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Discuss the F-35 Lightning II
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hornetfinn

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Unread post19 Mar 2020, 11:57

lbk000 wrote:
hornetfinn wrote:I totally fail to see any resemblance or connection between F-35 program and Maginot Line.

Canada and Belgium are both northern points of failure? :wink:


LOL, good point! :P
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boogieman

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Unread post28 Apr 2020, 13:12

Was over at the F35 and Airshows thread and had a look at this video:

https://youtu.be/G0hWzaKEeZo

Scrolled down to the comments and saw that Kurt Plummer was up to his old tricks:

You're all missing several points.

1. The F-16 can be beaten by the Typhoon, Rafale and Su-27/30/35 and F-22. On a good day, at or below 15K, it can be beaten by either Hornet. To say that the F-16 is matched by the F-35 is not a point of pride. It's performance should never have been the threshold bar for a 21st century replacement.

2. One of the several KPPs the F-35 failed was a promise that the jet would AT LEAST MATCH both the sustained turn capability of the F-16 and the instantaneous (alpha pointing) capability of the F/A-18. It does neither. In a situation where OPEVAL is pass/fail and IOT&E is pass/fix, the F-35 never met a key kinematic KPP.

3. Missiles and sensors drive air combat performance, much like bullets and optics drive the metrics of rifles, far more than physical performance.

Without the AIM-9X, which is fitted SOLELY to an outboard pylon because it cannot be bay launched (rail weapon, not ejector) the F-35 loses it's VLO. Without a close-in weapon, the F-35's superior DAS is pointless as indeed, IMO, the Falcon Knight or Falcon Eye could do 90% of what the DAS does, in air combat, (SAIRST and night time thermal visionics) back in the early 90s and would be vastly more reliable, in the present tense where they are effectively stripping the entire system for an untested alternate in the near term.

4. The true measure of an air combat platform's utility lies in it's energy addition because fights are expected to be won, BVR and the outcome of BVR is determined in the intercept phase whereby you control the geometry of the fight by being supersonic, cold, and warping around to an advantaged shot position whereby you are beyond the threat jet's radar cone and contrail expectation band. Whether the final shot is taken BVR or WVR, properly accomplished air combat is a murder, not a duel and the F-35 simply lacks the ability get supersonic, quickly, hold it outside of burner, or get high enough to avoid drawing cons which will increasingly be visible themselves, to modern optronics, even at night.

The F-16C.50, clean at about 30K, has a 29 second acceleration from Mach .85 to 1.2. The F/A-18C with GE-402 engines does the same in about 34 seconds. Again, this is nothing special, today, but formed the KPP range of sprint performances that it was expected the F-35A would fall between. And yet the Lightning is about 8 seconds lagged. The F-35B is 16 seconds slower to accelerate and the F-35C is some 43 seconds longer accelerating than either of the aircraft they are expected to replace.

This is a crucial difference in a jet which is bay-limited to the number and size (depth as well as length) of any BVR weapons it carries and whose 110lb/sqft wingloading prevents it from fighting in the 35-40,000ft regime where the F-22, J-20 and Su-57 are quite comfortable and have a 50% missile pole leverage, at Mach 1.4.

Perhaps most importantly, as the global standard for QWIP staring focal plane array IRST continues to become more and more normed around multi and even hyperspectral pixel densities in excess of 1,500X1,500 detectors, the ability to use burner to achieve and hold supersonic speeds will become less and less tactically relevant. You will be detected in excess of 50nm FQ and 80nm RQ and a high heat signature jet with no RCS return is as good as an IFF tag.

Where having a supersonic shock, prebuilt on the missile as it exits the airframe is equal to about 20% greater missile range in the 1.2 @ FL250 height band, having NO supersonics performance makes the fighter highly questionable in it's effectiveness, especially if it's operating on the wrong side of a 900nm combat radius and has no fuel to spare for dogfighting.

5. Fuel burn and flat-plating the airframe are also problems with dogfighting in a radar controlled threat airspace but when the shot goes wrong and you are nose on committed, sometimes there is no choice. In this, it is true that the F-16 is alpha limited (27.5, clean) and that this number drops a fair bit when cheek and belly stations are loaded. While the F-35 had a nominal ~60` capability and can combine this with helicopter yaw turns and the like. Does this matter? No.

First because, to put significant lateral loads on the pilot is unwise in either case and to be sufficiently slow to do what is shown by the F-35 is to have ZERO energy to defeat a Pyrrhic return shot from either the intended target or an outsider shooter threat. While HOBS capable missiles increasingly don't need the pointed-on sweetening of the shot.

You will notice that the F-35 loses altitude, significantly, in it's pedal turn and realizing that the majority of a stealth assets flight time is going to be at or above 25,000ft, to extend range, remain outside of SHORADS threat bubbles and provide best sensor slant, this becomes a significant vulnerability.

At FL250, the air is half as dense as it is at sea level. Just to maintain MINIMUM beyond-stall lift on the jet requires it to be a third again as fast. This rapidly develops into a situation where there is too much entrance G for the pilot or airframe (note, lateral loads are dangerous for heavy A2G munitions, whether they are freestream or in a weapons bay).

Secondly, the F-35 is going to be fighting at night, under conditions where it is likely carrying only 2 AIM-120 and even if those AMRAAMs are Deltas (with significantly more close-in dogfight performance), it will be foolish to withhold shots until after the radar merge at 10-15nm. If it misses with those shots, at these distances, it should separate and extend. Something which is made easy if the section wingman is providing midcourse guidance updates and the parent fighter can roll and displace, massively, to leave the fight plane.

Fighting at night pushes spatial disorientation and rapid target loss and while DAS can compensate for the latter, it is unwise to get into falling leaf, spinning horizon, conditions 'on purpose', in the primary advantaged condition F-35s can be expected to be fighting an air war with an active DCA threat component: stealth in low visibility.

Third, while some unfortunately equate high alpha with 'agility' as the ability to shoot your own a$$ off under complete control, the reality is that agile is to maneuverable as quick is to fast.

And this is particularly crucial in evaluating the F-16 vs. F-35 comparison in that the F-16 always has roll authority with which to reverse it's loaded turn. And always has speed of entry and sustained energy within the turn to not bleed everything when it does cut back.

This is largely because of the way the RSS design condition sets CofL and CofG harmoniously, allowing a nominally 300ft2 wing area to add another 150ft2 of stab lift as the wing LEF deflect upwards and the tails trim neutral, to supply added lift.


On the F-35, the need to maintain a neutral CL trim displacement in supporting a large weapons bay and STOVL meant small, straight, wings, near the CG.

And for this airframe configuration to not completely ruin transonics performance meant using the intake trunking and belly as 1G neutral lift augments, similar to fat LEX and pushing the heavy engine as far back as possible so that the wings may be similarly aft set and not totally screw up the area ruling.

Unfortunately, this then means that as the alpha comes up the tails immediately have to dig to keep it that way while the intakes and weapons bay area rapidly transition from thick airfoil to speed brake as the variance in effective AOA between the aft set wing and the forebody is considerable.

So that, instead of a complimentary lift curve in which the stabs are free to add roll authority as needed, you have a divergent set of curves which effects additive alpha capability as the authority inherent to the aft controls has to be bled off, more and more, just to keep the nose going up and the glowie bit pointed aft.

The result, as reported by F-35 TPs, is that the jet has a low-transitional-high (blended) AOA limit on the order of 18-20`, 23-25`, 27-30` whereas most modern jets don't begin to seriously self-limit maneuver authority in the high regime now until 35` or more.

While the F-35 can get there as a function of absolute alpha rates, by the time it does so, it's a monorail with the roll and pitch authority to rapidly un-point and recover the jet very slow. This is unacceptable as the standard defensive tactic is to simply roll under, tuck and reverse to spit the other jet out and the F-35 is going to lag on this, so badly that it cannot maintain a dominant position as everything is dedicated to stabilizing the achieved alpha.

Which is why the F-35 shown in the video, while it has similar or even greater total alpha range (square turn) for a given speed, shows an overall less fluid and more sluggish ability to change it's axis of maneuver in a fashion that can best be described as plodding.

Again, the F-35 Test Pilot report which highlights these shortcomings is quite explicit: In the simplest of BFM maneuvering, he not only could not prosecute an F-16D with a GE-100 engine and two wing bubbles but he could not prevent the subsequent threat reversal into his own six.

Where his fancy helmet sight and DAS were useless, due to the tight confines of the canopy and the bulky headrest which kept him from even SEEING the threat to maneuvering, defensively, against the Viper.

Subsequent OFPs have supposedly been released which open out the F-35's performance envelope from an F-101 level 4.5G sustained to something nearer 7Gs, at primary fight heights (the JSF also has severe low level performance limits, thanks to thermal issues).

This is about right for a 470sqft wing maneuvering in the 20-25K region, subsonic.

The F-22 does better, only because it is supercruise capable of generating four or five times the lift off an 840sqft wing area while exploiting TVC to max pitch rates.

The fact remains that the F-35 is not really competitive with ANY fourth gen fighter (excepting, perhaps, the Super Hornet) in the primary regime where it can be expected to fight, as nearly every other jet has the same or similar alpha limits, equal or better thrust to weight and vastly superior, canard-delta, aerodynamics for the transonic fight.

With appropriate munitions development (Peregrine/CUDA, AARGM-ER, JAGM-F, SPEAR 3) the F-35 will likely make a pretty good weasel airframe it has the ELS and global thermals to do so. It will never be, even with sidekick and LREW/JATM, more than an adequate air to air fighter.

And people who try to sell a long range multisensor interdiction platform as a DCA fighter because that is what their country needs are doing themselves and their nation's defense no honest benefit, whatsoever. The F-35 will remain exceptionally costly to maintain, throughout it's service life. Partially do to the added systems requirements for stealth and partially because hey, it's Lockheed and they have been screwing customers since the F-104 days.

But in terms of aerodynamic performance, what counts is the ability to overcome inertia in rapidly transitioning between maneuver modes across a wide speed band (thrust loading) and altitude regime (wing loading) to be able to rapidly change-state so as to drag the fight to a point on the EM globals where you can achieve dominance over the enemy airframe.

The F-35 doesn't have this and, as far as I can tell, it does not have a lot of the systems it needs (dense kinematic EXCM/MSDM and TADIRCM steerable dazzlers plus multishot missile loads with full 2-way datalinks and MEMS seekers) to be able to compensate for it's innate, kinematic, shortcomings.

I simply don't have the expertise to respond to the claims on kinematics but I am sure there are members on here that do. Have at it folks!
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Unread post28 Apr 2020, 14:01

Yeah, yeah, the F-35 is the worst thing since the bubonic plague, we've all heard it before :roll:
While it may not be the best dogfighter out there, it's more than good enough to bring its advantage in sensors and stealth to bear on unsuspecting opponents. Gotta love how the author (as always with F-35 haters) just brushes that off as irrelevant.
Russia stronk
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quicksilver

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Unread post28 Apr 2020, 16:12

...and the fan boy flame wars go on and on and on and on — like one of those gag birthday candles you can never blow out. Ya just gotta let them burn themselves out. And stop slipping them TV dinners under the door.

Many are masters of the old saying, “...if you can’t blind them with your brilliance, baffle ‘em with your bs.” Throw in some technical or pseudo-technical jargon and some semantic excess and you can live for an internet eternity.

And then we have non sequitur — in this case the writer contradicts himself in successive paragraphs —

“3. Missiles and sensors drive air combat performance, much like bullets and optics drive the metrics of rifles, far more than physical performance...
4. The true measure of an air combat platform's utility lies in it's energy addition...”

Bottom line? Don’t waste your time w ‘em.
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mixelflick

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Unread post28 Apr 2020, 17:06

Now I don't know what to believe about the F-35. It's not just this guys points.... it was the F-35 pilot interview on TFPP a few weeks back. It didn't sound like either that the F-35 could "rate like a Viper, and radius like a SH". Nor did I hear anything about its superior acceleration. That stand in stark contrast to what many F-35 supporters contend here. So which is it?

"Super maneuverable strike fighter with power to spare" or...
"Sort of maneuverable strike fighter, that's somewhat sluggish (that was the word used in TFPP)

NOTE: I don't doubt the bottom line - The F-35 will kill almost everything long before it knows its there.

I just want to know the truth as to its kinematic performance..
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Unread post28 Apr 2020, 17:46

You’ve been around here for years, mix. If you haven’t figured it out by now, nothing is going to convince you.
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Unread post28 Apr 2020, 18:20

When you have countless pilots with 1000s of hours in F-15/16/18/22, Typhoon, etc... say how impressed they are by how the F-35 flies, you should probably listen to them, and not lone anecdotes.
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Unread post28 Apr 2020, 18:39

mixelflick wrote:Now I don't know what to believe about the F-35. It's not just this guys points.... it was the F-35 pilot interview on TFPP a few weeks back. It didn't sound like either that the F-35 could "rate like a Viper, and radius like a SH". Nor did I hear anything about its superior acceleration. That stand in stark contrast to what many F-35 supporters contend here. So which is it?

"Super maneuverable strike fighter with power to spare" or...
"Sort of maneuverable strike fighter, that's somewhat sluggish (that was the word used in TFPP)

NOTE: I don't doubt the bottom line - The F-35 will kill almost everything long before it knows its there.

I just want to know the truth as to its kinematic performance..


I think the better way to answer your question is how will the pilot use their aircraft. You will always hear and read about F-22 pilots extolling the kinematic capabilities of the Raptor. When compared to other western fighter aircraft the F-22 is second to none. Yet there has been instances where the F-22 in ACM when the F-22 got defeated. Much like in the TFPP F-22 ep where the guest speaker talked about how anViper got the better of him because of the way he initially tried to fight the Viper.

The guest speaker of on TFPP F-35 ep did mention briefly about other pilots experience doing BFM and ACM in the F-35. He remarked that initially the veteran Viper pilots flew the F-35 like it was their old Viper. Then they gradually started to use more pedal input and greater AoA abilities to their advantage.
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quicksilver

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Unread post28 Apr 2020, 19:49

charlielima223 wrote:
mixelflick wrote:Now I don't know what to believe about the F-35. It's not just this guys points.... it was the F-35 pilot interview on TFPP a few weeks back. It didn't sound like either that the F-35 could "rate like a Viper, and radius like a SH". Nor did I hear anything about its superior acceleration. That stand in stark contrast to what many F-35 supporters contend here. So which is it?

"Super maneuverable strike fighter with power to spare" or...
"Sort of maneuverable strike fighter, that's somewhat sluggish (that was the word used in TFPP)

NOTE: I don't doubt the bottom line - The F-35 will kill almost everything long before it knows its there.

I just want to know the truth as to its kinematic performance..


I think the better way to answer your question is how will the pilot use their aircraft. You will always hear and read about F-22 pilots extolling the kinematic capabilities of the Raptor. When compared to other western fighter aircraft the F-22 is second to none. Yet there has been instances where the F-22 in ACM when the F-22 got defeated. Much like in the TFPP F-22 ep where the guest speaker talked about how anViper got the better of him because of the way he initially tried to fight the Viper.

The guest speaker of on TFPP F-35 ep did mention briefly about other pilots experience doing BFM and ACM in the F-35. He remarked that initially the veteran Viper pilots flew the F-35 like it was their old Viper. Then they gradually started to use more pedal input and greater AoA abilities to their advantage.


These kind of thoughts have all been explained many, many times before. It is a well-trafficked rabbit hole.
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Unread post28 Apr 2020, 20:07

quicksilver wrote:You’ve been around here for years, mix. If you haven’t figured it out by now, nothing is going to convince you.


Well from what I've seen, you can find anecdotes from different places/people to support either view. I have heard from F-16 pilots though, who could not "see" it on radar from 12 miles, and that was AFTER ground control told them where to look! That and the other pilots surveyed who almost unanimously picked it to go to war in.

Still, I'd love to really stick it to guys like this who painted it otherwise with a broad brush. Will be nice when it gets a more powerful engine, sidekick, Perigrine etc. or even better, when it's combat record reflects what was seen during Red Flag. I wouldn't want to be flying against it, that's for sure.
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Unread post28 Apr 2020, 20:11

There has been more than enough discussion here for anyone to come to their own conclusion(s) about the jet. Ultimately, you have to decide what you want to believe and form your own opinion accordingly.
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Unread post28 Apr 2020, 22:36

mixelflick wrote:Now I don't know what to believe about the F-35. It's not just this guys points.... it was the F-35 pilot interview on TFPP a few weeks back. It didn't sound like either that the F-35 could "rate like a Viper, and radius like a SH". Nor did I hear anything about its superior acceleration. That stand in stark contrast to what many F-35 supporters contend here. So which is it?

"Super maneuverable strike fighter with power to spare" or...
"Sort of maneuverable strike fighter, that's somewhat sluggish (that was the word used in TFPP)

NOTE: I don't doubt the bottom line - The F-35 will kill almost everything long before it knows its there.

I just want to know the truth as to its kinematic performance..

Yes I noticed that as well. I found his input puzzling, as he described the F35's high alpha performance as more comparable to that of a Strike Eagle than a Hornet. This is despite the fact that we have seen the F35 perform some of the Hornet's best tricks in the high alpha/low speed regime (pirouette, square loop, power slides, low speed/high alpha pass). These are all things that the Mud Hen simply can't do. My hunch is that he was being particularly conservative in his input, but why that was the case is hard to know. IIRC he was involved as a test pilot, not in an operational squadron, so maybe he didn't get much time exploring everything the 3F+ jets can do.

As for Kurt's trademark diatribe, my take away is that it is very entrenched in 4th gen thinking. That is to view BVR/ACM as a race for high energy state to both impart said energy into missile shots (maximise pK via added missile speed and range), while also using it to conduct defensive and subsequent offensive maneuvers. This is all well and good when all else is equal (eg. detection and engagement range), but with the F35 it isn't (by design).

The reality is that for the next ~20 years the OPFOR air threat will overwhelmingly consist of evolved Flanker derivatives, followed by J10, J20, Foxhound and Fulcrum with Su57 likely somewhere off in the distance. The vast majority of these will have parasitic drag issues in combat. On top of this you are also looking at threat aircraft that probably don't have the sensors to independently complete a reliable/viable kill chain on the F35 until somewhere in the neighbourhood of ~10nm. Even if it is double that (generous) you have still turned the BVR fight on its head, because zooming up to Mach1.5+ at 50k feet won't mean squat if the F35 sitting at M0.9 and 40k feet still has you locked and inside its AIM120/260 NEZ before you can shoot at it. On top of this, at such high altitude and speed OPFOR are stuck on a high speed train track with few available options for defensive maneuver (turn circle the size of Texas) while the F35 can crank away at a moment's notice. The fight becomes less about who can get/stay more energetic (4th gen) and more about who can take their high pK/NEZ missile shot first, using the combination of VLO and co-operative EW rather than raw kinematics to get there (5th gen).

The main point Kurt may have here is that the F35 does need to use AB to break the Mach barrier & stay above it for prolonged periods. It would certainly be handy for the F35 to be able to launch its missiles at or around Mach 1.2 without risking detection from enemy IRST due to AB use but alas, nobody's perfect! :wink: Even so, I suspect there is a tactical workaround if a supersonic AAM shot is desired. Simply speed up to desired Mach using AB from outside OPFOR IRST range, then back off to mil power to coast into the missile shot(s). The jet will undoubtedly bleed some of the additional speed once AB is extinguished, but with an airframe as slick as the F35's, I suspect it should hold much of it for the last few dozen nm until missile launch. Kind of reminiscent of the way Indian Fulcrum pilots would back off the throttle as they approached the merge to reduce the visual signature of their smokey engines. Now couple the above with an off-axis approach vector to place the F35(s) outside the threat IRST FOV altogether and you have yourself a routinely bad day for red air.
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Unread post29 Apr 2020, 06:04

boogieman wrote:Was over at the F35 and Airshows thread and had a look at this video:

https://youtu.be/G0hWzaKEeZo

Scrolled down to the comments and saw that Kurt Plummer was up to his old tricks:

You're all missing several points.

1. The F-16 can be beaten by the Typhoon, Rafale and Su-27/30/35 and F-22. On a good day, at or below 15K, it can be beaten by either Hornet. To say that the F-16 is matched by the F-35 is not a point of pride. It's performance should never have been the threshold bar for a 21st century replacement.

2. One of the several KPPs the F-35 failed was a promise that the jet would AT LEAST MATCH both the sustained turn capability of the F-16 and the instantaneous (alpha pointing) capability of the F/A-18. It does neither. In a situation where OPEVAL is pass/fail and IOT&E is pass/fix, the F-35 never met a key kinematic KPP.

3. Missiles and sensors drive air combat performance, much like bullets and optics drive the metrics of rifles, far more than physical performance.

Without the AIM-9X, which is fitted SOLELY to an outboard pylon because it cannot be bay launched (rail weapon, not ejector) the F-35 loses it's VLO. Without a close-in weapon, the F-35's superior DAS is pointless as indeed, IMO, the Falcon Knight or Falcon Eye could do 90% of what the DAS does, in air combat, (SAIRST and night time thermal visionics) back in the early 90s and would be vastly more reliable, in the present tense where they are effectively stripping the entire system for an untested alternate in the near term.

4. The true measure of an air combat platform's utility lies in it's energy addition because fights are expected to be won, BVR and the outcome of BVR is determined in the intercept phase whereby you control the geometry of the fight by being supersonic, cold, and warping around to an advantaged shot position whereby you are beyond the threat jet's radar cone and contrail expectation band. Whether the final shot is taken BVR or WVR, properly accomplished air combat is a murder, not a duel and the F-35 simply lacks the ability get supersonic, quickly, hold it outside of burner, or get high enough to avoid drawing cons which will increasingly be visible themselves, to modern optronics, even at night.

The F-16C.50, clean at about 30K, has a 29 second acceleration from Mach .85 to 1.2. The F/A-18C with GE-402 engines does the same in about 34 seconds. Again, this is nothing special, today, but formed the KPP range of sprint performances that it was expected the F-35A would fall between. And yet the Lightning is about 8 seconds lagged. The F-35B is 16 seconds slower to accelerate and the F-35C is some 43 seconds longer accelerating than either of the aircraft they are expected to replace.

This is a crucial difference in a jet which is bay-limited to the number and size (depth as well as length) of any BVR weapons it carries and whose 110lb/sqft wingloading prevents it from fighting in the 35-40,000ft regime where the F-22, J-20 and Su-57 are quite comfortable and have a 50% missile pole leverage, at Mach 1.4.

Perhaps most importantly, as the global standard for QWIP staring focal plane array IRST continues to become more and more normed around multi and even hyperspectral pixel densities in excess of 1,500X1,500 detectors, the ability to use burner to achieve and hold supersonic speeds will become less and less tactically relevant. You will be detected in excess of 50nm FQ and 80nm RQ and a high heat signature jet with no RCS return is as good as an IFF tag.

Where having a supersonic shock, prebuilt on the missile as it exits the airframe is equal to about 20% greater missile range in the 1.2 @ FL250 height band, having NO supersonics performance makes the fighter highly questionable in it's effectiveness, especially if it's operating on the wrong side of a 900nm combat radius and has no fuel to spare for dogfighting.

5. Fuel burn and flat-plating the airframe are also problems with dogfighting in a radar controlled threat airspace but when the shot goes wrong and you are nose on committed, sometimes there is no choice. In this, it is true that the F-16 is alpha limited (27.5, clean) and that this number drops a fair bit when cheek and belly stations are loaded. While the F-35 had a nominal ~60` capability and can combine this with helicopter yaw turns and the like. Does this matter? No.

First because, to put significant lateral loads on the pilot is unwise in either case and to be sufficiently slow to do what is shown by the F-35 is to have ZERO energy to defeat a Pyrrhic return shot from either the intended target or an outsider shooter threat. While HOBS capable missiles increasingly don't need the pointed-on sweetening of the shot.

You will notice that the F-35 loses altitude, significantly, in it's pedal turn and realizing that the majority of a stealth assets flight time is going to be at or above 25,000ft, to extend range, remain outside of SHORADS threat bubbles and provide best sensor slant, this becomes a significant vulnerability.

At FL250, the air is half as dense as it is at sea level. Just to maintain MINIMUM beyond-stall lift on the jet requires it to be a third again as fast. This rapidly develops into a situation where there is too much entrance G for the pilot or airframe (note, lateral loads are dangerous for heavy A2G munitions, whether they are freestream or in a weapons bay).

Secondly, the F-35 is going to be fighting at night, under conditions where it is likely carrying only 2 AIM-120 and even if those AMRAAMs are Deltas (with significantly more close-in dogfight performance), it will be foolish to withhold shots until after the radar merge at 10-15nm. If it misses with those shots, at these distances, it should separate and extend. Something which is made easy if the section wingman is providing midcourse guidance updates and the parent fighter can roll and displace, massively, to leave the fight plane.

Fighting at night pushes spatial disorientation and rapid target loss and while DAS can compensate for the latter, it is unwise to get into falling leaf, spinning horizon, conditions 'on purpose', in the primary advantaged condition F-35s can be expected to be fighting an air war with an active DCA threat component: stealth in low visibility.

Third, while some unfortunately equate high alpha with 'agility' as the ability to shoot your own a$$ off under complete control, the reality is that agile is to maneuverable as quick is to fast.

And this is particularly crucial in evaluating the F-16 vs. F-35 comparison in that the F-16 always has roll authority with which to reverse it's loaded turn. And always has speed of entry and sustained energy within the turn to not bleed everything when it does cut back.

This is largely because of the way the RSS design condition sets CofL and CofG harmoniously, allowing a nominally 300ft2 wing area to add another 150ft2 of stab lift as the wing LEF deflect upwards and the tails trim neutral, to supply added lift.


On the F-35, the need to maintain a neutral CL trim displacement in supporting a large weapons bay and STOVL meant small, straight, wings, near the CG.

And for this airframe configuration to not completely ruin transonics performance meant using the intake trunking and belly as 1G neutral lift augments, similar to fat LEX and pushing the heavy engine as far back as possible so that the wings may be similarly aft set and not totally screw up the area ruling.

Unfortunately, this then means that as the alpha comes up the tails immediately have to dig to keep it that way while the intakes and weapons bay area rapidly transition from thick airfoil to speed brake as the variance in effective AOA between the aft set wing and the forebody is considerable.

So that, instead of a complimentary lift curve in which the stabs are free to add roll authority as needed, you have a divergent set of curves which effects additive alpha capability as the authority inherent to the aft controls has to be bled off, more and more, just to keep the nose going up and the glowie bit pointed aft.

The result, as reported by F-35 TPs, is that the jet has a low-transitional-high (blended) AOA limit on the order of 18-20`, 23-25`, 27-30` whereas most modern jets don't begin to seriously self-limit maneuver authority in the high regime now until 35` or more.

While the F-35 can get there as a function of absolute alpha rates, by the time it does so, it's a monorail with the roll and pitch authority to rapidly un-point and recover the jet very slow. This is unacceptable as the standard defensive tactic is to simply roll under, tuck and reverse to spit the other jet out and the F-35 is going to lag on this, so badly that it cannot maintain a dominant position as everything is dedicated to stabilizing the achieved alpha.

Which is why the F-35 shown in the video, while it has similar or even greater total alpha range (square turn) for a given speed, shows an overall less fluid and more sluggish ability to change it's axis of maneuver in a fashion that can best be described as plodding.

Again, the F-35 Test Pilot report which highlights these shortcomings is quite explicit: In the simplest of BFM maneuvering, he not only could not prosecute an F-16D with a GE-100 engine and two wing bubbles but he could not prevent the subsequent threat reversal into his own six.

Where his fancy helmet sight and DAS were useless, due to the tight confines of the canopy and the bulky headrest which kept him from even SEEING the threat to maneuvering, defensively, against the Viper.

Subsequent OFPs have supposedly been released which open out the F-35's performance envelope from an F-101 level 4.5G sustained to something nearer 7Gs, at primary fight heights (the JSF also has severe low level performance limits, thanks to thermal issues).

This is about right for a 470sqft wing maneuvering in the 20-25K region, subsonic.

The F-22 does better, only because it is supercruise capable of generating four or five times the lift off an 840sqft wing area while exploiting TVC to max pitch rates.

The fact remains that the F-35 is not really competitive with ANY fourth gen fighter (excepting, perhaps, the Super Hornet) in the primary regime where it can be expected to fight, as nearly every other jet has the same or similar alpha limits, equal or better thrust to weight and vastly superior, canard-delta, aerodynamics for the transonic fight.

With appropriate munitions development (Peregrine/CUDA, AARGM-ER, JAGM-F, SPEAR 3) the F-35 will likely make a pretty good weasel airframe it has the ELS and global thermals to do so. It will never be, even with sidekick and LREW/JATM, more than an adequate air to air fighter.

And people who try to sell a long range multisensor interdiction platform as a DCA fighter because that is what their country needs are doing themselves and their nation's defense no honest benefit, whatsoever. The F-35 will remain exceptionally costly to maintain, throughout it's service life. Partially do to the added systems requirements for stealth and partially because hey, it's Lockheed and they have been screwing customers since the F-104 days.

But in terms of aerodynamic performance, what counts is the ability to overcome inertia in rapidly transitioning between maneuver modes across a wide speed band (thrust loading) and altitude regime (wing loading) to be able to rapidly change-state so as to drag the fight to a point on the EM globals where you can achieve dominance over the enemy airframe.

The F-35 doesn't have this and, as far as I can tell, it does not have a lot of the systems it needs (dense kinematic EXCM/MSDM and TADIRCM steerable dazzlers plus multishot missile loads with full 2-way datalinks and MEMS seekers) to be able to compensate for it's innate, kinematic, shortcomings.

I simply don't have the expertise to respond to the claims on kinematics but I am sure there are members on here that do. Have at it folks!

1) Typhoon, Rafale, Su-27/30/35 can also be beaten by F-16 though, so they are on equal footing. F-16 acceleration in dogfight regime is in fact better than all but the typhoon and its roll rate are likely the best among those.
https://www.theregister.co.uk/2011/06/0 ... en_by_f16/

2) F-35 can't match the sustain turn rate of a clean F-16, unfortunately, a clean F-16 is quite useless as it has nothing to defend itself. F-35 has better nose pointing than F-18 though. Nevertheless, F-35 has better ITR than F-16 and better STR than F-18 and better acceleration than both at dogfighting speed.

3) F-35 doesn't lose VLO with external AIM-9, the weapon certainly increase the total RCS, however the RCS is still hundred times smaller than a clean 4 generation aircraft, the launched were designed to have lower RCS than conventional launcher as well:
Image
Secondly, Falcon eye doesn't do 90 % the task of DAS, not even remotely close in fact. Falcon eye is a nose low-resolution IIR sensor without LRF, with the only role of helping the pilot get rid of the Night navigation binocular while DAS is a group of 6 high resolution IIR sensor with automatic target tracking and classification capability. Compare them is basically the same as comparing an Iphone X and Nokia 1120
s-l1600.jpg



4) The outcome of BVR combat is dictated by the information available to the pilot. This has been shown plenty of time in history, Mig-25 can fly far higher, far faster, than any F-16 and F-15, so how many time have Mig-25 shot down F-15 or F-16? zero time. While F-15, F-16 have shot down Mig-25 a few times. The main advantage of F-35 are stealth, sensor and networking.
F-16 acceleration isn't normal, even now, it is considered as one of the fastest in acceleration, better than Rafale and Su-27/30/35. And there is no such thing as he F/A-18C with GE-402 in production so it is irrelevant.
And wing loading value can't be directly compared like that because these aircraft don't have the same wing shape and wing thickness, F-35 while have higher wing loading, it also has lower wing sweep, so at any AoA, the CL is higher so flying at decently high altitude isn't a very hard task, fighting at 35-45k ft regime should be normal for F-35.
Flying at supersonic speed will give your missile more length, but at the same time will increase your own IR signature and that give enemy chance to detect and attack you from a greater distance.
QWIP isn't all that popular but even if it is, it doesn't get rid of the biggest weak point of IRST, that is they can't measure range without LRF or triangulation and infrared radiation can't go through cloud. LRF range are very short, on the order of 15-20 km for OLS-35. While triangulation requires datalink, without a stealth directional datalink like MADL, you pretty much let everyone know where you are when you use it, good luck turn and burn with Mach 6 SAM.

5) that just a bunch of techno sounding words group together but little fact.
HOBS missile increasing the value of nose pointing ability because sustain turn no longer enough to create enough angle separation to stay outside of missile's FoV. And no pilot start the fight with a post stall maneuver. His condition doesn't make any sense either, why does F-35 carry 2 heavy AG mution and only 2 AMRAAMs ? even if it is doing an air to ground mission, why not an asymmetric load of 2 AIM-132 /AIM-9X on wing tip, 4 AIM-120D and 4 SDB/SPEAR?. If he entered dogfight why not eject the bombs?
Secondly, talking about dogfighting at night? which aircraft can really dogfight at night? Rafale, Gripen, Typhoon, F-16, F-15, Su-57 all can't dogfight at night. Because they don't have anything that gives them 360 degrees view like DAS. Don't tell me about DDM-NG, the distorted fish eye view is the last thing you want in a dogfight. So that leaves F-35 and J-20 with night dogfighting ability.
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Unread post29 Apr 2020, 23:13

Subsequent OFPs have supposedly been released which open out the F-35's performance envelope from an F-101 level 4.5G sustained to something nearer 7Gs, at primary fight heights (the JSF also has severe low level performance limits, thanks to thermal issues).

Can anyone shed any light on this? I vaguely remember there being some heat management issues with the weapons bays at low altitude years ago but haven't heard any updates on if/how it has been addressed.
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Unread post29 Apr 2020, 23:30

Depending upon F-35 Variant the MAX G is 9 for A; 7 for B & 7.5 for C from LM F-35 Fast Facts April 2020: [full int load]

https://a855196877272cb14560-2a4fa819a6 ... l_2020.pdf (2Mb)

IIRC when taxiing in high temps there was a time limit for doors closed due to overheating however AFAIK the issue fixed by wiring changes in bomb bay a long time ago. The F-35A & B variants operate in high temp desert environments today.

Discussion about it here: viewtopic.php?f=60&t=52580 Weapons bay thermal environment 11 Dec 2016
A4G Skyhawk: www.faaaa.asn.au/spazsinbad-a4g/ & www.youtube.com/channel/UCwqC_s6gcCVvG7NOge3qfAQ/videos?view_as=subscriber
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