AIM 54 effective range question

[Thundercat710]

Greetings to all,

 

Got into a weird conversation on a DCS fb page. A user asked if the AI F-14s were currently bugged, because they weren't shooting their 54s at long range. Another user told him that AIM-54s only work against fighters between 30-40 miles, because anything longer than that was designed to intercept lumbering, non-maneuvering bombers. He then confidently stated multiple times that in both real life and DCS, the 54 can't kill MiGs past 40 miles. 
I mentioned that variables like altitude, speed, and closure rate play a big factor in that, and he doubled down. I showed him a youtube clip of me taking out 4 MiG-31s - yeah, I get that they're interceptors and not nimble fighters, but the tacview showed them going defensive as hell. The first two were shot at from just over 60 miles, and the last two I think were around 40 miles out or so. Splash 4 for 4 - Tomcat wins the day.

 

Of course his response was that I was just lucky lol

Anyway, he sealed his fate when he said it's impossible in real life AND DCS, when I knew he was wrong about the DCS part. But what about real life? Not too knowledgeable on the real life exploits of the 54. Thanks!

[DSplayer]

The AI F-14 currently doesn't employ the AIM-54 in the way that pilots do and therefore they're not a good indicator to the range of the 54 or how effective it is. It's going to be overhauled soon btw.

For long range kills in real life, the figures you're going to generally get are from test figures since the figures for combat kills are basically all Iranian and its super hard to get any really credible info outside of the knowledge of the kill itself. An article on The Aviation Geek Club states that during a test firing of the AIM-54, it shot down a drone from a distance of 120 miles (Source). So I'd say if the AIM-54 was able to hit a target at that sort of distance, it sure could hit a fighter sized target at 40+ nm. 

In terms of DCS, the AIM-54 is really hampered by the old API and the ease that the AWG-9 can lose tracks (notching, etc.) but it can easily get long range kills if you really get high and launch at a high speed. During a comp match, I was able to score a ~72nm kill on another F-14 while I was RIOing. The range will probably be increased with the new API comes out and makes the missile more efficient with speed management. Just tell him to git gud.

[Thundercat710]

19 minutes ago, DSplayer said:

In terms of DCS, the AIM-54 is really hampered by the old API and the ease that the AWG-9 can lose tracks (notching, etc.) but it can easily get long range kills if you really get high and launch at a high speed. 

Yeah that's what I found with the MiG-31s. They were sprinting to intercept me, and I was sprinting toward them at full burn in the B model while at 40k feet. The closure rate was pretty obscene lol

[Prez]

On 10/27/2021 at 12:18 AM, Thundercat710 said:

Greetings to all,

 

Got into a weird conversation on a DCS fb page. A user asked if the AI F-14s were currently bugged, because they weren't shooting their 54s at long range. Another user told him that AIM-54s only work against fighters between 30-40 miles, because anything longer than that was designed to intercept lumbering, non-maneuvering bombers. He then confidently stated multiple times that in both real life and DCS, the 54 can't kill MiGs past 40 miles. 
I mentioned that variables like altitude, speed, and closure rate play a big factor in that, and he doubled down. I showed him a youtube clip of me taking out 4 MiG-31s - yeah, I get that they're interceptors and not nimble fighters, but the tacview showed them going defensive as hell. The first two were shot at from just over 60 miles, and the last two I think were around 40 miles out or so. Splash 4 for 4 - Tomcat wins the day.

 

Of course his response was that I was just lucky lol

Anyway, he sealed his fate when he said it's impossible in real life AND DCS, when I knew he was wrong about the DCS part. But what about real life? Not too knowledgeable on the real life exploits of the 54. Thanks!

IRL, the AIM-54A was not deemed suitable against fighter targets by the US Navy. Iran used them because it's all they had and they were fighting export 50s/60s/70s Soviet aircraft. Even when 54C was introduced, some units used only sparrows through the Gulf War. However, the AIM-54C was quite good against fighters.  There is documentation on a test shot conducted against a high-G maneuvering QF-86 within 10NM where the phoenix scored a hit. But as far as legitimately being used against fighters at range, it really does heavily depend on parameters, but more so on the intelligence and technology of the other fighter. Not all aircraft have sophisticated RWRs, cold war Russian aircraft are a good example of that. I know AI are omnipotent, but as far as real life goes this is a major factor. Also, the training of the pilots. Are they even trained to fight against Fox-3 capable jets in a head on engagement? Can their RWR even detect if they've been spiked and launched on? (Examples from the Gulf War) There's more than just the kinematics at play. 

However, if you really care about the kinematics than you really should only be taking shots at a max of 40 or so miles against fighter targets above 30k. The air density in DCS decreases exponentially, so you'd never feasibly be able to make shots longer than 30NM below something like 20k especially with the current loft profile. IRL, it's the same thing. Fighters aren't usually cruising around at 30k like they are in DCS. Most non-interceptor engagements in history were conducted at very low altitude. You're just not hitting something maneuvering 50 miles away at 10k feet even with a phoenix. Plus, from the F-14 crewmembers that have spoken about the use of the AIM-54, you're going to get a fighter employment number between 30-45NM anyways. 

Edited October 28, 2021 by Prez

[Comstedt86]

4 hours ago, Prez said:

IRL, the AIM-54A was not deemed suitable against fighter targets by the US Navy. Iran used them because it's all they had and they were fighting export 50s/60s/70s Soviet aircraft. Even when 54C was introduced, some units used only sparrows through the Gulf War. However, the AIM-54C was quite good against fighters.  There is documentation on a test shot conducted against a high-G maneuvering QF-86 within 10NM where the phoenix scored a hit. But as far as legitimately being used against fighters at range, it really does heavily depend on parameters, but more so on the intelligence and technology of the other fighter. Not all aircraft have sophisticated RWRs, cold war Russian aircraft are a good example of that. I know AI are omnipotent, but as far as real life goes this is a major factor. Also, the training of the pilots. Are they even trained to fight against Fox-3 capable jets in a head on engagement? Can their RWR even detect if they've been spiked and launched on? (Examples from the Gulf War) There's more than just the kinematics at play. 

However, if you really care about the kinematics than you really should only be taking shots at a max of 40 or so miles against fighter targets above 30k. The air density in DCS decreases exponentially, so you'd never feasibly be able to make shots longer than 30NM below something like 20k especially with the current loft profile. IRL, it's the same thing. Fighters aren't usually cruising around at 30k like they are in DCS. Most non-interceptor engagements in history were conducted at very low altitude. You're just not hitting something maneuvering 50 miles away at 10k feet even with a phoenix. Plus, from the F-14 crewmembers that have spoken about the use of the AIM-54, you're going to get a fighter employment number between 30-45NM anyways. 

 

Isn't the "not against fighters" mostly because earlier doctrine and somewhat AWG-9 limitations?

 

Supply of AIM-54s were quite limited early on IIRC and the primary threat and target were bombers / attack aircraft which threatened the fleet. Perhaps this was a reason it was not to be employed against fighters? 

 

Was this perhaps changed later on and especially with the C version because of it's massive improvement in guidance. 

 

[lunaticfringe]

6 hours ago, Prez said:

IRL, the AIM-54A was not deemed suitable against fighter targets by the US Navy.

Because they had the AIM-7F that would already outrange anything in opposition.  The AIM-54A was evaluated as more capable against fighter targets than any other air to air missile in testing; at $1 million per round, however, and as the insurance policy for the fleet against LRA attack, deference was paid to the Sparrow. 

When the Soviets became able to match the F and M in range performance in the mid-80s, then came the shift.  

Edited October 28, 2021 by lunaticfringe

[GGTharos]

On 10/27/2021 at 12:18 AM, Thundercat710 said:

Anyway, he sealed his fate when he said it's impossible in real life AND DCS, when I knew he was wrong about the DCS part. But what about real life? Not too knowledgeable on the real life exploits of the 54. Thanks!

This depends very heavily on the specifics of the entire system, by this meaning the combination of AWG-9 capability and the missile's hardware.

Ignoring the AWG-9 issues for a moment, the goal is to shape the missile's trajectory in such a way that you have a sort of best balance between time-to-target (and constrained by the missile's own maximum TOF) and missile speed at intercept time.  More speed=more maneuvering.   Shorter time to target means the target has less time to do whatever it wants to do to make the missile miss.

So, shaping the trajectory is pretty tricky:  The missile has to fly where you can still receive the guidance commands from the AWG-9 (may not be an issue), while balancing a high lofted flight to maintain speed in the cruise phase and minimize speed reduction in the terminal phase.

At the same time, the 54A must be able to see a target reflection in SARH (SADL) mode to be able to steer it since it didn't have an INS mid-course capability.   In other words, the AWG-9 tells it where to look, the 54A looks there for reflections from the target as the AWG-9's TWS sweeps over the target, and adjusts its trajectory accordingly until it's time to go active.

So here a lower RCS (ie. a fighter) reduces the TWS launch capabilities.  The same is true of bombers but at much longer ranges.   In both cases shooting in STT gives you longer range because more energy is reflected from the target.

 

It's just one of many issues.  But yes as said above, the 54 was quite capable against fighters ... just very expensive to be used that way, until it wasn't.

[Victory205]

"IRL, the AIM-54A was not deemed suitable against fighter targets by the US Navy"?

"Not to be employed against fighters"? 

News to me.

Where do you gents get this stuff? It's remarkable.

[GGTharos]

3 minutes ago, Victory205 said:

Where do you gents get this stuff? It's remarkable.

Ever head of this 'internet' thing?  Me either.  It's new

[Victory205]

1 minute ago, GGTharos said:

Ever head of this 'internet' thing?  Me either.  It's new

Algore should have dubbed it the Bullshiternet when he invented it...

[Baz000]

Brush always called it the 'internets' so clearly there must be more than just one.

How do we find the right internets to be on and not the wrong one?

Oh the IRIAF would disagree, they used AIM-54A(tho not the same the USN was using, theirs was modified to not be so good at counter ECM) quite a bit in the Iran-Iraq war and have confirmed kills against fighter sized targets.

Eventually the Iraqi air force MiG pilots feared the F-14 so much that if they got wind of one on RWR, they would just turn around and not try pressing their luck. 

[stuart666]

Yes, agreed. Im sure the IRIAF jock that killed 3 mirages with one missile would perhaps disagree with the idea it wasnt to be used on fighters....

Didnt I read somewhere that by the mid to late 1980's, they were hanging at least one Phoenix on Tomcats on some CAPs, so they could in the face any Su27 or Mig29 they met?

Edited October 29, 2021 by stuart666

[Prez]

15 hours ago, GGTharos said:

At the same time, the 54A must be able to see a target reflection in SARH (SADL) mode to be able to steer it since it didn't have an INS mid-course capability.   In other words, the AWG-9 tells it where to look, the 54A looks there for reflections from the target as the AWG-9's TWS sweeps over the target, and adjusts its trajectory accordingly until it's time to go active.

The AIM-54A did have DL mid-course guidance. It didn't require being able to see radar reflections until the terminal phase. It would guide passively to target via mid course radar DL updates in both TWS and PD-STT until powering it's seeker for either active(in TWS) or semi-active(PD-STT) terminal guidance. In TWS, this is specifically called Sample Data/Active or SD/A. This is from a 1975 Phoenix flight test study done at California State University, Northridge.

[GGTharos]

2 hours ago, Prez said:

It didn't require being able to see radar reflections until the terminal phase. 

Passively means seeing reflections.  Unless you don't care about hitting targets.

2 hours ago, Prez said:

In TWS, this is specifically called Sample Data/Active or SD/A. This is from a 1975 Phoenix flight test study done at California State University, Northridge.

I have the weapons manual.   SD/A, the missile receives 'look here' commands and looks for reflections throughout mid-course.

Edited October 29, 2021 by GGTharos

[draconus]

2 hours ago, Prez said:

The AIM-54A did have DL mid-course guidance. It didn't require being able to see radar reflections until the terminal phase. It would guide passively to target via mid course radar DL updates in both TWS and PD-STT until powering it's seeker for either active(in TWS) or semi-active(PD-STT) terminal guidance.

That is some new information to me, that you didn't require to keep a lock in PD-STT launch. Are you sure about that?

[Prez]

1 hour ago, draconus said:

That is some new information to me, that you didn't require to keep a lock in PD-STT launch. Are you sure about that?

No, you are still required to maintain lock the entire time for PD-STT launches. It's just that the behavior of the missile mid-course is the same in both TWS and PD-STT. The terminal phase is what is different between the two launch methods. The AIM-54 doesn't have lock-on after launch capabilities as far as I am aware.

 

1 hour ago, GGTharos said:

I have the weapons manual.   SD/A, the missile receives 'look here' commands and looks for reflections throughout mid-course.

Would you mind posting a screenshot of the exact wording? Because from the missile testing documentation I have, it's more expressly stated that these are guidance updates from the AWG-9's own telemetry calculations than it is from the seeker looking for PD reflections. Looking for the reflections at range also wouldn't make much sense given the significantly smaller dish inside the missile and the fact that it is not a CW-guided weapon. I know it looks out for it in STT during the terminal phase as per my documentation, but not during the mid-course phase. 

[GGTharos]

12 minutes ago, Prez said:

Would you mind posting a screenshot of the exact wording? Because from the missile testing documentation I have, it's more expressly stated that these are guidance updates from the AWG-9's own telemetry calculations than it is from the seeker looking for PD reflections.

I'll post it when I get the opportunity to visit my PC.   SA/D mid-course is applied to TWS and STT - the missile is told 'look there' and it adjusts its trajectory based on seeing the reflections.

12 minutes ago, Prez said:

Looking for the reflections at range also wouldn't make much sense given the significantly smaller dish inside the missile and the fact that it is not a CW-guided weapon. I know it looks out for it in STT during the terminal phase as per my documentation, but not during the mid-course phase. 

It does it in mid-course as well.  And it makes plenty of sense, in fact it is probably the main reason why you are expected to have more successful long range shots in STT than in TWS  (Note, not TWS vs STT for accuracy, but for range).

The dish on the 54 is quite a bit larger than the sparrow, and the sparrow can see a sqm target over 30nm away (almost 40) with PD illumination.   The Phoenix has the added benefit of the datalink, so it might be able to fly its initial commanded portion without seeing its target; but, like a missile with INS guidance, it needs something to help it guide onto the target in mid-course.  That's SA/D.

[Prez]

23 minutes ago, GGTharos said:

I'll post it when I get the opportunity to visit my PC.   SA/D mid-course is applied to TWS and STT - the missile is told 'look there' and it adjusts its trajectory based on seeing the reflections.

It does it in mid-course as well.  And it makes plenty of sense, in fact it is probably the main reason why you are expected to have more successful long range shots in STT than in TWS  (Note, not TWS vs STT for accuracy, but for range).

The dish on the 54 is quite a bit larger than the sparrow, and the sparrow can see a sqm target over 30nm away (almost 40) with PD illumination.   The Phoenix has the added benefit of the datalink, so it might be able to fly its initial commanded portion without seeing its target; but, like a missile with INS guidance, it needs something to help it guide onto the target in mid-course.  That's SA/D.

I still can't seem to understand your reasoning or evidence for the AIM-54 actually looking for PD reflections during it's mid-course phase, especially in a multi-launch TWS situation. Would the missile not become confused by the reflections off multiple targets? I think that your interpretation of the SD/A functionality might be a bit too literal. Plus, if the missile were "actively" looking for the PD reflections during mid-course then it wouldn't be considered passive guidance. And again, from all I've read, the AIM-54 would guide all the way until the terminal phase strictly through updates from the radar, not from the missile's ability to see PD reflections. 

Also, as far as the radar dish is concerned: I know the 54 has a larger dish and therefore could have a longer seeker range for PD. I just don't know how much farther. On the note of the sparrow numbers you gave, from all the sources I've seen, the 7F had a max seeker range of 22NM, 26 for the 7M, and then somewhere in the low 30s for the 7P.

[GGTharos]

5 minutes ago, Prez said:

I still can't seem to understand your reasoning or evidence for the AIM-54 actually looking for PD reflections during it's mid-course phase,

It literally says so in the manual.

5 minutes ago, Prez said:

especially in a multi-launch TWS situation. Would the missile not become confused by the reflections off multiple targets?

Maybe?  I mean there are ways to deal with this by using at least say a doppler gate.  These are details and potential limitations that we don't know about.

5 minutes ago, Prez said:

I think that your interpretation of the SD/A functionality might be a bit too literal.

Well yes, the manual literally says that the missile uses the reflections to adjust trajectory.

5 minutes ago, Prez said:

Plus, if the missile were "actively" looking for the PD reflections during mid-course then it wouldn't be considered passive guidance. And again, from all I've read, the AIM-54 would guide all the way until the terminal phase strictly through updates from the radar, not from the missile's ability to see PD reflections. 

The missile - any missile - will always guide by itself.  There's no guidance coming the radar, but rather some form of position updates.  The AWG-9 still has to transmit data to tell the missile where to look for the target, and that's what it does IIRC, it says 'point the seeker there'.   But it doesn't command the missile ie. 'steer this way' so ... the radar is not doing any guiding, the missile is.

5 minutes ago, Prez said:

Also, as far as the radar dish is concerned: I know the 54 has a larger dish and therefore could have a longer seeker range for PD. I just don't know how much farther. On the note of the sparrow numbers you gave, from all the sources I've seen, the 7F had a max seeker range of 22NM, 26 for the 7M, and then somewhere in the low 30s for the 7P.

The 7F is 22nm vs a 2msq target.  It's over 30nm for 5msq.

[dundun92]

40 minutes ago, Prez said:

7F had a max seeker range of 22NM, 26 for the 7M, and then somewhere in the low 30s for the 7P.

Vs 2m^2, this goes to 32nm vs 5m^2 (this is for the 7F in CW, in PD it will be higher):

[Prez]

2 hours ago, GGTharos said:

It literally says so in the manual.

Maybe?  I mean there are ways to deal with this by using at least say a doppler gate.  These are details and potential limitations that we don't know about.

Well yes, the manual literally says that the missile uses the reflections to adjust trajectory.

The missile - any missile - will always guide by itself.  There's no guidance coming the radar, but rather some form of position updates.  The AWG-9 still has to transmit data to tell the missile where to look for the target, and that's what it does IIRC, it says 'point the seeker there'.   But it doesn't command the missile ie. 'steer this way' so ... the radar is not doing any guiding, the missile is.

The 7F is 22nm vs a 2msq target.  It's over 30nm for 5msq.

Again, I believe your interpretation of the wording is simply wrong. Obviously, I have know way of knowing whether or not this is the case besides reading your statements and then cross examining with my own documentation. 

Here, in this excerpt talking specifically about the TWS launch and track method, it specifically states that each missile is guided via assigned coded messages for the tracked target the missile was assigned to on launch. It would then guide to target using AWG-9 commands until commanded active. It even states that if active missile fails to lock then the missile would be guided all the way to target anyways via the AWG-9 messages. They even say that the missile going active is a "transfer" of guidance, and not simply activating the seeker. Nowhere in this does it state that the missile requires PD reflection to guide in TWS. If that were the case it would not be able to guide multiple missiles at once. Especially in a situation of a bomber formation. How would your supposed doppler gate work against an organized group of bombers all flying practically exactly the same? 

[ldnz]

So if I understand @GGTharos the missile is essentially doing intermittent SARH until such time as commanded active?

It makes sense that the messages are getting reflected off the target - the missile isn't necessarily in the radar scan volume (given its large loft) so 1. the F14 doesn't track it, and 2. couldn't transmit direct path to it. 

Questions I have:

1. what could the datalink message usefully communicate to the missile? If missile knows angular position of the target (monopulse from reflection) then it could communicate information on velocity, heading, which would allow it to refine the intercept?

2. what happens in a track hold target? Is the radar just blasting this coded DL message out in the hope it sweeps over the target and the missile still gets it? 

[GGTharos]

1 hour ago, ldnz said:

So if I understand @GGTharos the missile is essentially doing intermittent SARH until such time as commanded active?

It makes sense that the messages are getting reflected off the target - the missile isn't necessarily in the radar scan volume (given its large loft) so 1. the F14 doesn't track it, and 2. couldn't transmit direct path to it. 

Questions I have:

1. what could the datalink message usefully communicate to the missile? If missile knows angular position of the target (monopulse from reflection) then it could communicate information on velocity, heading, which would allow it to refine the intercept?

2. what happens in a track hold target? Is the radar just blasting this coded DL message out in the hope it sweeps over the target and the missile still gets it? 

The messages are embedded in the radar signal, so the missile is picking them up over sidelobes.

So 1) the missile's DL antennas are picking up the DL from the radar sidelobes, and it tells the missile where to look for the target

2) Yes.   It continues to transmit 'look there' messaging to the missile and if you get lucky the target will be there and the missile might see it.  You could conceivably still guide onto a missile notching the F-14 that way but obviously this a major reduction in Pk.

[FWind]

[Baz000]

"Estimated maximum SR-71 launch speed and altitude"

Damn! They launched that thing off of a SR-71 Blackbird!? Crazy!

Or planned a contingency to launch off a SR-71

Edited October 30, 2021 by Baz000