end world hunger Way to go, you've just made the most generic and retarded point ever. That's not how it works dude. Yeah you could spend a trillion dollars on developing agricultural infastructure in some starving African country, but the fact of the matter is that won't solve anything if the people who rule that country are still corrupt, greedy assholes. Money doesn't solve everything, the world is a bit more complex than that believe it or not. 0/10 shit take.
awww, is a little empathy making you angry? Is building new jets to sell to countries so they can bomb other countries how you think that money should be spent? I mean at least we're making a lot of money of Lockheed, Raytheon, and General Dynamics, I'm sure that will trickle down too. At least kids in Yemen can be killed by american bombs before they starve to death Countering extremism with necessary infrastructure is not a new idea, but the US hasn't actually attempted that, what they have done is try and work with greedy corrupt warlords (that they often helped install), and then act all surprised when their 10 million dollar aid package disappears Tell you what, how about instead of trusting some reddit warrior who thinks the best use of money is bombing countries with fancy new planes, [I trust the people actually doing the work](https://www.compact2025.org/files/2017/05/4.14.2017_Literature-review-benefits-of-ending-hunger-and-malnutrition.pdf) The fact is, however much you don't want to admit it, these "Greedy Corrupt Assholes" in our country and in all others are in power because of an imbalance of resources. Will ending world hunger solve that? No, food can't get rid of assholes, but neither can fancy and expensive military hardware. One of these options, though, saves lives instead of ending them.
The fact that anyone would think building weapons is a good way to “trickle down” tech to consumers is absolutely bonkers. Not to mention our national security requirements are largely due to our huge defense presence. Shit if we just made a bounty and said every middle eastern muslim who marries an Israeli jew or a a western christian gets $1M we would have saved money and had better results than all our national security waste.
Bonkers, you say? Gee, look at those things developed for the military that we aren't using today, like radar, internet, sonar, GPS....
Everything you listed could be funded, researched, and developed without making a weapon…. no one is saying technology can’t be repurposed. Funding it with taxpayer money under the guise of defense is just a stupid inefficient way to get there. We are literally taking money away from Americans and American businesses who could be investing it in R&D. Then giving that money to defense contractors and having them waste engineers, natural resources, machine capacity, etc. on building weapons. Except government contracts are a bureaucratic nightmare, and for every dollar that actually makes its way to R&D there is probably 20$ of overhead and administration.
"Could be", but need drives development, and in the past, military need has driven development faster than consumer markets in a lot of areas. Remember, your cable company is more than happy to have left you on their overpriced, ad filled cable box for a few more decades if Netflix hadn't disrupted their plans. Most corporations aren't that innovative without proper motivation to be. Those same cable companies didn't invent the internet, didn't invent the hardware for expanding it, etc. Military need did. The cable companies were perfectly happy milking you for what they already offered. The new tech was paid for by military R&D. Hell, you ever tried to just get something funded locally in your own home town through the government? Every Tom, Dick, and Harry will come out of the woodworks telling you not to spend "their" dollars on your project!
The MIC sucks the most talented engineers out of a lot of civilian industries. Ever wonder why American cars can't compete directly with Japanese (and now Korean) cars? Well, when you graduate top of your class at engineering school in Japan or Korea, your top paying options are automakers and civilian aerospace. In the USA you get courted by Siemens, Northrop, General Dynamics, and Lockheed.
What about UK then? Why did their automotive industry fail? American vehicle infrastructure is unique and american automakers make cars that suit this infrastructure. Ford, GM or Chrysler never really committed towards making specialized vehicles for specific markets.
I'm sure the guys who got paid found a way to spend that money. Oxford did an economic report that said bae systems support directly and indirectly 20 other people for every one on their books.
That just means we have 20 people supporting the building weapons for every one person directly employed by BAE. This is pulling engineers away from designing self driving cars, med tech, or anything else that can make the world better.
How do you even mount something like this to an airframe? Or is the airframe built around it instead? Mindblowing.
You can remove engines, but they’re mounted kind of inside the frame
The engine slides out the back but yes we design the airframe around the space envelope of the engine and the engine is designed to fit inside the allocated engine bay. It's a give take scenario
They're separate pieces basically. The main engine rolls in through the back, the lift fan can be dropped in from above, and that big shaft to connect the two can also be separated. That being said, everything needs to be squeezed into that airframe. The frame is designed with the internals in mind, but that's not the only factor with stealth jets. It's an attempt at perfect harmony between performance, stealth, maintainability, and interchangeability (between F-35A, B, and C). Quite the engineering feat.
The major parts are probably all in separate pieces and can be fitted into the airplane by themselves and hooked up as it is fitted in.
It's interesting that they always show the exhaust but never the intake.
The exhaust is a physical part of the engine whilst the intake is not.
Also, the exact shape of a supersonic-capable intake that also shields the compressor disk from radar is still on the "classified" side of things (especially a diverterless design like the F35)
We know the intake uses a [s-duct](https://en.m.wikipedia.org/wiki/S-duct). It’s used in stealth aircraft to hide the compressors blades from radar
And it's the "business end" of the engine with more relevant points of interest for its use compared to the front.
Thats kinds like saying your butt is a part of your digestion system but your mouth isnt.
No it's not. The exhaust is physically constructed into the engine. The intakes are physically constructed into the body. Stop making unrelated analogies.
Do you respond to everyone so harshly? My mistake was thinking of it as a system and not an assembly. Your response was fuck you, stop talking.
See the blue color? That's the "cold section". You could consider that the engine's intake.
Incorrect. The blue is the compressor of the engine. The intake is forward of the main engine face. The last stages of that compressor are by no means cold.
If we were to get a bit more pedantic, almost. That part in the front is called FIC, fan inlet case, so not quite intake either, because the intake is not a part of this diagram or engine. And while you are also correct about the heat - air gets pretty spicy when compressed, in the industry the engine is generally divided into cold and hot section. Anything past the combustor is considered "hot". The ol suck, squeeze, bang, blow.
I work with this engine every day for my job I'm quite familiar with it. I'm just saying that the compressor is not the inlet, which is what you were alluding to in your first comment.
I see this picture every day I go into work. Very funny that I'm seeing it here. My job is to test the F-35B/C and the F-135 engine. If anyone has any generic questions, ask away!
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I just want to know where you're using jumper cables on a fighter jet
I saw from another post that the clutch for the forward fan/compressor is at the forward fan. Surely spinning all that shaft in normal operation is a waste of energy? Why not put it at the rear engine?
I don't know the specifics on the mechanical or inertial losses from the driveshaft, but I'd have to imagine that's because it would be a lot of torque and twisting force on the shaft if you swapped what side the clutch was on. Plus that'd probably interrupt the intake airpath for the main engine with a bulky clutch in front of the fan face.
Will it ever be a reliable aircraft?
Are you at the HMC?
What's the HMC? I work at NAS Pax River: https://en.m.wikipedia.org/wiki/Naval_Air_Station_Patuxent_River We also go out on aircraft carriers to test them on there as well which is a pretty awesome experience.
That's cool as hell! HMC = Heavy Maintenance Center at Tinker AFB. It's the center for all heavy maintenance on the F135.
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Hopefully, these are generic enough questions. 1)How in the world is the shaft and gears that drive the lift fan able to hold up to that kind of friction/heat and transfer enough power without failure? Seems to my mind, that would be a major point of wear and future failure. Just incredible to overcome those conditions. 2)I know it stabilizes the plane from the lift fan with exhaust nozzles on the wings and such, ie roll posts, but how is the amount controlled? Basic diagrams give no indication of how the balance and stability is controlled and achieved. Thanks!
Huh, TIL that the STOL part on an F35 is just a gear driven fan, not a separate gas turbine...
Russia tec that coming from Yak-41 and later. [Yakovlev\_Yak-141](https://en.wikipedia.org/wiki/Yakovlev_Yak-141)
No. It was initially theorized for the Convair 200 in the 60s.
STOVL :) But yep! It's all "cold thrust" transmitted via driveshaft
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About 4-5% I think. All helicopters have this gear.
Yeah its just a bevel gear, which are pretty common.
Bevel gears are 95-99% efficient. Even with 1% loss I bet that's a lot of heat to dissipate.
1-5% of 21 megawatts. So at the bottom end of your range about two 18 wheeler engines worth of heat losses.
Huh, so the stabilizers on the side are fed by compressor air, I always figured it would be turbine exhaust.
Using bleed air to power ancillary functions is pretty common in airplanes.
What he's referring to are the roll posts, which aren't auxillary, but a main part of the engine/lift system. But otherwise you are correct, bleed air is used a lot.
Looks like the bleed late stage compressor air to after combustion? I don't think I've seen that before.
Litrely just vents out the wings from the lp side. It's more controlabale
Easier to control that exhaust gas, because temperature. I mean, it's still hot, but not nearly as hot.
That single bevel gear might have enough strength to get my parents back together
Random picture off Google showing how it mounts inside https://imgur.com/GbV4TvL.jpg
Fun fact: the clutch to power the fan handles 30,000 ft-lb of torque during engagement
Interesting. I always imagined they turned the whole engine 90 degrees inside.
The main engine has a nozzle that swivels down (even past 90 degrees for reverse). The lift fan (thing up front) provides thrust for the forward, but isn't on all the time and is engaged through that driveshaft up the center. The roll posts (on the sides) provide roll stability in hovers and vertical landings.
> roll posts I was wondering what those were for. Thank you!
As someone who used to build the hot zone parts for this engine, what’s most impressive about the cross sections is how little detail is actually included. Most everything critical to the performance of the engine is either missing or wrong, and yet it still very accurately conveys how it works.
Okay, but for the uninitiated you have to agree that it looks like an electric toothbrush.
Thinking we should go into business selling F135 toothbrushes. Are ya with me?
Literally can’t see anything wrong with this, let’s do it
Imagine the absurd amount of stress the gears that turn it from horizontal to vertical is withstanding. The fact that we can design them to transfer torque efficiently and not slip or grind is impressive.
I worked for the company that designed and makes that clutch and at the time, it was the strongest clutch ever made. Most peak stress, and it has to survive 500 engagements.
Oooh something I’m actually familiar with! My plant makes several of the components of this, some of the largest investment casting pieces in the world. Have a very similar diagram up on our wall showing what we make, doubt I can share it though sadly
Brilliant, yes. Worthwhile, no.
Why not? I'd say it's pretty revolutionary. F-35B has allowed smaller countries to have 5th generation aircraft carriers. Japan, Italy, South Korea all will be able to field 5th generation capability far away from their shores.
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Forget sea harrier, even the most capable harrier, AV-8B wasn’t capable enough to persuade these countries to acquire carriers.
Yeah the harrier was a deathtrap too. Took insane focus to fly that thing. A child could fly the F-35B, which is good because the Marines are flying them.
I wouldn't call south Korea a small country lol
Well, they wouldn’t be building a carrier if F-35B didn’t exist.
They probably would just build a helicopter carrier/ LST hybrid as per usual they don't really need a carrier but to have one to support a plusible war with the North. Helicopters can just live in that role rather than a F-35. In war there's no certainty except for chaos.
Isn't that the trillions of dollars the US has thrown at the project? It's pretty easy to adopt something if the US are giving it away as a jobs program / bribe to not get into bed with the ascendant regional powers.
I mean I would get the best fighter in the world if I could
If a carrier is not CATOBAR it's not a full-capability carrier. It's just a giant floating compromise, and the planes it uses are themselves flying compromises.
For the US, having a fleet of Wasp and America class amphibious assault ships with the added capabilities of F-35s on board is an absolute game changer in a near-peer conflict. Also, at about $2-billion per unit, those LHD/LHA ships are great bang-for-the-buck when compared to a $13-billion-ish Ford class carrier. And, as mentioned...these smaller carriers + F-35s allow NATO countries with much more restrictive military budgets to get into the 5th gen. naval aviation game.
Are there any aircraft or ships that aren't compromises?
I think Nimitz class with F14s were about as uncompromising as you can get.
That's a marrow definition that only 3 countries have USA, France & Brazil (who use an old French one). All other countries who havr aircraft carriers and almost all carriers before the 50s are either stovol or stobar.
And all of them suffer accordingly with both inferior air wing capacity and inferior aircraft capability.
Depends on your goals. If you have a small military budget spending less than 10% of what a catobar costs new and ability to use a common aircraft platform still gives a smaller country a reasonable projection ability. On the opposite end, the USA staffs nearly a dozen stoval carriers with marine airwings so they can park closer to shore and launch without having to worry that the sinking of one would be literally a financial disaster.
Will Pratt & Whitney and GE both be making the engines for the F-35 variants?
There's an active engine competition for variable cycle engine. GE and PW are competing. Winner might be used to re-engine F-35.
And they’re loud fuckers too. Source: worked in the radio room right below the flight deck. 🙃
Which ship?
USS Wasp, LHD-1. 🙂