AIM-7 loses guidance when TGT maneuvers through the Beam/Notch - even if briefly

[Notso]

Related to potential AIM-7 errors, I've been noticing a lot lately that AIM-7s go "stupid", i.e. discontinue tracking completely, when the Target passes through the beam, even if only for a moment.  This is incorrect behavior, at least for the newer 7M and MH.  I'm pretty sure the 7F as well.  If the RDR itself is able to handle tracking the TGT through the beam, the missile will continue tracking the TGT.  It does NOT get automatically "trashed".  

I don't know about other jets, but the F-15C and E both have a part of their A/A WEZ display called Rtr - "Range Turn and Run".  This WEZ display exists for both AIM-7 and AIM-120.  The definition of RTR is:  

Quote

"Rtr indicates the maximum launch range against a target executing an evasive turn and run maneuver at launch.  This zone assumes that the target executes a maximum g level maneuver with instantaneous g onset in the shortest direction to tail aspect".

So there is no way to turn and run from a HOT aspect to a tail aspect without turning through the beam.  Ergo, the missile should be able to continue tracking the TGT even if it passes through the beam momentarily.  And the F-15E has track memory that will allow it to maintain track on TGTs as they pass through the beam.  Obviously, it the Maneuver breaks the RDR lock - the AIM-7 will lose guidance.  But with a good track, currently in DCS - any momentary beam maneuver loses the missile completely.

If you need further supporting documentation, please DM me.  Thanks.

[spazz212]

On 1/16/2024 at 4:18 AM, Notso said:

Related to potential AIM-7 errors, I've been noticing a lot lately that AIM-7s go "stupid", i.e. discontinue tracking completely, when the Target passes through the beam, even if only for a moment.  This is incorrect behavior, at least for the newer 7M and MH. 

I Suspect this is a legacy thing as every missile get spoofed in the notch, I think that the  MH/M/P don't have the Inverse Monopulse simulated as with it there isn't a "classic" notch. The Flood antenna works pretty well however.

[GGTharos]

On 1/15/2024 at 12:18 PM, Notso said:

Related to potential AIM-7 errors, I've been noticing a lot lately that AIM-7s go "stupid", i.e. discontinue tracking completely, when the Target passes through the beam, even if only for a moment.  This is incorrect behavior, at least for the newer 7M and MH.  I'm pretty sure the 7F as well.  If the RDR itself is able to handle tracking the TGT through the beam, the missile will continue tracking the TGT.  It does NOT get automatically "trashed".  

I don't know about other jets, but the F-15C and E both have a part of their A/A WEZ display called Rtr - "Range Turn and Run".  This WEZ display exists for both AIM-7 and AIM-120.  The definition of RTR is:  

So there is no way to turn and run from a HOT aspect to a tail aspect without turning through the beam.  Ergo, the missile should be able to continue tracking the TGT even if it passes through the beam momentarily.  And the F-15E has track memory that will allow it to maintain track on TGTs as they pass through the beam.  Obviously, it the Maneuver breaks the RDR lock - the AIM-7 will lose guidance.  But with a good track, currently in DCS - any momentary beam maneuver loses the missile completely.

If you need further supporting documentation, please DM me.  Thanks.

There is a section in the -34 which describes very briefly the AIM-7 split-s protection.  A similar technique could easily be used to coast through the notch, so I think that would be a good section of the document to look through.  This behavior affects all DCS missiles, including ARH, it's just that ARH are more capable of recovering in-game for whatever reason.