The F-35 Thread

[garrya]

Hehe, first of all clmax isn't uniform at the same AoA across all speed ranges

Which is why the table give both max AoA and CL value in respect to speed

 

secondly your simple math exercise fails to even consider the lift generated by the fuselage, which is over half of the total lift in the case of the Su-27 with its massive and highly optimized true lifting body design heavily influenced by the F-14

As a result the Su-27 features a lift loading lower than that of most fighters, esp. at low speeds, which is what provides it with such amazing low speed agility. It would make a mockery of the F-35 in a classic dogfight.

No, body lift already been taken into account in the CL and CLmax value ( those are CL of the whole aircraft , not just the airfoil). Why else do you think CLmax of F-15 so much smaller than F-16 and Su-27 value ?

 

In other words it's a pretty poor comparison with both the F-16 & F-35.

How is is it any poorer than your comparison with F-15 ?

F-15 lack LERX , LEF , negative stability . On the other hand , those features all appeared on F-16 , Su-27 , F-35. Another feature that Su-27 share with F-35 is the fact that they both have extremely long range with internal fuel load. With that being said the bottom line is to show that AoA of 20-22 degrees can be hold at Mach 0.7-0.8 which result in much higher CL than at 15 degrees

Also you would've been better off by simply showing the Su-27's EM chart...

Soviet aerodynamic booklet of Su-27 doesnt give EM like the Western one , they give CL instead

Edited November 18, 2016 by garrya

[Basher54321]

Basher54321,

F-16.net has a list of all RDAF F-16, here you can see the active, stored, destroyed, etc F-16. AFAIK, all active F-16 in the RDAF are consider block 20, but to what tape and what capabilities they posses is on a aircraft to aircraft bases. I am not disputing what you said nor contradicting it, just trying to provide a good source/reference link for everyone in the conversion to see.

 

 

The information was supposed to be direct from 730 Squadron and is very recent - will find the source later the Mag was online somewhere.

 

 

The reason for not upgrading the Block 10 airframes was given as due to the weight the nose wheel can handle - they are structurally different to the block 15 which was the first to get the cheek station provisions. Not certain why AIM-120 cant go on - thinking major hardware and rewiring changes are required.

(The RAF are in a similar position with Tranche 1 Typhoons as I understand)

 

 

The Block 20 designation is confusing - did wonder if they were referring to a software block not an airframe block. The Block 10 MLU were clearly not rebuilt (or probably cant be rebuilt) to the Block 15 structure. (although most got bigger horizontal stabs at some point)

 

To confuse things further all the F-16As built in the late 1980s and early 1990s (some are now designated Block 20s) were Block 15 OCU which were basically heavier C airframes despite the missing base tail antenna (closest I would think is Block 32) - so would be different in structure again to Block 1-10 and 40 on.

Edited November 18, 2016 by Basher54321

[mvsgas]

The information was supposed to be direct from 730 Squadron and is very recent - will find the source later the Mag was online somewhere.

 

 

The reason for not upgrading the Block 10 airframes was given as due to the weight the nose wheel can handle - they are structurally different to the block 15 which was the first to get the cheek station provisions. Not certain why AIM-120 cant go on - thinking major hardware and rewiring changes are required.

(The RAF are in a similar position with Tranche 1 Typhoons as I understand)

 

 

The Block 20 designation is confusing - did wonder if they were referring to a software block not an airframe block. The Block 10 MLU were clearly not rebuilt (or probably cant be rebuilt) to the Block 15 structure. (although most got bigger horizontal stabs at some point)

 

To confuse things further all the F-16As built in the late 1980s and early 1990s (some are now designated Block 20s) were Block 15 OCU which were basically heavier C airframes despite the missing base tail antenna (closest I would think is Block 32) - so would be different in structure again to Block 1-10 and 40 on.

 

I suggest we move this part of the conversation to an F-16 related thread;

We (the community) have talk about this here

 

I think what your looking to identify this aircraft is the tail. Limited updated block 10 would have the square tip on the horizontal stab.

 

I doubt the reason for the limited update would be the nose tire or landing gear since is the same, the intake is different, that is more likely a reason since it would require major structural changes.

As for the -120 there could be many reason why they do not carry it. (software, radar, structural wiring, cost, etc.) There is more that just software updates, it appears some of those specific F-16 might have gotten cockpit upgrades like MFD/CMFD, JHMCS, etc.

 

Not all F-16A built in that time where 15 OCU, but yes block 15 to 32 have many similarities. But keep in mind that F-16 are in a constant state of change, where you have to look at an aircraft by aircraft basis. Many aircraft are like this now and is something I think we will see in the F-35.

[Hummingbird]

No, body lift already been taken into account in the CL and CLmax value ( those are CL of the whole aircraft , not just the airfoil). Why else do you think CLmax of F-15 so much smaller than F-16 and Su-27 value ?

 

Are you telling me that the CL values are for the whole aircraft adjusted for use with the reference wing area as the basis for calculating load factors? (I don't read russian, so you'll have to translate it for me)

 

How is is it any poorer than your comparison with F-15 ?

F-15 lack LERX , LEF , negative stability . On the other hand , those features all appeared on F-16 , Su-27 , F-35. Another feature that Su-27 share with F-35 is the fact that they both have extremely long range with internal fuel load. With that being said the bottom line is to show that AoA of 20-22 degrees can be hold at Mach 0.7-0.8 which result in much higher CL than at 15 degrees

 

It's a poorer comparison because it's not an aircraft with performance somewhat similar to the one it's being compared with. If your only criteria is LERX + LEF + Neg Stability, well then I can give you wide a range of aircraft that fit that criteria but each features wildly different performance characteristics.

 

Soviet aerodynamic booklet of Su-27 doesnt give EM like the Western one , they give CL instead

 

There are EM charts for the Su-27.

 

[Hummingbird]

Read the second quote in his post.

 

Missed it, but it's all subjective between the different opponents anyway as each pilot didn't fly all the aircraft listed and is just doing a "mine vs F-35" survey, hence the F-35 is rated differently between each comparison - i.e. the F-16 & F-15 ratings don't end up accurate compared to each other for that simple reason.

 

Anyway the important parts to take away from the survey are the closeness of the F-16 vs F-35 in ITR and the rather big difference in STR. The first one I didn't expect due to the high alpha capability of the F-35, but that might be due to a 7G limit, whilst the large STR difference was very much expected and won't really change regardless of wether there's a 7 G limit - after all the F-16's max STR is at around 7.5 G's at the altitude I expect they were comparing, and as the article explains the other jets were limited to 8 G's or less anyway due to non-jettisonable targeting pods etc...

Edited November 18, 2016 by Hummingbird

[Basher54321]

I think my favorite part of the charts is the 10% of pilots preferring the A-10 close in :)

 

Yes the configuration given in ref [23] for the F-16CM is the USAF wild weasel config with all 3 pods on.

 

So after jettison this would still leave around 3300 lbs in added weight and a Drag Index of 114. The drop in performance due to the weight alone is quite substantial and I guess that is the point he is trying to make. (didn't seem to do as badly as you might expect in this report though!)

 

However he didn't factor in the small tail RDAF Block 10s intercepting airliners and Cessnas in their combat configuration of 2 x AIM-9s and a centreline pylon :thumbup:. In comparison this only adds ~562 lbs in weight and Drag Index of ~7.

[Hummingbird]

I think my favorite part of the charts is the 10% of pilots preferring the A-10 close in :)

 

Weas that the guy who couldn't decide wether he prefered the more comfortable seat & ipad instrument panel over the titanium tub & 30mm Avenger? :P

 

:D

Edited November 19, 2016 by Hummingbird

[garrya]

Are you telling me that the CL values are for the whole aircraft adjusted for use with the reference wing area as the basis for calculating load factors? (I don't read russian, so you'll have to translate it for me)

When they give CL , CLmax value for aircraft. Those are value for the whole body rather than just the airfoil .The table is simple , first line is Mach , second one is AoA , third one is respective lift coefficient. If you dont believe me , feel free to post in Russian part of ED forum ( https://forums.eagle.ru/forumdisplay.php?f=199 there loads of Russian-speaking member there)

 

 

It's a poorer comparison because it's not an aircraft with performance somewhat similar to the one it's being compared with. If your only criteria is LERX + LEF + Neg Stability, well then I can give you wide a range of aircraft that fit that criteria but each features wildly different performance characteristics.

And F-15 is somehow closer to F-35 because of what ???

Moreover , we are talking about CL and ITR here , so only factors that increase lift is important to me ( aka LEF , LERX , Negative stable ). The whole point of my comparison wasnt to show that F-35 will get the same ITR as Su-27 , it is to show that maintain more than 15 degrees AoA at Mach 0.8 is possible ( 20 degrees in case of Su-27 ), and a slight different in AoA can increase CL significantly , so there is no reason to believe that F-35 cant have better ITR than F-16 at dogfight speed.

 

 

There are EM charts for the Su-27.

 

I wouldnt really call it an EM graph since you dont know the SEP , but it fine , that graph work for me too. If you look at the highest curve ( i already high light important parts in red )

when Height is 200 meters ( aka sea level )

speed is 600 km/h (aka 0.49 Mach )

then Su-27 ITR is just over 30 degrees/second , which is exactly the value i calculated for you earlier

Edited November 19, 2016 by garrya

[Hummingbird]

When they give CL , CLmax value for aircraft. Those are value for the whole body rather than just the airfoil .The table is simple , first line is Mach , second one is AoA , third one is respective lift coefficient. If you dont believe me , feel free to post in Russian part of ED forum ( https://forums.eagle.ru/forumdisplay.php?f=199 there loads of Russian-speaking member there)

 

I didn't say I didn't believe you, I asked you wether you were sure those CLmax figures were for use with only the reference wing area. The reason I ask you this is because modern jets aren't like the fighter aircraft of old which didn't feature a lifting body from where a large portion of their lift derives. Also today pilots (western ones at least) aren't just given a Cl figure to work with, and it isn't really necessary either as a detailed EM chart is provided.

 

Thus in my experience usually when talking Cl figures it applies only to the airfoil or reference wing area and not the whole aircraft unless otherwise specifically stated - which I can't tell wether or not is the case when things are written in cyrillic Russian ;)

 

And F-15 is somehow closer to F-35 because of what ???

 

To the F-16, not the F-35. The F-35 as mentions lacks the lift of those other two aircraft, and compared with the Su-27 it's way behind. The Su-27 is a very large and highly optimized blended wing lifting body design (same as the F-14), which is the main reason it can throw itself around like it does despite weighing over 50,000 lbs.

 

I wouldnt really call it an EM graph since you dont know the SEP , but it fine , that graph work for me too. If you look at the highest curve ( i already high light important parts in red )

when Height is 200 meters ( aka sea level )

speed is 600 km/h (aka 0.49 Mach )

then Su-27 ITR is just over 30 degrees/second , which is exactly the value i calculated for you earlier

 

According to the chart the ITR is ~31.5 deg/sec at M 0.5 (612 km/h), and the load factor is ~9.5 G. However the Su-27 is limited to 8.5 G's and max ITR is 30 deg/sec @ M 0.47.

 

This is a lot higher an actual ITR than the F-35 will be capable of, even if it could swing it's nose around for split second even quicker like an F-18.

Edited November 19, 2016 by Hummingbird

[garrya]

I didn't say I didn't believe you, I asked you wether you were sure those CLmax figures were for use with only the reference wing area. The reason I ask you this is because modern jets aren't like the fighter aircraft of old which didn't feature a lifting body from where a large portion of their lift derives. Also today pilots (western ones at least) aren't just given a Cl figure to work with, and it isn't really necessary either as a detailed EM chart is provided.

 

Thus in my experience usually when talking Cl figures it applies only to the airfoil or reference wing area and not the whole aircraft unless otherwise specifically stated - which I can't tell wether or not is the case when things are written in cyrillic Russian ;)

Firstly, even a tube body would generate lift if you put it at an angle to the air stream ( so technically speaking , all body of all aircraft can generate lift when they turn at an AoA , question is how much )

Secondly, if CL was given to airfoil , they would give you name of airfoil as well (AFAIK F-16 use NACA 64A-204 )

Thirdly, the reference wing area included the part inside the body as well, it not just the area of the wing alone ( if you dont believe me , go ahead and measure wing area with tips and chord).The references wing area is meant to be used with CL of aircraft

 

 

To the F-16, not the F-35. The F-35 as mentions lacks the lift of those other two aircraft, and compared with the Su-27 it's way behind.

Again ,all F-16 , F-35 , su-27 has leading edge devices that improve their lift coefficient.The problem with F-15 is that it lack devices to improve CL, so that limit its ITR . The problem of F-16 is that the single vertical rudder loses effectiveness at high AoA , so it cant take advantage of airframe high lift coefficient when perform high G turn. And that limit its ITR.

By contrast, Su-27 has LERX , LEF which give it much higher CL than F-15 .Its double rudders also loses effectiveness at much higher AoA than F-16s , so it has higher CL when performing high G turn. As a result Su-27 has much higher ITR than both F-15 and F-16.

On to F-35 , it features all LEF , LERX, negative stability ( which would contribute decent amount of lift with its big tail ). It also has ability to manage high AoA well ( even better than Su-27 in this aspect ) .So there is no reason to conclude that it doesnt have good ITR. You can argue that Su-27 is a more optimum lifting body , but if F-35 can maintain higher AoA in a turn , it likely that will compensate for that too.

 

The Su-27 is a very large and highly optimized blended wing lifting body design (same as the F-14), which is the main reason it can throw itself around like it does despite weighing over 50,000 lbs.

How is F-14 lifting body any better than F-35 one ?? because it looks more flat ? , what about effect of vortex generator device ?

 

According to the chart the ITR is ~31.5 deg/sec at M 0.5 (612 km/h), and the load factor is ~9.5 G. However the Su-27 is limited to 8.5 G's and max ITR is 30 deg/sec @ M 0.47.

 

This is a lot higher an actual ITR than the F-35 will be capable of, even if it could swing it's nose around for split second even quicker like an F-18.

 

You cannot possibly know that , there is simply not enough evidence, you dont know what AoA that F-35 can hold when it reach 9G , you dont know what will be its CLmax . It impossible to concluded that it cant reach same ITR level of Su-27. Even if you assume that airframe of F-35 will have less CL than Su-27 when they are at the same AoA because it is less optimized . How can you be sure that F-35 doesnt use slightly higher AoA to compensate for that ?

Edited November 19, 2016 by garrya

[garrya]

Actually come to think of it , probably possible to estimate F-35 CL since its ITR at7G is close to F-16 at 8G (assuming we talking about 10K altitude here ).Though there probably inaccuracy due to fuel load.

Then there is this weird 28 degrees/second pedal turn that affected by G limit

“Even pre-IOC,[26] this jet has exceeded pilot expectations for dissimilar combat. (It is) G-limited now, but even with that, the pedal turns[27] are incredible and deliver a constant 28 degrees/second. When they open up the CLAW, and remove the (7) G-restrictions, this jet will be eye watering.”

Edited November 19, 2016 by garrya

[Hummingbird]

Firstly, even a tube body would generate lift if you put it at an angle to the air stream ( so technically speaking , all body of all aircraft can generate lift when they turn at an AoA , question is how much )

Secondly, if CL was given to airfoil , they would give you name of airfoil as well (AFAIK F-16 use NACA 64A-204 )

Thirdly, the reference wing area included the part inside the body as well, it not just the area of the wing alone ( if you dont believe me , go ahead and measure wing area with tips and chord).The references wing area is meant to be used with CL of aircraft

 

Now with the tubes again.. but it's funny you feel the need to mention it as you previously believed that airfoils generated zero lift at zero AoA, but I guess your talks with Johnwill have helped.

 

Also I am well aware that the reference area includes part of the body, but far from all of it, which is very important.

 

Example:

 

Again ,all F-16 , F-35 , su-27 has leading edge devices that improve their lift coefficient.The problem with F-15 is that it lack devices to improve CL, so that limit its ITR . The problem of F-16 is that the single vertical rudder loses effectiveness at high AoA , so it cant take advantage of airframe high lift coefficient when perform high G turn. And that limit its ITR.

 

and yet the F-15's ITR was rated higher than the F-35's. -waiting on you to mention the 7 G limit, problem is the other aircraft were in roughly the same boat due to targeting pods etc..

 

By contrast, Su-27 has LERX , LEF which give it much higher CL than F-15 .Its double rudders also loses effectiveness at much higher AoA than F-16s , so it has higher CL when performing high G turn. As a result Su-27 has much higher ITR than both F-15 and F-16.

 

and the F-35...

 

On to F-35 , it features all LEF , LERX, negative stability ( which would contribute decent amount of lift with its big tail ).

 

It doesn't really feature true LERX, it features chines that generate a vortice, but nothing as strong as on the F-16 or Su-27, I even doubt its stronger than that generated by the F-14 along its wing glove.

 

It also has ability to manage high AoA well ( even better than Su-27 in this aspect )

 

Better than the Su-27? Where did you get that from? If there's an aircraft than manages high AoA well it's the Su-27, it spends most of its time at airshows demonstrating just that.

 

So there is no reason to conclude that it doesnt have good ITR.

 

I never said it didn't have good ITR, I said it's ITR is permitted primarily by its high AoA limit - i.e. it's a very short lived ITR and more of a "pulling the brake" maneuver than an ITR it can sustain for long.

 

You can argue that Su-27 is a more optimum lifting body , but if F-35 can maintain higher AoA in a turn , it likely that will compensate for that too.

 

The Su-27 can be snapped past 110 deg AoA as well as maintain a very high AoA, so I doubt that. Also once again relying on achieving max ITR at such a high AoA is not a good thing as it only serves to very rapidly slow you down (low L/D ratio), which in turn also quickly decreases lift & rate.

 

How is F-14 lifting body any better than F-35 one ?? because it looks more flat ? , what about effect of vortex generator device ?

 

Because it's shaped like an airfoil, blending in perfectly with the wings. It's the same with the Su-27 and to a great extend also the MiG-29.

 

The F-14 is basically a flying wing:

 

You cannot possibly know that , there is simply not enough evidence, you dont know what AoA that F-35 can hold when it reach 9G , you dont know what will be its CLmax . It impossible to concluded that it cant reach same ITR level of Su-27. Even if you assume that airframe of F-35 will have less CL than Su-27 when they are at the same AoA because it is less optimized . How can you be sure that F-35 doesnt use slightly higher AoA to compensate for that ?

 

The F-35 might be able to achieve a high Cl, but at a very high AoA and crucially lacking the surface area to apply it on. That also the reason it's STR is so limited.

Edited November 19, 2016 by Hummingbird

[Ktulu2]

Better than the Su-27? Where did you get that from? If there's an aircraft than manages high AoA well it's the Su-27, it spends most of its time at airshows demonstrating just that.

 

I never said it didn't have good ITR, I said it's ITR is permitted primarily by its high AoA limit - i.e. it's a very short lived ITR and more of a "pulling the brake" maneuver than an ITR it can sustain for long.

 

The Su-27 can be snapped past 110 deg AoA as well as maintain a very AoA, so I doubt that. Also once again relying on achieving max ITR at such a high AoA is not a good thing as it only serves to very rapidly slow you down (low L/D ratio), which in turn also quickly decreases lift & rate.

 

The F-14 is basically a flying wing

 

 

 

 

The F-35 might be able to achieve a high Cl, but at a very high AoA and crucially lacking the surface area to apply it on. That also the reason it's STR is so limited.

 

Actually, the -35 has been at similar AoA (at LEAST 110°, most likely more if you search). Any high AoA (past stall point) will decrease lift and will leave the aircraft in a super-draggy state.

While this might not seem good in a fight, just remember that the plane will have a 9X, you don't need a high STR in many situations.

 

BTW flying wing means no rudder...

[Hummingbird]

Actually, the -35 has been at similar AoA (at LEAST 110°, most likely more if you search). Any high AoA (past stall point) will decrease lift and will leave the aircraft in a super-draggy state.

While this might not seem good in a fight, just remember that the plane will have a 9X, you don't need a high STR in many situations.

 

110 deg means partly flipped backwards, popularly known as a cobra maneuver.

 

As for the 9X, sure but that's not what the discussion is about. If all the F-35's sensors work as advertised and no ECMs are developed that can defeat them, well then the airplane won't have to maneuver at all.

 

BTW flying wing means no rudder...

 

No it doesn't...

 

 

Also note I said "basically", as it's about as close you're going to come to a flying wing without it being one under traditional design criteria.

Edited November 19, 2016 by Hummingbird

[Ktulu2]

Fair enough, minimized rudder than, just compare it to any plane of it's size and you'll see.

 

And what's the discussion about? The best WW2 turn fighter?

[Sweep]

And what's the discussion about? The best WW2 turn fighter?

 

It's a contest for the title of Best Level Turn Forum BFMer 2016.

[garrya]

Now with the tubes again.. but it's funny you feel the need to mention it as you previously believed that airfoils generated zero lift at zero AoA

No i didnt , dont try to put words in my mouth , i said aircraft fuselage generate 0 lift at 0 AoA ( because i assumed you referred to their body)

 

Also I am well aware that the reference area includes part of the body, but far from all of it, which is very important.

Example:

You still dont get the point , point is when they give CL for an aircraft it not just the airfoil alone , as you can see the reference area included the part inside the body that doesnt have airfoil shape at all. All these body lift are represented by CL, CLmax value

About the picture , same one for F-35 can be draw

and yet the F-15's ITR was rated higher than the F-35's. -waiting on you to mention the 7 G limit, problem is the other aircraft were in roughly the same boat due to targeting pods etc..

I dont think F-15 would be affected much by targeting pod , F-16 may be. Then there are altitude , and fuel factor as well (technically speaking F-35 need half as much internal fuel to stay in the air for similar amount of time as F-16 , F-15C , however in exercise they are likely fully loaded with fuel )

 

and the F-35

Can only be concluded with further info regarding CLmax

 

It doesn't really feature true LERX, it features chines that generate a vortice, but nothing as strong as on the F-16 or Su-27

better than nothing , and the intensity is similar to vortex device on Typhoon

Mig-29 LERX create very weak vortex too , doesnt stop it from being a decent dogfight aircraft

 

I even doubt its stronger than that generated by the F-14 along its wing glove.

the only pic of F-14 with vortex that i saw is when it at some where around 40-60 degrees AoA , F-35 chines can generate vortex at much shallower AoA

 

 

Better than the Su-27? Where did you get that from? If there's an aircraft than manages high AoA well it's the Su-27, it spends most of its time at airshows demonstrating just that. .

Iam not talking about Sukhoi with TVC , iam talking about normal Su-27 , with AoA limiter at 26 degrees AoA while AoA limiter of F-35 is at 50 degree AoA

 

 

I never said it didn't have good ITR, I said it's ITR is permitted primarily by its high AoA limit - i.e. it's a very short lived ITR and more of a "pulling the brake" maneuver than an ITR it can sustain for long.

It is the same case for Su-27 and its CLmax of 1.85 , its AoA is 9 degrees higher than F-16 , yet you dont have problem with that

 

The Su-27 can be snapped past 110 deg AoA as well as maintain a very high AoA, so I doubt that.

both aircraft can go to very high AoA , but the question is where their CLmax located ( at what AoA )IF F-35 CLmax is at 27 degrees AoA then going further than that is unnecessary. Take for example Su-27 CLmax is at 24 degrees AoA so going any further doesnot help at all. On the other hand, for F-16 airframe CL max is at 35 degrees AoA , if it can go past 15 degrees AoA it can have better ITR

 

Also once again relying on achieving max ITR at such a high AoA is not a good thing as it only serves to very rapidly slow you down (low L/D ratio), which in turn also quickly decreases lift & rate.

Obviously using ITR will slow you down , but F-35 has very powerful engine and can accelerate very good at subsonic speed unlike F-14

 

Because it's shaped like an airfoil, blending in perfectly with the wings. It's the same with the Su-27 and to a great extend also the MiG-29.

 

The F-14 is basically a flying wing:

I honestly dont see how F-14 body and wing bend in any better than F-35 , moreover , you dont really have any number to show how much more effective that sort of body would be , especially consider aircraft will turn at an AoA

There are loads of lifting body that doesnot look like airfoil at all

 

The F-35 might be able to achieve a high Cl, but at a very high AoA and crucially lacking the surface area to apply it on. That also the reason it's STR is so limited.

F-35 STR is limited mainly because it is very heavy and carry load of fuel

Edited November 20, 2016 by garrya

[Hummingbird]

It's a contest for the title of Best Level Turn Forum BFMer 2016.

 

lol

 

STR, ITR, roll rate, acceleration, climb rate & top speed combined is traditionally what a good fighter aircraft needs. Today ofcourse sensor capability might have advanced to the stage where many of these attributes can be neglected to a large degree, but woe the day ECMs advance to the stage where we're back to the days of the tailchase - or even just if missiles are reduced to 50/50 weapons, with many aircraft in the air that could very well end up in a gunfight as we saw in Vietnam.

[garrya]

ECM would favor aircraft with lower RCS

[Darkbrotherhood7]

Quick reminder: The F-35 ECM is not just for self-defense as most of the ECMs are, it is also meant to electronic attack just as the ALQ-99.

[Boagrius]

... the day ECMs advance to the stage where we're back to the days of the tailchase - or even just if missiles are reduced to 50/50 weapons, with many aircraft in the air that could very well end up in a gunfight as we saw in Vietnam.

 

This hypothetical is so oversimplified and devoid of evidence as to be nigh on meaningless. What leads you to think "ECM" might get to this point? What guidance methods do you think would be afffected? Why? Why do you think that this would see combat aircraft default to tail chase gunfights "like in Vietnam"?

 

I might as well say "but what if OPFOR develop shield devices that deflect all incoming bullets".

 

The reality is that Vietnam was the very first showcase of AAMs on a large scale, the technology has changed fundamentally many times over since then.

Edited November 20, 2016 by Boagrius

[garrya]

Hypothetically in future when DEW are more common , speed and agility would be kinda useless

[Hummingbird]

No i didnt , dont try to put words in my mouth , i said aircraft fusalege generate 0 lift at 0 AoA

 

Which is blatantly false, esp. for aircraft such as the Su-27, F-14, F-16, MiG-29 etc. which all feature an airfoil shaped fuselage.

 

You still dont get the point , point is when they give CL for an aircraft it not just the airfoil alone , as you can see the reference area included the part inside the body that doesnt have airfoil shape at all. All these body lift are represented by CL, CLmax value

 

It's you who don't understand what I'm writing. I said that CL & CLmax figures usually aren't provided for pilots in the manual, instead they are given EM charts. Hence why I asked.

 

I dont think F-15 would be affected much by targeting pod , F-16 may be. Then there are altitude , and fuel factor as well (technically speaking F-35 need half as much internal fuel to stay in the air for similar amount of time as F-16 , F-15C , however in exercise they are likely fully loaded )

 

It's the G limitations of the pods which matter, if they aren't rated for more than say 7.5 G's well then that's the load limit unless you wanna lose it.

 

Can only be concluded with further info regarding CLmax

 

So you actually seriously believe the F-35 will be able to match the Su-27 in ITR?

 

better than nothing , and the intensity is similar to vortex device on Typhoon

Mig-29 LERX create very weak vortex too , doesnt stop it from being a decent dogfight aircraft

 

The MiG-29 also features an airfoil shaped lifting body, hence it again produces a lot of lift simply by virtue of its very large available lifting area.

 

As for the EF2000, it's a delta wing with a very low wing loading. It's wing loading is approaching half that of the F-35, so do you believe the CLmax is also half? It isn't...

 

the only pic of F-14 with vortex that i saw is when it at some where around 40-60 degrees AoA , F-35 chines can generate vortex at much shallower AoA

 

These are not extreme AoA turns (which 40-60 AoA would be), they are simply high rate:

 

Iam not talking about Sukhoi with TVC , iam talking about normal Su-27 , with AoA limiter at 26 degrees AoA while AoA limiter of F-35 is at 50 degree AoA

 

That limit can be pulled through by the pilot or simply turned off.

 

Also lets see where the F-35's AoA limiter will be at in the end when 9 G's are to be pulled at faster speeds.

 

It is the same case for Su-27 and its CLmax of 1.85 , its AoA is 9 degrees higher than F-16 , yet you dont have problem with that

 

No I didn't because the Su-27 can generate a high ITR without producing as much drag in the process because of its large optimized lifting area, which also provides it a great STR at low speeds despite not the best T/W ratio.

 

both aircraft can go to very high AoA , but the question is where their CLmax located ( at what AoA )IF F-35 CLmax is at 27 degrees AoA then going further than that is unnecessary. Take for example Su-27 CLmax is at 24 degrees AoA so going any further doesnot help at all. On the other hand, for F-16 airframe CL max is at 35 degrees AoA , if it can go past 15 degrees AoA it can have better ITR

 

A CLmax at 35 deg will be at low speed, same for the other two which will most likely have a CLmax at a similar AoA. This is also quite clear when looking at the ITR figures.

 

Obviously using ITR will slow you down , but F-35 has very powerful engine and can accelerate very good at subsonic speed unlike F-14

 

The F-14 is no slouch in acceleration, but it won't need it as much either as it can keep up a turn at a higher rate thanks to its swing wings & airfoil shaped fuselage providing it with a very high L/D ratio, thus it loses less speed in turns.

 

I honestly dont see how F-14 body and wing bend in any better than F-35 ,

 

So you don't see how the F-14's fuselage is a giant airfoil whilst the F-35's is very boxy? and neither do you see how an airfoil shape produces lift more efficiently than a boxy shape?

 

moreover , you dont really have any number to show how much more effective that sort of body would be , especially consider aircraft will turn at an AoA

There are loads of lifting body that doesnot look like airfoil at all

 

garrya, you're confusing certain pure (as in wingless) lifting body aircraft, which were designed to test the flight characteristics of a flyable re-entry spaceshuttle, with the airfoil shaped fuselage designs of fighters also refered to as featuring a "lifting body".

 

F-35 STR is limited mainly because it is very heavy and carry load of fuel

 

That's the problem, it lacks the L/W & L/D ratio of the F-16, F-14, F-15, Su-27 etc, in other words it has to resort to extreme AoA maneuvers to produce a high ITR that lasts extremely briefly due to the drag generated.

Edited November 20, 2016 by Hummingbird

[Hummingbird]

This hypothetical is so generalised and devoid of evidence as to be nigh on meaningless. What leads you to think "ECM" might get to this point? What guidance methods do you think would be afffected? Why? Why do you think that this would see combat aircraft default to tail chase gunfights "like in Vietnam"?

 

Meaningless? So you think chaff & flares have been useless all this time? I mean why do you think stealth was developed in the first place?

 

During the gulf war several misses happened due to flares and chaff, even twice in a row for the same aircraft during some engagements.

 

Fact is countermeasure technologies are evolving just like sensor technologies are, and whilst right now sensors might be ahead in the race don't fool yourself into believing that countermeasure tech can't catch up.

 

Next up in the countermeasure arsenal is likely lasers that will blind incoming IR missiles, and later when the power increases even set off warheads on radar guided missiles. Then even later down the line when these lasers become powerful enough to be turned into actual weapons to replace missiles then once again the balance will turn for a while.

Edited November 20, 2016 by Hummingbird

[Boagrius]

Meaningless? So you think chaff & flares have been useless all this time? I mean why do you think stealth was developed in the first place?

 

During the gulf war several misses happened due to flares and chaff, even twice in a row for the same aircraft during some engagements.

 

Fact is countermeasure technologies are evolving just like sensor technologies are, and whilst right now sensors might be ahead in the race don't fool yourself into believing that countermeasure tech can't catch up.

 

Next up in the countermeasure arsenal is likely lasers that will blind incoming IR missiles, and later when the power increases even set off warheads on radar guided missiles. Then even later down the line when these lasers become powerful enough to be turned into actual weapons to replace missiles then once again the balance will turn for a while.

 

I'll try to keep this simple:

 

- It's meaningless in the sense that without context the conversation revolves around vague generalities rather than anything with real world implications. Saying that there "could" be a time when countermeasures overtake AAMs in a systematic way says nothing of how likely it is to transpire, or when. Force planners don't get the luxury of making procurement decisions based on what "might potentially happen eventually", they have to make some sort of judgement about what is probable in a given timeframe.

 

- If we (for argument's sake) reach the point where Directed Energy Weapons (DEWs) render AAM's obsolete during the F35's lifetime then kinematics will almost certainly be FAR less relevant than ever before. I'd argue that the F35's "first look, first kill" design philosophy - where information dominance takes precedence over all else - would be substantially more useful than that of any 4.5 gen aircraft in existence since the OODA loop would be dramatically compressed, and evading "fire" via maneuvering would be nigh on impossible.

Edited January 24, 2017 by Boagrius