The F-35 No Holds Barred topic

[TaiidanTomcat]

Absolutely. The air campaign's success was entirely the product of one aircraft type, rather than the plan or the people executing it. It had nothing at all to do with the mix of different assets and capabilities or how they were employed.

Good point, the Harrier helped a lot too. ;D For an airplane that played such a minor role in the conflict it sure hooked the Air Force on stealth... and the point was casualties, think there are more if conventional aircraft try to go to Baghdad the first night like the F-117s?

Yup, DESERT STORM really hooked the Air Force on stealth. Immediately afterward USAF started a new low observable strategic bomber program, a new low observable strategic cruise missile program, and a low observable air superiority fighter program.

Thats a good point. It has changed the way US forces wage war. It confirmed the concept. Stealth is way of life now, previously it was a unconfirmed gamble.

What we'll never know is whether Macs' LPLC concept would have been better. I have never seen a T/W for the lift fan engine, but one could guess somewhere between the proposed RB.202 (higher BPR, so heavier) at 11:1 and the XJ99 (pure jet) at 20. 15:1 would give you a mass of 1300-some lb for the fan. The lift/cruise engine would be lighter (smaller LPT and lighter shaft). If it had the same T/W as an F110-GE-132 (8:1) it would be about 5000 lb vs. 6500 lb for the F135.

So now we're at 6300 lb vs 10400 lb for the present system. Of course, I still need a main engine thrust deflector and roll control (off the top of my head I can't remember how Macs were going to do that), but are those going to add 4000 lb?

By the way, Macs used a blocker and side nozzles on the lift-cruise engine, which may have added complexity in the engine but avoided cutting a big hole in the bottom of the airplane, with huge doors - and would have left you with a place to put the tailhook.

I still get a kick out of how the "JSF concept Is impossible" then you wait a second and hear how the X-32 and the McDD planes could have also done it. Not only is it possible, its possible 3 different ways!!

 

[LowObservable]

Exactly, JFC. Of course, STOVL advocates fiercely deny anything of the sort, and the claim of "no penalty for STOVL" has been made a few times in this thread.

How does STOVL mess up the CTOL/CV solution? Let me count the ways, as the Bard says.

1 - It forces the use of a single engine. We don't know how to build a multi-engine STOVL fighter that does not fall precipitously out of the sky if one donk quits, or even suffers a major transient, in powered-lift mode - thus adding engines makes you less safe, not more.

1a - Because of the jet's size, this means a new engine (I doubt that there are many F119 parts left in the F135).

1b - Also, the JSF STOVL concept makes the lift-cruise engine more complex, heavier and more expensive because it needs an oversized LP turbine and shaft. The F135 weighs 2000 pounds more than two F414s and is more expensive, and the weight is subject to a growth factor (that is, the structure needs to be heavier to carry the engine weight).

2 - As well as being able to do STOVL, the B has to fit on an LH-class ship. Wingspan is constrained by the requirement to park six jets on the starboard aft deck (folding wings being ruled out by weight) and length by elevator size. The A/B wingspan is only 5 feet more than that of the F-16, which in its initial production version was a tidge more than half the F-35's weight, and the F-35 is 10 feet shorter than the similarly sized Super Hornet. Since body volume is driven by fuel and weapon stowage requirements, shorter = bigger cross section = less slender.

2a - Absent B2FB technology, this results in direct hits on drag-due-to-lift (aka induced drag) and wave drag (influenced by slenderness).

3 - The SDLF system drives the fuselage design.

3a - Structure, systems and stowage have to be arranged around two 50+ inch-diameter cavities, which adds complexity. Quite possibly, a non-STOVL twin could have ended up with a more flexible weapon bay, but that's speculative.

3b - The fuselage cross-section behind the cockpit is unusually large with a steep increase in c/s area from nose to the inlet line - this is likely to be nonoptimal in terms of area ruling.

3c - The main engine has to be far forward so that the 3BSM nozzle is in the right place for balance in hover (the further aft you put it, the more power you have to divert through the fan, and the shaft gets longer). One result on the A/C is a long jetpipe between the augmentor and final nozzle - which in design terms means that your structure is enclosing a whole lot of hot air, anathema on something as volume-critical as a supersonic aircraft.

4 - STOVL has delayed the program. The weight increases that caused the 2004 redesign were not critical for the A/C. The redesign resulted in reduced commonality and a more complex structure, and since then almost all JSFs have been delivered late to contract, apparently due to manufacturing issues.

Whether all this is worth it, to put six jets on to a normally configured LH-class boat, is a separate discussion.

To address TT's point - I agree that any discussion of the Macs proposal is speculative (but that's what this forum is here for).

 

[Mike Pryce]

It could also be argued that the need for the A & C CTOL versions have messed up the STOVL B one. The need to design a lift system that can be 'removed' to make the other versions has led to a very complex STOVL aircraft, anathema to the simplicity that made the Harrier work.

Hats off to the engineers who have made all this work to a condsiderable degree, but the really impressive achievement was in ever selling this concept of 'all for one and one for all' as cheap - it ain't one, it's three, and each constrained by the other.

 

[LowObservable]

Harrier - In a perfect world, we'd have gone the way JAST originally intended, which was to develop a common technology and component set and let the issue of common-versus-optimized airframes sort itself out. Think of the Airbus range.

I don't think that such a process would have ended up with an affordable supersonic, stealthy STOVL fighter - but we didn't get that out of JSF, either. We just hid the cost in a tri-service program.

 

[Mike Pryce]

an affordable supersonic, stealthy STOVL fighter

Pick any two S's and it may be technically do-able without too much hardship. Pick any one and it may be affordable. Trying for all three was always going to be hard and expensive, even more so if CTOL and CV variants are required.

 

[sferrin]

There is no denying that the STOVL system is a neat bit of engineering, and that making it work acceptably without major glitches, and deliver what seems to be quite smooth handling (given all the blending and transition of control modes) has been one of the program's achievements.

What we'll never know is whether Macs' LPLC concept would have been better. I have never seen a T/W for the lift fan engine, but one could guess somewhere between the proposed RB.202 (higher BPR, so heavier) at 11:1 and the XJ99 (pure jet) at 20. 15:1 would give you a mass of 1300-some lb for the fan. The lift/cruise engine would be lighter (smaller LPT and lighter shaft). If it had the same T/W as an F110-GE-132 (8:1) it would be about 5000 lb vs. 6500 lb for the F135.

So now we're at 6300 lb vs 10400 lb for the present system. Of course, I still need a main engine thrust deflector and roll control (off the top of my head I can't remember how Macs were going to do that), but are those going to add 4000 lb?

By the way, Macs used a blocker and side nozzles on the lift-cruise engine, which may have added complexity in the engine but avoided cutting a big hole in the bottom of the airplane, with huge doors - and would have left you with a place to put the tailhook.

I don't know the impact off the top of my head, but for completeness the W in T/W should include the weight of the fuel burned and the fuel system required to provide the fuel burned in STOL and VTOL operations.

Add in things like reinjestion, deck requirements (exhaust would probably be much hotter than the F135s tail), etc.

 

[LowObservable]

The lift-engine exhaust would be hotter than the shaft-driven fan, but not anything like the F135 core exhaust, and the latter's flow is not exactly cold - "not your grandma's attic fan".

Also, the twin aft nozzles are farther above the deck than the single 3BSM, and twin nozzles with equal area give the plumes more total perimeter for mixing.

 

[Triton]

It could also be argued that the need for the A & C CTOL versions have messed up the STOVL B one. The need to design a lift system that can be 'removed' to make the other versions has led to a very complex STOVL aircraft, anathema to the simplicity that made the Harrier work.

Hats off to the engineers who have made all this work to a condsiderable degree, but the really impressive achievement was in ever selling this concept of 'all for one and one for all' as cheap - it ain't one, it's three, and each constrained by the other.

Would Congress have funded two or three stealth fighter programs in the post-Cold War/New World Order era to create aircraft suited to the unique requirements of the United States Marines, United States Air Force, and United States Navy? By making it a joint program with participation of the United Kingdom, doesn't it make the program virtually immune from cancellation? Would Congress have gone along with funding the Common Affordable Light Fighter (CALF), Multi-Role Fighter (MRF), and Attack/Fighter Experimental (A/FX) programs through to manufacture and deployment?

 

[LowObservable]

Would Congress have funded two or three stealth fighter programs in the post-Cold War/New World Order era to create aircraft suited to the unique requirements of the United States Marines, United States Air Force, and United States Navy?

No, because it would have been seen to be unaffordable. On the other hand, something like a Super-Rafale for the USAF and USN might have emerged successfully (with some level of LO) and something more "Harrier III"-like for the USMC.

By making it a joint program with participation of the United Kingdom, doesn't it make the program virtually immune from cancellation?

It makes it more difficult. That is not a good thing, because it allowed program leaders to blunder forward for years in complete denial of their cost and schedule problems.

 

[Triton]

Is it possible that some existing F-18 and F/A-18 aircraft will be replaced by the Boeing F/A-18 Super Hornet "International" instead of the F-35C in the United States Navy or some existing F-16 aircraft will be replaced by the Lockheed F-16 Super Viper instead of the F-35A in the United States Air Force or some other 4.5 generation version of these legacy aircraft? Can the AV-8B Harrier II be upgraded to the 4.5 generation or new construction AV-8B with upgrades and LO? Boeing F-15SE Silent Eagle?

 

[LowObservable]

Is it possible that some existing F-18 and F/A-18 aircraft will be replaced by the Boeing F/A-18 Super Hornet "International" instead of the F-35C in the United States Navy

Depends when the F-35 comes on board. Delays could make such an action non-optional.

or some existing F-16 aircraft will be replaced by the Lockheed F-16 Super Viper instead of the F-35A in the United States Air Force

So far, this is happening in the sense that 300-350 F-16s are to be SLEPped and given a major upgrade. Nominally that does not "replace" any of the F-35As in the program, but it delays them.

Can the AV-8B Harrier II be upgraded to the 4.5 generation or new construction AV-8B with upgrades and LO?

Probably not, but many of the Marine F-35Bs are supposed to replace F/A-18s used for CAS and FAC-A.

How many STOVL aircraft are needed for the LH-classes? Remember that the USN has only nine of them and may get to 10 later in the decade, that the normal air wing includes six tactical jets and the US just acquired 74 recently refurbed airframes from the UK.

 

[TaiidanTomcat]

1 - It forces the use of a single engine. We don't know how to build a multi-engine STOVL fighter that does not fall precipitously out of the sky if one donk quits, or even suffers a major transient, in powered-lift mode - thus adding engines makes you less safe, not more.

Why do you need two when one will do? why double the fuel burn?

1a - Because of the jet's size, this means a new engine (I doubt that there are many F119 parts left in the F135).

Nope! what are you basing that on? any facts to support that assertion?

1b - Also, the JSF STOVL concept makes the lift-cruise engine more complex, heavier and more expensive because it needs an oversized LP turbine and shaft. The F135 weighs 2000 pounds more than two F414s and is more expensive, and the weight is subject to a growth factor (that is, the structure needs to be heavier to carry the engine weight).

Your math Sucks according to GE and F135.com:

F414
Dry weight: 2,445 lb (1,110 kg) max weight

F135
Dry weight: 1,701 kg / 3,750 lbs

So unless the F414 weighs 875 lbs you are wrong. in fact two f414s weigh 4890 lbs. F135 also has a higher thrust to weight ratio. Its no secret that the Harriers engine ( big single) had more power than the combined f404 equipped F-18.

F135 43,000 lbs thrust @ 3,750 lbs dry weight
F414 22,000 lbs thrust X2 =44,000 lbs thrust at a combined 4890 lbs dry weight. so for an additional 1140 lbs (and thats not including the additional weight of the extra engine log book!) you get another 1,000 lbs of thrust.

But wait! Theres more:

In August 2010, Pratt & Whitney revealed that the F135 was able to generate in excess of 50,000 lb of thrust

So other than adding 1140 lbs to get 6,000 lbs less in thrust and doubling the maintenance requirements and cost, do you have any other ideas?

2 - As well as being able to do STOVL, the B has to fit on an LH-class ship. Wingspan is constrained by the requirement to park six jets on the starboard aft deck (folding wings being ruled out by weight) and length by elevator size. The A/B wingspan is only 5 feet more than that of the F-16, which in its initial production version was a tidge more than half the F-35's weight, and the F-35 is 10 feet shorter than the similarly sized Super Hornet. Since body volume is driven by fuel and weapon stowage requirements, shorter = bigger cross section = less slender.

How slender is an F-18 when you start adding fuel tanks and jamming pods again? Is this the part where you tell me having to jam in two engines side by side saves area?
It couldn't be because the F-35 is a more efficient, advanced design? Or did we reach perfection with the Super Hornet? Which is of course itself a enlarged legacy (1970s fighter)

With an internal weapons bay slender was going out the window anyway. The F-22 isn't wasp waisted is it? Not only that but compactness is a factor on any carrier aircaft. and even though its smaller it carries more weapons, and has more range, and it only needs one engine to do it. Typically when a smaller something does more work thats called "efficiency"

Don't know how you got so caught up in size, youve mentioned it a few times before and I still don't get it.

2a - Absent B2FB technology, this results in direct hits on drag-due-to-lift (aka induced drag) and wave drag (influenced by slenderness).

The F-35 has a large lifting body, slender is moot.

3a - Structure, systems and stowage have to be arranged around two 50+ inch-diameter cavities, which adds complexity. Quite possibly, a non-STOVL twin could have ended up with a more flexible weapon bay, but that's speculative.

Two engines means twice the maintenance, double the fuel consumption, double the chance of fire, additional structure, additional equipment, additional weight for redundancy and safety purposes. double the IR signature, double the administration/paperwork. Even if your math on the F414 wasn't horrific, there is more to the weight than just the engines themselves!

3b - The fuselage cross-section behind the cockpit is unusually large with a steep increase in c/s area from nose to the inlet line - this is likely to be nonoptimal in terms of area ruling.

Likely?

4 - STOVL has delayed the program. The weight increases that caused the 2004 redesign were not critical for the A/C. The redesign resulted in reduced commonality and a more complex structure, and since then almost all JSFs have been delivered late to contract, apparently due to manufacturing issues.

Luckily that weight reduction also made the F-35 A/C a lighter, better aircraft, amiright?

 

[TaiidanTomcat]

How many STOVL aircraft are needed for the LH-classes? Remember that the USN has only nine of them and may get to 10 later in the decade, that the normal air wing includes six tactical jets and the US just acquired 74 recently refurbed airframes from the UK.

Those airframes have already been cannibalized for spares.

Not only that but the USMC wing does not just operate from ships LHs AND CVNs of course, but it operates from airfields as well. The entire F-18D community is land based. So we actually do need (and use) more than just 60 aircraft. Thanks though.

Even then F-35B is supposed to get shore side ASAP, so that number can vary greatly. (IE 6 are on board NORMALLY but even if the worst happens we can have more joining and or just refueling and flying off and basing elsewhere. ARGs can carry an amazing amount of F-35Bs as well, and ARGs have deployed before with nothing but AV-8s aboard)

The beauty of the F-35B is it can go on any of the above and brings all those communities together, while only having to have one type of aircraft. even with the 80 F-35Cs it will save a bundle. Its not just about being able to carry on from an LH ship, its about rough fields and dispersion as well.

 

[LowObservable]

TT - Let's deal with your points in order.

Why double the fuel burn?

You don't. Fuel burn is related to total thrust, not the number of engines.

Nope! what are you basing that on? any facts to support that assertion?

I said"doubt" because I don't have hard facts to hand, but I know that many of the engine conditions and requirements are different and the two were developed a decade apart. If you have a figure for part-number commonality between the 119 and 135, this would be a good time to present it.

Your math Sucks according to GE and F135.com:

F414
Dry weight: 2,445 lb (1,110 kg) max weight

F135
Dry weight: 1,701 kg / 3,750 lbs

That would be an amazing weight figure, but it is wrong. Correct weight is around 6500 lb, confirmed directly by PW and reported publicly. Look it up. (I admit I was 10 per cent off on the F414 weight. So sue me.)

Its no secret that the Harriers engine ( big single) had more power than the combined f404 equipped F-18.

Complete bilge. The original F404 had 16K, and no Pegasus delivers more than 24K.

The F-35 has a large lifting body, slender is moot.

Provide a reputable source (not another fan) to confirm that the F-35 has a "lifting body" design and that slenderness has no impact on wave drag.

Luckily that weight reduction also made the F-35 A/C a lighter, better aircraft, amiright?

Produce sources confirming that any A/C weight reduction was worth delaying the program for years.

Two engines means ... double the fuel consumption

I think that by repeating that statement, you confirmed that you know less than nothing about aircraft design.

 

[bobbymike]

Would Congress have funded two or three stealth fighter programs in the post-Cold War/New World Order era to create aircraft suited to the unique requirements of the United States Marines, United States Air Force, and United States Navy?

No, because it would have been seen to be unaffordable. On the other hand, something like a Super-Rafale for the USAF and USN might have emerged successfully (with some level of LO) and something more "Harrier III"-like for the USMC.

By making it a joint program with participation of the United Kingdom, doesn't it make the program virtually immune from cancellation?

It makes it more difficult. That is not a good thing, because it allowed program leaders to blunder forward for years in complete denial of their cost and schedule problems.

Bolding mine

What the real issue for Mr. LO is that a successful F-35 program marks the end of European fighter aircraft design, development and definitely production and complete domination by the US. Sure Europe will be a niche player with maybe 4th gen avionics and upgrade work and probably helicopters I guess.

 

[LowObservable]

Ha ha!

A swing and a miss, Bobbymike. I'm actually in favor of competition as a way of improving the breed and fostering innovation, unlike corporate socialists who want to drive the US combat aircraft industry into an national-arsenal model run by a monopoly corporation.

If you disagree, please explain where the F-35's replacement will come from, under the present plan.

Also, for those who argue that the F-35 will be wonderfully cheap because, PBL done by the private sector - Please show where LM will open up its taxpayer-funded IP to permit competition.

As for helicopters, we Europeans already took most of that business over while the stealth enthusiasts and the US Manly Corpse were faffing around with Comanche and V-22.

 

[quellish]

Yup, DESERT STORM really hooked the Air Force on stealth. Immediately afterward USAF started a new low observable strategic bomber program, a new low observable strategic cruise missile program, and a low observable air superiority fighter program.

Thats a good point. It has changed the way US forces wage war. It confirmed the concept. Stealth is way of life now, previously it was a unconfirmed gamble.

Exactly. Because before 1991, there had never been an operational vehicle designed with signature reduction as a requirement. Many posts on this very forum confirm that.

 

[LowObservable]

Quellish - Look out. There are some people remarkably immune to irony.

 

[TaiidanTomcat]

Quell I agreed with you

[/i]I said"doubt" because I don't have hard facts to hand, but I know that many of the engine conditions and requirements are different and the two were developed a decade apart. If you have a figure for part-number commonality between the 119 and 135, this would be a good time to present it.

Do your own homework.

That would be an amazing weight figure, but it is wrong. Correct weight is around 6500 lb, confirmed directly by PW and reported publicly. Look it up. (I admit I was 10 per cent off on the F414 weight. So sue me.)

Are you talking about the f135-PW 600? If so the weight beyond the conventional engine is of course due to the lifting fan and other associated STOVL requirements. So its an apples and oranges comparison. You could strap 6 F414s on there and it still won't be able to hover. The regular F135 (for the CTOL) numbers according to the Pratt Website, are legit. so its not what I would call a compromise of the design, as the regular versions are still more powerful at less weight-- provided it was going to be a single engine design. single engine design was probably going to happen STOVL or not if only to keep it cheaper. Single engined like your beloved Gripen.

Provide a reputable source (not another fan) to confirm that the F-35 has a "lifting body" design and that slenderness has no impact on wave drag.

I actually saw a response to the wing loading Q on F-35.com. But I know you don't trust them.

A swing and a miss, Bobbymike. I'm actually in favor of competition as a way of improving the breed and fostering innovation, unlike corporate socialists who want to drive the US combat aircraft industry into an national-arsenal model run by a monopoly corporation.

Actually it was the end of the cold war that saw defense industry companies either merging or disappearing. With less demand fewer survived. We could have spent gobs of money just to keep all of them open and continue producing redundant weapons for no real reason, but even we thought that was a little excessive. Luckily Europe decided they didn't want to play at all anymore so here we are.

US Manly Corpse were faffing around with Comanche

Comanche was army, Bill. Looks like we both fail at the basics.

 

[GTX]

Exactly, JFC. Of course, STOVL advocates fiercely deny anything of the sort, and the claim of "no penalty for STOVL" has been made a few times in this thread.

And many F-35 detractors such as yourself seem to deny there is any requirement for STOVL...despite multiple customers wanting it. And as for the comment of no penalty, I seem to recall that what was actually asked was for details of what the exact penalties were. Moreover, I seem to recall pointing out that all aircraft design (as for most complex undertakings) is a matter of compromises.

1 - It forces the use of a single engine. We don't know how to build a multi-engine STOVL fighter that does not fall precipitously out of the sky if one donk quits, or even suffers a major transient, in powered-lift mode - thus adding engines makes you less safe, not more.

I am sure that if a twin engined STOVL fighter were developed there would be a horde of detractors screaming " why two engines...harrier did it with one!". I also tend to think you will find that the single engine concept was largely driven by customer requirements.

1a - Because of the jet's size, this means a new engine (I doubt that there are many F119 parts left in the F135).

And yet, you accuse the F-35 supporters of not having evidence to back up claims... :

1b - Also, the JSF STOVL concept makes the lift-cruise engine more complex, heavier and more expensive because it needs an oversized LP turbine and shaft. The F135 weighs 2000 pounds more than two F414s and is more expensive, and the weight is subject to a growth factor (that is, the structure needs to be heavier to carry the engine weight).

And the bigger space requirements + intake trunks etc for two F414 would not have led to equal or greater structural weight I suppose? This is all speculation and should be stated as such.

3a - Structure, systems and stowage have to be arranged around two 50+ inch-diameter cavities, which adds complexity. Quite possibly, a non-STOVL twin could have ended up with a more flexible weapon bay, but that's speculative.

Yay, you actually acknowledge this is speculative. Therefore, just as easily, I could speculate that it wouldn't have been as flexible. Kind of a pointless argument then isn't it? :

3b - The fuselage cross-section behind the cockpit is unusually large with a steep increase in c/s area from nose to the inlet line - this is likely to be nonoptimal in terms of area ruling.

Yet more speculation... :

 

[Tailspin Turtle]

"Why double the fuel burn?

You don't. Fuel burn is related to total thrust, not the number of engines."

Strictly speaking, having two engines generally does increase the fuel burn compared to a single-engine airplane designed to the same payload/range requirements if the total combined thrust of the two engines is greater than that of the single engine configuration, which is usually true if one-engine-inoperative flight is desired. The reason is that specific fuel consumption (sfc) decreases with thrust. At the thrust desired for cruise, the twin's engines are operating at a lower percentage of power and therefore a higher sfc. An early answer to that was to shut down one engine and raise the thrust of the other to decrease the sfc at the required thrust. However, that only works if the operating altitude is constrained and winds aloft are not a factor. At least for early jets, a twin could climb higher with both engines operating and get better specific range (as opposed to sfc) than it would on one engine at the lower ceiling achievable.

Another single versus twin effect that affects specific one-on-one comparisons (e.g. A-7 vs. F-18) was standard mission definition. Some partx of mission scenarios are usually defined at maximum thrust for convenience rather than operational necessity. This penalizes the twin.

However, in neither case does the fuel burn double with twice the engines, unless the twin has really, really inefficient engines. You may now return to your arguments based on guesses, assumptions, speculation, and facts from the interweb.

 

[sferrin]

Exactly, JFC. Of course, STOVL advocates fiercely deny anything of the sort, and the claim of "no penalty for STOVL" has been made a few times in this thread.

And many F-35 detractors such as yourself seem to deny there is any requirement for STOVL...despite multiple customers wanting it.

Before it's all over both Japan and South Korea will be in the carrier business. And they'll do it with the F-35B. You read it here first. ;-)

 

[TaiidanTomcat]

"Why double the fuel burn?

You don't. Fuel burn is related to total thrust, not the number of engines."

Strictly speaking, having two engines generally does increase the fuel burn compared to a single-engine airplane designed to the same payload/range requirements if the total combined thrust of the two engines is greater than that of the single engine configuration, which is usually true if one-engine-inoperative flight is desired. The reason is that specific fuel consumption (sfc) decreases with thrust. At the thrust desired for cruise, the twin's engines are operating at a lower percentage of power and therefore a higher sfc. An early answer to that was to shut down one engine and raise the thrust of the other to decrease the sfc at the required thrust. However, that only works if the operating altitude is constrained and winds aloft are not a factor. At least for early jets, a twin could climb higher with both engines operating and get better specific range (as opposed to sfc) than it would on one engine at the lower ceiling achievable.

Another single versus twin effect that affects specific one-on-one comparisons (e.g. A-7 vs. F-18) was standard mission definition. Some partx of mission scenarios are usually defined at maximum thrust for convenience rather than operational necessity. This penalizes the twin.

However, in neither case does the fuel burn double with twice the engines, unless the twin has really, really inefficient engines. You may now return to your arguments based on guesses, assumptions, speculation, and facts from the interweb.

Thank you. Double was the wrong word. Increase is what I should have said (Sue me : ) -- especially when that F135 is more efficient than the f414.

Regarding STOVL it seems to me that Bill had a predetermined idea of what the next fighter should be and anything that doesn't fit his theoretical, super cheap, awesome fighter is a letdown. The speculative plan is also devoid of real world military requirements which makes it even easier to design. Luckily for him the JSF has been suffering delays and increased in cost so he can use that against it while yet another "Imagination fighter" continues to beat it in every measure, (even development like the C-17 LOL)

Luckily all of Bill's speculation is impossible to prove so he always has the edge in the "prove my non existent aircraft wrong" category, while the rest of us suffer with reality. Meanwhile in reality the RAAF just purchased 12 Growlers at a cost of $1.5 billion. or $125 million each and just for the wiring. Can't wait to see what the as yet undeveloped Ultra Hornet costs!

 

[LowObservable]

TTomcat - Since you have thoroughly demonstrated you don't have a clue about anything, I am not going to waste any more of my time on you.

GTX - I'm not sure that you have posted here once without mis-stating my views.

Of course I agree that some customers want STOVL. The question is whether that requirement is important enough to justify the production and deployment of a $138 million jet (at full rate, base 2012 APUC) that can haul two 1000 lb bombs and two AMRAAMs 450 miles, while compromising the performance and cost of 2,000+ AF and Navy aircraft.

I would also suggest that some of the things that you label "speculative" are more correctly considered as the interpretation of the F-35 configuration based on generally recognized principles of aircraft design.

 

[JFC Fuller]

Of course I agree that some customers want STOVL. The question is whether that requirement is important enough to justify the production and deployment of a $138 million jet (at full rate, base 2012 APUC) that can haul two 1000 lb bombs and two AMRAAMs 450 miles, while compromising the performance and cost of 2,000+ AF and Navy aircraft.

I would also suggest that some of the things that you label "speculative" are more correctly considered as the interpretation of the F-35 configuration based on generally recognized principles of aircraft design.

Exactly, I agree entirely. Simply branding things as speculative seems to me to be a way of avoiding any sort of critical review of the programmes formulation rather than a credible line of defence. If one wants to maximise defence procurement it is imperative that programmes are reviewed and lessons learned and I think there is a strong case to be made that including the USMC STOVL requirement in the USAF F-16 and USN F/A-18 (effectively LWF replacement) programme was a mistake that has had all sorts of consequences.

 

[TaiidanTomcat]

TTomcat - Since you have thoroughly demonstrated you don't have a clue about anything, I am not going to waste any more of my time on you.

Better quit while you're behind.

GTX - I'm not sure that you have posted here once without mis-stating my views.

Your views seem to mold and alter with every inconvenient fact that pops up. in GTX's defence it hard to keep track. One second the C-17 is a model program the next its:

The C-17 is a good example of a program turned around after a gun was pointed at its head.

See how that is confusing?

Of course I agree that some customers want STOVL. The question is whether that requirement is important enough to justify the production and deployment of a $138 million jet (at full rate, base 2012 APUC) that can haul two 1000 lb bombs and two AMRAAMs 450 miles, while compromising the performance and cost of 2,000+ AF and Navy aircraft.

Well thats a matter of opinion and we know your opinion on it so you can stop beating the STOVL horse. Its not going anywhere the Marines are on their way to standing up their first squadron soon, and the UK already has their first F-35B running. Now that the requirement has totally corrupted the design in your opinion, you might as well keep the B.

I would also suggest that some of the things that you label "speculative" are more correctly considered as the interpretation of the F-35 configuration based on generally recognized principles of aircraft design.

I guess that makes you sound smarter than saying things like "probably" or "I doubt" and then when called on it, asking others to do the research for you.

 

[sferrin]

The question is whether that requirement is important enough to justify the production and deployment of a $138 million jet (at full rate, base 2012 APUC) that can haul two 1000 lb bombs and two AMRAAMs 450 miles,

I guess you didn't know about the F-35's weapons pylons? :

 

[sferrin]

Of course I agree that some customers want STOVL. The question is whether that requirement is important enough to justify the production and deployment of a $138 million jet (at full rate, base 2012 APUC) that can haul two 1000 lb bombs and two AMRAAMs 450 miles, while compromising the performance and cost of 2,000+ AF and Navy aircraft.

I would also suggest that some of the things that you label "speculative" are more correctly considered as the interpretation of the F-35 configuration based on generally recognized principles of aircraft design.

Exactly, I agree entirely. Simply branding things as speculative seems to me to be a way of avoiding any sort of critical review of the programmes formulation rather than a credible line of defence. If one wants to maximise defence procurement it is imperative that programmes are reviewed and lessons learned and I think there is a strong case to be made that including the USMC STOVL requirement in the USAF F-16 and USN F/A-18 (effectively LWF replacement) programme was a mistake that has had all sorts of consequences.

Would have been interesting if they'd gone with the Convair 200 and it's variants instead of the F-16/F/A-18

 

[AeroFranz]

However, in neither case does the fuel burn double with twice the engines, unless the twin has really, really inefficient engines. You may now return to your arguments based on guesses, assumptions, speculation, and facts from the interweb.

Might I add for completeness of the discussion that Reynolds numbers and tip losses effects favor the aerodynamics of larger engines. That being said, we're talking about few percents effect on SFC in said cases.
TT, always glad to read your posts, I wasn't aware of some of the operational considerations.

There are some statements regarding the penalties of STOVL that you could say are speculation, but are backed by pretty solid physics.

If you put a very large hole in the middle of a load bearing structure and you have to split it as a result, it IS going to be heavier than the corresponding unitary structure. I'm not talking about small holes in ribs, I'm talking large honking hole that spans three-quarters of the width of the fuselage.

Slenderness is your friend when you are trying to minimize (supersonic) wave drag. Having that large cross section where it is drives what the sections forward and aft look like. The absolute value of that cross section makes it hard to get a smooth distribution in a reasonable length. Add internal weapons bay to that.
As an example of the very real effects of this issue, you can look at the post-1127 supersonic direct-lift solutions, which adopted unconventional layouts (Like the MDD canard) to try to get the area distribution right.

 

[LowObservable]

I guess you didn't know about the F-35's weapons pylons?

Oh, those. Yes, it can carry more stuff over a proportionately shorter distance.

Moreover, the range numbers provided to Norway in 2008 show that the A/B configuration at least is ultra-sensitive to external load, because the drop tanks (which have apparently been deleted from the SDD program) provided <10 per cent more range for >30 per cent more fuel.

AF - Correct. Smaller engines do tend to have lower SFC. However, I suspect that the difference has diminished with 3D modelling (which gives you better understanding of tip and root effects), and the F414 ain't exactly small - the EPE version would have more poke than a J75, which was considered an adequately large engine when I was a sprog.

 

[sferrin]

I guess you didn't know about the F-35's weapons pylons?

Oh, those. Yes, it can carry more stuff over a proportionately shorter distance.

Moreover, the range numbers provided to Norway in 2008 show that the A/B configuration at least is ultra-sensitive to external load, because the drop tanks (which have apparently been deleted from the SDD program) provided <10 per cent more range for >30 per cent more fuel.

AF - Correct. Smaller engines do tend to have lower SFC. However, I suspect that the difference has diminished with 3D modelling (which gives you better understanding of tip and root effects), and the F414 ain't exactly small - the EPE version would have more poke than a J75, which was considered an adequately large engine when I was a sprog.

The EPE version may as well be a unicorn. I've been reading about 26,500lb thrust "potential" for the F414 for over a decade. Where is it?

As for the fuel tank claim I'm reminded of the F-22 detractors back in the day who said it wouldn't be able to manuever because it was "boxy" and probably wouldn't be able to supercruise either. Until a few airshows finally shut them up anyway. Until then though the "prophets" were utterly convinced. Looking forward to the F-35 doing the same thing. And you can be sure I'll be grinding salt in wounds at every opportunity.

 

[AeroFranz]

Gobs of thrust are all you need to go supersonic, even if you are flying a barn door. But it's not an efficient way of doing things.

 

[LowObservable]

Almost anything with two F119s will go supersonic, and almost anything with as much wing and tail as an F-22, and thrust vectoring, will get around corners pretty well.

Nor was there much time for any doubters about maneuver (I don't recall many in public) because the F-22 started high-alpha testing less than two years after first flight.

http://www.fas.org/man/dod-101/sys/ac/docs/n19990813_991511.htm

By the way, I was at Pax a few months ago and looked at the X-35C. It's like Kate Moss compared to the production jet.

 

[GTX]

GTX - I'm not sure that you have posted here once without mis-stating my views.

Pot calling kettle...

 

[sferrin]

By the way, I was at Pax a few months ago and looked at the X-35C. It's like Kate Moss compared to the production jet.

I take it you mean the X-35 is hideous compared to the production jet? I'd have to agree.

 

[AeroFranz]

I believe Kate Moss was the poster child for scheletric anorexia, back in the day.

Always glad to show off my gossip/pop culture knowledge on this forum.

 

[TaiidanTomcat]

I believe Kate Moss was the poster child for scheletric anorexia, back in the day.

Always glad to show off my gossip/pop culture knowledge on this forum.

;D

From Code One Magazine

 

[TaiidanTomcat]

An interesting AEW solution:

Honeycombing the Pacific: Crafting Scalable Forces

A new Pacific strategy can be built in part around the cultural revolution that the new F-35 engenders in interconnecting capabilities through the C4ISR-D enablement strategy. No platform fights alone, and shaping a honeycomb approach where force structure is shaped appropriately to the local problem but can reach back to provide capabilities beyond a particular area of interest within the honeycomb is key. The strategy is founded on having platform presence. By deploying such assets as those of the U.S. Coast Guard (for example, the National Security Cutter—or Navy surface platforms such as Aegis, LCS, or other surface assets) and by deploying sub-Service assets and having bases forward-deployed, the Nation has core assets that, if networked together, are capable of making significant gains possible. Scalability is the crucial glue to making a honeycomb force possible. That is why a Navy, Marine Corps, and Air Force common fleet is the crucial glue. And when “Aegis becomes my wingman” or “the SSGN [guided missile submarines] becomes the ARG fire support” through the F-35 C4ISR-D systems, a combat and cultural revolution is both possible and necessary. Basing becomes transformed as allied and U.S. capabilities become blended into a scalable presence and engagement capability. Presence is rooted in basing; scalability is inherently doable because of C4ISR enablement, deployed decisionmaking, and honeycomb robustness...

...The recent decision by Japan to buy the F-35A is a significant move forward in shaping a new Pacific approach and capability. The Japanese understand the opportunity to leverage the F-35 combat systems enterprise, and that is a key reason why the Japanese down-selected the aircraft. The Japanese—a key Aegis partner—also understand the significant opportunity provided by integrating the Aegis with the F-35. Combining the Aegis with the F-35 means joining their sensors for wide-area coverage. Because of a new generation of weapons on the F-35 and the ability to operate a broad wolf pack of air and sea capabilities, the JSF can perform as the directing point for combat action. With the Aegis and its new SM-3 missiles, the F-35 can leverage a sea-based missile to expand its strike area. Together, the F-35 and Aegis significantly expand the defense of land and sea bases.

The commonality across the combat systems of the F-35’s three variants provides a notable advantage. Aegis is a pilot’s wingman whether he is flying an F-35A, B, or C. Eighty percent of the F-35s in the Pacific are likely to be F-35As, many of them coalition aircraft. Therefore, building an F-35 and Aegis global enterprise provides coverage and capability across the Pacific, which is essential for the defense of Japan.

Moreover, the commonality of the fleet allows hubs to be built in the region supporting common operations, shaping convergent capabilities. The distributed character of allied forces in the region as well as the connectivity which the F-35 allows as an interdependent flying combat system diversifies capabilities with which a core adversary would have to cope. Reducing concentration of forces and targets is a significant enhancer of deterrence.

The reach from Japan to South Korea to Singapore to Australia is about how allies are reshaping their forces and working toward greater reach and capabilities.

http://www.ndu.edu/press/the-f-35.html

Australia is cited as a key JSF hub.

 

[quellish]

Quell I agreed with you

I don't think you did.
Employment of the F-117 in DESERT STORM did not significantly alter USAF doctrine or even procurement plans. The F-117 had already proven itself several times over against both US and threat systems, and previous generations of low observable aircraft had been proven in combat decades before.
If that was a gamble, I like the odds.

Instead, some of the things learned from DESERT STORM *did* affect doctrine and procurement. Bombing from low altitude was out, medium altitude was in. From medium altitude weather became more of a problem, which affected the performance of precision guided munitions. The same munitions were sometimes also extremely expensive, and were often too destructive given the precision available. That experience drove the requirements that became JDAM, and later SDB.

Interestingly enough, the GAO DESERT STORM analysis (as well as others) concluded that a major factor in the outcome was the *mix* of capabilities available. A diverse mix of aircraft and munition types were considered a great strength by GAO in their analysis:

"A range of target types, threat conditions, and tactical and strategic objectives was best confronted with a mix of weapon systems and strike and support assets with a range of capabilities."

If you are looking for something that greatly reduced losses in DESERT STORM, look no further than RED FLAG.

 

[LowObservable]

I was really trying to ignore you, TT, but...

The Japanese understand the opportunity to leverage the F-35 combat systems enterprise

"Speak English!' said the Eaglet. 'I don't know the meaning of half those long words, and I don't believe you do either!" - Lewis Carroll

Look, networking is fine and very important. Ask the Swedes, they have done more than most of the world has put on a PowerPoint. (By the way, it is noteworthy that JSF is the first major program conceived in the era of large-scale PowerPoint use.)

However, if you wanted to design a very, very cr@p AEW platform, you would incorporate the following features:

- Unrefueled endurance <2 hours in standard mission
- Radar with 120 degree scan limit
- Radar aperture constrained by SWaP (size, weight and power) and over-the-nose visibility for CV ops
- Long-haul connectivity limited to Link 16
- No provision whatsoever for CEC, which is the key to the Aegis capability.

Oddly, the Marines could get a VTOL AEW platform quite easily, on an almost completely non-developmental basis that does not add a platform to the fleet, that would also offer proven surface surveillance in the littorals, and could probably be made CEC-compatible (a very important improvement in capability for a non-CV operation). They have shown no interest in it whatsoever.