The F-35 Discussion Topic (No Holds Barred II)

[sferrin]

I treat one as an engineering test pilot's internal report and the other as a press-conference aside lacking essential information.

Except the engineering test report never claimed they were "dogfighting". They were testing the flight control rules of the F-35. The whole "dogfight" nonsense is pure, manufactured, fertilizer.

 

[Triton]

Except the engineering test report never claimed they were "dogfighting". They were testing the flight control rules of the F-35. The whole "dogfight" nonsense is pure, manufactured, fertilizer.

Did the Joint Program Office err in its official response to the "War is Boring" blog by calling the tests a "dogfighting scenario"?

"Joint Program Office Response to “War is Boring” Blog"
July 01, 2015

The tests cited in the article were done earlier this year to test the flying qualities of the F-35 using visual combat maneuvers to stress the system, and the F-16 involved was used as a visual reference to maneuver against. While the dogfighting scenario was successful in showing the ability of the F-35 to maneuver to the edge of its limits without exceeding them, and handle in a positive and predictable manner, the interpretation of the scenario results could be misleading.

Source:
https://www.f35.com/news/detail/joint-program-office-response-to-war-is-boring-blog?sf10503378=1

 

[sferrin]

Except the engineering test report never claimed they were "dogfighting". They were testing the flight control rules of the F-35. The whole "dogfight" nonsense is pure, manufactured, fertilizer.

So the Joint Program Office erred in its official response to the "War is Boring" blog by calling the tests a "dogfighting scenario"?

"Joint Program Office Response to “War is Boring” Blog"
July 01, 2015

The tests cited in the article were done earlier this year to test the flying qualities of the F-35 using visual combat maneuvers to stress the system, and the F-16 involved was used as a visual reference to maneuver against. While the dogfighting scenario was successful in showing the ability of the F-35 to maneuver to the edge of its limits without exceeding them, and handle in a positive and predictable manner, the interpretation of the scenario results could be misleading.

Source:
https://www.f35.com/news/detail/joint-program-office-response-to-war-is-boring-blog?sf10503378=1

Is the term "dogfighting" mentioned in the test report? Not to split hairs but "dogfighting scenario" could mean something entirely different than what one typically imagines when they hear the term "dogfight".

 

[bobbymike]

Except the engineering test report never claimed they were "dogfighting". They were testing the flight control rules of the F-35. The whole "dogfight" nonsense is pure, manufactured, fertilizer.

So the Joint Program Office erred in its official response to the "War is Boring" blog by calling the tests a "dogfighting scenario"?

"Joint Program Office Response to “War is Boring” Blog"
July 01, 2015

The tests cited in the article were done earlier this year to test the flying qualities of the F-35 using visual combat maneuvers to stress the system, and the F-16 involved was used as a visual reference to maneuver against. While the dogfighting scenario was successful in showing the ability of the F-35 to maneuver to the edge of its limits without exceeding them, and handle in a positive and predictable manner, the interpretation of the scenario results could be misleading.

Source:
https://www.f35.com/news/detail/joint-program-office-response-to-war-is-boring-blog?sf10503378=1

Is the term "dogfighting" mentioned in the test report? Not to split hairs but "dogfighting scenario" could mean something entirely different than what one typically imagines when they hear the term "dogfight".

I thought I read in a report on either Red Flag or Green Flag exercises the 'scenario' being used often when artificially setting some specific flight regime to see how blue force counters. Something like, "OK three fighters have gotten behind you execute the mission to escape or evade or protect the tankers or whatever" meaning very scripted.

 

[kcran567]

But speaking of "utterly naïve", "An independent evaluation would be the only way for the "others" to know whether the government effort is cost-effective." it's, quite literally, NOYFB. Joe Blow (that's you) doesn't have the expertise nor experience to grasp whether or not such an effort is "cost-effective".

ROFL, now I see the problem.
You are ignorant about the concept of democracy and the relevant economic theory (and yes, economics is what rules supreme in regard to how to allocate resources).

The citizens may delegate the decision (technocracy), but they may also be uncomfortable with delegating the decision to technocrats and favour maintaining a democratic decision process. The democratic decision process is the only one known to make full use of the population's preferences. It doesn't matter how competent technocrats are at a subject matter. They are 100% ignorant about the population's preferences and thus have no clue whatsoever about the utility of a program to the population.
So you're in favour of technocracy, I was writing about a country that uses democracy instead. As I mentioned before, the technocracy approach is used whenever the population doesn't show interest in the government's activities. Once it does, democracy trumps technocracy in all democratic countries.

The customer has been tasked with defending the country. THEY are who have to use the equipment they decide to buy.

1. The F-35 isn't about "defending the country". It's about the much less noble activity of "bombing other countries".

2. The budget authority is Congress' privilege, not the Armed Services'. Politicians are in power, not generals.

3. There's no reason why anybody should ever give anyone else a blank cheque to buy tools for his/her own use. It's a recipe for spectacular waste and inefficiency.

There is Congressional oversight. Thanks for playin' though.

Congressional Oversight yeah right! The entire program should have been far more cost effective than it ever was. There is nothing groundbreaking about the F-35, its not hypersonic, cant get to the moon, can't read minds, its a fiasco and a boondoggle and a fraud to put it any other way. Its a plane that was tasked to replace a few aircraft which was a mistake to begin with. There should have been a seperate A-10 replacement, seperate F-16 replacement (another topic), maybe a possible harrier replacement and as much shared software, engines, parts etc. but the entire concept was a mistake.
Seperate aircraft would have helped keep everyone honest by spreading out the funds and keeping the contractors/corporations viable instead of having one company replace three aircraft.

 

[sferrin]

Congressional Oversight yeah right!

And who put them in power? Exactly.

The entire program should have been far more cost effective than it ever was.

How? Tell us how you would do exactly the same thing, meet exactly the same requirements, but cheaper.

There is nothing groundbreaking about the F-35, its not hypersonic, cant get to the moon, can't read minds, its a fiasco and a boondoggle and a fraud to put it any other way.

Except for that stealthy, supersonic STOVL thing. : And "fraud"? Show us the evidence of fraud. Oh right, you can't. Shocker.

Its a plane that was tasked to replace a few aircraft which was a mistake to begin with.

Would have been more expensive the other way. (And here you were saying you wanted to be more cost effective. LOL)

There should have been a seperate A-10 replacement, seperate F-16 replacement (another topic), maybe a possible harrier replacement and as much shared software, engines, parts etc. but the entire concept was a mistake.

Ah, now it all makes sense. You think an A-10 would actually survive going after anything but camels in undefended airspace. (Not to mention the fact that a dedicated A-10 replacement would cost even more. So much for "cost effective".) And this will probably come as news to you but the different variants of the F-35 already share software, engines, parts, etc.

Seperate aircraft would have helped keep everyone honest by spreading out the funds and keeping the contractors/corporations viable instead of having one company replace three aircraft.

Oh please. If company X were producing the Harrier replacement how is the fact that company Y is producing the F-16 replacement going to keep company X "honest". Loosen up the tinfoil for god's sake.

 

[LowObservable]

I treat one as an engineering test pilot's internal report and the other as a press-conference aside lacking essential information.

Except the engineering test report never claimed they were "dogfighting". They were testing the flight control rules of the F-35. The whole "dogfight" nonsense is pure, manufactured, fertilizer.

I try to avoid the word "dogfighting" except in indirect or direct quote, and didn't introduce it here.

As reported, the test was intended to stress the high-AoA control laws, but the first (and most significant) observation was the energy-maneuverability deficiency relative to an F-16D Block 40.

So to state that the test was not a "dogfight" is to restate what is already known.

 

[LowObservable]

I don't think anyone believes that a supersonic, stealthy STOVL aircraft would have been affordable for the Marines/RN alone.


However, you can't make the actual cost of developing and building such a machine magically disappear by combining it with USAF and USN needs. STOVL has been a factor in making the JSF program slower and more costly and the procurement cost of the B versus the A speaks for itself.


The two questions are (1) was STOVL/supersonic/stealth good value as originally projected and (2) is it good value at its current price?

 

[sferrin]

I don't think anyone believes that a supersonic, stealthy STOVL aircraft would have been affordable for the Marines/RN alone.


However, you can't make the actual cost of developing and building such a machine magically disappear by combining it with USAF and USN needs. STOVL has been a factor in making the JSF program slower and more costly and the procurement cost of the B versus the A speaks for itself.


The two questions are (1) was STOVL/supersonic/stealth good value as originally projected and (2) is it good value at its current price?

In a perfect world they'd have picked the Convair 200 over the XFV-12 and it would have replaced the Harrier in the 1980's time frame. (Except we'd still be in the situation of needing a replacement by now so. . .) As for the value of stealth, with CVN numbers coming down, the likely flashpoints growing in size and lethality, I think we'll see the day when the USMC is lucky it has something as capable as the F-35B. The whole South Pacific situation was something that was not anticipated when the F-35 was initially conceived. In THOSE conditions, yeah, the F-35B might have been overkill but what were they going to do? Stealth is built in so you can't really leave it off. And there was no way a separately designed STOVL aircraft would make it on it's own as the low production numbers would have priced it out of affordability. It likely would have cost MORE than the F-35B simply because it would have had to eat ALL of the costs of it's development. As for it being a good value at it's current price how do you quantify that? If it can do the job the Harrier would have never been able to I'd say it's definitely worth the cost. Now, the usual argument is something along the lines of "if they needed something more than a Harrier they'd send a CVN so you don't need something better than a Harrier". I'd hope that doesn't really need to be refuted as that assertion has some pretty obvious problems.

 

[DrRansom]

For the Harrier replacement, why did it have to be full stealth and supersonic? As that platform was going to be a niche weapon within the US, wouldn't it have been far simpler to do a partial stealth, like the Rafale / Gripen, and subsonic?

The Marines should never have been the tail wagging the dog of US military aircraft procurement. If the British and the Marines want STOVL, then the two should have gotten together to hast out something.

 

[sferrin]

For the Harrier replacement, why did it have to be full stealth and supersonic?

Because it was based on the F-35.

As that platform was going to be a niche weapon within the US, wouldn't it have been far simpler to do a partial stealth, like the Rafale / Gripen, and subsonic?

Would you want to fight a Mig-29 or J-31 with one of those? Me either. Not to mention it still wouldn't be cheap.

 

[SpudmanWP]

For the Harrier replacement, why did it have to be full stealth and supersonic?

Had to be supersonic = saves lives
It is able to respond to calls for help quicker and going faster makes you less of a target


Had to be stealth = saves lives
Harder to detect, intercept, shoot down, etc

 

[donnage99]

Because it was based on the F-35.

Wrong. The f-35 is wrapped around marines requirements.

 

[Arjen]

For the Harrier replacement, why did it have to be full stealth and supersonic?

Had to be supersonic = saves lives
It is able to respond to calls for help quicker and going faster makes you less of a target


Had to be stealth = saves lives
Harder to detect, intercept, shoot down, etc

"Insanity: doing the same thing over and over again and expecting different results."

Albert Einstein

 

[mz]

Stillion's presentation has two main highlights

1. most successful air to air kills through history have mostly been against surprised targets, not dogfights and
2. there has been a trend toward increased use of BVR missiles and networks.

It's still a bit strange to me then that the F-22 was specified with such high maneuverability. Couldn't it have been a mini B-2 with Phoenix missiles?

The F-16 maneuverability makes sense as it was specified at a time when there were still very few missile kills.

Slow stealthy platforms are essentially what he's proposing for the future. You don't need maneuverability because it's too late if you let the enemy get so close. You also can't have high speed as infrared sensors have made somewhat of a comeback, and you actually give the enemy the least time to react by sneaking instead of charging.

http://csbaonline.org/publications/2015/04/trends-in-air-to-air-combat-implications-for-future-air-superiority/

 

[sferrin]

Because it was based on the F-35.

Wrong. The f-35 is wrapped around marines requirements.

Go back and read what was actually said. AFAIK the only Marine requirement that translates across the family is the length. The USMC didn't demand supersonic speed. You think if they'd have said "subsonic is best" that the USAF and USN would have said, "sounds good to us, let's do it"?

 

[sferrin]

Stillion's presentation has two main highlights

1. most successful air to air kills through history have mostly been against surprised targets, not dogfights and
2. there has been a trend toward increased use of BVR missiles and networks.

It's still a bit strange to me then that the F-22 was specified with such high maneuverability. Couldn't it have been a mini B-2 with Phoenix missiles?

Too specialized. And I don't imagine a subsonic, Phoenix-laden, flying wing would do such a hot job running down Bear bombers off Alaska. One could almost imagine the Bear pilots laughing, giving it the gas, and leaving the poor thing eating it's dust.

 

[mz]

Stillion's presentation has two main highlights

1. most successful air to air kills through history have mostly been against surprised targets, not dogfights and
2. there has been a trend toward increased use of BVR missiles and networks.

It's still a bit strange to me then that the F-22 was specified with such high maneuverability. Couldn't it have been a mini B-2 with Phoenix missiles?

Too specialized. And I don't imagine a subsonic, Phoenix-laden, flying wing would do such a hot job running down Bear bombers off Alaska. One could almost imagine the Bear pilots laughing, giving it the gas, and leaving the poor thing eating it's dust.

Good points. Perhaps such a specialized craft was developed but kept in secret, in case there would be a higher level opponent

 

[SpudmanWP]

Wrong. The f-35 is wrapped around marines requirements.

Wrong, The B had little impact on the overall F-35 layout or specs.

"Insanity: doing the same thing over and over again and expecting different results."

Since both speed and stealth are new to the mission of a Harrier replacement, how is this "doing the same thing"?

 

[sferrin]

(Any idea why some posts end up with little tiny text? ??? )

 

[SpudmanWP]

small text = a problem with cut&paste

 

[kcran567]

An aircraft this early in the program having reliability issues. I'm shocked. Shocked I tell you. (I would like to know how "only half" and "more than 65%" were arrived at.) I wonder if anybody actually believes that even an aircraft that had been in service for decades would be available 100% of the time. Ah, just noticed the author. . .

The thing about the F-35 is that it is magnitudes more complicated than all legacy aircraft combined how can it be more reliable as a ship board fighter. in operation, very few F-35s will be operating, probably less than the Harrier example. f-35 much more complicated than a Harrier ever was. even Harrier direct lift system was not as capable, but was far less complex than system on the F-35. Not to mention software complexity, real world effect on the aircraft's sensitive coatings, engine and airframe wear and tear. Look how many setbacks and cost so far, will only conclude the F-35 is going to be a hangar queen and maintenance nightmare.

 

[bobbymike]

Stillion's presentation has two main highlights

1. most successful air to air kills through history have mostly been against surprised targets, not dogfights and
2. there has been a trend toward increased use of BVR missiles and networks.

It's still a bit strange to me then that the F-22 was specified with such high maneuverability. Couldn't it have been a mini B-2 with Phoenix missiles?

Too specialized. And I don't imagine a subsonic, Phoenix-laden, flying wing would do such a hot job running down Bear bombers off Alaska. One could almost imagine the Bear pilots laughing, giving it the gas, and leaving the poor thing eating it's dust.

Good points. Perhaps such a specialized craft was developed but kept in secret, in case there would be a higher level opponent

I've posted about a large stealthy BWB aircraft carrying dozens and dozens of long range next generation A2A missiles but with an added bonus, as the enemy is licking its' wounds low on gas after losing 30, 40 or 50% or more from the first salvo they head for home only to be chased down by high flying, supercruising F-22s

 

[sferrin]

The thing about the F-35 is that it is magnitudes more complicated than all legacy aircraft combined how can it be more reliable as a ship board fighter.

How can a Super Hornet be when it's orders of magnitude more complex than an F-4?

in operation, very few F-35s will be operating, probably less than the Harrier example.

Pure speculation.

f-35 much more complicated than a Harrier ever was. even Harrier direct lift system was not as capable, but was far less complex than system on the F-35. Not to mention software complexity, real world effect on the aircraft's sensitive coatings, engine and airframe wear and tear. Look how many setbacks and cost so far, will only conclude the F-35 is going to be a hangar queen and maintenance nightmare.

Reality will demand it gets addressed. As for complexity there's no going backwards. Across the board, every generation has been more complex than it's predecessor. If you can't play, stay on the porch.

 

[kcran567]

Couldn't something like the B-1 be equipped for that missile carrier mission? Maybe the Russians would similarly equip the Blackjack.


And about the f-22s maneuverability, was it mainly for Soviet missile evasion as a priority?


sferrin, I agree that there is natural progression of complexity and it is a good thing in many ways, but as for the F-35 being touted all along as needing less maintenance, increase operational readiness I am having a hard time believing it.

 

[Jeb]

It's still a bit strange to me then that the F-22 was specified with such high maneuverability. Couldn't it have been a mini B-2 with Phoenix missiles?

The F-22's maneuverability and excess power are there to make it SAM-proof, not for dogfighting. It'll transit hostile areas higher and faster than anything else and can make the turns needed to outfly pretty much any weapon lofted toward it. It's just gravy that this also means it'll turn inside any other fighter if Red Air lucks out and gets visual on a Raptor before getting killed.

 

[SpudmanWP]

um, no

 

[sferrin]

sferrin, I agree that there is natural progression of complexity and it is a good thing in many ways, but as for the F-35 being touted all along as needing less maintenance, increase operational readiness I am having a hard time believing it.

It's not that unlikely. Today's cars for example, are far more complex than those built in the 70's but are much more reliable.

 

[AeroFranz]

The F-22's maneuverability and excess power are there to make it SAM-proof, not for dogfighting. It'll transit hostile areas higher and faster than anything else and can make the turns needed to outfly pretty much any weapon lofted toward it. It's just gravy that this also means it'll turn inside any other fighter if Red Air lucks out and gets visual on a Raptor before getting killed.

Rule of thumb is you need one third the load factor of a missile in order to avoid it. Say an F-22 is limited to 9gs, which are not sustained anyway...that leaves a missile that has to pull 27 g's for a hit-to-kill (which it may not need). That's not much for a missile except at the very edge of range, and then again ramjet powered AAMs can sustain thrust almost till the end. The other thing is that if two or more SAMs are fired at you, that leaves you with very slim margins to be clever about maneuvering. Outmaneuvering one might leave you as a sitting duck for the next one. I am more inclined to say maneuverability requirements were dictated by AA combat.

"Wrong, The B had little impact on the overall F-35 layout or specs."

Spudman, please show me one VTOL aircraft whose design is not dominated by VTOL requirements. Take your pick among the fifty or so shown in the wheel of VSTOL misfortune.
I cannot think of a most pervasive requirement than VTOL. Down to details such as where you put the pitot probe (actually flush air data sensors...). I believe Lockheed tried very hard to minimize the compromises and were successful to as large a degree as possible - one reason why they won against the X-32. That being said, if you had told the Skunkworks to design just the A and C, it would have looked different. Structures and weapons bay layout for sure. Powerplant, debatable.

 

[sferrin]

Spudman, please show me one VTOL aircraft whose design is not dominated by VTOL requirements. Take your pick among the fifty or so shown in the wheel of VSTOL misfortune.

The Mirage IIIV / Balzac comes to mind.

https://www.youtube.com/watch?v=uvv6PZtDaLg

The Convair 200 is another.

That being said, if you had told the Skunkworks to design just the A and C, it would have looked different. Structures and weapons bay layout for sure. Powerplant, debatable.

Sure, it would have been longer. But that's not STOVL related, it's related to the size of amphibious assault ships. (I've heard both elevator size and deck footprint. Take your pick.)[/quote]

 

[DrRansom]

Well, the F-35 certainly has a lower fineness ratio than most modern fighters. Some of that is imposed by the internal weapons bays, but the rest is driven by VTOL. Ditto with the engine bay mounted behind the cockpit, to accommodate the lift fan.

Back to Harrier replacement, Harrier was designed for short-range ground support, primarily CAS. Which leads to two questions, when has the ground support / CAS mission required supersonic capability and what changed? It surely wasn't the threat environment, because the 1990s were about as low a threat environment as any decade. Nor it was air threats, because the F-22 was going to handle that. Face it, the Harrier replacement was given supersonic dash capability because the Marines were getting technologically greedy. That supersonic dash produces an engine which makes dispersed STOVL operation almost an impossibility (see heat load requirements), thereby undoing the original concept. Of course, that greediness costs the US military billions and years in opportunity cost...

Side question, why make STOVL aircraft have a large combat radius? Surely as a STOVL plane, it would operate close to the conflict and not require large internal fuel fraction.

As for why this matters, the Marines have sunk much of there modernization dollars into the F-35. They will still be operating the hopelessly obsolete AAV-7 for much longer. Funny, to save Marine Air, the Marines had to leave their ground capability completely obsolete.

 

[SpudmanWP]

show me one VTOL aircraft whose design is not dominated by VTOL requirements.

Easy, the F-35A and they have said as much (not sure if it was DoD, JPO, or a LM rep that said it).

Structures and weapons bay layout for sure. Powerplant, debatable.

There would have still been just a single engine as this was a demand of the USAF.


The position of the weapons bay is dictated by the size of the single, large engine. Btw, the size of the bay is driven by the F-35C requirement of a 2k bomb as the F-35A originally had a requirement for only a 1k bomb.


The engine and weapons bay dictate the overall cross-section of the F-35.


Since the cross-section is a given, then the length cannot be increased much because it would make it too heavy which would dictate a larger engine.

 

[AeroFranz]

Spudman, please show me one VTOL aircraft whose design is not dominated by VTOL requirements. Take your pick among the fifty or so shown in the wheel of VSTOL misfortune.

The Mirage IIIV / Balzac comes to mind.

https://www.youtube.com/watch?v=uvv6PZtDaLg

The Convair 200 is another.

That being said, if you had told the Skunkworks to design just the A and C, it would have looked different. Structures and weapons bay layout for sure. Powerplant, debatable.

Sure, it would have been longer. But that's not STOVL related, it's related to the size of amphibious assault ships. (I've heard both elevator size and deck footprint. Take your pick.)

[/quote]


You mean the ones with holes in the middle of the fuselage where things like efficient structural load paths and fuel tanks would normally be in any non-VSTOL aircraft? ???

Easy, the F-35A and they have said as much (not sure if it was DoD, JPO, or a LM rep that said it).

To paraphrase Mandy Rice-Davies: "Well (giggle), they would, wouldn't they?"
I am no structures guys (but i do seat next to two), and they don't put holes in the middle of the fuselage or cantilever large tails sized for maneuvering loads as far as is done on the F-35.

 

[SpudmanWP]

Nobody said that there are not "any" influences on design of the F-35 (and the Mirage IIIV & Convair 200) from STOVL requirements. We were just showing you designs that were not "dominated" by their STOVL requirements (as you claimed).


The four main items that "dominated" the F-35's design are:
1. VLO requirements
2. Single engine
3. Range requirements
4. Weapon bay requirements

 

[sferrin]

You mean the ones with holes in the middle of the fuselage where things like efficient structural load paths and fuel tanks would normally be in any non-VSTOL aircraft? ???

Holes? You mean holes like weapons bays, inlet ducts, ammo cans, fuel tanks, things like that?

 

[donnage99]

Go back and read what was actually said. AFAIK the only Marine requirement that translates across the family is the length. The USMC didn't demand supersonic speed. You think if they'd have said "subsonic is best" that the USAF and USN would have said, "sounds good to us, let's do it"?

The straw man came out again..... the marines didn't demand it to be subsonic, that's why the USAF and USN agreed to write their measurements around the marine's ruler.


But the bigger straw man is the fact that that kind of argument can be used by the other side. Example - "you think the marines would agree if the USN has said "2 engines is best." See? Both statements achieve absolutely nothing.

 

[AeroFranz]

Yes, precisely. Why add more holes? they all add weight. Do you see extra holes on F-22s and Grippens that are not required by the mission?


Look, take a look at any modern airplane's cutaway. There's no empty space anywhere. Simply finding real estate for the extra components and subsystems required by VSTOL requires volume, and volume entails a cost, starting with weight. What's worse is that those volumes want to be in very specific places for weight and balance and stability issues, they can't be just thrown wherever it's convenient. then there's the weight spiral of carrying the VSTOL systems themselves (lift fan, ducting for reaction control system, doors, actuators). For a given level of performance that means the wing has to be bigger to keep the wingloading constant.
What else? Flight controls. How many lines of code does it take to enable the graceful ballerina-like VTOL or rolling takeoff and landing of the F-35? That's not weight, it sure as hell is NRE $$$.


If VSTOL was not pervasive, then you could take ANY aircraft already flying and convert it to VSTOL.


good read on the subject : Kohlman "An introduction to V/STOL airplanes"

 

[SpudmanWP]

But the bigger straw man is the fact that that kind of argument can be used by the other side. Example - "you think the marines would agree if the USN has said "2 engines is best." See? Both statements achieve absolutely nothing.

A single engine was as USAF requirement, not a USMC one. There were designs on the table that used a gas-driven fan and ones that used lift engines (as opposed to a shaft driven fan in the F-35) that could both have been adapted to two engines.

Look, take a look at any modern airplane's cutaway. There's no empty space anywhere. Simply finding real estate for the extra components and subsystems required by VSTOL requires volume, and volume entails a cost, starting with weight. What's worse is that those volumes want to be in very specific places for weight and balance and stability issues, they can't be just thrown wherever it's convenient. then there's the weight spiral of carrying the VSTOL systems themselves (lift fan, ducting for reaction control system, doors, actuators). For a given level of performance that means the wing has to be bigger to keep the wingloading constant.

There is no wasted space in the F-35A/C either. They take the spaces that normally house the F-35B's unique equipment and use it for fuel.

Look at these 4th & 5th get jets. Only the F-35 is STOVL yet they all look similar.

 

[AeroFranz]

This where the skill of the Lockheed engineers came into being. You're right in that from a certain distance i probably wouldn't be able to tell if i'm looking at a -B, or -A. OTOH, the X-32 definitely looks different from everything else in that chart...or anything else, for that matter.
That being said, internally there's a lot of new stuff that goes in, we can't just look at the OML.
The entrails are different, and the commonality desirement meant that compromises were made. I'm saying that the optimized structure for an A and C designed in isolation of each other is much closer than between either of them and a -B.

 

[sferrin]

Go back and read what was actually said. AFAIK the only Marine requirement that translates across the family is the length. The USMC didn't demand supersonic speed. You think if they'd have said "subsonic is best" that the USAF and USN would have said, "sounds good to us, let's do it"?

The straw man came out again..... the marines didn't demand it to be subsonic, that's why the USAF and USN agreed to write their measurements around the marine's ruler.


But the bigger straw man is the fact that that kind of argument can be used by the other side. Example - "you think the marines would agree if the USN has said "2 engines is best." See? Both statements achieve absolutely nothing.

Compared to what you've offered (nothing) a "strawman" (or occam's razor) is a step in the right direction. In short re. your claim that, "The f-35 is wrapped around marines requirements." you've offered just shy of squat to support it. I'm reminded of this quote:

“What can be asserted without proof can be dismissed without proof.”
- Christopher Hitchens

Come back when you can show us the USMC requirements doc dictating what everybody else would use.