AIM-7 behavior

[Spurts]

Not sure if this is a bug yet so not putting it as such.  Last night I flew to intercept a few Tu-22s with AIM-7MHs.  When I fired the bombers broke and dove, sure, no big deal.  After a bit I decided the first missile was trashed and I fired a second one.  My pilot (I was backseat) managed to snap our wings off but I was able to watch a bomber explode before we ejected.  Later I checked the Tacview.

We never lost lock, but the two missiles seemed to go after two different targets.  Oddity number 1

Missile 1 stopped guiding the instant I fired missile 2.  I will have to check my reference docs, but I was pretty sure the Tomcat had 6 channels for communicating with Sparrows, shouldn't that let me guide more than one at a target?  Oddity number 2

[speed-of-heat]

tomcat has 6 channels for communicating  with Phoenix.. not sparrow

[Naquaii]

It had different frequencies for AIM-7 as well. But this isn't modelled in DCS. In DCS we just give the missile a target and tell it if we track that target or not. Guiding against two separate targets should not be possible.

[Harlikwin]

23 minutes ago, Naquaii said:

It had different frequencies for AIM-7 as well. But this isn't modelled in DCS. In DCS we just give the missile a target and tell it if we track that target or not. Guiding against two separate targets should not be possible.

Maybe it went HOJ? I've seen various SARH missiles hit different bombers than what I had locked before, both in the cat and FC3 modules for example. I always figured it was likely a HOJ thing. 

 

Edited July 20, 2022 by Harlikwin

[Spurts]

22 minutes ago, Naquaii said:

It had different frequencies for AIM-7 as well. But this isn't modelled in DCS. In DCS we just give the missile a target and tell it if we track that target or not. Guiding against two separate targets should not be possible.

So for issue #2 of losing track as soon as I fire a second missile, is that a current DCS-ism?  For issue one of guiding to the wrong target, I will review my tacview for the first shot but it LOOKED like it tracked a different target than what missile 2 destroyed.  I initially assumed it was because both targets were within the beam, but I don't know how big the beam in DCS is.

2 minutes ago, Harlikwin said:

Maybe it went HOJ? I've seen various SARH missiles hit different bombers than what I had locked before, both in the cat and FC3 modules for example. I always figured it was likely a HOJ thing. 

 

 

I can check the Mission Editor to see what the jamming settings were to see if we can rule this out.

[Naquaii]

4 minutes ago, Spurts said:

So for issue #2 of losing track as soon as I fire a second missile, is that a current DCS-ism?  For issue one of guiding to the wrong target, I will review my tacview for the first shot but it LOOKED like it tracked a different target than what missile 2 destroyed.  I initially assumed it was because both targets were within the beam, but I don't know how big the beam in DCS is.

I can check the Mission Editor to see what the jamming settings were to see if we can rule this out.

It should be possible to guide multiple missiles as long as it's against the same target. The lobe-width of the illuminator is not a factor in DCS for missile guidance due to how that works.

[Spurts]

2 minutes ago, Naquaii said:

It should be possible to guide multiple missiles as long as it's against the same target. The lobe-width of the illuminator is not a factor in DCS for missile guidance due to how that works.

hmm, then issue #2 might be dumb luck timing with the first missile running out of power as soon as I fired the second...  And thank you for verifying that illuminator lobe-width is not something in DCS.

[Harlikwin]

58 minutes ago, Spurts said:

So for issue #2 of losing track as soon as I fire a second missile, is that a current DCS-ism?  For issue one of guiding to the wrong target, I will review my tacview for the first shot but it LOOKED like it tracked a different target than what missile 2 destroyed.  I initially assumed it was because both targets were within the beam, but I don't know how big the beam in DCS is.

I can check the Mission Editor to see what the jamming settings were to see if we can rule this out.

Yeah check that. IDK. But Ive seen weird stuff in online servers, like you have a 4 ship of bombers, you have one locked, you shoot, missile goes and hits a different bomber in the formation. This is ofc after you are in burn thru range for ECM so hard to tell which one is jamming. And OFC in the cat there is no burn thru cuz the AWG9 doesn't have ECM stuff modeled yet.

Edited July 20, 2022 by Harlikwin

[draconus]

Missile #1 could also be notched/lost a lock/chaffed and went for a first thing the flood illuminated. Just upload the tacview file so we could stop guessing.

[Spurts]

Tacview-20220719-212057-DCS-backseat trainer.zip.acmi

 

no ECM settings at all in ME, so I don't know what the defaults are.

Edited July 21, 2022 by Spurts

[Harlikwin]

34 minutes ago, Spurts said:

Tacview-20220719-212057-DCS-backseat trainer.zip.acmi 802.76 kB · 0 downloads

 

no ECM settings at all in ME, so I don't know what the defaults are.

 

IDK I'd assume they self defend with ECM and flares, that seems to be default. 

[Spurts]

It's a fox1, I never lost lock.

[henshao]

mechanically I have no idea why guiding a second sparrow would make the first sparrow go dumb

 

therefore I was confused by this statement by a former Tomcat pilot? rio?
 

"Leo fires a second sparrow, which makes the first one go stupid"

[RustBelt]

I believe each sparrow is set to a discrete code as it launches that’s Pulse Width Modulated embedded in the illumination. So that multiple aircraft can fire simultaneously on separate targets without the sparrows getting confused. 
 

You can only light up one target for one designated missile at a time. 

[Spurts]

2 minutes ago, RustBelt said:

So that multiple aircraft can fire simultaneously

If that's the reason for the multiple channels then it makes sense.

3 hours ago, henshao said:

therefore I was confused by this statement by a former Tomcat pilot? rio?

Mooch is a RIO

[RustBelt]

Channels are I believe another level of that. Because depending where you are and what else is going on, you may have interference and noise on certain channels or other since it’s just part of the radar spectrum and in a war zone there may be all kinds of noise. 
 

Especially if you have stuff like high altitude burst Nukes EMPing in theater, which was an actual cold war consideration prior to full MAD.

Edited July 28, 2022 by RustBelt

[henshao]

supposing you do have a set multiple search/track/guidance channels for a given radar, if the purpose is to deconflict with other aircraft why would it would switch between launches on the same jet

[GGTharos]

Possibly for ECCM reasons.

[henshao]

reminds me of a tidbit I read about during ACEVAL/AIMVAL, some of the techniques pilots were using to try to get around the revenge fox-2 vulnerability due to visual id requirements on sparrow launches, and tomcats guiding one another's sparrows. I assume the lead ship would visual ID (confirm hostile) shoot sparrow and break away from revenge fox-2 while the distant trailing fighter held lock and guided. don't know if it worked or not, though.

[near_blind]

3 minutes ago, henshao said:

reminds me of a tidbit I read about during ACEVAL/AIMVAL, some of the techniques pilots were using to try to get around the revenge fox-2 vulnerability due to visual id requirements on sparrow launches, and tomcats guiding one another's sparrows. I assume the lead ship would visual ID (confirm hostile) shoot sparrow and break away from revenge fox-2 while the distant trailing fighter held lock and guided. don't know if it worked or not, though.

The Booker T. Washington shuffle was to satisfy the VID requirement for an engagement. The lead aircraft would exit without firing, the trailing aircraft would engage from beyond visual range with the intent the Fox-1 would time out (i.e. hit) before the bandit closed to Fox 2 range. One aircraft guiding another aircraft's missile isn't really a thing, at least not until potentially very recently. 

[GGTharos]

8 minutes ago, henshao said:

tomcats guiding one another's sparrows

No.  Channel separation was implemented specifically to prevent this, and the poor Pk it brings due to EMI.

[henshao]

I didn't say it worked, just that they apparently tried it

[near_blind]

21 minutes ago, henshao said:

I didn't say it worked, just that they apparently tried it

They did not, at least not in AIMVAL/ACEVAL

Quote

Early on, this spawned a bunch of ideas; the "Booker T. Washington Shuffle," the "Piston," the "Spincter" just to name a few. The BTW was designed to work with 2, 4, or 6-plane formations, where one/two/three of the F-14s would fly ahead of the other one/two/three, VID at 5-8mi, break and run, then the following F-14's would all fire at the F-5's from well beyond the AIM-9L's range, ensuring kills while staying out of the Sidewinder envelope, and then kill any survivors with their own AIM-9's or with GUNS, failing the former. The kill-to-loss from the BTW was better than 6:1. "Hawk" Smith came one weekend and found a way to ruin the BTW (after a few flights), so the "Piston" was developed, which caused a resurgence in K:L. The "Spincter" has to do with passing off a target lock to a weapon in flight. Can it be done? Can't say, but given the BTW, you can see it was of prime interest to the Blue Force.

It also goes without saying they weren't actually firing missiles at the F-5s, so I'm not sure where we're getting the idea of outsourced guidance from. 

[henshao]

5 minutes ago, near_blind said:

The "Spincter" has to do with passing off a target lock to a weapon in flight.

 

[near_blind]

I don't see mention of another aircraft or actually _trying it_. I _do_ see incredulousness that it would work.