F-14 + AIM 54 in fleet defense

[T. A. Gardner]

And that's the basics of "proportional targeting" which is very simple to implement.

Well, today the engineers for guidance systems have moved beyond that. Proportional control, Cartesian or polar is no longer the go to. Today, they're using linear quadradic control theory (lots of papers online about it).

 

[Ronny]

No. Look, constant bearing works like this:

View attachment 716925
As long as your missile seeker track the target on the same bearin, you are leading the target. You don't need precise range measurement; all you need is just to be sure that range decreasing (otherwise there are 50/50 probability that you are actually going away from target).

So even with home-on-jam, your seeker would be able to use this method.

So after reading carefully about capibilities of AWG-9, it seem that HoJ allow direct path flight, to loft the missile, pilot need to estimate range with ADR

 

[NMaude]

Today, they're using linear quadradic control theory (lots of papers online about it).

Any relevant examples?

 

[TomS]

The main reason Typhon wasn't proceeded with came down to the use of a ramjet missile, along with cost. This limited its maneuverability to somewhere around 4 to 6G at most as more severe maneuvers would or could result in loss of airflow and the engine flaming out. The ramjet was necessary at the time to get the range desired out of the missile. Solid fuel technology hadn't proceeded to a point where you could get a missile that could fly out 75+ miles on solid fuel. Technology simply needed to mature more before an effective, and cost effective, multichannel air defense missile system could be produced.

That's not what I've seen. From the APL histories, it came down to the failure of SPS-59. The radar was very complex, hard to build, very hard to program, not very reliable, and suffered so much internal signal loss that it had an inadequate range.

The Typhon LR missile worked (it flew 10 times in 1961-62) but without SPG-59, the existing fleet radars could not take advantage of its range. Given that it was meant as a bomber-killer, high-g maneuvering wasn't critical, but the configuration did evolve to keep the air flowing into the ramjet at high AOA.

 

[Heatloss]

So after reading carefully about capibilities of AWG-9, it seem that HoJ allow direct path flight, to loft the missile, pilot need to estimate range with ADR

Thanks for the follow-up! I was very confused.

 

[Dilandu]

The main reason Typhon wasn't proceeded with came down to the use of a ramjet missile, along with cost. This limited its maneuverability to somewhere around 4 to 6G at most as more severe maneuvers would or could result in loss of airflow and the engine flaming out. The ramjet was necessary at the time to get the range desired out of the missile. Solid fuel technology hadn't proceeded to a point where you could get a missile that could fly out 75+ miles on solid fuel. Technology simply needed to mature more before an effective, and cost effective, multichannel air defense missile system could be produced.

Considering that targets for Typhon-LR were supposed to be either heavy jet bombers or cruise missiles, launched from those bombers - both targets aren't exactly maneuverable - I rather doubt that maneuvering at more than 4-6 G was required.

 

[golani]

The f-14 was part of a system to prevent an AS-4 from slamming into a carrier. Kill the archer. Then aegis would backstop and would also be used against ss -n-19s from Oscar class ssgns. Keep in mind both the kitchen and shipwreck missiles could carry a nuke and nuclear warfare at sea is a lot easier to manage

 

[T. A. Gardner]

Considering that targets for Typhon-LR were supposed to be either heavy jet bombers or cruise missiles, launched from those bombers - both targets aren't exactly maneuverable - I rather doubt that maneuvering at more than 4-6 G was required.

The target criteria was changing and other than the G limit on ramjets, was the altitude limit. Standard became the choice as solid fuel missiles could go exo-atmospheric.

 

[T. A. Gardner]

Any relevant examples?

There are dozens of papers on this. This one is a good primer:

https://secwww.jhuapl.edu/techdigest/Content/techdigest/pdf/V29-N01/29-01-Palumbo_Homing.pdf

 

[TomS]

The target criteria was changing and other than the G limit on ramjets, was the altitude limit. Standard became the choice as solid fuel missiles could go exo-atmospheric.

Standard didn't even dabble with exo-atmospheric intercepts until the Terrier LEAP experiments in the early 1990s and that needed a separate third-stage motor. Standard SM2ER isn't exo-atmospheric at all (indeed, how would it steer outside an atmosphere?)

 

[NMaude]

There are dozens of papers on this. This one is a good primer:

https://secwww.jhuapl.edu/techdigest/Content/techdigest/pdf/V29-N01/29-01-Palumbo_Homing.pdf

That's very interesting, however is there a list of other papers I could look at, please?

 

[Scott Kenny]

That's not what I've seen. From the APL histories, it came down to the failure of SPS-59. The radar was very complex, hard to build, very hard to program, not very reliable, and suffered so much internal signal loss that it had an inadequate range.

The Typhon LR missile worked (it flew 10 times in 1961-62) but without SPG-59, the existing fleet radars could not take advantage of its range. Given that it was meant as a bomber-killer, high-g maneuvering wasn't critical, but the configuration did evolve to keep the air flowing into the ramjet at high AOA.

Did the Typhon LR missile fly like a Talos? Climb well above the long-range target and then dive down on top?

 

[A Tentative Fleet Plan]

Did the Typhon LR missile fly like a Talos? Climb well above the long-range target and then dive down on top?

Yes, that one of the ways that both Typhon missile variants (LR and MR) got improved range over their beam-riding predecessors Terrier and Tartar.

 

[Dilandu]

Yes, that one of the ways that both Typhon missile variants (LR and MR) got improved range over their beam-riding predecessors Terrier and Tartar.

RIM-24 Tartar was homing from the very beginning. Later versions of RIM-2 Terrier (HT) were also homing missiles, not beam-riders.

 

[NMaude]

Later versions of RIM-2 Terrier (HT) were also homing missiles, not beam-riders.

The RIM-2E was the first SARH variant.

 

[Dilandu]

The RIM-2E was the first SARH variant.

Exactly. To be exact (sorry for the tautology), the ideas of SARH Terrier circulated since early 1950s. It was suggested to equip Terrier with interferometer-based seeker, the same as on Talos - both to improve the accuracy, and as fallback measure in case there would be serious problems with beam-riding guidance.

 

[NMaude]

It was suggested to equip Terrier with interferometer-based seeker, the same as on Talos

An interferometer type SARH seeker? I wasn't aware of that, do you have any links to information about this?

 

[Dilandu]

An interferometer type SARH seeker? I wasn't aware of that, do you have any links to information about this?

Yep. It's mentioned in "The Terrier: a capsule history of missile development" by M. Kelly.

The very modest effort on an interferometer homing system that had been started in 1948 was viewed only as a possible alternative in case satisfactory beam-riding guidance should prove unattainable

As I said above, it was mainly a fallback measure - there were considerable doubts about beam-riding guidance and the ability of the missile to follow the beam to fast-moving target - and interferometer seeker was a potential solution.

 

[NMaude]

Yep. It's mentioned in "The Terrier: a capsule history of missile development" by M. Kelly.

Thanks, looks like an interesting read.

 

[Dilandu]

Thanks, looks like an interesting read.

You are welcome)

 

[T. A. Gardner]

Did the Typhon LR missile fly like a Talos? Climb well above the long-range target and then dive down on top?

Yes, and so did many long range SAMs at the time. This was done to improve range as well as avoid jamming during the midcourse flight to the target. Following a ballistic trajectory was energy efficient, while the missile and its guidance beam weren't pointed at the target.

 

[NMaude]

Standard didn't even dabble with exoatmospheric intercepts until the Terrier LEAP experiments in the early 1990s and that needed a separate third-stage motor. Standard SM2ER isn't exoatmospheric at all (indeed, how would it steer outside an atmosphere?)

This! The Standard Missile variant that flies exo-atmospherically is the SM-3 all other SM variants can only operate within the atmosphere (The effective operational ceiling is probably not much more than 100,000Ft).

 

[Scott Kenny]

This! The Standard Missile variant that flies exo-atmospherically is the SM-3 all other SM variants can only operate within the atmosphere (The effective operational ceiling is probably not much more than 100,000Ft).

As small as the strakes and fins are, I'd be surprised if it can maneuver much above 80kft...

 

[T. A. Gardner]

As small as the strakes and fins are, I'd be surprised if it can maneuver much above 80kft...

Don't quote me on this, but I think the latest variants can maneuver to a limited extent using a moving exhaust nozzle on the engine.

 

[NMaude]

Don't quote me on this, but I think the latest variants can maneuver to a limited extent using a moving exhaust nozzle on the engine.

I think that you're referring to the Mk-136 ASAS's TVC nozzle, the Mk-136 is the third-stage of the SM-3 ABM.

Edit: All of the two-stage Standard missiles (SM-2/3/6) Mk-72 launch-booster use jetavator type TVC but the booster only burns for six seconds before separating (The Mk-104 DTRM has no TVC).

 

[TomS]

Don't quote me on this, but I think the latest variants can maneuver to a limited extent using a moving exhaust nozzle on the engine.

I think there may be confusion about this.

Yes, there is a thrust-vectoring module that can be bolted onto the tail of a Standard Missile. It's basically the MR alternative to the big Mk 72 ER booster. But like it's big brother, it only really does vectoring to tip and point the missile immediately after launch. Steering during flight is done via aerodynamic tail surfaces.

Here's a solicitation that describes the combination of Thrust Vectoring Assembly and Control Actuation System that drives the fins. It dates back to when they were planning a new single split line nozzle but it also references the older jet tab assembly as well. Note that the jet tab assembly can actually be jettisoned after launch. (It's not clear when the JTA would be retained or jettisoned).

FY17-FY20 Standard Missile (SM) Steering Control Section (SCS) Redesign

Federal Contract Opportunity for FY17-FY20 Standard Missile (SM) Steering Control Section (SCS) Redesign. Posted May 17, 2016. Due Jun 3, 2016. Naval Sea Systems Command (DOD - Navy)

govtribe.com

 

[NMaude]

Note that the jet tab assembly can actually be jettisoned after launch. (It's not clear when the JTA would be retained or jettisoned).

If it's anything like the ESSM's TVC module it's immediately jettisoned after it has been used.

 

[TomS]

If it's anything like the ESSM's TVC module it's immediately jettisoned after it has been used.

The solicitation specifically notes that the Mk 72 is jettisoned and the JTA may be jettisoned. So it seems there are times that it is not. Given that the JTA is only for the MR versions, it might be retained in cases where the intercept happens while the motor is still burning (i.e. at very short range)

 

[Ronny]

Anyone know why there was such a massive change in F-14 SAC in 1974 and 1977?
In 1974, F-14 with six phoenix can reach Mach 1.9, in 1977 it is limited to Mach 1.7

 

[Grey Havoc]

Possibly related to the issues with the Pratt & Whitney TF-30 engine?

 

[Ronny]

Possibly related to the issues with the Pratt & Whitney TF-30 engine?

It weird that in 1977, F-14 seem to be faster at high altitude compared to in 1974

 

[Grey Havoc]

Possibly a case of one successful fix unexpectedly creating or revealing a new problem.

 

[LANTIRN40K]

Anyone know why there was such a massive change in F-14 SAC in 1974 and 1977?
In 1974, F-14 with six phoenix can reach Mach 1.9, in 1977 it is limited to Mach 1.7
View attachment 759271
View attachment 759272

The non-technical term would be that the engine was "de-tuned" for reliability and increased MTBO. This meant some reduction in installed thrust.

 

[Archibald]

The TF30 was such a piece of junk... killed way too many Tomcat crews.

 

[NMaude]

Last year (I can't remember which thread it was in) someone had posted a quarterly technical progress report from YT from the lates 60s concerning the development of the AIM-54. Now one of the milestones in that video was the first guided launch where the AIM-54 prototype homed in onto a Firebee drone using the its' seekers' HOJ mode, so it occurred to me that after the AIM-54C's were retired why weren't they converted into AGM-54 anti-radiation missiles instead of being scrapped and recycled?

 

[Colonial-Marine]

Perhaps it was determined the AIM-54 wasn't very fond of being jolted around on the wing pylons at M1.9 or so? Changes to that chart elsewhere don't seem as pronounced, although generally it seems more "angular" than before if that makes any sense.

The TF30 was such a piece of junk... killed way too many Tomcat crews.

Once some initial problems were fixed it seemed to give a good account for itself on the F-111 and a few other platforms, but for the F-14 it was ill-suited for the job and it's shameful it took as long as it did to replace them with something better. As much as the early F100s may have had problems with compressor stalls, afterburning failing to ignite, etc. it didn't seem to result in as many airframes lost as the TF30s on the Tomcat.

 

[TomS]

Last year (I can't remember which thread it was in) someone had posted a quarterly technical progress report from YT from the lates 60s concerning the development of the AIM-54. Now one of the milestones in that video was the first guided launch where the AIM-54 prototype homed in onto a Firebee drone using the its' seekers' HOJ mode, so it occurred to me that after the AIM-54C's were retired why weren't they converted into AGM-54 anti-radiation missiles instead of being scrapped and recycled?

Because the USN was already flying HARM (and soon AARGM) on F/A-18s, which were replacing the Tomcats anyway.

 

[NMaude]

Because the USN was already flying HARM (and soon AARGM) on F/A-18s, which were replacing the Tomcats anyway.

An anti-radiation modification of the AIM-54 I strongly suspect would not have needed the the AN/AWG-9 fire-control system also it was a large high-speed missile carrying a large warhead plus there were thousands of now surplus Phoenixes that could've been modified (Just like how surplus AIM-9Cs were modified into the AGM-122A Sidearm light anti-radiation missile), a case of "Waste not, want not".

 

[TomS]

An anti-radiation modification of the AIM-54 I strongly suspect would not have needed the the AN/AWG-9 fire-control system also it was a large high-speed missile carrying a large warhead plus there were thousands of now surplus Phoenixes that could've been modified (Just like how surplus AIM-9Cs were modified into the AGM-122A Sidearm light anti-radiation missile), a case of "Waste not, want not".

HARM already existed and was optimized for the role. Modifying Phoenix for the role would require an additional expenditure. And even without the need for AWG-9, hanging Phoenix on a Hornet would be a significant project. Even under the wings on the Tomcat, it has a specialized pylon not used for other ordnance.

And what's the point? Carrier magazines are finite. You don't carry a bunch of large but obsolete missiles just in case. You carry as many of the modern, up to date ones as you can cram in there, in general.

 

[Ronny]

The non-technical term would be that the engine was "de-tuned" for reliability and increased MTBO. This meant some reduction in installed thrust.

But if that was the case then why F-14 in 1977 is faster at high altitude than F-14 in 1974?