I don't know if anybody else has read Osprey's Duel 72 F-15C vs MIG-23/25 by Douglas Dildy&Tom Cooper. While the overall quality of the Duel series is highly variable, I was quite surprised by the description made by the authors about the MIG-23ML "Flogger-G" and its RP-23MLAE Sapfir III (N003E). Here's an excerpt from the book:
"For this version, the Sapfir had been redesigned for engaging only airborne targets in the “front quarter” (head-to-head). The radar had no capability for detecting or tracking targets it was chasing (i.e. the “rear hemisphere”)"
On rear engagements:
"Because the Sapfir III was designed exclusively for front-quarter intercepts and R-24R employment, the TP-23 IRSTS was provided to allow MiG-23 pilots to engage targets in their “rear hemisphere.” In a “stern chase” look-down scenario the TP-23 could locate a high-speed, afterburning (i.e. thermally “hot”) target ahead and the S-23 system would “slave” the seeker head of the IR-guided R-24T, the lock-on being indicated by an aural tone in the pilot’s headset. Range determination was, however, problematic and exacerbated because, in the “tail chase” mode, the R-24 had significantly reduced range, depending on the MiG’s overtake airspeed."
Comments anyone? Undoubtly this is a major limitation.
On the "look down" capability:
"For closing targets at or above the “Flogger’s” altitude, the radar could track (“lockonto”) a target inside 18.9nm (35km), which was approximately the maximum range of the R-24R missile when fired head-on at high altitude. To detect targets below the radar’s altitude, the AVM-23 computer used an “external coherence method” to detect a target passing across/through the “clutter” caused by the earth’s radar return (called “moving target indicator”). This computer process had severe limitations due to numerous “blind zones” in multiples of the radar’s PRF, being able to only detect targets in the duration between successive pulses, and was limited to much shorter detection ranges (16.2nm/30km)."
This seems similar to the Cyrano IVM "Look down" system, which, accoding to the pilots I`ve met, was quite unsuccesful.