This is a discussion on Is the F-35 doomed? within the Air Force & Aviation forum, part of the Global Defense & Military category; Originally Posted by Feanor
Todjaeger what if the range of engagement in your scenario is more like 100 nm? Then ...
Todjaeger what if the range of engagement in your scenario is more like 100 nm? Then does it change? What if fighter A fires from the very edge of the engagement envelope, and then uses superior speed to escape? Then can it outrun the missile?
The situation has a number of different variables, so changing the details of a scenario around canl have a large impact. Within an engagement there will an NEZ (No Escape Zone), this basically the range at which an aircraft cannot escape from an inbound missile. This range is of course variable depending on the missile, as well as the speed of both the launching and targeted aircraft, the max acceleration of the targeted aircraft, and other factors...
As for Fighter A, there is no need for it to 'escape' since it is the launching platform. The scenario I had given was whether or not Fighter B could escape a missile fired from Fighter A. Given a range of just 30 n miles (IIRC edge of BVR/WVR envelope) Fighter B would not have the ability to escape.
-Cheers
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So there is an egagement range at which fighter b would be able to use greater speed to escape from the missile? In that case the speed still has relevance. A fighter that has M3, will be able to escape from much closer engagement ranges, then a fighter that hits it's limits at M1.6.
Opinions based on a lack of understanding and research...
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Well you can interpert as you like but the fact that in standard configuration F-22 carries 6 AIM-120 and F-35 only 2 says enough for itself.
What "standard" configuration?
F-35 will have the ability to carry 4x AIM-120C/D AMRAAM internally at Block III and have a defined growth path to 6x AIM-120C/D AMRAAM internally for F-35 Block IV/V depending on customer requirements.
If air to ground payloads are carried internally, BOTH aircraft feature reduced air to air payloads, the difference being that F-35A/C can carry 2000lbs class munitions (and obviously smaller ones) internally whereas F-22 can only carry 1000lbs JDAM and SDB.
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Yes. You had a interview with Vympel director some while ago in witch it mentioned some hudge internal bay being constructed for next generation AAM and based on F-35 analisis I have no doubt China will make same mistake in constructing its own 5th generation.
So keep on the good work. Range does not depend only on factors you remembered to mention.
Please note the F-22's 1600nm range is ONLY achieved with the addition of external drop tanks. This is a ferry configuration, NOT a combat configuration for the F-22A.
It's range on internal fuel only is less impressive. F-35A/C's range is always measured on internal fuel only since external fuel tanks were dropped for integration in the SDD phase.
However, I did mention range/payload rather than simply range, so whilst I do firmly believe the F-35's range exceeds the F-22's on internal fuel alone, the performance I was referring to was a combination of range AND payload.
No fighter on earth besides the F-35 can carry 5000lbs+ of weapons internally AND carry it's sensors internally AND carry 18500lbs+ fuel internally.
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Well Pogosyan already said PAK-FA is made to match F-22 not F-35 and something similar announced China so as you see no one really cares mutch about F-35 and that is problem since F-22 producton stoped.
Very easy to announce things. Much more difficult to design, build and test an ACTUAL 5th Generation fighter. Something L-M has done twice now and no other manufacturer in the world has yet achieved.
I'll believe Pogosyan's claims when I see PAK-FA make it's first flight. You know, that flight that was meant to take place in June, then August, then November and now apparently it's December 2009???
They should care. By the time F-35 is finished production, the USA will have a fleet of 2600 5th generation fighter aircraft in-service. Even the most ardent critic should be prepared to admit that, this presents a rather large threat to ANY force...
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Following your logic it was mistake in the first place to make fighter that can go above the speed of sound.
No, I mentioned quite clearly that supersonic speeds ARE regularly achieved by tactical fighters. What is not regularly achieved are M2 + speeds and the reasons are because of how long it takes to get there, how much fuel it burns and it's operational utility in ANY scenario except fleeing a fight trying to save one's own skin...
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Where did you get this from?
Google. It's your friend...
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Oke .. where did you get this from? That would be good but than again same can be said about any fighter than.
1) Its its KPP speed so max one is lets say 30 percent higher .. hehe
2) Su-24 can go Mach 2 or so but still flies at KPP Mach 1.4 lol
You seem fixated on maximum speed. It is almost entirely irrelevent, for the majority of combat roles. If pure speed was the most important factor for a tactical fighter, every fighter would be built like the MiG-25 Foxbat.
As should be patently obvious they are not. Not even Russian and Chinese fighters, so perhaps you could draw an inference or 2 from this, eh?
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Smalest T/W ratio. If its any smaller I doubt It could even fly.
T/W. Really in what configuration, the usual 50% internal fuel rubbish? A REALLY useful metric. Do you comprehend that at 50% fuel a fighter is either on the way home OR on the way to the tanker? It is NOT a combat configuration that a fighter would WANT to be in, if a fight was likely, so why it's considered useful for thrust to weight comparisons baffles me a little bit, however it is popular, so I'll use it too.
Please bear in mind also that 50% fuel for the F-35A/C is more than 9200lbs of fuel. That is greater than the total internal fuel capacity of some current tactical fighters including the F-16, Rafale and Gripen and very close to being the same as the total internal fuel load of fighters including F/A-18 Hornet and Eurofighter Typhoon.
If you want to compare T:W ratios, perhaps you could try it at the same fuel weights and see how F-35 goes? You'll see it stacks up VERY well...
Or perhaps we could just compare the F-35 to a modern "threat" fighter - the SU-30Mk. (This is done not to try and prove which is better in a pi**ing contest but rather to illustrate that the F-35's physical characteristics is not as bad as some like to make out. I will NOT discuss a comparison between the 2 any further in accordance with the rules of the board).
Weight: ~12.7 tons (F-35A) vs ~17.7 tons (SU-30)
Internal Fuel: ~8.4 tons (F-35A; configuration 240-4.7) vs ~9.4 tons (SU-30; max. overload w/modifications)
Fuel Fraction: ~0.40 (F-35A) vs ~0.35 (SU-30MK)
Wing Area: 42.7 sq-m (F-35A) vs 62 sq-m (SU-30)
Engine type: 1 x P&W F135-PW-100 (F-35A) vs 2 x Saturn AL-31FL (SU-30MK)
Engine bypass: 0.57:1 (F-35A) vs 0.59:1 (SU-30MK)
Engine thrust (A/B): 19.5 tons (F-35A) vs 24.9 tons (SU-30MK)
Engine thrust (Dry): 12.7 tons (F-35A) vs 15.3 tons (SU-30MK)
Thrust to weight (A/B w/50% fuel): 1.15:1 (F-35A) vs 1.11:1 (SU-30MK)
Thrust to weight (Dry w/50% fuel): 0.75:1 (F-35A) vs 0.68:1 (SU-30MK)
Radar: 700mm class AESA (F-35A) vs 1000mm class MSA or PESA (SU-30MK)
RCS: ~0.0014 sq-m (F-35A) vs ~10 sq-m (SU-30MK)
So there is an egagement range at which fighter b would be able to use greater speed to escape from the missile? In that case the speed still has relevance. A fighter that has M3, will be able to escape from much closer engagement ranges, then a fighter that hits it's limits at M1.6.
Speed certainly has relevance, but only to a degree.
For starters, fighters are still going to be mostly flying at subsonic speeds since it is more fuel efficient. Even for an aircraft designed with the ability to supercruise for tactically useful distances (i.e. the F-22 Raptor), the extra speed has a drastic negative impact on range and flight duration. IIRC the F-22 has an unrefueled range of ~ 700 miles, which drops to around 500 miles total, including a 100 mile supercruise dash.
The long and short of the above means that an aircraft capable of flying at Mach 3 will still need a chance to accelerate to reach that speed, while the inbound missile will most likely already be traveling at Mach 3+.
Another important distinction to remember is that the target aircraft is not really trying to (or capable...) of outrunning a missile. Taking the MiG-25 Foxbat as an example of a fighter, it has a top speed of ~Mach 3.2, which is still not enough to keep an AMRAAM from being able to close on the MiG since it has a top speed of ~Mach 4. Rather, an aircraft which has been targeted with missile needs to get itself to a location further from the point of launch than the missile's range is. Additionally, it needs to do this faster than the missile can.
Will a high speed aircraft can help the above situation, it is much easier to be at long range already.
-Cheers
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That was my only point. We are in agreement then that speed is tactically relevant, but is not the decisive feature.
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I'll believe Pogosyan's claims when I see PAK-FA make it's first flight. You know, that flight that was meant to take place in June, then August, then November and now apparently it's December 2009???
To the best of my knowledge it's still supposed to fly this month. Do you have a source stating otherwise?
Yes, speed does have a role, but not the one referenced above. The duration of a missile's flight is determined by the range to the target. It is not a direct correlation to the speed of the target aircraft.
This is wrong, it's a simple question of math, but without doing the equation(s) of motion, think of it in this (incorect, though instructive) way:
Iniially there is distance D between shooter and target, in the time span, t, that it takes the missile to cover the distance d, the target vill have moved s=v_t*t, where v_t is the speed of target. So the missile will have to also cover distance s which it will do in s/v_m, where v_m is the speed of missile.... etc (becarefull that you don't end up ith Zenon's paradoks )
If you do it the correct way you end up with a system of differential equations, where the important parameters is d,v_t and v_m, and if I am not much mistaken you can recast that only to depend on d and R where R is the ratio between v_m and v_t. So the point is proven if the ratio between v_t and v_m is significant. Without knowing the specs of a modern long range air to air missile I think it's fair to assume that the speed of the missile is less than, say, three times greater than the speed of target, in other words the ratio significant.
In the comparative analysis between a faster and a slower jet, it will only be the difference of speed between them that's interesting. Let's say that the difference is 0.5M, then I will guess (from the top of my head) that the faster yet holds some 15% range advantage in the above example.
This is ofcourse "everything equal". I am not saying that the above is crucial or make or break - I am just saying that there is an not-insignificant effect of higher speeds, but ofcourse "everything is seldomly equal"
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Originally Posted by Todjaeger
The max speed of an aircraft (and its ability to sustain that speed) determine an aircraft's ability to close with, or possibly escape from, an engagement or target. That may, or may not matter depending on the engagement. For example, Fighter A has a lock on and shoots an AIM-120C-7AMRAAM at Fighter B from a range of 30 n miles... Whether Fighter B's max speed if Mach 2.5, or 'only' Mach 1.6 does not really matter. Either way, Fighter B still cannot effectively outrun the inbound missile.
Yes, if you recast the question in such away that no matter what the target is within the envolope of the missile, distance is irrelevant and hence the relative speeds are irrelevant. Though - everything equal - in such a scenario you end up with a high probability of a "kill-kill" (both planes destroy each other).
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Originally Posted by Todjaeger
The poster seems to be ignoring the significant amount of work done in a number of discplines to allow the F-35 to achieve information/situational dominance. The is a combination of changes to and developments in sensors to provide more all-aspect information, changes to avionics in how information is both processed, as well as how the pilot will interaction with the avionics.
If you carefully read what I write I am not ignoring it. I am acknowledging the cutting edge electronics of the new plane, though I add that, that those electronics are not cutting edge in the near future. This plane will, just like any other plane need constant updates to stay cutting edge.
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Originally Posted by Todjaeger
Lastly, there is the work done to reduce the signature of the JSF so that it is LO.
Yes. That's the interesting question vis a vis the F35.
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Originally Posted by Todjaeger
Taking the above example of Fighter A vs. Fighter B, even if the range is increased to a much greater degree... The max speed of Fighter B again becomes moot if Fighter A can detect and engage Fighter B without Fighter B becoming aware of it. Speed allows one to act, but if one is ignorant of the need to act, it does no good.
-Cheers
This is wrong, it's a simple question of math, but without doing the equation(s) of motion, think of it in this (incorect, though instructive) way:
........SNIP.....
In the comparative analysis between a faster and a slower jet, it will only be the difference of speed between them that's interesting. Let's say that the difference is 0.5M, then I will guess (from the top of my head) that the faster yet holds some 15% range advantage in the above example.
This is ofcourse "everything equal". I am not saying that the above is crucial or make or break - I am just saying that there is an not-insignificant effect of higher speeds, but ofcourse "everything is seldomly equal"
I have to agree with this. We need to remember the missile is not flying at an aircraft, its flying at a piece of sky that off board sensors are saying the aircraft will be at a certain point in the future. Thus the effective engagement envelope of a missile is significantly effected by the targets course and speed; a head-on shot with both shooter and target at high speed and altitude (shooter) will significantly increase the missiles maximum range.
Tod's point about a NEZ/V is indeed true; if a target is within that range it cannot out run the missile. However the target's top speed and acceleration partially determine the size of the NEZ. In simple terms the faster the other guy can move the closer you have to be to prevent him from outrunning your shot. The other critical element in determining the NEZ is information. If the target does not know he has been fired upon he cannot utilise his speed advantage to outrun the missile. Having a top speed of Mach 2 won’t do squat if you are in a low energy state and the first sign of a missile shot is your RWR goes off and the incoming's seeker has acquired you. This is why the F-35’s speed “disadvantage” will not really be relevant vs. 4th gen fighters in the BVR regime, the level of information dominance will mean that most targets will be engaged without even knowing it.
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Yes, if you recast the question in such away that no matter what the target is within the envolope of the missile, distance is irrelevant and hence the relative speeds are irrelevant. Though - everything equal - in such a scenario you end up with a high probability of a "kill-kill" (both planes destroy each other).
Opinions based on a lack of understanding and research...
What "standard" configuration?
F-35 will have the ability to carry 4x AIM-120C/D AMRAAM internally at Block III and have a defined growth path to 6x AIM-120C/D AMRAAM internally for F-35 Block IV/V depending on customer requirements.
If air to ground payloads are carried internally, BOTH aircraft feature reduced air to air payloads, the difference being that F-35A/C can carry 2000lbs class munitions (and obviously smaller ones) internally whereas F-22 can only carry 1000lbs JDAM and SDB.
Me? I've never heard of the director of Vympel...
Please note the F-22's 1600nm range is ONLY achieved with the addition of external drop tanks. This is a ferry configuration, NOT a combat configuration for the F-22A.
It's range on internal fuel only is less impressive. F-35A/C's range is always measured on internal fuel only since external fuel tanks were dropped for integration in the SDD phase.
However, I did mention range/payload rather than simply range, so whilst I do firmly believe the F-35's range exceeds the F-22's on internal fuel alone, the performance I was referring to was a combination of range AND payload.
No fighter on earth besides the F-35 can carry 5000lbs+ of weapons internally AND carry it's sensors internally AND carry 18500lbs+ fuel internally.
Very easy to announce things. Much more difficult to design, build and test an ACTUAL 5th Generation fighter. Something L-M has done twice now and no other manufacturer in the world has yet achieved.
I'll believe Pogosyan's claims when I see PAK-FA make it's first flight. You know, that flight that was meant to take place in June, then August, then November and now apparently it's December 2009???
They should care. By the time F-35 is finished production, the USA will have a fleet of 2600 5th generation fighter aircraft in-service. Even the most ardent critic should be prepared to admit that, this presents a rather large threat to ANY force...
No, I mentioned quite clearly that supersonic speeds ARE regularly achieved by tactical fighters. What is not regularly achieved are M2 + speeds and the reasons are because of how long it takes to get there, how much fuel it burns and it's operational utility in ANY scenario except fleeing a fight trying to save one's own skin...
Google. It's your friend...
You seem fixated on maximum speed. It is almost entirely irrelevent, for the majority of combat roles. If pure speed was the most important factor for a tactical fighter, every fighter would be built like the MiG-25 Foxbat.
As should be patently obvious they are not. Not even Russian and Chinese fighters, so perhaps you could draw an inference or 2 from this, eh?
T/W. Really in what configuration, the usual 50% internal fuel rubbish? A REALLY useful metric. Do you comprehend that at 50% fuel a fighter is either on the way home OR on the way to the tanker? It is NOT a combat configuration that a fighter would WANT to be in, if a fight was likely, so why it's considered useful for thrust to weight comparisons baffles me a little bit, however it is popular, so I'll use it too.
Please bear in mind also that 50% fuel for the F-35A/C is more than 9200lbs of fuel. That is greater than the total internal fuel capacity of some current tactical fighters including the F-16, Rafale and Gripen and very close to being the same as the total internal fuel load of fighters including F/A-18 Hornet and Eurofighter Typhoon.
If you want to compare T:W ratios, perhaps you could try it at the same fuel weights and see how F-35 goes? You'll see it stacks up VERY well...
Or perhaps we could just compare the F-35 to a modern "threat" fighter - the SU-30Mk. (This is done not to try and prove which is better in a pi**ing contest but rather to illustrate that the F-35's physical characteristics is not as bad as some like to make out. I will NOT discuss a comparison between the 2 any further in accordance with the rules of the board).
Weight: ~12.7 tons (F-35A) vs ~17.7 tons (SU-30)
Internal Fuel: ~8.4 tons (F-35A; configuration 240-4.7) vs ~9.4 tons (SU-30; max. overload w/modifications)
Fuel Fraction: ~0.40 (F-35A) vs ~0.35 (SU-30MK)
Wing Area: 42.7 sq-m (F-35A) vs 62 sq-m (SU-30)
Engine type: 1 x P&W F135-PW-100 (F-35A) vs 2 x Saturn AL-31FL (SU-30MK)
Engine bypass: 0.57:1 (F-35A) vs 0.59:1 (SU-30MK)
Engine thrust (A/B): 19.5 tons (F-35A) vs 24.9 tons (SU-30MK)
Engine thrust (Dry): 12.7 tons (F-35A) vs 15.3 tons (SU-30MK)
Thrust to weight (A/B w/50% fuel): 1.15:1 (F-35A) vs 1.11:1 (SU-30MK)
Thrust to weight (Dry w/50% fuel): 0.75:1 (F-35A) vs 0.68:1 (SU-30MK)
Radar: 700mm class AESA (F-35A) vs 1000mm class MSA or PESA (SU-30MK)
RCS: ~0.0014 sq-m (F-35A) vs ~10 sq-m (SU-30MK)
Your turn...
Damn AD, you didn't leave much for the rest of us?!
I don't agree that the electronics systems can be discounted from the equation because "we can expect that from any new fighter". The F-35's electronic systems are a level above anything being demonstrated by other manufacturers and countries
Well, demonstrated, that's propably correct. That'll be, it's correct for now. Just like other airplanes also demonstrated superiority when they where new and fresh out of the "design office".
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Originally Posted by Bonza
so I don't think it's fair to treat it as though it's merely a typical development rather than something exceptional.
Well, perhaps I am not so easely impressed.
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Originally Posted by Bonza
Remember too that low observability/signature management isn't a static thing. The capability of detection systems will increase, but the capability of technology to respond to those systems will increase also.
I am not so certain that you can improve stealth in the same order as electronics are improved. And certainly, the builded plane, can only marginally be improved in a number of the factors that add up to the stealthy characteristics of the plane.
Well, demonstrated, that's propably correct. That'll be, it's correct for now. Just like other airplanes also demonstrated superiority when they where new and fresh out of the "design office".
The bulk of the F-35's new capability lead is in its "electronics", and it's been the lions share of the R&D too. The F-35 is miles ahead of the competition in this respect, and the fact is avionics are the most readily upgraded element of the platform i.e. the F-35 is miles ahead of the competition and this lead is not entrenched in the design. It CAN and WILL be upgraded constantly. Just look at the evolution of the F-16 family, it still offers avionics options that even the Typhoon and Flanker family do not. I doubt anyone will "catch up" ever.
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I am not so certain that you can improve stealth in the same order as electronics are improved. And certainly, the builded plane, can only marginally be improved in a number of the factors that add up to the stealthy characteristics of the plane.
Electronics are a critical part of "stealth". LPI sensors/comms and countermeasures are just as important to maintaining an F-35 information dominance as airframe materials and plan form alignment. Anyway the F-35 of 2030 WILL have a smaller RCS than the F-35 of 2015 simply throught improvements in signature management tech.
To the best of my knowledge it's still supposed to fly this month. Do you have a source stating otherwise?
According to latest edition of Jane's Defence Weekly, in speaking with Russian engineers involved with the program, Jane's was told that the PAK-FA would most likely be ready for flight in March 2010. They expect that there will still be a roll-out ceremony in December, however, as a face-saving measure.
Well, demonstrated, that's propably correct. That'll be, it's correct for now. Just like other airplanes also demonstrated superiority when they where new and fresh out of the "design office".
Granted - although if you can name another "design office" that has the kind of money and expertise flowing through it as can be found in the US, I'm all ears. Such a thing becomes relevant when discussing the timescale of a similar system being fielded.
Given the ever increasing pace of technological advancement however I take your point that such systems will proliferate, but I don't think it's going to be soon given the lead time the US have, and given the ease with which the F-35 can incorporate new developments (which I mention in more detail below).
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Originally Posted by Palnatoke
Well, perhaps I am not so easely impressed.
Perhaps.
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Originally Posted by Palnatoke
I am not so certain that you can improve stealth in the same order as electronics are improved. And certainly, the builded plane, can only marginally be improved in a number of the factors that add up to the stealthy characteristics of the plane.
As Ozzie said, electronic systems are a significant part of signature management, it's not just RAM and fuselage shaping and all that. If you can coax GF into a response on signature management he'd probably be the best person to ask about this, I'll freely admit to having pretty limited knowledge of the topic.
As far as improvements of the completed platform go, the software architecture of the F-35 - being all C++ - is specifically intended to allow for future developments and ease of upgrading. This is one of the issues the F-22 has - it's architecture isn't nearly so easily modified, so upgrades become (from some accounts) extremely problematic. I know this isn't the point you were addressing specifically but as electronics improvements came up I thought it was relevant (you may already know though).
I appreciate that you were referring specifically to RCS reductions, and as I said I have limited knowledge so I don't know what degree of change would be expected over the next few decades.
Last edited by Bonza; November 22nd, 2009 at 08:26 AM.
I think that the argument, "Well this is the US and therefore the electronics are beyound other people" is not only dangerous but is also becoming quickly outdated, if it is not outdated. You can't rest on your laurels. While I am inclined to agree that there is a good chance that certain american aviation companies are a "horse head ahead", I don't think it's a very sound nor fruitfull way of argumenting.
In respect to stealth. As I understand it, structual "stealth" (reflection) as well as subression of radar ressonance are pretty well understood and not something one would expect big breakthroughs in. The dissipation of energy in material (the coating, I think it's called RAM) is probably something that holds a larger potential for improvements as do different techniques for always presenting the optimal angle to attacking radar, or mangement of EM radiation etc.
The last areas are btw not techs that are specific to F35, but could in principle be applied to any airplane's update cycle.
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