IRL, even F-14 (which is a much older aircraft) can fire the AIM-54 in IRST track mode.
So I would be quite surprised if Su-27SM and MiG-29SMT didn’t have the same capability.
Especially since it would be quite trivial to implement. As an ARH missile basically only needs azimuth, elevation and target closure to lock onto a specific target, and all of that can be provided in IRST track mode. (F-14 can fire AIM-54 with IRST track without even providing a closure rate)
It would make the IRST on some planes way more useful as well, right now it can only be used for finding other people without pinging them and the occasional long range IR shot. Would definitely diversify top tier if you only have 16km warning rather than however far they fired from.
I’m not exactly a radar expert so call me out here but wouldn’t that be significantly worse than a regular ACM mode due to the Crusaders slow(ish) radar refresh and acquisition?
Airframes of Su-25 and Su-25K are already over-ranked at 10.3 BR, because of their capability to carry R-60M missiles.
Even at 10.3 BR of Air RB, you never get to the enemy bases first, you can hardly defend yourself with those two very short-ranged and flair-hungry missiles, and if anyone gets in your tail - you might as well eject.
I think Su-39 with radar-guided missiles at a higher BR (even as high as 13.7 BR), would fair better then Su-25SM3 at 12.3 BR, or even Su-25T and Su-25BM at 11.3/11.7 BR of Air RB.
