Sea Phoenix

[TomS]

Sea Phoenix is 1970s, so VLS boosters don't exist. And we're now talking about a missile basically the same size of SM1MR. At which point, why not just do that?

 

[NMaude]

ASROC may have been a poor choice on my part, but I'd still grab something that was already in production.

In this scenario use the Phoenix's existing Mk-47/60 rocket-motor but instead with a high burn-rate propellant with a boost only burn profile.

 

[A Tentative Fleet Plan]

In the 1978 Naval Engineers Journal, Sea Phoenix is intended to be vertically launched from VLS tubes alongside the superstructure, although this is also tied in with the paper's attempt to design a small 3419 ton (deep displacement) frigate. The Standard Missile airframe variant could presumably be launched from existing Tartar/Standard ships, provided they have the correct fire control systems.

 

[Pioneer]

In the 1978 Naval Engineers Journal, Sea Phoenix is intended to be vertically launched from VLS tubes alongside the superstructure, although this is also tied in with the paper's attempt to design a small 3419 ton (deep displacement) frigate. The Standard Missile airframe variant could presumably be launched from existing Tartar/Standard ships, provided they have the correct fire control systems.

The stated 'small 3419 ton (deep displacement) frigate', would this be the design that Firefinder posted in drawing form on Post#12 of this thread?

Regards
Pioneer

 

[A Tentative Fleet Plan]

The stated 'small 3419 ton (deep displacement) frigate', would this be the design that Firefinder posted in drawing form on Post#12 of this thread?

Regards
Pioneer

Yes

 

[Scott Kenny]

Sea Phoenix is 1970s, so VLS boosters don't exist. And we're now talking about a missile basically the same size of SM1MR. At which point, why not just do that?

Sea Phoenix has better internal electronics, and an active radar seeker in the nose, so can be fire and forget. Plus, the AWG-9 has a small and lightweight radar antenna, at least by shipboard standards, so you can install enough radars to have staring 360 coverage.

Interestingly, Phoenix is a fatter missile than Standards. 15" diameter versus 13.5".

 

[Scott Kenny]

In this scenario use the Phoenix's existing Mk-47/60 rocket-motor but instead with a high burn-rate propellant with a boost only burn profile.

That makes the Sea Phoenix different from the air Phoenix, but that may not be an issue.

 

[Firefinder]

Honestly the most expensive part of the AIM54 was its radar systems. The one IN the missile.

If you managed to find other uses for the system, like other missiles for example, it would go a long way to dropping the cost.

Not as much as just buying more AIM54s but a good bit more then it was IRL.

Also if the the system get used for naval or army usage we likely seen the B models get built since they are a sealed system unlike the A which needed coolant from the hardpoint to worked. Dont see that being great for...

Any of the none-plane launch versions no matter how you try to do it.

 

[A Tentative Fleet Plan]

Sea Phoenix has better internal electronics, and an active radar seeker in the nose, so can be fire and forget. Plus, the AWG-9 has a small and lightweight radar antenna, at least by shipboard standards, so you can install enough radars to have staring 360 coverage.

The AWG-9 was essentially a replacement for existing fire-control radars. Maintaining long-range air search was left to other radars on the ship, with a modified APS-116 being used to provide close-in low-altitude search (installed in the same modules as the AWG-9s, being in the second radome on the two-radome module above the bridge).

Interestingly, Phoenix is a fatter missile than Standards. 15" diameter versus 13.5".

Not a problem, the nose was enlarged to accommodate Phoenix electronics:

 

[Scott Kenny]

The AWG-9 was essentially a replacement for existing fire-control radars. Maintaining long-range air search was left to other radars on the ship, with a modified APS-116 being used to provide close-in low-altitude search.

Odd, since the AWG-9 is capable of acting as a pretty good search radar.

Not a problem, the nose was enlarged to accommodate Phoenix electronics:

View attachment 709857
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Oh. out-freaking-standing!!!

Using the Standard-Phoenix "Medium Range Missile" as a replacement for the SM1MR for ships not fitted with a VLS would have been amazing.

And that Phoenix-with-a-booster "Extended Range Missile" in VLS might have allowed a twin pack in the Mk41 cells, though I doubt that it was intended for Mk41.

Is it bad that I want both options pursued?

 

[A Tentative Fleet Plan]

Odd, since the AWG-9 is capable of acting as a pretty good search radar.

When guiding missiles or in TWS mode it can only cover a single sector. The APS-116 would cue the AWG-9 onto other sectors if necessary.

Oh. out-freaking-standing!!!

Using the Standard-Phoenix "Medium Range Missile" as a replacement for the SM1MR for ships not fitted with a VLS would have been amazing.

Certainly superior to SPG-51, given that that the software changes to the shipboard AWG-9s were supposed to enable them to track 24 targets and engage 12 of them simultaneously (increased to 48 and 24 respectively for a twin AWG-9 setup). Of course this requires significant stocks of Phoenix-seeker-equipped Standards on hand (or upgrading existing stocks of SM-1s), I'm not sure shipboard AWG-9 would have been backwards compatible with conventional SM-1s.

I can see how this would have been a competitor to Aegis, it offers some anti-saturation capability to existing Standard ships, and relatively little ship-impact compared to Aegis for new-build ships.

 

[TomS]

So, it seems to me that there are two quite different Sea Phoenix proposals here. The angled box launcher in Post #1 looks like it uses something close to stock Phoenix missiles. It was intended as an alternative to Sea Sparrow and was relatively compact.

Then we have these evolved designs using VLS: either SM1MR plus the Phoenix seeker or that 15-inch Phoenix plus booster. That's a local area defense missile and does seem like a pretty direct competitor to AEGIS/SM-2.

It's a philosophical choice, I think, whether it makes sense to pack much of the "smarts" of the guidance system into the missile, as in Phoenix, or to make the missile relatively "dumb" and rely on the weapon control system on the ship for the clever bits, as in AEGIS.

Either way, you would still need something akin to SPY-1 for area surveillance, for the same reason that F-14s still needed the E-2s for surveillance and control.

 

[zen]

An ARH homing variant of Standard could have swung the RN around back in the day if it had been available, as could a VLS Pheonix system.

Arguably the Pheonix/AWG.9 system was what the RAF wanted at one point too.

 

[A Tentative Fleet Plan]

Either way, you would still need something akin to SPY-1 for area surveillance, for the same reason that F-14s still needed the E-2s for surveillance and control.

In the small frigate design area surveillance was to be done by a combination of SPS-49 for long-range air search and modified APS-116 essentially acting as a Target Indication Radar/dedicated low-altitude air search and warning radar.

 

[A Tentative Fleet Plan]

An ARH homing variant of Standard could have swung the RN around back in the day if it had been available, as could a VLS Pheonix system.

Arguably the Pheonix/AWG.9 system was what the RAF wanted at one point too.

The article dates from 1976, so the RN would have just introduced Sea Dart into service within the last few years.

 

[TomS]

In the small frigate design area surveillance was to be done by a combination of SPS-49 for long-range air search and modified APS-116 essentially acting as a Target Indication Radar/dedicated low-altitude air search and warning radar.

Yep, but this was the point where the benefit of fixed phased arrays over rotating antennas was becoming clear. This setup would become obsolete rather quickly. (Except maybe for the APS-116, whose role was taken by SPQ-9.)

 

[Scott Kenny]

When guiding missiles or in TWS mode it can only cover a single sector. The APS-116 would cue the AWG-9 onto other sectors if necessary.

So use enough AWG-9s to provide 360 staring, whether that's 4x or 12x is immaterial. I mean, those are (relatively) small and light radars, so even if you need 12 antennas that's probably lighter than a big SPS-49 or SPG-51.

Certainly superior to SPG-51, given that that the software changes to the shipboard AWG-9s were supposed to enable them to track 24 targets and engage 12 of them simultaneously (increased to 48 and 24 respectively for a twin AWG-9 setup). Of course this requires significant stocks of Phoenix-seeker-equipped Standards on hand (or upgrading existing stocks of SM-1s), I'm not sure shipboard AWG-9 would have been backwards compatible with conventional SM-1s.

I can see how this would have been a competitor to Aegis, it offers some anti-saturation capability to existing Standard ships, and relatively little ship-impact compared to Aegis for new-build ships.

Definitely an "Aegis-for-frigates" option at the very least. I suspect that the much larger diameter SPY antennas have other advantages at extreme range.

 

[Scott Kenny]

So, it seems to me that there are two quite different Sea Phoenix proposals here. The angled box launcher in Post #1 looks like it uses something close to stock Phoenix missiles. It was intended as an alternative to Sea Sparrow and was relatively compact.

Then we have these evolved designs using VLS: either SM1MR plus the Phoenix seeker or that 15-inch Phoenix plus booster. That's a local area defense missile and does seem like a pretty direct competitor to AEGIS/SM-2.

Even the "Sea Sparrow Replacement" version probably needs that booster for launch, the Phoenix booster is designed around having an air launch from a good 500-600mph at 30kft to get the long range.

I'm afraid to ask what the expected range would be for a surface launched Phoenix, probably something horrible like 25-30nmi.

It's a philosophical choice, I think, whether it makes sense to pack much of the "smarts" of the guidance system into the missile, as in Phoenix, or to make the missile relatively "dumb" and rely on the weapon control system on the ship for the clever bits, as in AEGIS.

Either way, you would still need something akin to SPY-1 for area surveillance, for the same reason that F-14s still needed the E-2s for surveillance and control.

It's proven out that putting the smarts into the missile is desirable, at least for a small portion of the missile load. SM6 says hi.

 

[TomS]

I'm afraid to ask what the expected range would be for a surface launched Phoenix, probably something horrible like 25-30nmi.

That's maybe twice the range of Sea Sparrow. Would be considered quite satisfactory, or even excessive, for point defense in the era when it was proposed.

 

[Scott Kenny]

That's maybe twice the range of Sea Sparrow. Would be considered quite satisfactory, or even excessive, for point defense in the era when it was proposed.

Fair point.

Have the Phoenix set in Dogfight mode so the radar was active from launch and you're good to go. Radar can stop guiding as soon as the missile locks on, allowing for a very impressive "missile numbers required to swamp the defenses" or whatever the fancy term is for that.

 

[A Tentative Fleet Plan]

That's maybe twice the range of Sea Sparrow. Would be considered quite satisfactory, or even excessive, for point defense in the era when it was proposed.

Twice the range of Sea Sparrow, and simultaneous engagement of anything between six and twelve targets per AWG-9 (I don't know if the point defence version of Sea Phoenix would have received the same software improvements as the frigate version), much better than Mk 115 or Mk 95 guiding Sea Sparrow. With up to three systems onboard a carrier, that's a pretty decent way of dealing with a very large number of leakers. I suppose the fixed box launchers could have difficulties dealing with diving AS-4s though.

 

[Scott Kenny]

Twice the range of Sea Sparrow, and simultaneous engagement of anything between six and twelve targets per AWG-9 (I don't know if the point defence version of Sea Phoenix would have received the same software improvements as the frigate version), much better than Mk 115 or Mk 95 guiding Sea Sparrow. With up to three systems onboard a carrier, that's a pretty decent way of dealing with a very large number of leakers. I suppose the fixed box launchers could have difficulties dealing with diving AS-4s though.

They're still angled at a ~45deg angle, the missile will know to look up rather than down. Trick there would be AWG-9 tracking angles.

 

[TomS]

Twice the range of Sea Sparrow, and simultaneous engagement of anything between six and twelve targets per AWG-9 (I don't know if the point defence version of Sea Phoenix would have received the same software improvements as the frigate version), much better than Mk 115 or Mk 95 guiding Sea Sparrow. With up to three systems onboard a carrier, that's a pretty decent way of dealing with a very large number of leakers. I suppose the fixed box launchers could have difficulties dealing with diving AS-4s though.

I know we call AS-4 a "high diver," but its terminal dive angle is around 30 degrees, so it's not like the Phoenix would need to snap up to make the intercept.

 

[pathology_doc]

I would tend towards the Standard-Phoenix lash-up to retain compatibility with existing Mk 11 (if still present) and Mk 13 launchers in all ships operating Standard in Western navies. The Phoenix seeker is the most expensive part of the AIM-54, so that brings economies of scale in that area at least.

Whether you could or even should put "Active Standard" on the tip of an SM-2ER setup is an altogether different question, although by the mid-late 70s you are getting into the era where the "forward-pass" idea of allowing AWACS aircraft to handle late midcourse guidance for surface-launched missiles is becoming practical. Late SM-2 blocks had a kinematic performance that went beyond the ability of a surface radar system to handle illumination or even detection (because of horizon effects), and this seems like an ideal platform for that concept.

 

[TomS]

I would tend towards the Standard-Phoenix lash-up to retain compatibility with existing Mk 11 (if still present) and Mk 13 launchers in all ships operating Standard in Western navies. The Phoenix seeker is the most expensive part of the AIM-54, so that brings economies of scale in that area at least.

OTOH, the box-launch Sea Phoenix was intended for ships that would not have Mk 11/13 launchers for Standard.

IMO, the surprising omission was "SAMRAAM" (if you will). It took an awfully long time to get around to an active seeker on Sea Sparrow/ESSM, and converting to an AMRAAM-based missile earlier seems like an obvious road not taken.

 

[pathology_doc]

IMO, the surprising omission was "SAMRAAM" (if you will). It took an awfully long time to get around to an active seeker on Sea Sparrow/ESSM, and converting to an AMRAAM-based missile earlier seems like an obvious road not taken.

Agreed. The paper on Sea Phoenix was prepared in the 1970s so I went with it in that context, but the obvious solution to the cheap-and-cheerful anti-saturation system on the cheapest possible hull is to wait for AMRAAM and press RIM-120 into service in some form as early as possible. Hell, if you wanted to use existing RIM-7-capable box launchers, you could even go with Active Skyflash for starters, though you'd clearly need to retrofit a fire control system that was capable of talking to those missiles.

 

[NMaude]

In addition to the Sea Phoenix was there any idea of a Land Phoenix? Imagine the MIM-23 HAWK system having its' HAWK missiles replaced with MIM-54s.

 

[Scott Kenny]

In addition to the Sea Phoenix was there any idea of a Land Phoenix?

Probably not. Though the Army is less allergic to things that originated with the USN than the USAF is, the USAF was heavily pushing the narrative that they'd provide all air defense necessary for the Army to work under.

Imagine the MIM-23 HAWK system having its' HAWK missiles replaced with MIM-54s.

Every current and former member of the Army ADA units just broke out into maniacal laughter and they don't know why...

 

[NMaude]

Every current and former member of the Army ADA units just broke out into maniacal laughter and they don't know why...

Good or bad laughter?

 

[Scott Kenny]

Good or bad laughter?

Very good. They'd have given their left testicle to have missiles as capable as Phoenix!

 

[NMaude]

Very good. They'd have given their left testicle to have missiles as capable as Phoenix!

A thought just occurred to me that after the F-14 was retired instead of destroying the remaining AIM-54s (Don't want the Iranians given any chance to get their grubby mitts on some of these retired AAMs) why recondition them and use them as SAMs in the USMC and US Army.

 

[Firefinder]

Do remember reading somewhere that tge Army did look at using the Pheonix as a base to upgrade tge Hawks during out of the times the Patriot program was being...


Bitched at by Congress.

But well it was the Patriot, even the early models was more then good enough for what was needed. That and the Pheonix was concurrent systems so it end up being a nonstarter much as the Sea Patriot was.

The Marines might have had use for a Pheonix enhance Hawk but well they never have budget.

 

[NMaude]

What I was suggesting is that after the USN retired the AIM-54 instead destroying the remaining stocks give them and their associated spares to the USMC and/or US Army.

 

[Grey Havoc]

That would have been too logical, alas.