US Navy 6th Gen Fighter - F/A-XX

[Josh_TN]

Two ocean wars, they've happened before.

Are you suggesting the EU would pick a fight with the U.S. or host Chinese forces?

 

[DWG]

Are you suggesting the EU would pick a fight with the U.S. or host Chinese forces?

No, I'm suggesting Russia might pick a fight with NATO if it thinks the US is distracted. Or all kinds of theatre-level issues might kick-off for similar reasons. And the local carrier group is the US's favourite tool for getting involved.

 

[Josh_TN]

No, I'm suggesting Russia might pick a fight with NATO if it thinks the US is distracted. Or all kinds of theatre-level issues might kick-off for similar reasons. And the local carrier group is the US's favourite tool for getting involved.

What Russian threat would F-47/FA-XX address?

 

[EmoBirb]

Who is going to bother CSGs in the Ned, IO, and Atlantic?

Regardless, the need for the FA-XX is for strike more than air defense, and axing the program will do nothing to advance the U.S. ship building industry.

Pakistan, one of the closest allies of China, has direct access to the Arabian Sea and from there to the Indian Ocean. Fielding 5 French made SSKs and having ordered 8 SSKs from China. They also have 4 Type 054A export variants and export versions of the Type 053, I can't remember how many however (also the planned Jinnah frigates are worth considering)

Russia, as much an ally of China as simply also having the US as a mutual enemy and threat, is active in the Atlantic and Pacific, as well as occasionally active in the Mediterranean Sea. The Russians are aware that kneecapping the US only has advantages for them, so at the very least they'd show presence and put Western Europe under uncomfortable pressure while the US is completely distracted by a war where they're at a disadvantage. Certainly, Yasen-Ms (3 in the Northern and 3 in the Pacific Fleet as of 2025) are not the company you want to have when operating in the Atlantic or Pacific, neither are Belgorod and Khabarovsk.

In the theoretical of a Sino-American War you'd see plenty of powder kegs in the Middle East and Europe erupting again as the US presence decreases due to the material and personnel demands of such a war. Especially when things like DDGs and CVNs get sunk you'll have to pull units from elsewhere to fill the gap again. And with China being the de-facto leader of an entire bloc of countries that view the US and their allies not particularly favorable and the overarching reach of the Chinese economic soft power, you wouldn't be short on regional allies and guerrillas in other regions of the world outside of the Western Pacific. Think USVs and drones harassing shipments of US goods leaving or entering Europe or Gulf States.

 

[Josh_TN]

Do any of the countries you mentioned represent a credible air threat to USN surface forces currently, in your opinion?

 

[insidersource]

I expect though there is enough other work needed for F/A-XX, including funding the derivative engine, that 750 million still isn't enough post contract award.

$750 million is easily enough to cover the engineering of the wing folding mechanism and carrier specific parts of a F-47 derivative for the Navy.

Boeing can only spend so much money.

 

[insidersource]

I have a mild sneaking suspicion that, while we may dislike the idea, that Boeing may be offering the F-47 for this job too. If the design evolution stuff or whatever its called is true, we may very well get a plug and play platform with a core component and swappable engines, landing gear, weapons bays, cockpits, and maybe even more we haven't taken seriously like DEW integration in future models. It sounds far-fetched but who knows.

I don't see why anything needs to be plug and play. Both USAF and US Navy requirements are pretty much identical. The Rafale provides the perfect example with extremely high commonality between the Navy and Air Force version. The only person who thinks the F/A-XX needs an extremely large weapon bay is a single member on this forum. The oversized standoff missiles can be carried on the MQ-25.

Boeing is smart enough to design the F-47 with a landing speed slow enough to make it carrier capable. It explains the visible canards.

 

[Training_Dummy]

It has been reported here in this forum several times that Boeing built the USN demonstrator, so asking what it would take to navalize the F-47 doesn’t appear to be a crazy speculative question.

 

[Ozair]

$750 million is easily enough to cover the engineering of the wing folding mechanism and carrier specific parts of a F-47 derivative for the Navy.

Boeing can only spend so much money.

I expect 750 million is nowhere near enough for both of those things, likely five to ten times not enough. Even though the F-35A and C share a common engine, radar, avionics etc there is no way it cost only $750 million to develop the extra bits the Cee needed over the A or B.

I don't see why anything needs to be plug and play. Both USAF and US Navy requirements are pretty much identical. The Rafale provides the perfect example with extremely high commonality between the Navy and Air Force version.

The Rafale is not a 6th gen fighter jet. The F-35 is a much better comparison and the costs to develop the Cee are not insignificant.

The only person who thinks the F/A-XX needs an extremely large weapon bay is a single member on this forum. The oversized standoff missiles can be carried on the MQ-25.

While I don't think the F/A-XX will need to carry as many of those weapons internally as suggested planning on the MQ-25 doing that is flawed. Even though the USN wants the unmanned to manned mix to be 40/60 % there will not be enough MQ-25s to fulfil that role.

Boeing is smart enough to design the F-47 with a landing speed slow enough to make it carrier capable. It explains the visible canards.

There is no indication the F-47 has canards. Hasn't it been stated that the visuals are just artists impressions?

 

[EmoBirb]

Do any of the countries you mentioned represent a credible air threat to USN surface forces currently, in your opinion?

Nope (at most Tu-22M3s with AShMs in low level flight but that's kind iffy if we're honest). But the US uses their carrier groups as tools of power projection, they signify US presence and are utilized like that. US presence is where these carriers are and where these carriers are, are also their planes.

So I can definitely understand the argument of calling into question how 200 something (at the very max) F-47s tied up in the WESTPAC would have the Navy at ease with regards to their other remaining assets around the world.

Either way however, I think we all (DWG, you and me) should let this bit rest and come back to the actual topic.

 

[Josh_TN]

It has been reported here in this forum several times that Boeing built the USN demonstrator, so asking what it would take to navalize the F-47 doesn’t appear to be a crazy speculative question.

While I could see both machines having a similar airframe layout (delta/lambda wit canards, the other requirements are far off: I expect USAF wanted just 6-8 AAMs while USN wants a strike fighter, perhaps 4x JSOW/AARGM-ER/MACE/Mk83 (or even mk84. The powerplant is also going to be different (no adaptive engines for USN).

While the Boeing FA-XX submission might look visually similar I would be surprised if the internals were related outside avionics.

 

[Josh_TN]

Nope (at most Tu-22M3s with AShMs in low level flight but that's kind iffy if we're honest). But the US uses their carrier groups as tools of power projection, they signify US presence and are utilized like that. US presence is where these carriers are and where these carriers are, are also their planes.

So I can definitely understand the argument of calling into question how 200 something (at the very max) F-47s tied up in the WESTPAC would have the Navy at ease with regards to their other remaining assets around the world.

Either way however, I think we all (DWG, you and me) should let this bit rest and come back to the actual topic.

I cannot imagine anyone but China posing a serious air threat to a current CVW. My point is less about the F-47 - there is no way the USN would assume any of these would fly defensively for their formations - and more that the USN specifically wants a strike fighter. Neither land based nor carrier based F-47 is likely to address that issue.

 

[FighterJock]

While I still like NorthropGrumman to win, chances are it will be Boeing that wins the F/A-XX competition due to the fact that they won the NGAD now F-47.

 

[Training_Dummy]

While I could see both machines having a similar airframe layout (delta/lambda wit canards, the other requirements are far off: I expect USAF wanted just 6-8 AAMs while USN wants a strike fighter, perhaps 4x JSOW/AARGM-ER/MACE/Mk83 (or even mk84. The powerplant is also going to be different (no adaptive engines for USN).

While the Boeing FA-XX submission might look visually similar I would be surprised if the internals were related outside avionics.

A silver lining of the current XA102/103 timelines means that like F/A-XX, F-47 will fly - at least initially - with a non adaptive engine, so at least that isn’t a massive issue.

 

[Scott Kenny]

Both USAF and US Navy requirements are pretty much identical.

No, they are NOT.

The USAF is unlikely to have specified a weapons bay deep enough for even a 2000lb weapon or B61 nuke, because they want an Air Dominance fighter.

The USN is likely to have specified a weapons bay able to carry at least 2x AGM-158s and quite possibly 4x. Because the USN wants a strike fighter that can fly BARCAP.

The Rafale provides the perfect example with extremely high commonality between the Navy and Air Force version. The only person who thinks the F/A-XX needs an extremely large weapon bay is a single member on this forum. The oversized standoff missiles can be carried on the MQ-25.

The reason I'm pushing the large bays for F/A-XX is because I'm assuming that it's got the same core weapons requirement as the old ATA and A/F-X. ATA required 2x bays, each capable of holding 1x AGM-84 and 1x GBU-15; and I just updated the weapons to current equivalents. The AGM-84 replacement is either the NSM/JSM or AGM-158, and the GBU-15 replacement is the JDAM-ER.

Bays sized to hold AGM-158s will also hold AIM-174s.

 

[insidersource]

No, they are NOT.

The USAF is unlikely to have specified a weapons bay deep enough for even a 2000lb weapon or B61 nuke, because they want an Air Dominance fighter.

That is your opinion. The aircraft can have the exact design and exterior shape. The US Navy version can simply trades internal fuel capacity for a larger and deeper weapon bay. It is actually the USAF version that needs the greater internal fuel capacity due to the mission profile having a significant supercruise segment.

The F-22 has a big drop in combat radius when it adds a small 100nm supercruise segment to the flight profile. I could see the USAF NGAD requirement having a 200nm supercruise segment.

The Super Hornet and F-35C mission profiles are entirely subsonic. The F/A-XX engines can be set to their most efficient setting and cruise at subsonic speeds. It can then fly long range while having a bigger weapons bay and less fuel than the USAF version.

The USN is likely to have specified a weapons bay able to carry at least 2x AGM-158s and quite possibly 4x. Because the USN wants a strike fighter that can fly BARCAP.

All of the reports from the last 6 months points to the MQ-25 taking over the role of being a standoff missile launcher. The recent budget shows billions allocated by both the USAF and USN for a standoff strike platform. The money is seperate to the NGAD and F/A-XX funding. This unknown platform could be an improved MQ-25 or something entirely new. This means the Navy doesn’t plan to use the F/A-XX as a standoff cruise missile carrier. No big weapon bays needed.

Bays sized to hold AGM-158s will also hold AIM-174s.

A 6th gen, stealthy and fast platform doesn't need ultra long range missiles. The AIM-174 appears to be nothing more than a stop gap solution for the slow Super Hornets.

 

[Scott Kenny]

That is your opinion. The aircraft can have the exact design and exterior shape. The US Navy version can simply trades internal fuel capacity for a larger and deeper weapon bay. It is actually the USAF version that needs the greater internal fuel capacity due to the mission profile having a significant supercruise segment.

That same-OML plan only works when the thing on the back side of the weapons bays isn't the inlets. Which is most certainly not the case for the F-22 or F-35.

Running numbers from carrier landing limits to come up with planned empty weight and then doubling empty weight to get MTOW, the FAXX would not be unreasonable as a ~40,000lb empty/80,000lb MTOW aircraft with 28,000lbs of fuel onboard.

All of the reports from the last 6 months points to the MQ-25 taking over the role of being a standoff missile launcher. The recent budget shows billions allocated by both the USAF and USN for a standoff strike platform. The money is seperate to the NGAD and F/A-XX funding. This unknown platform could be an improved MQ-25 or something entirely new.

Last I heard, MQ-25 only has 2 weapons stations.

This means the Navy doesn’t plan to use the F/A-XX as a standoff cruise missile carrier. No big weapon bays needed.

It's a strike fighter. It needs space for things like AARGM-ER. Which are just as wide as AGM-158 at ~25".

NSM is huge, it's 28" wide when packed. Fortunately, that seems to be surface-launched only.

JSM is better, it's 19" wide and 20" tall. Only 13ft long, so you don't need to stretch the weapons bay's length.

So, when your basic standoff weapons that the mission was written around are now some 20-28" wide FOLDED, well, it kinda defines your bay sizes.

As to bay length, it would be foolish to not make FAXX bays 16+ft long so that they could pack AIM174s internally, so that any weapon that can fit on the carrier weapons elevators can be carried.

Picture the weapons bay and inlets section of the F-22. The main bays are 14ft long, side bays less than 12ft long. You know what happens when you stretch the entire weapons bay section 2 feet? Your main bays are now 16ft long and the side bay is long enough to hold AMRAAMs.

A 6th gen, stealthy and fast platform doesn't need ultra long range missiles. The AIM-174 appears to be nothing more than a stop gap solution for the slow Super Hornets.

I'm not willing to accept that as given, yet.

 

[NMaude]

It needs space for things like AARGM-ER. Which are just as wide as AGM-158 at ~25".

Is the AGM-88G's strake-span 25"?

 

[insidersource]

That same-OML plan only works when the thing on the back side of the weapons bays isn't the inlets. Which is most certainly not the case for the F-22 or F-35.

That is so easily solved. Space the engines slightly further apart like the Su-57 or YF-23. The middle part of the central weapon bay can then be as long and deep as you like.

A potential loadout could then be 2 AIM-260 under the left inlet, two larger JASSM or AGM-88G sized missiles in the middle of the weapon bay and another 2 AIM-260 under the right inlet.

The best way to add the extra fuel for the USAF version would be to have a semi-permanent conformal style fuel tank that mounts entirely inside the weapon bay. The conformal tank can then have four additional recessed AIM-260 pylons and these missiles are also hidden when the weapon bay doors are shut. The USAF version then can carry 8 AIM-260.

Once the air dominance mission is covered I expect the USAF to continue purchasing the F-47. It could take orders away from the F-35A and also replace the F-15E fleet in the long run. So the USAF can use the deep central weapon bags to carry larger munitions.

Last I heard, MQ-25 only has 2 weapons stations.

Boeing has already displayed a version with 4 pylons and also a USAF version without folding wingtips and 40% more fuel capacity. Boeing will just evolve the design and add capability with each block. The MQ-25 with the long wing and high endurance makes it perfect for many roles. It just needs the software to be written.

As to bay length, it would be foolish to not make FAXX bays 16+ft long so that they could pack AIM174s internally, so that any weapon that can fit on the carrier weapons elevators can be carried.

The AIM-174 has a wingspan of 1.57 metres. To put it into perspective 6 AMRAAM missiles on a rotary launcher could fit in the same space as a single AIM-174. Two JASSM missiles one on top of each other in the same depth as a single AIM-174.

With AIM-120D and AIM-260 having a range over 100nm there will be little reason to have a ultra long range missile. Stealth versus stealth will see targets detected at closer range.

The patriot missile family is far more suitable for internal carriage of a stealth fighter. It does away with the huge fins and uses solid rocket motors in the nose to hit targets. An air-to-air missile could easily be developed with more range than the AIM-174 while fitting in the much smaller footprint of AGM-88G.

 

[allendoc]

Regurgitation of other articles.
https://nationalsecurityjournal.org/f-a-xx-the-ghost-fighter-of-the-us-navy/
But I like the end quote but the author, Dr. Andrew Latham "Bottom line: We must have a bold vision of the future through the F/A-XX and not be afraid to realize that vision. The future of naval aviation — and, in fact, the future of American military power — depends on it.

If we let the F/A-XX slip away, we won’t be playing catch-up — we’ll be left behind in a world where the skies over it are not ours and the seas no longer ours to command.

The time to act is now."

 

[RegularGuy12]

https://breakingdefense.com/2025/07...-fighter-in-its-annual-wishlist-to-lawmakers/

 

[Josh_TN]

No, they are NOT.

The USAF is unlikely to have specified a weapons bay deep enough for even a 2000lb weapon or B61 nuke, because they want an Air Dominance fighter.

The USN is likely to have specified a weapons bay able to carry at least 2x AGM-158s and quite possibly 4x. Because the USN wants a strike fighter that can fly BARCAP.




The reason I'm pushing the large bays for F/A-XX is because I'm assuming that it's got the same core weapons requirement as the old ATA and A/F-X. ATA required 2x bays, each capable of holding 1x AGM-84 and 1x GBU-15; and I just updated the weapons to current equivalents. The AGM-84 replacement is either the NSM/JSM or AGM-158, and the GBU-15 replacement is the JDAM-ER.

Bays sized to hold AGM-158s will also hold AIM-174s.

Why would AGM-158 be the requirement? There is no shortage of much smaller stand off weapons on the market and USN purchases are something like 300-400 AFAIk. It isn’t a weapon you build an aircraft around.

I would assume mk84 or similar 2000# penetrators at the top end.

 

[Jimmo952]

The Navy hasn't given up on FA XX just yet. Still trying to get it funded.

https://breakingdefense.com/2025/07...-fighter-in-its-annual-wishlist-to-lawmakers/

 

[DWG]

It's a strike fighter. It needs space for things like AARGM-ER. Which are just as wide as AGM-158 at ~25".

Or perhaps more particularly, the AARGM-ER derived Stand-in Attack Weapon, with its bigger target set, which is sized to fit F-35 bays.

 

[NMaude]

So you think unescorted Tu-22s are a threat in the med or North Atlantic in this day and age?

Tu-22M Backfiress (Specifically the Tu-22M3) are currently in service not the Tu-22, the Tu-22 Blinders were retired in 1991 when the USSR collapsed.

 

[Scott Kenny]

Is the AGM-88G's strake-span 25"?

Looks like. I haven't found a reference so I've had to eyeball it. Strakes appear to be half the diameter of the weapon on each side, so at least ~23" give or take.

The AIM-174 has a wingspan of 1.57 metres. To put it into perspective 6 AMRAAM missiles on a rotary launcher could fit in the same space as a single AIM-174. Two JASSM missiles one on top of each other in the same depth as a single AIM-174.

The AIM-174 also has the same folding wings as the surface launched SM6. SM6 pack into a 21" square box, therefore AIM-174 does as well.

Or perhaps more particularly, the AARGM-ER derived Stand-in Attack Weapon, with its bigger target set, which is sized to fit F-35 bays.

IIRC, still ~25" wide across the strakes.

 

[Scott Kenny]

Why would AGM-158 be the requirement? There is no shortage of much smaller stand off weapons on the market and USN purchases are something like 300-400 AFAIk. It isn’t a weapon you build an aircraft around.

I would assume mk84 or similar 2000# penetrators at the top end.

JSM is still 19"x20", while AGM-158s are 25"x18".

AARGM-ER is on the order of 25" wide across the strakes, and I expect SiAW to be comparable in size.

And of course AIM-174s are 21" square (with fins folded) and 15.5ft long.

Whatever the Naval air-launched hypersonic happens to be is likely to be about the size of the old ASALM, ~25" wide and 18" deep.

So you think unescorted Tu-22s are a threat in the med or North Atlantic in this day and age?

Do you think they aren't?

 

[Josh_TN]

Do you think they aren't?

In their current strength, not especially. There were around 60 pre war, but at least seven of those appear to be non operational and there have been about a dozen casualties. I think Russia would struggle to put a regiment together and think they would be slaughtered before they could fine a target, especially if AIM-174 and AIM-260 were in play. FA-XX need not apply. What the USN really needs/wants is increased strike capability. I expect the new jet would not only have a lot of internal capacity but a lot of optional/ejectable external hard points as well.

 

[Nx4eu]

Tu-22M3 looks at you in disbelief

I'm pretty sure he was saying that the backfires were still in service not the blinders which were retired in 1991. Pointing out to the original comment by Josh_TN that Tu-22's and Tu-22M's are not the same and they should be designated as such.

 

[NMaude]

Tu-22M3 looks at you in disbelief

If you'd been paying attention to my post you'd see that I mentioned that the Tu-22 Blinders (NOT the Tu-22M Backfires) were retired in 1991. I edited my previous post as I wasn't clear in what I was trying to say.

From the Tu-22M wikipedia article:

The Tu-22M designation was used to help get approval for the bomber within the Soviet military and government system.[11]

The Tu-22M designation was used by the Soviet Union during the SALT II arms control negotiations, creating the impression that it was a modification of the Tu-22. Some suggested that the designation was deliberately deceptive, and intended to hide the Tu-22M's performance. Other sources suggest the "deception" was internal to make it easier to get budgets approved. According to some sources, the Backfire-B/C production variants were believed to be designated Tu-26 by Russia, although this is disputed by many others. The US State and Defense Departments have used the Tu-22M designation for the Backfire.[12]

So properly speaking it would appear that the Tu-22M should be designated the Tu-26, it would certainly save a lot of confusion.

Edit: Although the Tu-22 is long retired in Russia apparently the Russian airforce still has ten Tu-22 airframes in its' reserve fleet that can be reactivated.

 

[JetBrain]

The Navy hasn't given up on FA XX just yet. Still trying to get it funded.

https://breakingdefense.com/2025/07...-fighter-in-its-annual-wishlist-to-lawmakers/

WASHINGTON — The US Navy’s annual Unfunded Priorities List for fiscal 2026 includes $1.4 billion for a sixth-generation fighter aircraft as well as $2.2 billion to bolster the munitions industrial base and resupply key stockpiles, according to documents obtained by Breaking Defense.

The military services and combatant commanders each year send Congress their “unfunded priority lists,” which outline specific funding requests the services were not able to include in the president’s formal budget request.

 

[Yellow Palace]

So properly speaking it would appear that the Tu-22M should be designated the Tu-26, it would certainly save a lot of confusion.

That confusion may be part of the reason it's the Tu-22M. Either confusing NATO, or confusing Soviet politicians into approving the project.

 

[Scott Kenny]

In their current strength, not especially. There were around 60 pre war, but at least seven of those appear to be non operational and there have been about a dozen casualties. I think Russia would struggle to put a regiment together and think they would be slaughtered before they could fine a target, especially if AIM-174 and AIM-260 were in play. FA-XX need not apply.

Still need to be shot at, regardless of what's carrying the weapons.

Also, FAXX able to carry AIM174s internally would have a much better range/loiter time than Super Bugs. (I'm honestly not sure the Murder Hornets have any loiter time at all with how draggy that loadout must be!)

What the USN really needs/wants is increased strike capability. I expect the new jet would not only have a lot of internal capacity but a lot of optional/ejectable external hard points as well.

The problem is max catapult load. France is saying that the EMALS can throw 100,000lbs, but the steam cats on the Nimitz are limited to somewhere around 90,000lbs (or at least the USN has never had a plane over ~85k MTOW on the carriers).

Rolling back to my example design of 80klb MTOW with a 12klb bay capacity and 28klbs of fuel, if you added external stores you're losing fuel capacity at takeoff and would have to take on lots more fuel after launch. And, you're going to be unable to trap with all those weapons still onboard because you're over the arresting gear limits of ~55klbs.

But you're right, I'd be very surprised if the FAXX did not have a "beast mode" carrying another ~12klbs or more externally. My first suspicion for load would be 4x AGM-158s, not quite 12klbs. As I've mentioned before, another option would be a weapon comparable to ASALM, which was ~2700lbs per missile so four of those would be ~11klbs. I'm ignoring carrying small JDAMs externally, since you'd have to carry that high-RCS load over the target.

 

[Ozair]

The US Navy’s annual Unfunded Priorities List for fiscal 2026 includes $1.4 billion for a sixth-generation fighter aircraft as well as $2.2 billion to bolster the munitions industrial base and resupply key stockpiles, according to documents obtained by Breaking Defense.

Assuming this is added to the 750 million then we get much closer to a realistic budget to progress past a tender selection.

 

[Josh_TN]

@Scott Kenny :

I suspect future AShM weapons will be much smaller the AGM-158. The MACE RFI did not list a weight, but it did specify F-35 internal carriage, which probably makes it a 1000# or smaller weapon. Were something like the Barracuda 500 to be adopted for the role, it would probably be more like a 500# class weapon (and the USAF ERAM also seems to be in this weight range). Future AShMs will almost certainly <= 1000 lbs in my opinion, and be carried externally on tandem BRUs.

 

[DWG]

I suspect future AShM weapons will be much smaller the AGM-158. The MACE RFI did not list a weight, but it did specify F-35 internal carriage, which probably makes it a 1000# or smaller weapon. Were something like the Barracuda 500 to be adopted for the role, it would probably be more like a 500# class weapon (and the USAF ERAM also seems to be in this weight range). Future AShMs will almost certainly <= 1000 lbs in my opinion, and be carried externally on tandem BRUs.

Remember Mace's small size comes with (or is that courtesy of?) a 75lb warhead.

AFM-158 warhead, 1000lbs.

 

[Scott Kenny]

@Scott Kenny :

I suspect future AShM weapons will be much smaller the AGM-158. The MACE RFI did not list a weight, but it did specify F-35 internal carriage, which probably makes it a 1000# or smaller weapon. Were something like the Barracuda 500 to be adopted for the role, it would probably be more like a 500# class weapon (and the USAF ERAM also seems to be in this weight range). Future AShMs will almost certainly <= 1000 lbs in my opinion, and be carried externally on tandem BRUs.

Dimensionally, the JSM isn't all that much smaller than an AGM-158. 400x48x52cm LWH for the JSM, 429x55x48cm LWH for the AGM-158. That extra length buys you an extra 200kg of warhead.

 

[Josh_TN]

Remember Mace's small size comes with (or is that courtesy of?) a 75lb warhead.

AFM-158 warhead, 1000lbs.

Yes, but that is sufficient to mission kill an escort, and likely whatever missile the USN adopts will be 1/10th the cost of LRASM on top of being carried in much greater numbers by tactical aircraft.

Also only ~240 lbs of that 1000 is HE; the WDU-42 is a very suboptimal warhead for attacking ships.

 

[Josh_TN]

Dimensionally, the JSM isn't all that much smaller than an AGM-158. 400x48x52cm LWH for the JSM, 429x55x48cm LWH for the AGM-158. That extra length buys you an extra 200kg of warhead.

…and JSM is also almost just as expensive. The USN has no interest in JSM; you are thinking of the USAF who is buying a small batch of ~500 over five years as a “bridge” to LRASM integration.

Also see above; most of that 1000 lb weight is titanium penetrator.

 

[insidersource]

The AIM-174 also has the same folding wings as the surface launched SM6. SM6 pack into a 21" square box, therefore AIM-174 does as well.

The AIM-174 rear fins are mechanically spring loaded and lock into place as soon as it exits the launch tube.

It would require a full redesign of the missile to make the the fins electronically fold on command to fit an internal weapons bay.

The motors that control the fins as the missile turns are not designed to pass an electronic or hydraulic signal to a folding mechanism. Such a folding mechanism would add significant weight to the fins. I don't think there is a single supersonic missile in the world that has fins that can retract on command. Only subsonic cruise missiles have such a feature. A Mach 4 missile that must pull 30G you are talking about pure fantasy. Please stop.