so once super hornet lets off an amraam or 2 what will it do?will it/or will it need to give amraam a midcourse update ?
That depends on the situation. If its an AIM-120D then the missile can be updated directly from a 3rd party (i.e. another Rhino further away). Then the F/A-18F can disengage, hit the Flanker with an EA or follow up with another missile if need be.
and if so would the super hornets rcs now be large enough for flanker to see it, as they have closed the distance and get off a return shot?
If they were closing head on towards an eventual merge then yes. But the whole point of limited RCS reduction is to achieve detection before counter detection (first look). What first look allows you to do is set the terms of the engagement; If there are too many to engage the SH can disengage before it is detected, it can maneuver with the intent of launching a missile from outside the Flankers sensor footprint (remember radars only look straight ahead) or at the very minimum launch first (first shot).
Half the advantage of shooting first is you will force the other guy to maneuver before you have to. If you are both supporting your missiles with mid course updates (and neither missile is being updated via a 3rd party) the fact that yours is flying first means that yours will get there first. What this means is if he wants to support his missile throughout the flight path up until end game your missile is going to get there first i.e. he will be dead. So he will have to maneuver and stop supporting his shot which reduces the pk significantly. At extreme range without updates a BVR missile shot is not going to have much chance of success.
Additionally shooting first and remaining undetected at the time of launch provides other benefits. By delaying detection of the threat you increase your missiles No Escape Volume/Zone because you delay the targets evasive reaction. Outrunning a missile only works if you run early enough, and even within the NEZ delaying evasive maneuver means your shot will arrive at a higher end game energy state thus increasing the pk.
So yes the Flanker can shoot back, but with missiles already in the air the Rhino has a significant advantage by setting the terms of the engagement. Again if the SH was able to launch on an unsuspecting Flanker from outside its radar footprint and the missile remained undetected throughout its flightpath the Flanker might only recognize the threat at the terminal stage. That means a high energy missile with you in the center of its engagement basket and your in a low energy state. Not good.
or would the amraam shot be true fire and forget from the start?and if fire and forget, does that mean a reduction or major reduction in probability of a hit versus a mid course update shot?
Yes you can use an AMRAAM as a fire and forget weapon, relying on GPS and INS to get the missile to the terminal stage where its seeker can take over, but at long range the pk is going to be low. Thats why they have data-link systems installed.
also when superhornet lets off its shot its going to eventually have to do an about face and leave the area so its side and rear rcs profiles will be facing flankers radar,so would that be flankers cue to detect and get off a shot if still heading on its original course,as im assuming APG-79 mightnt have been detected and amraam radiates in the terminal phase.
Yes but by your assuming the F/A-18F stayed within the Flankers radar footprint, it may well not have. But in any case the SH has got the first shots off, so the Flanker needs to maneuver to survive and cant support its missile shots for long.
Achieving first shot is a huge advantage, and thats what the RCS reduction on the super hornet is designed to achieve. It's not F-22A style VLO which for the most part render's the platform invulnerable in the BVR regime. With superior LPI radar and ESM/RWR, its designed to allow the Rhino to set the terms of the engagement by achieving detection and track before counter-detection.
