Navy AX and A/F-X projects

Abraham Gubler said:

donnage99 said:

And I never argued against it. I suggest you get my point first before trying to argue with it.

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See my edit above to include in direct quotes from your post that I am responding to.

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But that's not the point I'm making if you read further up. I was responding to F-14D who knows perfectly I'm comparing supercruise to reheat. Supercruising like that of raptor is definitely gonna be hotter than subsonic cruise. That's a no brainer. Yet you emphasize the statement that supercruise does bring IR signature penalty comparing to subsonic cruise like I did think that supercruise brings IR signature advantage to all regime of flight.

To your point about interception: make sense.

The point about supercruise might emit IR signature more than afterburner: I just don't think so. What you say does prove one thing, which I always have agreed, that supercruise does increase IR signature comparing to subsonic cruise, but stretching that to it possibly having as big as the IR signature of after burner is not convincing. Also, 2 things to notice here: f-22 airframe is designed to emit less IR signature, and the engines got cool air injected into it. However, these measures of reduction become irrelevant and meaningless once in after burner, but not in supercruise.

donnage99 said:

The point about supercruise might emit IR signature more than afterburner: I just don't think so.

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Most people think that afterburning is the be all and end all of IR signature. Boyd back in the seminal Aerial Attack study made it clear that even in the 1950s with first generation Sidewinder afterburning exhaust plume was not the be all and end all of IR signature.

This is the simple problem of people assuming (the root of all evil) things about an IR signature based on a visual signature (big flame out the back), and basic knowledge (flame is hot) and a simple logical extrapolation (big flame is hotter than ‘cool’ looking airframe or non visible exhaust gas). Running cooling air around the engine is a lot more about cooling the airframe (as heat from the engine isn’t passed to the rest of the aircraft) not cooling the exhaust gas.

As I mentioned before jet thrust is created by the mass flow rate: the amount of air coming out the back and the velocity of that air. The hotter it is the higher the velocity. Reheat is just a simple way of producing more velocity without increasing the temperature of the turbine (which requires better and more materials). In the case of an engine designed to supercruise it achieves the higher velocity of the air within the turbine. The heat (and therefore exhaust plume IR signature) is going to be similar but just a lot less fuel burned to produce it. Also this heat won’t be in a visual wavelength. Because of this design when using reheat the F119 has a TW of 9:1 which is far above legacy engines like the F100’s 7.8:1.

So I wouldn’t assume that the exhaust plume of an F-22 at Mach 1.6 is going to be less than a similar sized aircraft at the same speed (say an F-14) using reheating.

Donnage99:

I think you may be taking what Abraham and I are saying a little too personally. Of course, having supercruise is better than not having supercruise, but there's more to it than that. In the notional airwing of the 1990s-200s, as seen from the late '80s, the F-14, F-18 and A-6 would be gone. In their place would be the NATF and the ATA. NATF, doing the fighter mission with a secondary attack role would probably have had supercruise if it didn't cost to much. ATA, would be replacing the A-6, which was the Navy's highest priority. It had no need for supercruise or any supersonic flight at all, since that would compromise its superstealth.

Cut to the early to mid 90s. NATF is gone, and now so is ATA, but A-6 still needs to be replaced. This is still the highest priority. Now, actually listening to the Fleet, AX comes on the scene. Stealthy, but not as much. Strike is still the driver. However, it now becomes apparent that F-14 is not going to be saved so there is now a requirement to get back some of that fighter capability. Hence, again with Fleet input, we have A/FX. This is a strike aircraft first and foremost, with a secondary fighter role. As Abraham said, Navy fighter missions are different. They no longer envision the broad fighter sweeps AF does, which is a big driver for F-22 and its supercruise. What it comes down to is performing the strike mission and having air-to-air capability that, while good enough for the Navy's needs-- escort, TARCAP, Fleet Air Defense, self defense, etc. may not be the best in the business.

Everything is tradeoffs. Supercruise is definitely valuable Personally, I feel that supercruise and being able to zoom around regularly at 60,000 feet are greater assets to Raptor than its stealth Payload/range, though, was much, much more important to A/FX. Yes, supercruise would absolutely have made A/FX even more formidable in fighter roles (it never would have been a pushover), but to have it with what the Navy needed in A/FX probably would have required too many compromises, if even possible, and certainly would have cost a lot more. Therefore, they didn't require it. I think that, more than weight was why it wasn't in any of the submissions). Navy didn't forbid supercruise after all. There's only so much money, and they weren't going to cut back on their strike needs.

Now, as to IR and IRSTs in general : Not wanting to put words on Abraham's keyboard, but maybe he was saying that a lower thrust engine using afterburner may not emit more IR as a higher thrust engine at max military power. While the F-22 uses some techniques to cool its exhausts, its clear that that portion of stealth was not as important to them as IR was to Northrop on the YF-23. The latter in addition to cooling the exhaust, also buried the engines and used special materials behind the exhausts. Neither of those options are available to the Raptor because of where the exhausts are located and the fact that the F-22 uses vectored thrust. In addition, the design of the aft fuselage and empennage is designed to mask "views" of the engine. Take a look at photos and videos of the F-22 and the YF-23. On the former you can see the burner plume from all over, even from the front. On the latter, have you ever seen a picture or move of the YF-23 except from a narrow cone at the rear where you could see the flame? Lockheed read the AF right, they weren't as concerned with IR stealth. The Navy, however, was.

They knew that modern IRSTs would be able to see and track supercruising aircraft from what they radiated zooming through the air. The first meaningful attempt to address that would have been with the "smart skin" originally considered for JSF (I think that initiative died). Of course an afterburner plume you can see emits more IR than the skin, but at supersonic speeds the skin still emits enough to be tracked, albeit at reduced ranges relative to 'burner, even if you can't look at the engine exhaust. That'd be true even if you had impulse drive and emit no IR from the engines. In the next decades stealth breakthroughs may meant that's no longer true, but they were spec'ing the plane in the early-mid 1990s.

The salient facts here are the wavelength of the IR radiation and the magnitude of the radiation emitted as well how well the wavelengths propagate in the atmosphere.

The best transmission of IR energy occurs in several distinct windows. 1.5-1.8 microns, 2.1-2.5, 3-5, and 8-14 microns. Each of these windows corresponds to a particular range of temperatures.

Looking at the graph attached, one technique available for IR stealth is clear. Emit energy at the right wavelengths and the atmosphere will soak it up for you, making detection far more difficult. This can work against IR missile seekers - for example the 3-5 micron band is used by most modern IR seekers, but at just above 4 microns is a point where tranmissivity is almost zero. If you can dump most of your hot IR radiation at the right temperature to hit this sweet spot, or above 5 microns, IR SAMs /AAMs will have trouble locking on at a useful distance.

The 8-14 micron band (LWIR) used in some modern IRSTs corresponds to low enough temperatures that IR stealth becomes far harder. However, an object at 30 degrees celcius puts out much less IR energy than one at 2000 celsius, so the detection range is greatly reduced. You therefore need a much more sensitive seeker to get a useful range.

F-14D - I don't understand why you told me the history of navy's accquisitions. Once again, I'm NOT arguing against navy's decision to forgo supercruise. I AGREE with their decision. What I'm arguing is your particular reasoning that the one of the reasons navy forgone supercruise is because they understood the importance of IRS. If your logic follows through, than the A/F-X would be a subsonic fighter because if they are afraid of using supercruise, they as hell are afraid of reheat, which eliminates the ability to fly supersonic as those are the only 2 approaches we had to go supersonic. Range, weight, cost, difference in requirements that are based on likely operational scenarios: I agreed. But I don't think IRS was one of the reason.

Abraham Gubler - afterburning exhaust plume was not the be all and end all of IR signature: YES! But please don't mistake the difference between "solely important" and "most important." Boyd understood that it's not just the exhaust plume that produces IR signature, but that does not address whether afterburner exhaust plume still produce the most IR signature or not.

Running cooling air around the engine is a lot more about cooling the airframe (as heat from the engine isn’t passed to the rest of the aircraft) not cooling the exhaust gas.

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Yes, which helps reducing the overall IR signature of the aiframe during supercruise. However, this IR stealth technique is useless during reheat, as it is the afterburning exhaust plume that are torching and emitting IR.

donnage99 said:

F-14D - I don't understand why you told me the history of navy's accquisitions. Once again, I'm NOT arguing against navy's decision to forgo supercruise. I AGREE with their decision. What I'm arguing is your particular reasoning that the one of the reasons navy forgone supercruise is because they understood the importance of IRS. If your logic follows through, than the A/F-X would be a subsonic fighter because if they are afraid of using supercruise, they as hell are afraid of reheat, which eliminates the ability to fly supersonic as those are the only 2 approaches we had to go supersonic. Range, weight, cost, difference in requirements that are based on likely operational scenarios: I agreed. But I don't think IRS was one of the reason.

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Aha! The nub of the matter approaches!

In our history of this electronic electronic exchange, you opined on Oct. 7, "However, it doesn't have engines with supercruising features as the f-22 because of weight saving". I took that as you meaning to say that the main reason for no supercruise was engines that weighed less.

Meanwhile, later that same day (as they used to say in the old movie serials), I riposted with "A/FX didn't have supercruise because the missions of the aircraft were different from that of F-22, the Navy, unlike USAF, understood and believed in IRST systems and supercruise does tend to make you hotter, they were more interested in range than supercruise and for their needs they weren't wiling to pay what it would cost.".

It appears that you felt I was saying that IR signature was the reason for no supercruise. I wasn't. I was merely saying that Navy didn't think for A/FX it was worth the cost, so didn't require it. Navy, more than AF, alsoseemed to be aware that the mere fact of moving a big hard thing through the air supersonically gives off detectable and trackable IR emissions (though certainly not as much as with a/b) even if you mange to shoot ice cubes out the tail. Navy was aware that supercruising doesn't make the whole IR thing go away.

As the sun peaked over the hills (at least where I am) the next day, came your missive which began, "You completely missed it, F-14D. I'm arguing against Navy's decision of not having supercruise requirements...". Looking back with the benefit of hindsight --knowing the retorts to follow-- I suspect that the intention there was for the word "not" to appear in front of "arguing", which would change a great deal.

For this forum, my blatherings have always been in the context of the A/FX, not on supercruise or IR detection in general. It seems our only point of disagreement was whether the Navy forgoed (is that a word?) a supercruise requirement principally because of weight or for a combination of reasons, including range/payload and cost. After all, the NATF, which had different priorities, almost certainly would have supercruised.

Overscan,

Thanks for your valuable post. I learned something, regarding the "sweet spot". IRSTs are continuously evolving. For example, the IRST for the Super Hornet, while based on the one used by the Tomcat, will cover a broader range, and last longer before needing service Regarding useful range, I was told that the F-14D could IR track targets "...at Phoenix ranges...", which I took to mean in the 10s of nm, so I'd bet they could do better today, 15 years later.

In the context of this forum, A/FX, your point about dumping IR emissions at the right temperature sounds like part of the "smart skin" effort proposed for JSF (which may have been dropped). Doing developing that for A/FX in the '90s would have really upped the cost, which is probably why they didn't consider it. After all, they may have wanted to be able to buy two of the planes!

F-14D said:

As the sun peaked over the hills (at least where I am) the next day, came your missive which began, "You completely missed it, F-14D. I'm arguing against Navy's decision of not having supercruise requirements...". Looking back with the benefit of hindsight --knowing the retorts to follow-- I suspect that the intention there was for the word "not" to appear in front of "arguing", which would change a great deal.

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That's correct. I didn't notice that I didn't put the word "not" before "arguing" until now. I apologize for my typo which led you to waste time on that long post.

For this forum, my blatherings have always been in the context of the A/FX, not on supercruise or IR detection in general. It seems our only point of disagreement was whether the Navy forgoed (is that a word?) a supercruise requirement principally because of weight or for a combination of reasons, including range/payload and cost. After all, the NATF, which had different priorities, almost certainly would have supercruised.

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I agree. Priorities would be the main factors, but there might be possibly other factors such as techinical differences. The A/F-X has weapon bays much bigger than the f-22 (which probably also translates to NATF version also). I'm not sure but I think the side weapon bays where the f-22 houses its sidewinders, the A/F-X would house AMRAAM.

donnage99 said:

I agree. Priorities would be the main factors, but there might be possibly other factors such as techinical differences. The A/F-X has weapon bays much bigger than the f-22 (which probably also translates to NATF version also). I'm not sure but I think the side weapon bays where the f-22 houses its sidewinders, the A/F-X would house AMRAAM.

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How much bigger are the A/F-X bays compared to F-22? Width and lenghtwise they look about the same to me?

Evil Flower said:

How much bigger are the A/F-X bays compared to F-22? Width and lenghtwise they look about the same to me?

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From flight global:

"Weapons-bay length was set by the dimensions of the AGM-86E stand-off land-attack missile, while width was determined by those of the GBU-24 laser-guided bomb. Air-to-air missiles would have been housed in F-22-style side bays."

I have that same article, but I'm quite sure AGM-86E is a typo and they really mean the AGM-84E SLAM, which isn't that enormous. Also the F-22's bay looks pretty big to me, yet is referenced as being very small so what's up with that? Is it a really shallow bay whereas the AFX is deeper?

Evil Flower said:

Is it a really shallow bay whereas the AFX is deeper?

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Yes! And remember that A/F-X's side weapon bays can also carry AMRAAM for defense, which would leave space for the main weapon bays to carry air to ground ordinance exclusively.

On A/FX (which had more of a air-to-air role than envisioned for AX) vs. F-22's bays, we can infer a few things.

We've got to keep in mind that AAAM was a going concern back when the requirements were first conceived. AAAM was larger than AIM-120, and Navy had a requirement that it carried by any aircraft that could carry AIM-7 (F-14, F-15, F/A-18, etc.). One of the reasons USAF opposed development of AAAM was that a reasonable number of them would not fit in F-22's main bay, I don't know about F-23. Since AAAM was supposed to the principal a/a armament of A/FX, we can assume that the main bay was at least large enough to hold 4-6 of them when not operating air to ground. We can see this with F-35. It has a noticeably larger bay that Raptor, and one of the planned upgrades is to have an insertable launcher for up to eight AIM-120. It would seem reasonable that the A/FX would have been required to do at least that, of course sacrificing internal a/g ordnance when acting as a fighter, which means there would be plenty of room for AAAM.

I agree with donnage99; it is inconceivable that Navy would have been satisfied with an NATF that didn't have a large enough bay to accommodate AAAM.

Which variant of the AAAM are we talking about? Looking at the GD tube-launched concept that one looks as if it's much smaller than the AIM-120 diameter-wise since the latter has fins whereas the AAAM does not.

NilsD said:

Which variant of the AAAM are we talking about? Looking at the GD tube-launched concept that one looks as if it's much smaller than the AIM-120 diameter-wise since the latter has fins whereas the AAAM does not.

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If you're referring to the two-stage one that does appear to be very compact compared to the Hughes ramjet. With it's folding fins I wouldn't be surprised if it were more compact than AIM-120.

NilsD said:

Which variant of the AAAM are we talking about? Looking at the GD tube-launched concept that one looks as if it's much smaller than the AIM-120 diameter-wise since the latter has fins whereas the AAAM does not.

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On the AAM topic, I posted a drawing of the two versions side by side at http://www.secretprojects.co.uk/forum/index.php/topic,2548.msg34344.html#msg34344 . You'll note that both are 12 feet long. I think the diameter of the GD missile body was 14cm/5.5" and Hughes 23cm/9". Presumably that's folded, and for GD outside of its launch tube (which if required for internal launch would naturally increase its size).

Actually, it doesn't matter which version we're talking about. At the time in question, the Navy didn't know which submission would win the competition. What it would have specified for AAM dimensions would be a "box" in three dimensions in which the missile would have to "fit" for carriage, and any planned aircraft being designed to use it would have to accommodate that "box". Keep in mind that prior to the advent of stealth Navy has historically not been a fan of internal missile carriage, for their purposes feeling it had more penalties than advantages.

F-14D said:

We can see this with F-35. It has a noticeably larger bay that Raptor, and one of the planned upgrades is to have an insertable launcher for up to eight AIM-120.

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Do you have any information about this, can it carry the AIM-9X too? Don't mean to drag us off topic.

Colonial-Marine said:

Do you have any information about this, can it carry the AIM-9X too? Don't mean to drag us off topic.

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There have been studies conducted by the (US) Air Force Research Laboratory (AFRL) into carriage of more AMRAAM sized weapons inside the F-35’s internal bay. It certainly has the volume to carry far more than two in each bay. These studies are to explore the possibilities and look at a range of options for later development.

The F-35 program however is in the System Development and Demonstration (SDD) phase until 4Q 2014. After SDD ends then derivatives and enhancements will begin in which case new weapons bay configurations and other things (maybe DEW) will be developed as part of the F-35 program.

Until further development theF-35’s internal weapons bay will be limited to AIM-120 and AIM-132 (ASRAAM) as air to air weapons.AIM-9X can be carried externally.

Abraham Gubler said:

Colonial-Marine said:

Do you have any information about this, can it carry the AIM-9X too? Don't mean to drag us off topic.

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There have been studies conducted by the (US) Air Force Research Laboratory (AFRL) into carriage of more AMRAAM sized weapons inside the F-35’s internal bay. It certainly has the volume to carry far more than two in each bay. These studies are to explore the possibilities and look at a range of options for later development.

The F-35 program however is in the System Development and Demonstration (SDD) phase until 4Q 2014. After SDD ends then derivatives and enhancements will begin in which case new weapons bay configurations and other things (maybe DEW) will be developed as part of the F-35 program.

Until further development theF-35’s internal weapons bay will be limited to AIM-120 and AIM-132 (ASRAAM) as air to air weapons.AIM-9X can be carried externally.

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This is my understanding as well. The new launcher module is considered highly likely, but not until after SDD. The dates I've heard for incorporation work are 2015 or later. If the AMRAAM follow-on (the name escapes me at the moment) actually enters service this module my allow the F-35 to carry twice as many (it's a more compact missile) as Raptor. This may have been discussed in one of the F-35 threads. No speculation yet as to whether the module will be accelerated now that we've lost the F-22.

And now we're really off topic.

BTW, also off-topic, but the technology was mentioned in this thread and this may be worthwhile as a jumping off point for discussing elsewhere, the current issue of Air and Space Smithsonian has a very nice article of some of the technologies involved in Smart Skin, although they don't call it that.

Any diagrams of what this launcher is supposed to look like? I can't really visualize it. The lack of internal AIM-9X capability on initial production variants is a major problem in my opinion. Especially when you consider the F-35 is at a disadvantage compared to designs with TVC when it comes to maneuverability.

Regarding the A/F-X, were official specifications for speed, range, and performance ever issued. And did the Navy try to put up a fight to save the program? Obviously JAST/JSF was mentioned but wasn't it clear that was going to be a single-engined, less capable design?

Colonial-Marine said:

Any diagrams of what this launcher is supposed to look like? I can't really visualize it. The lack of internal AIM-9X capability on initial production variants is a major problem in my opinion. Especially when you consider the F-35 is at a disadvantage compared to designs with TVC when it comes to maneuverability.

Regarding the A/F-X, were official specifications for speed, range, and performance ever issued. And did the Navy try to put up a fight to save the program? Obviously JAST/JSF was mentioned but wasn't it clear that was going to be a single-engined, less capable design?

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Since the proposed launcher is so far in the future, I doubt if publicly releasable detailed drawings exist because at this point it's still a concept. It hasn't yet been fully designed, it's just that there is ample space for it and the concept has a good deal of support. We'd probably best leave this here because talking too much more about the F-35 could lead this thread astray.

As for the performance parameters and required capabilities, these were specified in 1992 in the Concept Exploration Phase based on the operational requirements Navy had defined by that time. No, I haven't seen them in detail.

Regarding the end of A/FX, it became apparent that it was going to come into service not too far behind that of Super Hornet. Congress started making noises that it didn't see the need for funding two aircraft so (relatively) close together, and so it would fund one but not both. USAF was again making noises that it didn't really want to buy A/FX, it'd rather by more of its own planes. Congress, of course, was really getting into joint projects by this time. Plus, you had a new Administration coming in. Finally, the Super Hornet lobby in the Navy by this time was was super strong. Navy may have also felt that a Super Hornet in the hand was better than an far superior A/FX that might never get built in the bush, and they needed to have something on carrier decks for the future. So, A/FX got offered up in the 1993 Bottom Up Review.

Quite a shame if you ask me. Although we could have ended up with neither aircraft if enough stupidity had occurred. If the radome ended up being a bit longer and more streamlined (similar to the F-22 or Lockheed's NATF concept), the AFX-653 would have been an amazing looking bird.

Obviously a full collection of air-to-ground modes would be wanted for the radar, but when it came to air-to-air, was there a requirement to match the APG-71 in areas like range? What was the Navy willing to "trade" in interception capabilities?

Colonial-Marine said:

Quite a shame if you ask me. Although we could have ended up with neither aircraft if enough stupidity had occurred. If the radome ended up being a bit longer and more streamlined (similar to the F-22 or Lockheed's NATF concept), the AFX-653 would have been an amazing looking bird.

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Then you couldn't see over the nose and landing A/F-X on a carrier would be a dicy business.

As to previous post questions about AIM-9X, TVC, etc. This kind of stuff is covered in a range of other threads. I think you will find that the HOBS LOAL capability of the F-35 and EODAS with AIM-120D and the next generation Boeing JDRADM (Jay-Drad-Emm and F-14D's missile he can't remember) that will replace AIM-9, AIM-88 and AIM-120 you will have no problem defeating others in visual range knife fights.

TVC: Thrust Vectored Control
HOBS: High angle Off Bore Sight
LOAL: Lock On After Launch
NGES: Northrop Grumman Electronic Systems
EODAS: Electro Optical Distributed Aperture System
JDRADM: Joint Dual Role Air Dominance Missile
AIM: Aerial Intercept Missile
ARE: Acronym Rich Environment

Well the pilots could see over the nose of the F-14, F/A-18, F-4, and so on. But no matter, it is just me rambling about aesthetics, nothing more.

I am sure AIM-120D will be a fine missile, however when it it comes to a short range knife fight, your certainly going to want something like the AIM-9X. Especially if you are to take advantage of EODAS and that that advanced helmet mounted display. It just seems to be a mistake to leave out that capability on the hope that this new missile will enter service and replace the AIM-9X, which could be many years away if the program survives. Sort of like expecting the AIM-152 to be around for the Super Hornet I guess.

The concept of a missile replacing both the AIM-120 and AIM-9 is interesting, but size must be a serious concern to it's designers. How are you going to provide long range while fitting it into the side bay of the F-22 for example, or the wing pylons of many 4.5 generation designs? I don't think the warhead could be large enough to replace the AGM-88 either.

Okay now this is really off-topic.

Colonial-Marine said:

Quite a shame if you ask me. Although we could have ended up with neither aircraft if enough stupidity had occurred. If the radome ended up being a bit longer and more streamlined (similar to the F-22 or Lockheed's NATF concept), the AFX-653 would have been an amazing looking bird.

Obviously a full collection of air-to-ground modes would be wanted for the radar, but when it came to air-to-air, was there a requirement to match the APG-71 in areas like range? What was the Navy willing to "trade" in interception capabilities?

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Like Abraham said, you'd have to redesign the nose, which would change the profile of the aircraft with all that entails. It might be possible for an AESA equipped A/FX to match the range of the APG-71 with a mechanically scanned antenna, but certainly not what would be achievable in the same timeframe with an APG-71 mated with an AESA matched to it. You'd be talking about a much larger plate matched with a lot of transmitter power. As some put it at the time of the development of the F-14D, no one in the late 1980s would put an antenna that big in a new US fighter they were designing then. But, given that it's already there, might as well make use of it.

Given the role envisioned for A/FX, I don't see the Navy requiring that kind of range. They'd probably just want a range that could see far enough to find targets for AAAM, counting on off aircraft sensors to deal with anything further away.

Colonial-Marine said:

Well the pilots could see over the nose of the F-14, F/A-18, F-4, and so on. But no matter, it is just me rambling about aesthetics, nothing more.

I am sure AIM-120D will be a fine missile, however when it it comes to a short range knife fight, your certainly going to want something like the AIM-9X. Especially if you are to take advantage of EODAS and that that advanced helmet mounted display. It just seems to be a mistake to leave out that capability on the hope that this new missile will enter service and replace the AIM-9X, which could be many years away if the program survives. Sort of like expecting the AIM-152 to be around for the Super Hornet I guess.

The concept of a missile replacing both the AIM-120 and AIM-9 is interesting, but size must be a serious concern to it's designers. How are you going to provide long range while fitting it into the side bay of the F-22 for example, or the wing pylons of many 4.5 generation designs? I don't think the warhead could be large enough to replace the AGM-88 either.

Okay now this is really off-topic.

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Couple of things. Again, to get F-14D AESA ranges, you're going to have to change the nose, which means you change the crew positions, which means you change the mold line, etc. Doable, but given the roles they planned for it, they probably wouldn't do it. Otherwise they would have specified it to being with, and that would compromise what they wanted the plane to do.

AIM-152 would have been on Super Hornet; in fact, one of the SH arguments regarding its fighter capability was that AIM-152 would make up for it. However, that backfired in that Congress asked why the Navy was developing a missile that could fly further than its new fighter (the SH) could see?.

Even if AIM-152 had been developed, it's likely that something like JDRADM (thank you, Abraham) would still be developed, and would have ended up on A/FX (touching on our topic here) . In fact, it would be a better match for A/FX than AIM-152, although would be showing up a least after its projectted IOC, and probably more.

JDRADM is not to repace AIM-120 and AIM-9X, but rather AIM-120 and AGM-88. Therefore, it wouldn't have to fit into the side bays of the F-22, it would be carried where AIM-120 is now. AS far a s the pylons of other fighters, given the parameters they're talking about, that wouldn't be that much of a problem if you could do the interface. Regarding warhead compared with HARM, my understanding is that it would impact at a much higher speed and with even more accuracy. The kinetic energy transferred to the target would make up for a smaller warhead.

If the A/FX were in service today, the Program Office would be slathering to get something like JDRADM, given the roles of A/FX. It would simplify the weapons loadout enormously.

F-14D said:

JDRADM is not to repace AIM-120 and AIM-9X, but rather AIM-120 and AGM-88. Therefore, it wouldn't have to fit into the side bays of the F-22, it would be carried where AIM-120 is now.

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To calrify the JDRADM won't replace the AIM-9X for the F-22 (side bay issues) but it will replace it for the F-35 and the F/A-18E/F. Since in the JDRADM's service timeframe (>2020) that is a difference of 100 aircraft to 2,000 to 3,000 aircraft (not counting remaining F-15 and F-16 AIM-9X users) its easy to imagine a time when the F-22 is insignificant to these issues. Capability wise JDRADM will be able to perform the WVR dogfight mission. At least that's the plan to date...

F-14D said:

Regarding the end of A/FX, it became apparent that it was going to come into service not too far behind that of Super Hornet. Congress started making noises that it didn't see the need for funding two aircraft so (relatively) close together, and so it would fund one but not both.

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A/F-X would become operational 10 years after super hornet, given that the A/F-X would be delivered on time, which history has shown to be doubtful to say the least. The super hornet was viewed at the time as filling the gap until A/F-X arrived. Ironically, when Navy had to choose 1 out of the 2, the A/F-X, with all the reasons you have given, also would leave navy with fighter gap as its operational date is too far into the future and without any super hornet to fill in the gap.

donnage99 said:

F-14D said:

Regarding the end of A/FX, it became apparent that it was going to come into service not too far behind that of Super Hornet. Congress started making noises that it didn't see the need for funding two aircraft so (relatively) close together, and so it would fund one but not both.

Click to expand...

A/F-X would become operational 10 years after super hornet, given that the A/F-X would be delivered on time, which history has shown to be doubtful to say the least. The super hornet was viewed at the time as filling the gap until A/F-X arrived. Ironically, when Navy had to choose 1 out of the 2, the A/F-X, with all the reasons you have given, also would leave navy with fighter gap as its operational date is too far into the future and without any super hornet to fill in the gap.

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Super Hornet was not delivered in quantity on time, though that wasn't it's fault. The original schedule for A/FX was more aggressive, BTW, but it was also slipped early on. As far as fighter gap goes, remember the USN was more concerned about strike than fighter. It knew and accepted the timeframe to get A/FX into service. Given there was some, but not strong chance at that point the F-14D could be restored (the production tooling still existed), the gap could have been filled by not prematurely retiring the A-6, and using some more F/A-18C/Ds (or maybe a plus model). Don't forget that at the time, the Navy freely acknowledged that the C/D was more agile than the E/F and probably a better fighter. Then, you could have had the money and the time to get A/FX, which would have been much better for the Navy than its present and foreseeable future state.

But then, the above ignores the ever-present power plays so prevalent in DC.

I dug this up on the JDRADM development:



These represent the different technologies that comprise the JDRADM:
MR ROKM is the warhead tech
SITES is the seeker
DRADM-T is propulsion and airframe tech

2010 will be an interesting year for JDRADM tech.

My thoughts on how to extend the range... Restartable rocket motors and higher rocket energetics. I liked GD's AIM-152 idea of a two stage missile. This way the missile could take a long range, lofting profile and still have an active TVC rocket for the endgame engagement. Also, the smaller 2nd stage was lighter and could pull higher G's than the missile as a whole. The second benefit of a 2 stage missile is that for a 9X replacement, a smaller 1st stage booster can be installed. On the other end of the scale, a larger booster could be added for a VERY long range shot. The largest benefit is that they would all use the same 2nd stage, therefore keeping costs down.

Here is Boeing's only publicly released JDRADM image.



Notice the very small tail fins. Obviously they are thinking TVC. The question is... will it be under active rocket thrust at the end of a long range shot.

F-14D said:

Super Hornet was not delivered in quantity on time, though that wasn't it's fault. The original schedule for A/FX was more aggressive, BTW, but it was also slipped early on. As far as fighter gap goes, remember the USN was more concerned about strike than fighter. It knew and accepted the timeframe to get A/FX into service.

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It accepted the timeframe for A/F-X because of super hornet. And I know that the navy has shifted from dedicated air superiority fighters to multi-role strike fighters, but I'm unaware of the fact that USN was more concerned about strike than fighter.

donnage99 said:

F-14D said:

Super Hornet was not delivered in quantity on time, though that wasn't it's fault. The original schedule for A/FX was more aggressive, BTW, but it was also slipped early on. As far as fighter gap goes, remember the USN was more concerned about strike than fighter. It knew and accepted the timeframe to get A/FX into service.

Click to expand...

It accepted the timeframe for A/F-X because of super hornet. And I know that the navy has shifted from dedicated air superiority fighters to multi-role strike fighters, but I'm unaware of the fact that USN was more concerned about strike than fighter.

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Navy repeatedly and publicly made it clear that its priority was replacing the A-6 for both all-weather and deep strike. A-6F was ordered as a hedge against ATA (A-12) slipping. It was canceled partly because it was thougth that ATA was on track and would enter service soon after it. ATA was Navy's highest aviation priority. Remember, Navy pulled out of NATF partly out of fear it wouldn't have enough strike potential, and partly to insure ATA would have enough funding. It was perfectly willing to carry on with the F-14 because it didn't see fighters as being as important in the short term as strike, and F-14D with enhancements could meet its needs for the forseeable future. When AX was first mooted, it was a pure strike aircraft whose only air-to-air role was self defense. When it evolved into A/FX, fighter role was always secondary, quite powerful, certainly more than SH, but secondary. When Super H was ordered by DoD, it was advertised not as a fighter but as an interim strike aircraft until AX-A/FX arrived. Its relative fighter performance was explained away by saying that would be remedied by AIM-152.

Note also that Navy began an extensive rewinging program on the A-6 to extend its operational life until a definitive replacement could be fielded, even though SH was under development. The rewinging program was working and units had already entered the Fleet. This was another sign of how important the Navy considered strike. Rewinging program died for a number of reasons. One of, but not the only one, was Congress asking why there was an urgent need to extend life of A-6 if SH was supposedly good enough to handle the interim need? The result was a stop work order on the rewinging to the point that rewinged aircraft in the air undergoing flight test were ordered to land immediately and those in the middle of the process were ordered scrapped. With the loss of A/FX and the future being the SH, Navy permanently abandoned the deep and all-weather strike mission to the Air Force.

SpudmanWP said:

I dug this up on the JDRADM development:



These represent the different technologies that comprise the JDRADM:
MR ROKM is the warhead tech
SITES is the seeker
DRADM-T is propulsion and airframe tech

2010 will be an interesting year for JDRADM tech.

My thoughts on how to extend the range... Restartable rocket motors and higher rocket energetics. I liked GD's AIM-152 idea of a two stage missile. This way the missile could take a long range, lofting profile and still have an active TVC rocket for the endgame engagement. Also, the smaller 2nd stage was lighter and could pull higher G's than the missile as a whole. The second benefit of a 2 stage missile is that for a 9X replacement, a smaller 1st stage booster can be installed. On the other end of the scale, a larger booster could be added for a VERY long range shot. The largest benefit is that they would all use the same 2nd stage, therefore keeping costs down.

Here is Boeing's only publicly released JDRADM image.

Notice the very small tail fins. Obviously they are thinking TVC. The question is... will it be under active rocket thrust at the end of a long range shot.

Click to expand...

On the other hand, two stages does add complexity. You could get the range and energy at the ends of the envelope with a rocket ramjet as well, although other factors come into play here. Maybe a JDRAM thread should be started. Although with the things we've seen about where the DoD direction might go, JDRADM may always remain just be a picture.

The Navy used a two stage system very successfully (SM series of missiles), and has for many years.

A ramjet combo has it's own set of problems, which is why the Meteor is STILL not in operation.

Bear in mind that GD’s A3M could be called a three stage missile (or more accurately three phases). Stage 1 is the booster to provide velocity and is then jettisoned (like SM-1ER, SM-2 Block IV, SM-3, SM-6, etc) the missile’s sustainer motor is then fired up to cruise to the target. At some point it is turned off to allow the missile to coast to target and then fired up again for terminal manoeuvre energy.

I think this is what Spudman is suggesting may be part of JDRADM’s capability. The ability to operate the motor based on the mission. For WVR this could be burn until kill, for ARM burn and then coast to kill and for BVR burn until coast and then re-burn for kill (obviously for those targets at the outside edge of the engagement range).

Abraham Gubler got it right.

Wish I had more warning on this. Boeing had a trailer with promotional stuff at the Edwards open house, and there was a JDRADM picture in there.

Here's some more JDRADM images.

quellish said:

Wish I had more warning on this. Boeing had a trailer with promotional stuff at the Edwards open house, and there was a JDRADM picture in there.

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So do I. I was there the day before when they were setting up the show and didn't see that.

SpudmanWP said:

The Navy used a two stage system very successfully (SM series of missiles), and has for many years.

A ramjet combo has it's own set of problems, which is why the Meteor is STILL not in operation.

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Wasn't trying to force ramjet down anyone's throat. BTW, I suspect it would not be a rocket-ramjet combo, but rather an integral rocket/ramjet. The Soviets/Russians have known how to do that for decades. Meteor is not in operation not because it's a ramjet but because it's subject to the vagaries that are universal to posturing politicians. They're always in favor of a newer more advanced capability as long as someone else has done it before and it's in the future where you don't actually have to come up with the bucks for it. Meteor has been moved further and further back because it's approaching the point where the serious funding is coming due, so the can is being repeatedly kicked down the road. This is not meant as a slam at Europe. After all, this was basically the US method of weapons development for most of the '90s (as well as the late '70s).

The complexity issue with multi-stage missiles I referred to was only referring to air launched. The SM series as a multi-stage missile was surface launched. The air-launched Standard missiles that were used in the anti-radiation role for a while dispensed with the booster. Similarly, air-launched Harpoon and air-launched Tomahawk, before it was canceled (some say partly due to Air Force lobbying), both dispensed with their booster stages.

I don't know if they've got to the point yet where they have definitively decided the propulsion method for JDRADM, many pictures seem to be notional. Could be start/stop rocket, integral rocket/ramjet or something else entirely. If I had had the opportunity to talk to Boeing this weekend I sure would have asked (did get to talk to F-35 folks, though). I just hope JDRADM actually sees the light of day. Again, I suspect detailed discussion of this weapon deserves its own thread.