I wonder if Russian missiletronics designers are deliberately dissembling or if perhaps it's an engineering cultural difference.
1. When the F-4 fires the AIM-7E, the weapon picks up CW from the wing pylons as a kind of 'tether' which provides true distance based on pulsed coding in the FMICW. This is then compared to the returns coming in through the seeker of the missile to provide a distance from target vs. distance from launch condition to shape a proportional lead trajectory with. It is why 25G Sparrows, when they worked in SEA, could seemingly cut square corners to pull target lead.
2. An autopilot is not an IMU (Inertial Measurement Unit, different from an INS In the number of feeds it can take from external sensors like radar altimeters, doppler velocity sensors and AHRS) in that an autopilot steers based on perceived target/launch platform attitude and rate differences fed to it via seeker deviations whereas an IMU steers from an internal rate and angle gyro that will put the missile in a given position downrange in time+X seconds. It is a great deal easier to do exotic homing algorithms with a 3D spatial predictive IMU than a 2D X+Y angle off predictive target lead. Indeed, the seeker doesn't have to 'see' the target radar returns, at launch or any time before terminals, to lock it up and start homing at the endgame. The missile simply drives itself to a point where the seeker is in-range.
3. Early ARH datalinks were not CW (which APG-63/66/68 did not support, though AWG-9 still did) but still used imbedded radar secondary channels (AMRAAM was an 'M' band sideband) that fed range and range rate to the weapon to perform internal midcourse update corrections, based on the IMU. This likely limited the number of missiles which could be supported to only those which were tuned to the parent jet radar at or shortly after takeoff.
AIM-120C6/7 (sources vary) added a more sophisticated, midcourse trajectory enabled, datalink which was separate from the tuned fighter radar homing to allow other aircraft to hand off midcourse data which effectively mean you were not supporting the round through seeker activation by a lead jet but could rather launch and chainsaw with the trailing aircraft using a generic waveform but missile specific encryption code to pass tracking data, easing the shooter vs. guider airframe closure issue. I believe AIM-120C7 now uses a GPS enabled IMU which knows it's own position far more precisesly and can tell the guiding jet (parent or illuminator) it's own position as a function of shot clock TOF remaining on whatever loft it is on. It probably also includes remaining weapon speed and offset to inform the pilot as to likely intercept SSPK but there is of course (TRD, expendable Bright Cloud, threat airframe extension etc.) guarantee on this. The first I heard of such a capability was on Python 5 as what differentiated it from Python 4. So if the Israelis can stuff the tech into a 6.3" diameter, 10ft long, missile, they can probably put into a 7"X12ft AMRAAM.
The important point to note here is that an R-27ER/ET with a sophisticated (silent running, encrypted MCU) could theoretically be almost as capable as a (shorter ranging) AMRAAM _if the trajectory steering midcourse guidance_ could come from an offset wingman or trailing stinger airframe. It would certainly make sense when you hear about jets being able to 'track 20 targets and engage 4' with HDTWS off a planar array vs. an AESA/PESA electronic scan.
Such a concept may go as far back as the AIM-7MH from the 1990s era (Janes F-18 Super Hornet had these) and it would be worth noting that the avionics could shift from TWS to High Data Rate TWS and then STT to support the onset of SARH guidance as a graduated PRF step that had nothing to do with actual launch.
You fire your own weapons AFTER you guide other folk's shots, as you close up and clean up on the missed-target survivors. Given you are another 10-20nm further behind the SARH round than the jet which shot it, as long as it doesn't need actual target illumination until the endgame (IMU vs. Autopilot difference, the latter must generate steering differentials through the seeker) and can time share with other missiles when it does go active, you can hit multiple threats which fired on the lead jets at say 30nm and Mach 1.2 (at FL300) or 50nm and Mach 1.5 (at FL450), with the threat not realizing that the actual illuminator who was responsible for the missile shots was in-trail on the lead jets which pumped off, sometime after launch.
Again, F-16s/18s actually have a named tactic for this, it's called Chainsaw, presumably as a function of the rotation of the teeth along the retreating blade. Having remote, offboard, guidance by powerful Zhuk/Bars/Irbis radars, would change everything about DCS gameplay without necessarily requiring mirror image missile types.
Keep in mind that Russia suffered a terrible blow when she and Ukraine went their separate ways as there were a lot of shared programs whose next-gen technology development programes, including seekers, that were effectively abandoned or likely given over to the West. Added to the budgetary woes of the corrupt Gorbachev/Yeltsin period and there was also simply no money to redevelop more advanced SEEKERS. But not strapdown navigators. Nor datalinks.
These are likely what is in the upgraded R-27 missiles, along with perhaps some variant of the R-27EM seeker from the Su-33.
