AIM-174 Very Long Range AAM (SM-6)

[TomS]

I'm not seeing a quick answer, does the SM6 have divert thrusters like Patriot?

No, it does not. It relies strictly on aerodynamic flight controls. (Note that only PAC-3 has divert thrusters, PAC-2 is likewise strictly aerodynamic.)

 

[Scott Kenny]

No, it does not. It relies strictly on aerodynamic flight controls. (Note that only PAC-3 has divert thrusters, PAC-2 is likewise strictly aerodynamic.)

Bugger.

Need to add divert thrusters to SM6...

 

[NMaude]

Need to add divert thrusters to SM6...

Use a modified scaled up version of the SM-3's TDACS.

 

[Forest Green]

I'm not seeing a quick answer, does the SM6 have divert thrusters like Patriot? Because that'd make for a really evil AShM, using drunkwalk semi-random jinks all the way down to impact...

SM-6 IA does not, but there was talk about the BMD capabilities for SM-6 IB, so it's possible that has something to do with GPI. Not a lot know at present, or whether it would evolve into an AIM-174C (not sure we had an A version though???).

 

[FighterJock]

That was what I was thinking when I first heard that it was going to be the AIM-174B Forest Green. Where the AIM-174A went? Strange.

 

[jsport]

If a Next Gen capability is the goal the B-21 is already missioned out and older gen manned are phasing out, guess what, one doesnt look to CCAs but something else that can carry sufficient numbers, something larger.

 

[ST21]

One thing i have been wondering lately about the F/A-18E/F + AIM-174 combo is if the Super Bug will even be able to go supersonic when carrying those missiles. The AIM-174 is very heavy and will add a lot of drag to an already draggy (and slowish) airplane. I had a look at the F/A-18E/F NATOPS manual and according to a flight performances chart, when carrying a meaningful loadout of 5x AIM-120 and 2x AIM-9 + a FLIR pod and an external fuel tank, the SH struggles to reach Mach 1.2 and can only do it above 30K feet... This raises questions about how carrying AIM-174s will affect its flight performances.

One thing is certain is that the SH with its weak transonic performances and barely passable range is a suboptimal platform for the long-range intercept mission. It is just not something it was designed to do. I get that the Navy doesnt have much choices due to the decisions of the past 30+ years and is making the best of a bad situation since, for better or worse, they are stuck with the SH but F/A-XX cant come soon enough.

 

[Hpela]

That was what I was thinking when I first heard that it was going to be the AIM-174B Forest Green. Where the AIM-174A went? Strange.

RIM-174A it's SM-6 Block I. RIM-174B is SM-6 Block Ia. AIM-174B is based on RIM-174B, so no A version.

 

[paralay]

weight 812 kg

 

[Andreas Parsch]

That was what I was thinking when I first heard that it was going to be the AIM-174B Forest Green. Where the AIM-174A went? Strange.

If the starting point for the air-launched SM-6 development was the SM-6 Block Ia (RIM-174B), then the suffix AIM-174B would be the logical choice. No need to designate the first AIM-174 version with suffix "A".

 

[BDF]

One thing i have been wondering lately about the F/A-18E/F + AIM-174 combo is if the Super Bug will even be able to go supersonic when carrying those missiles. The AIM-174 is very heavy and will add a lot of drag to an already draggy (and slowish) airplane. I had a look at the F/A-18E/F NATOPS manual and according to a flight performances chart, when carrying a meaningful loadout of 5x AIM-120 and 2x AIM-9 + a FLIR pod and an external fuel tank, the SH struggles to reach Mach 1.2 and can only do it above 30K feet... This raises questions about how carrying AIM-174s will affect its flight performances.

One thing is certain is that the SH with its weak transonic performances and barely passable range is a suboptimal platform for the long-range intercept mission. It is just not something it was designed to do. I get that the Navy doesnt have much choices due to the decisions of the past 30+ years and is making the best of a bad situation since, for better or worse, they are stuck with the SH but F/A-XX cant come soon enough.

It could be like the phoenix and sparrow on the F-14. The Phoenix performed best at high altitudes and the Sparrow preferred high speeds. Meaning that Tomcat crews were to prioritize altitude before speed with the phoenix.

 

[NMaude]

but there was talk about the BMD capabilities for SM-6 IB

Although it would be a beast to carry (Especially for an F/A-18E/F) an air-launched SM-6 Block-IB with a Mk-72 mounted would probably be able to intercept an ICBM's MIRV.

whether it would evolve into an AIM-174C (not sure we had an A version though???).

Where the AIM-174A went? Strange.

Well, you have the RIM-174A then the RIM-174B so the AIM-174B is just an air-launched SM-6 without its' Mk-72 launch-booster and modifications to enable to be launched from an ejector-rack.

Now as for supersonic launch from an F/A-18E/F, what the Super Hornet could do is climb to 45,000Ft (Service ceiling is 52,000Ft) go supersonic and go into a shallow powered dive to 40,000Ft before levelling out and launching its' AIM-174Bs.

 

[Forest Green]

Although it would be a beast to carry (Especially for an F/A-18E/F) an air-launched SM-6 Block-IB with a Mk-72 mounted would probably be able to intercept an ICBM's MIRV.

Nah, it would need DACT for that.

 

[NMaude]

Nah, it would need DACT for that.

I just realised I had a brain-fart, I realised I was thinking of the SM-3 Block-II and somehow got the two muddled in my head, now an air-launched SM-3 Block-II could work against an ICBM's MIRV (An SM-6 Block-IB might work but only in the terminal reentry phase and that would be a close call).

 

[kqcke for you]

I think that the AiM-174 is a great idea. Taking an SM-2 Block IIIC and adding anything that the sm-6 has over the SM-2 Block IIIC (and structure modifications for Air Launch) is a good idea. Tought isn't Ursa working on an improved MK 104? Could make it even better

 

[NMaude]

I wonder if the AIM-174B has a semi-active radar guidance mode?

 

[kqcke for you]

I wonder if the AIM-174B has a semi-active radar guidance mode?

It has / should have as any sm-6

 

[TomS]

I wonder if the AIM-174B has a semi-active radar guidance mode?

The SM-6 seeker is largely the same as AMRAAM, which does not have any sort of semi-active mode. SM-6 can get mid-course updates via datalink (which is the same principle as both SM-2 and AMRAAM) but there's no reason for it to use semi-active illumination in the endgame.

 

[kqcke for you]

The SM-6 seeker is largely the same as AMRAAM, which does not have any sort of semi-active mode. SM-6 can get mid-course updates via datalink (which is the same principle as both SM-2 and AMRAAM) but there's no reason for it to use semi-active illumination in the endgame.

Standard Missile

Standard Missile 2 (SM-2) is the U.S Navy's primary surface-to-air air defense weapon. It is an integral part of the AEGIS Weapon System (AWS) aboard Ticonderoga-class cruisers and Arleigh Burke-class

www.navy.mil

 

[TomS]

Standard Missile

Standard Missile 2 (SM-2) is the U.S Navy's primary surface-to-air air defense weapon. It is an integral part of the AEGIS Weapon System (AWS) aboard Ticonderoga-class cruisers and Arleigh Burke-class

www.navy.mil

View attachment 734535

Interesting. I guess they wanted to ensure you could use the shipboard illuminators to burn through jamming?

 

[sferrin]

The SM-6 seeker is largely the same as AMRAAM,

Which makes one wonder if there is a bunch of empty space up front or if they repackaged it with new boards and a bigger array, more power, etc.

 

[Scott Kenny]

That was what I was thinking when I first heard that it was going to be the AIM-174B Forest Green. Where the AIM-174A went? Strange.

The *IM-174A is a ship-launched version.
The AIM-174B is mechanically a RIM-174B, but air launched.

When there's a launcher change (first letter of the MDS designation), the suffix letter stays the same between all launch platforms.

Example: Harpoon missiles can be launched from aircraft (AGM), surface ships (RGM), submarines (UGM), and shore batteries (BGM). The -L variant is the Harpoon Block II, and is available in Air, Surface Ship, or Submarine launched variants. The AGM-84E/G SLAM and AGM-84H/K SLAM-ER are air launched only, so E, G, H, and K have been skipped for RGM/UGM/BGM-84s. Harpoon Block 1D was not available for submarine launch for whatever reason, so it was AGM-84F and RGM-84F only. ​

I think that the AiM-174 is a great idea. Taking an SM-2 Block IIIC and adding anything that the sm-6 has over the SM-2 Block IIIC (and structure modifications for Air Launch) is a good idea. Tought isn't Ursa working on an improved MK 104? Could make it even better

AIM-66M-6 would be interesting. Still a super heavy missile to carry around, but if the SM2 Block IIIC keeps the IR guidance from the Block III and AIM-7R it'd be wicked. It might, the IR seeker isn't in the nose.

Which makes one wonder if there is a bunch of empty space up front or if they repackaged it with new boards and a bigger array, more power, etc.

As I understand it, it's only the 13.5" antenna that is different between the SM6 and AMRAAM seekers.

 

[kqcke for you]

AIM-66M-6 would be interesting. Still a super heavy missile to carry around, but if the SM2 Block IIIC keeps the IR guidance from the Block III and AIM-7R it'd be wicked. It might, the IR seeker isn't in the nose.

This is my guess tought what i meant was that AIM-174 is just an modified SM-2 Block IIIC with all the stuff of sm-6 added (or to be more specific its an Air Launched SM-2 Block IIICU which will be an booster less sm-6 Block IAU). But it ain't have an IR seeker if i remember it right...

 

[TomS]

This is my guess tought what i meant was that AIM-174 is just an modified SM-2 Block IIIC with all the stuff of sm-6 added (or to be more specific its an Air Launched SM-2 Block IIICU which will be an booster less sm-6 Block IAU). But it ain't have an IR seeker if i remember it right...

What makes you think this? It seems far more likely that the AIM-174 is just what the designation says, an SM-6 upper stage adapted for air launch.

SM-2 Block IIIC is different, starting with having a different rocket motor designed with a boost phase that an air-launched missile does not need.

And we have no idea whether Block IIIC preserves the side IR seeker anyway. I suspect it does not, for basically the same reason that SM-6 lost the side IR seeker from Block IVA. It's not necessary once you have active radar.

 

[NMaude]

SM-2 Block IIIC is different, starting with having a different rocket motor designed with a boost phase that an air-launched missile does not need.

Wouldn't that boost phase burn give extra range for an air-launched version?

 

[TomS]

Wouldn't that boost phase burn give extra range for an air-launched version?

On rethinking this, you do need some boost phase still, to get the missile up to supersonic speed. But every bit of boost phase in the motor is less sustain time, and sustain is what translates into range.

 

[kqcke for you]

What makes you think this? It seems far more likely that the AIM-174 is just what the designation says, an SM-6 upper stage adapted for air launch.

Because to my knowledge the SM-6 upper stage is (more or less) the same as an Sm-2 Block IIIC(U). Or atleast to the SM-6 Block 1A from which the IIICU gets it GS EU and the new TDD.

SM-2 Block IIIC is different, starting with having a different rocket motor designed with a boost phase that an air-launched missile does not need.

Now here comes the big pie. Atleast to me both use the MK.104 DTRM and alteast i couldnt find an official source stating that the engine is any different which is why for Block IIIC they could easily exchange the guidance system and electronics. And at that point there the same (to my knowledge) except the SM-6 have some structure to have an booster (don't know if the Aim-174 still has it).

And we have no idea whether Block IIIC preserves the side IR seeker anyway.

We have as it IS an evolution of the Block III and IIIA not IIIB which got the SM-2 its IR seeker.

Edit: the PDF is for the evolution part.

 

[Scott Kenny]

We have as it IS an evolution of the Block III and IIIA not IIIB which got the SM-2 its IR seeker.

Edit: the PDF is for the evolution part.

Bugger. Having an IR seeker is nice for when some joker tries jamming the crap out of you with AESAs.

 

[kqcke for you]

weight 812 kg

MK.72 is only 1.72m long and sm-2 only 4.72m. ERAM is based on Wiki 6.6m long or around 4,87m. (Ignoring the smaller Numbers for the size for now).

 

[Josh_TN]

Did we ever get a final answer on the bring back weight per store the F-18 can manage?

Alternate question: I assume those weights and rules are relatively conservative - would a waiver be given for such ordnance being brought back in war time? I believe F-18E/F operate with a peacetime waiver for the centerline fuel tank as is. Would it be physically impossible to bring back 1850 lbs or just mildly dangerous? I would assume the failure mode still results in the aircraft stopping with mild pylon damage and the ordnance proceeding over the deck, which while sub optimal does not seem catastrophic.

 

[GeorgeA]

As a stopgap long-range missileer, there’s always the potential for something like this.

 

[TomS]

As a stopgap long-range missileer, there’s always the potential for something like this.

On what planet is a PowerPoint aircraft with a non-existent engine a "stopgap" solution to anything?

 

[GeorgeA]

Well I did say “something like this”, but that’s a bold statement. You’re 100% sure it’s vaporware? It suggests that AA, UA, Leonardo, Safran, Honeywell, Kratos, and Northrop Grumman are willfully misleading their investors.

 

[kqcke for you]

An interresting question would be if they could fold the control surfaces for internal weapons bay. Then the wingspan is reduced to something around 530mm

 

[Colonial-Marine]

Bugger. Having an IR seeker is nice for when some joker tries jamming the crap out of you with AESAs.

I wonder if the active radar seeker takes up physical space that would preclude an IR seeker like the SM-2MR Block IIIB had? They must be rather confident in the performance of the active radar seeker. I can't say I've ever seen a good picture of the protrusion for the IR seeker's lens on the Block IIIB.

 

[Josh_TN]

I wonder if the active radar seeker takes up physical space that would preclude an IR seeker like the SM-2MR Block IIIB had? They must be rather confident in the performance of the active radar seeker. I can't say I've ever seen a good picture of the protrusion for the IR seeker's lens on the Block IIIB.

It is rather obscure in terms of pictures. I could not find the original picture of it that I saw years ago but apparently TWZ did an article on this particular sub type.

Obscure 23-Year Old Navy SAM Was So Ahead Of Its Time That It's Still In High Demand Today

The SM-2 Block IIIB's dual-mode guidance system is still unique among the missiles the Navy's fleet uses to defend against aerial threats.

www.twz.com

In the future I suspect AESA antennas would allow for non standard antenna shapes that would allow for an EO or IR system right in the missile nose. It might not work as the primary guidance system but instead act as a check against the radar being decoyed in a very narrow field of view. My understanding is that the SM-2 Blk III B used its IR the same way - it was not a mechanism for guided the missile independently but a counter measure against jamming*.

EDIT: the article above claims that the IR can operate independently of the radar seeker, but that is the first time I've see it explicitly claimed. If nothing else I would expect its position on the missile to create blind spots, even the IR seeker was capable of locking on without any radar guidance. One wonders given modern technology if SM-6 or SM-2 blk IIIC does not have some kind of micro camera that fills a similar role of proof checking radar returns as an ECCM measure.

 

[TomS]

Well I did say “something like this”, but that’s a bold statement. You’re 100% sure it’s vaporware? It suggests that AA, UA, Leonardo, Safran, Honeywell, Kratos, and Northrop Grumman are willfully misleading their investors.

I'm not saying it isn't a sincere effort, but it does not yet exist in any tangible form. Developing it will be a full scale effort, not a stopgap. A stopgap is something would could field in the near future, which Boom is not.

 

[NMaude]

MK.72 is only 1.72m long

The Mk-72 booster is 68" long.

I wonder if the active radar seeker takes up physical space that would preclude an IR seeker like the SM-2MR Block IIIB had?

The IIR seeker could be put in the tip of the radome just like on the AIM-7R.

 

[GeorgeA]

I'm not saying it isn't a sincere effort, but it does not yet exist in any tangible form. Developing it will be a full scale effort, not a stopgap. A stopgap is something would could field in the near future, which Boom is not.

Poor choice of words on my part.

 

[Manuducati]

Did we ever get a final answer on the bring back weight per store the F-18 can manage?

Alternate question: I assume those weights and rules are relatively conservative - would a waiver be given for such ordnance being brought back in war time? I believe F-18E/F operate with a peacetime waiver for the centerline fuel tank as is. Would it be physically impossible to bring back 1850 lbs or just mildly dangerous? I would assume the failure mode still results in the aircraft stopping with mild pylon damage and the ordnance proceeding over the deck, which while sub optimal does not seem catastrophic.

No firm answer that I could find, but at least 1488lbs (SLAM-ER).