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

Well they have multiple weapons that can't be brought back. Why bother with those then?

I'm not saying AIM-174 @ 1890 lbs is definitely impossible to be brought back. But there is no evidence to suggest anything heavier than a Mk 83 has ever been brought back...

Eaton refueling pod.
 
Certainly less bulky.

But the plans in the 1980s involved Tomcats packing 4x Phoenix. And it's looking like Super Bugs can carry 4x SM6 with 2 or 3 fuel tanks.
Hum, no.

With a weight of nearly 1900 lb, the AIM-174 can only be carried on the inner and middle wings pylons. If four are carried then there is only room for a single external fuel tank (on the centerline). I do wonder how realistic a loadout of 4x AIM-174 is. The SH isnt exactly renowned for its long legs and with 4x AIM-174 on those silly canted out pylons, the drag penalty should be massive and significantly affect its range. My guess is that a balanced loadout of 2x AIM-174, 2x AIM-120, 2x AIM-9 plus a least one external fuel tank will probably be the norm but what do i know...
 
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Does the Super Hornet have conformal fuel-tanks it can mount?

No. The Navy considered them and decided they didn't offer enough advantage of over regular tanks. There were issues with carrier compatibility in particular, it seems.

 
Super Hornet with the AGM-158C LRASM achieved operational capability in late 2019. The Navy is also procuring the AGM-158B JASSM-ER for the Super Hornet. Both these cruise missiles weight about 2,500 lbs.
 
Super Hornet with the AGM-158C LRASM achieved operational capability in late 2019. The Navy is also procuring the AGM-158B JASSM-ER for the Super Hornet. Both these cruise missiles weight about 2,500 lbs.

I think only the -158C1 and -158C2 are purchased, but the C2 drops the RF guidance capability so is more or less a naval JASSM. Also it is not clear if these can be brought back.
 
You could take sizes and give a general estimation of performance as a percentage of size(?) if PL-17 size is known or could be estimated... I don't know if that could be any more accurate than the aim-174 range "estimations" where people are just doubling the surface launched range of the ERAM SM-6 though lol
For missiles going the other direction, from air launched at speed to ground launched, the rubric seems to be 1/3 the air launched range. It's been consistent across early Sea Sparrows (NOT ESSMs), Chaparrals, SLAMRAAMs, ASRAAMs, etc.

So comparing a surface launched missile with a large booster that burns for several seconds and the air launched range of the same missile without booster, doubling seems not-unreasonable. And if you could figure out a way to launch that whole 5000+lb stack with the booster on it, I would straight up triple the range from surface launched as my first guesstimate.
 
Does the Super Hornet have conformal fuel-tanks it can mount?
No, they block access to some of the avionics panels on top of the LERX and in the spine.


Hum, no.

With a weight of nearly 1900 lb, the AIM-174 can only be carried on the inner and middle wings pylons if you want to carry four. Which means there is only room for a single external fuel tank (on the centerline). I do wonder how realistic a loadout of 4x AIM-174 is. The SH isnt exactly renowned for its long legs and with 4x AIM-174 on those silly canted out pylons, the drag penalty should be massive and significantly affect its range. My guess is that a balanced loadout of 2x AIM-174, 2x AIM-120, 2x AIM-9 plus two or three fuel tanks will probably be the norm but what do i know...
See if I have the wing layout correct here:
Wingtip stations 1/11​
(wing fold)​
outer pylon stations 2/10​
mid pylon stations 3/9​
inner pylon stations 4/8​
intake conformal stations 5/7​
Centerline station 6?​

And:
Something I missed at first glance is this latest picture shows SM-6 mounted on stations 3 and 9, whereas in previous pictures the orange test round hung on 4 or 8.

Are stations 2 and 10 on a Super Bug not plumbed for tanks?

=================================


So does mean the Block-1B would look like the ESSM Block-I on steroids with the 13.5" seeker and warhead section mated to the 21" DTRM by a conical adapter section?
Not clear. Any slides I've seen have been 21" up all the way, but it would be easier to use the existing seeker and warhead sections. But now I'm only seeing SM3Blk2A in the 21" all the way shape...

A 21" body all the way up would make space for one hell of a radar in the nose, though. Fighter sized, almost. Can you imagine the trouble you could get into with a 21" diameter GaN radar? *evil grin*
 
A 21" body all the way up would make space for one hell of a radar in the nose, though.

Not just a bigger and much more capable radar-seeker (We're talking BOMARC territory here) but also able to carry a much larger warhead which would make it much more dangerous for its' secondary AShM and ASM missions.
 
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Not clear. Any slides I've seen have been 21" up all the way, but it would be easier to use the existing seeker and warhead sections. But now I'm only seeing SM3Blk2A in the 21" all the way shape...

SM-6 Block Ib necks down to 13.5 inches. Google inexplicably throws up SM-3 images if you search for SM-6.

But here is the slide that shows it. It also shows Block 1b as exclusively ASuW, which does not seem to be true anymore, as we have seen docs mention how the new motor improves AAW range.

208984-c2f584176a778b2f7cc9073fe2400be4.png

I've also seen budget docs describing Block 1B as the front section of the existing SM-6 mated to a new 21-inch motor. Can't track them down this morning, of course.
 
Aside from low-res renders, I don't think I've seen any pictures of SM-6 Block 1B, not even of maquettes for arms shows.

True. It's being kept very quiet.

One interesting thing to me is that the low-res renders we do have are consistently grey, unlike all the other white Standards. Wonder if that is accurate, and if so, if it is a thermal management issue or something else.
 
Are stations 2 and 10 on a Super Bug not plumbed for tanks?
No. 2 and 10 would be overloaded by a full 480gal tank anyway.
Not clear. Any slides I've seen have been 21" up all the way, but it would be easier to use the existing seeker and warhead sections. But now I'm only seeing SM3Blk2A in the 21" all the way shape...

A 21" body all the way up would make space for one hell of a radar in the nose, though. Fighter sized, almost. Can you imagine the trouble you could get into with a 21" diameter GaN radar? *evil grin*
Cost would get out of control, and other than the seeker it would be mostly empty space. The full-phallic SM-3 makes sense because it allows a larger upper stage, but SM-6 is just warhead, seeker, and brains above the motor. They could develop all new guidance hardware and maybe a pancake warhead to cram in a little mores motor length, and still may in the future. But for now 1B is keeping as much 1A as it can.
 
Not just a bigger and much more capable radar-seeker (We're talking BOMARC territory here) but also able to carry a much larger warhead which would make it much more dangerous for its' secondary AShM and ASM missions.

Actually most of the slides I’ve seen seem to emphasize it is an AShM first that might also have AA/ABM ability…
 
can the terminal radar seeker of AIM-174B acquire a ship in anti surface mode?. Or will it fly purely based on datalink and GPS in that case?
Can F-18 guide AIM-174 directly with datalink or does it have to send back data to the ship then the ship will guide the missile?
 
can the terminal radar seeker of AIM-174B acquire a ship in anti surface mode?. Or will it fly purely based on datalink and GPS in that case?
Can F-18 guide AIM-174 directly with datalink or does it have to send back data to the ship then the ship will guide the missile?
SM-6 can and it is its normal capability.
So comparing a surface launched missile with a large booster that burns for several seconds and the air launched range of the same missile without booster, doubling seems not-unreasonable.
1/3(or less, there is also optimization going both ways here) is reasonable for boosterless weapons.

Booster, especially one as huge as sm-6 one, throws second stage to launch parameters that even mig-31 will not match . Much less a hornet(which with this load is probably subsonic)
 
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can the terminal radar seeker of AIM-174B acquire a ship in anti surface mode?. Or will it fly purely based on datalink and GPS in that case?
Can F-18 guide AIM-174 directly with datalink or does it have to send back data to the ship then the ship will guide the missile?

We really don't have details, likely intentionally. That said, DOT&E says SM-6 relies on the active seeker or shipboard illuminators for terminal engagement. No mention of GPS only.
 
SM-6 definitely uses its radar for OTH ship targets. Whether an F-18 can fire the AIM-174 in such a mode is an open question. It also is not clear to what extent the AIM retains the SM-6 capabilities, but if the electronics are equivalent then it should be able to be guided by the larger NIFCA infrastructure, which would offboard guidance from the F-18. It is possible that AIM-174 has simplified guidance modes, but on the other hand given its potential range it seems like it would need to leverage off board targeting to reach its full potential. Indeed, that feature is one of the things that make its adoption as an air launched long range AA missile so advantageous.
 
SM-6 Block Ib necks down to 13.5 inches. Google inexplicably throws up SM-3 images if you search for SM-6.

But here is the slide that shows it. It also shows Block 1b as exclusively ASuW, which does not seem to be true anymore, as we have seen docs mention how the new motor improves AAW range.
There was also a document referencing ABM capability testing.

BINGO, found it:
1720535259744.png
 
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The SM-6 Block 1B motor prototyping contract is N689362090008 , awarded to Aerojet Rocketdyne on 6/29/2020 . The BAA, N00024-20-R-5402 has an informative description:

The Naval Sea Systems Command plans to issue a Broad Agency Announcement (BAA), as contemplated in FAR 35.016, to solicit for innovative approaches to rapidly prototype and demonstrate technologies for solid propellant rocket motors. The Navy’s primary propulsion interests are the application of Highly Loaded Grain (HLG) and associated Electronic Ignition Safety Device (EISD) technologies to address tactical performance requirements for a new missile variant in the Standard Missile family. Government prototypes have been demonstrated with the intent to use them as point-of-departure to offeror designs.

A separarte effort was awarded to General Dynamics-OTS, Inc. in 2019 as N6893619C0073 for 21-inch extended range motors.
 
There was also a document referencing ABM capability testing.

BINGO, found it:
View attachment 734159
Nice Find!


1/3(or less, there is also optimization going both ways here) is reasonable for boosterless weapons.

Booster, especially one as huge as sm-6 one, throws second stage to launch parameters that even mig-31 will not match . Much less a hornet(which with this load is probably subsonic)
What altitude does the Mk72 booster burn out at, though? I'm under the impression that it only burns for ~5-10 seconds, so while it might get the missile up to mach 1+ it's not out of the thick part of the atmosphere where all the drag is. While an air launch at subsonic speeds from 33,000ft/10km gets the missile above most of the atmosphere so it deals with far less drag.

Which would give a subsonic air launched SM6 better range because the missile doesn't have to burn any range to overcome drag.

Although even if we're talking a 500km range air launched, that's ~20% over what is being talked about for AIM260 (200nmi).


No. 2 and 10 would be overloaded by a full 480gal tank anyway.
Bugger.

Okay, Super Bugs are down to 2x 480gal, 2x SM6, 4x AMRAAM, and 2x AIM9s for the "waiting for the party to start" loadout. I'd bet that the deck ready-5 birds could have 4x SM6 at the cost of no external tanks or just the belly tank (and letting the airborne Super Bugs with Legion pods on the centerline give IRST data to the ready-5s).

I hope the USAF is looking at buying a few SM6s. Eagle 2s can carry 6 in the "feck you and all your friends" loadout, while still packing up to 8x AMRAAMs (or 4x AMRAAMs and 4x AIM9s). Though I realize this would be competing with the LREW project. Waitaminnit. LREW was a Raytheon project, right? SM6 is a Raytheon project.


Cost would get out of control, and other than the seeker it would be mostly empty space. The full-phallic SM-3 makes sense because it allows a larger upper stage, but SM-6 is just warhead, seeker, and brains above the motor. They could develop all new guidance hardware and maybe a pancake warhead to cram in a little mores motor length, and still may in the future. But for now 1B is keeping as much 1A as it can.
I mean, the SM6 took the AIM-120 seeker and gave it a 13.5" radar. As far as I know, the seeker brains are still a 7" diameter box. Adding a 21" radar antenna would give roughly 2.4x radar range (and 2.4x more TRMs to the antenna, so obviously 2.4x more $$ there).

And if Block 1B is really intended mostly as a ballistic/hypersonic missile, stuffing a bigger warhead inside is a good idea. Or even just a warhead with more fragmentation to work with on the same bursting charge. 140lbs of boom is pretty wimpy for an AShM, but it does compare nicely to 16" HE.
 
The remarks are slightly worrying: BTW, we accidentally put $100.1Bn in the wrong account.
Some accounting clerk typo'd. Hopefully someone caught it relatively quickly, before a large chunk of money was spent.

I had some accounting clerk stop a third of my pay because I had less than 4 years time in service, even though I was an E5. Caused me a LOT of trouble.
 
I'm not sure if these are to the correct scale as shown in these photos, but here's an image from Instagram comparing the AIM-174 to the AIM-120 and AIM-9X:
View attachment 734178
Note that the length given (21.5 feet) is actually the missile and booster combined. The actual length without the Mark 72 booster is around 15.5 feet.
The missile alone doesn't have a 21" diameter either, just the booster does. And that weight would also be for the full RIM-174 with the booster as well.
 
Nice Find!



What altitude does the Mk72 booster burn out at, though? I'm under the impression that it only burns for ~5-10 seconds, so while it might get the missile up to mach 1+ it's not out of the thick part of the atmosphere where all the drag is. While an air launch at subsonic speeds from 33,000ft/10km gets the missile above most of the atmosphere so it deals with far less drag.

Which would give a subsonic air launched SM6 better range because the missile doesn't have to burn any range to overcome drag.

Although even if we're talking a 500km range air launched, that's ~20% over what is being talked about for AIM260 (200nmi).



Bugger.

Okay, Super Bugs are down to 2x 480gal, 2x SM6, 4x AMRAAM, and 2x AIM9s for the "waiting for the party to start" loadout. I'd bet that the deck ready-5 birds could have 4x SM6 at the cost of no external tanks or just the belly tank (and letting the airborne Super Bugs with Legion pods on the centerline give IRST data to the ready-5s).

I hope the USAF is looking at buying a few SM6s. Eagle 2s can carry 6 in the "feck you and all your friends" loadout, while still packing up to 8x AMRAAMs (or 4x AMRAAMs and 4x AIM9s). Though I realize this would be competing with the LREW project. Waitaminnit. LREW was a Raytheon project, right? SM6 is a Raytheon project.



I mean, the SM6 took the AIM-120 seeker and gave it a 13.5" radar. As far as I know, the seeker brains are still a 7" diameter box. Adding a 21" radar antenna would give roughly 2.4x radar range (and 2.4x more TRMs to the antenna, so obviously 2.4x more $$ there).

And if Block 1B is really intended mostly as a ballistic/hypersonic missile, stuffing a bigger warhead inside is a good idea. Or even just a warhead with more fragmentation to work with on the same bursting charge. 140lbs of boom is pretty wimpy for an AShM, but it does compare nicely to 16" HE.

Re: Mk72 - I saw slide that indicated separation at 1800 feet, but was never able to confirm. I think it is a very fast burn though. I assume since it has 450 kg of fuel, the stack is moving *very* fast at separation, even if it is still in thick air.

F-18: Definitely only the four inner stations. The next pair is not plumbed and only rated for 1000 lbs. Centerline might be possible weight wise, but I think unlikely to be safe for landing, or even launching. So probably four max, two with drop tanks more practical. I would think these weapons would be primarily to kill opponent ISR platforms at long range, or else break up a formation of bombers or fighters before engaging with AIM-120.

F-15EX: not sure where you fit all the missiles you are talking about. I think the inner wing and center line stations could all host one, and perhaps two more on the fuselage stations. Not sure what the ejector requirements are but there would be enough clearance and weight capacity for that. I doubt any other positions are possible.

AFAIK SM-6 blk1B still uses the 1A front end. Adding a bigger antenna to the old AIM-120 guidance system seems like diminishing returns on investment. Either design a new AESA seeker or use what's on the shelf.
 
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Mk72 gets the stack to around Mach1, based on unclassified SM-3 performance. That's quite good, but it's not nearly a match for dropping the weapon slightly slower at 30,000ft.

I am surprised it is that slow, given the fuel involved. But I agree that air launch at altitude and high subsonic is going to be quite superior.
 
SM-6 can and it is its normal capability.
How do you know SM-6 terminal seeker can acquire a ship though? I don’t think there is available document mention that?, may be it use the same anti surface mode as SM-2 which require terminal illumination by CW radar
 
How do you know SM-6 terminal seeker can acquire a ship though? I don’t think there is available document mention that?, may be it use the same anti surface mode as SM-2 which require terminal illumination by CW radar

They have certainly implied that the terminal seeker can gather the target, though I cannot quickly find an article that states so. The max range of a SARH guided missile to the horizon is probably 30nm on a good day.

"“We are going to create a brand-new capability,” Carter told reporters in San Diego on Wednesday. “We’re modifying the SM-6 so that in addition to missile defense, it can also target enemy ships at sea at very long ranges.”
The modification – part of a $2.9 billion missile purchase over the next five years – will give the Navy’s fleet of guided missile cruisers and destroyers a Mach 3.5 supersonic weapon with a range of more than 200 nautical miles."

 
F-15EX: not sure where you fit all the missiles you are talking about. I think the inner wing and center line stations could all host one, and perhaps two more on the fuselage stations. Not sure what the ejector requirements are but there would be enough clearance and weight capacity for that. I doubt any other positions are possible.
One on each wing, two on each CFT inner pylon (front and back).There's space and weight capacity for them. Might get a bit odd on the angles, the aft racks are pointed pretty nose-down while on the ground but they put 2000lb bombs back there. A GBU31 JDAM is 3.9m long, so leaving the center rack empty on the CFTs leaves clearance between the two SM6s.

And that means you have CFTs for range.


AFAIK SM-6 blk1B still uses the 1A front end. Adding a bigger antenna to the old AIM-120 guidance system seems like diminishing returns on investment. Either design a new AESA seeker or use what's on the shelf.
They already went from a 7" antenna to a 13.5" antenna when they stuck the AIM120 seeker into the Standard, more than tripling the antenna area compared to baseline AMRAAM. If the seeker could handle going up to 21" I'd be surprised, that's 8.25x the antenna area. But if it can handle that many TRMs...
 
The Navy’s primary propulsion interests are the application of Highly Loaded Grain

What do they mean by highly loaded grain?

I'm under the impression that it only burns for ~5-10 seconds

IIRC (It was stated in a post in the Standard Missile thread) that the Mk-72 has a six second burn time.

and 2.4x more TRMs to the antenna, so obviously 2.4x more $$ there

TRM?

that's 8.25x the antenna area. But if it can handle that many TRMs..

An antenna sized for a 21" diameter missile would have a significantly higher power-gain than one sized for a 13.5" diameter missile.
 
What do they mean by highly loaded grain?


Corvid Technologies, in partnership with Aerojet-Rocketdyne, proposes the development of a highly loaded grain (HLG) rocket motor that will exceed the total impulse of the current baseline motor by a minimum of 20%. To achieve this, Corvid will first define a baseline rocket motor that is consistent with current available technologies. Next, Corvid will develop an advanced nozzle concept to improve efficiency throughout the flight profile and allow the propellant combustion chamber to be expanded. Corvid will then develop an innovative three-dimensional, functionally-graded propellant grain for the HLG rocket motor, leveraging high burn-rate, high specific-impulse propellants to achieve the desired burn-rate and surface regression profile while maximizing propellant mass within the grain.

 
Doublers to keep it from bending.

I'm not so sure about that, if you look at the whole missile they extend the whole length of the rocket-motor but instead cluster around where the missile is attached to the pylon's ejector unit so I'm thinking that maybe those bands are there to mounted launch lugs so it can be mounted on an ejector unit.
 
I'm not so sure about that, if you look at the whole missile they extend the whole length of the rocket-motor but instead cluster around where the missile is attached to the pylon's ejector unit so I'm thinking that maybe those bands are there to mounted launch lugs so it can be mounted on an ejector unit.
When the missile is trying to pull itself off the pylon where's it going to bend?
 
IIRC (It was stated in a post in the Standard Missile thread) that the Mk-72 has a six second burn time.
Thank you!

Transmit-Receive Module. The building block of an AESA.


An antenna sized for a 21" diameter missile would have a significantly higher power-gain than one sized for a 13.5" diameter missile.
It would. That's why it'd be a question of the seeker head can handle the increased gain.

Though I suppose someone will have to request a new, heavier warhead, probably for better antiship effects, before anyone thinks about increasing the size of the antenna. If they kept the warhead the same length, it'd be 2.4x heavier. 336lb warhead, probably blast-frag. No, that'd really reduce range and probably terminal speed. Bugger. I can't imagine anyone enlarging a missile diameter like that without doing something with the warhead, though. Leaving a 13.5" warhead in the middle of a 21" tube would drive everyone insane.
 

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