What do we Know About the Sparrows That we are Getting?

[Biggus]

Being a mostly Navy Phantom enjoyer, I hadn't really had a good look through the USAF docs until this week.  I was able to have a look at the 1990 dated F-4E flight manual and noted that the AIM-7F and AIM-9L and M are listed in the external stores limitations chapter.

This got me thinking about the AIM-7M a little more, and so I went looking in the fount of all modern wisdom, Phantom-related Facebook groups.  So take the next bunch of sentences with a particularly large helping of salt.

One F-4G driver recalled having -7Ms around 1992/93 and mentioned that they initally didn't integrate well, something about a solution not being found in the Tech Order.  A second commenter who I believe was ground crew mentioned that he was involved in trying to integrate it for foreign military sales and they couldn't get it to work following the T.O.  He accidentally destroyed a missile in the process.  A third poster mentioned that he had written a set of instructions for the steps required to integrate the -7M and passed it up the chain of command but nothing came of it.

I've got three hypotheses that probably aren't anywhere close to the truth:

1.  That those posts I discovered were garbage;

2.  That at some point in the early 1990s, USAF Phantom squadrons were considering doing what the RAF did with their FG.1s and FGR.2s when they received the inverse monopulse Skyflash, i.e, provided new hardware to support -7Ms.  I don't think that this is particularly likely, given that the snippets I found relate to F-4Gs which I wouldn't expect to be getting funding for air to air radar upgrades nearing the end of their lives;

3.  That the AIM-7P program (which apparently was able to use both CW and PD illumination like the -F did) enabled some upgrades to flow through to the -7M inventory.  It's worth noting that the AIM-7M F1 build uses a guidance unit in the same series (albeit earlier) as the one from the -P, and it seems to have appeared around mid 1992.  Foreign military sales certainly gives me reason to think that perhaps CW-supporting upgrade kits to existing -M inventories would make sense, and it wouldn't require much additional funding.  Perhaps there were enough new parts in the system to cobble together a workable AIM-7M for the Phantom?

I'd really like to see the 1995 flight manual to see if anything about a Sparrow later than an -F is mentioned!

[KlarSnow]

There is an F-4G -1 from ~1993 that has AIM-7M in the approved list of loadouts. After TO 1F-4-1167, that TO is a F-4 (all types) TO, not an F-4G (specific)TO, so it is the same modification across any phantom that has it.

If you look in the F-4E -1 from 1986 it has the same TO in it as the F-4G-1, even though it doesn't explicitly state it could carry an AIM-7M, just says AIM-7F.

Conclusion I draw from this is that whatever that TO did made it compatible with both the AIM-7F and M, however they did not approve the AIM-7M until later on, There is no indication that anything other than them adding the letter M to the TO was required to be able to employ it.

Essentially, the F-4G and F-4E had the exact same A/A capability and the same radar, if an AIM-7M was cleared for flight on an F-4G it was cleared for flight on an F-4E, now this probably only happened in the last couple of years before the F-4E was retired in the 1990's, but it is a completely reasonable.

[Biggus]

Thanks @KlarSnow, that's a really informative post.

Perhaps you've stumbled onto the same issue as one of the posts I'd found, that the fix to integrate the AIM-7M wasn't found in the TO?  The -7F didn't need anything to illuminate a bandit that wasn't already needed for the -7E.  It was able to guide with both CW and PD illumination.  There would be a range penalty, certainly.  But it was still a decent step up from the late -7E variants.  I'd really like to know whether they modified the plane for the inverse monopulse seeker or whether they modified the -7M to work with CW, though.

But that's all pretty unimportant window-dressing for DCS, the reality is that there's a black and white statement that the -M was integrated before retirement.  This raises the question of whether the last of the Navy Phantoms ever had a -7M strapped to them?  Probably not, given the timeframe.

I'll go hunting for a copy of 1F-4-1167.

[KlarSnow]

The AIM-7M worked with CW, it was compatible with pulse and the CW Illuminator on the tomcat.

Edited October 12, 2022 by KlarSnow

[Biggus]

45 minutes ago, KlarSnow said:

The AIM-7M worked with CW, it was compatible with pulse and the CW Illuminator on the tomcat.

 

That's contrary to everything I've ever read on the matter.  The Tomcat had the CW/PD illumination switch in the back seat for the late -7E variants it used in the first couple of years of service.  The -7F was able to be guided with either signal, but the -7M was not able to use CW due to it's inverse monopulse seeker.  There was a good post about this in the Tomcat forum a year or two ago, I wish I could find the post now.

Having said that, I'm open to the possibility that later on in the development of the -7P which once again supported CW guidance, some of that new hardware flowed into the rebuilt -7Ms at some point.  The timing certainly looks about right.  Looking at the Navy side of the house, if the -7M supported CW guidance, they'd have been sending their Phantoms out on cruises with it almost immediately. 

[KlarSnow]

You can support an AIM-7M in Pulse with CW, and use flood in the tomcat with zero issues, whatever the position of the PD switch is. You can even swap between PD and CW mid flight with no issue.

I think this is a fallacy that has to do with a poor understanding of inverse monopulse.

There are many reasons why phantoms may or may not have been upgraded until late in their life. I seriously doubt CW vs PD had anything to do with it.

[Northstar98]

On 10/12/2022 at 12:23 PM, Biggus said:

The -7F was able to be guided with either signal, but the -7M was not able to use CW due to it's inverse monopulse seeker.  There was a good post about this in the Tomcat forum a year or two ago, I wish I could find the post now.

CW doesn't necessarily mean it doesn't have monopulse encoding - which is the more important thing here IMO.

Regardless though I'm fairly sure the AIM-7M doesn't necessarily need monopulse encoding to guide, given that it has a HOJ mode available which doesn't require the jammer to provide it.

 

Though on my end, with an 84' F-4E-1 revised 1990 doesn't list the AIM-7M in the stores limitation diagram, it does list TO 1F-4-1167 in the TO summary Klarsnow mentioned, but the only things mentioned are improvements to the fuel feed system, self sealing fuselage cells and provisions for mounting selective armour.

Edited October 18, 2022 by Northstar98

[SgtPappy]

On 10/12/2022 at 7:42 AM, KlarSnow said:

You can support an AIM-7M in Pulse with CW, and use flood in the tomcat with zero issues, whatever the position of the PD switch is. You can even swap between PD and CW mid flight with no issue.

I think this is a fallacy that has to do with a poor understanding of inverse monopulse.

There are many reasons why phantoms may or may not have been upgraded until late in their life. I seriously doubt CW vs PD had anything to do with it.

The idea that the AIM-7M needs monopulse guidance is quoted a lot in books so maybe its sort of just a pervasive fallacy now.

Juts like how some books still quote the equal transit bull crap to explain lift... Although I think that's far worse.

[plasma1945]

I put together a little video about all the different sparrow types .. I still cant figure out if the F4E should or SHOULD NOT have Aim7M Aim7P.. I am leaning towards the should not.. but I cant find 100% proof either way.

 

[Kalasnkova74]

On 10/12/2022 at 3:20 AM, Biggus said:

Thanks @KlarSnow, that's a really informative post.

Perhaps you've stumbled onto the same issue as one of the posts I'd found, that the fix to integrate the AIM-7M wasn't found in the TO?  The -7F didn't need anything to illuminate a bandit that wasn't already needed for the -7E.  It was able to guide with both CW and PD illumination.  There would be a range penalty, certainly.  But it was still a decent step up from the late -7E variants.  I'd really like to know whether they modified the plane for the inverse monopulse seeker or whether they modified the -7M to work with CW, though.

But that's all pretty unimportant window-dressing for DCS, the reality is that there's a black and white statement that the -M was integrated before retirement.  This raises the question of whether the last of the Navy Phantoms ever had a -7M strapped to them?  Probably not, given the timeframe.

I'll go hunting for a copy of 1F-4-1167.

Mike “Starbaby” Pietrucha noted that the F-4G WW (and by extension the F-4E) shared the same AIM-7 capability as the period F-15 Eagle. This came up in his interview as recalled USAF brass restricted the Phantom IIs Sparrow parameters in exercises, but those same limits weren’t applied to the F-15 even though both could use the same missile. 

[Temetre]

vor 14 Stunden schrieb plasma1945:

I put together a little video about all the different sparrow types .. I still cant figure out if the F4E should or SHOULD NOT have Aim7M Aim7P.. I am leaning towards the should not.. but I cant find 100% proof either way.

Tbh, Im usually going with "make it dependant on the scenario". The integration is technically viable and even has been possibly done on some F-4Es, and at least on similar F-4Gs. And after all its a nuanced discussion without a clear answer, so by default Id say "add it".

 

After all, even the difference between E1/2 and F is gonna be quite big, and same with the Aim-9. Allowing the 7M gives more flexibility for the scenario (fictional or export-craft), and doesnt really change the requirement of limiting equipment to the timeframe. Same can be said for weapons like the GBU-15, for example.

Idk about the Aim-7P tho; at least the mid course guidance would be unusable on the F-4E, so it would be somewhat strange to have.

Edited April 30 by Temetre

[Stackup]

21 hours ago, plasma1945 said:

I still cant figure out if the F4E should or SHOULD NOT have Aim7M Aim7P

We're getting the M but not the P