But what platform Ukr have that can launch HARM? Modified su-24 / 25 mig-29??? I am puzzled.
I suppose it's time for me to chip in. The information is still scarce but we've managed to put bits of data together on another Polish forum and it might be the explanation you're looking for.
The guidance of an anti-radiation missile is similar to semi-active homing. The seeker head is a passive antenna that calculates angle of the wave over time to establish the "head on" trajectory toward the strongest signal. The only difference between SARH and anti-radiation missiles (ARM) is that SARH follows the signal of the aircraft's radar while ARM follows strongest signal with characteristics that match enemy radar.
Because of that ARM works like an WVR IR-guided missile and is capable of acquiring the target signal on its own and can be fired blind toward source of radiation. The missile follows the angle which changes over distance and when emissions are cut there in correction and the missile follows on ballistic trajectory missing the target. This tactic is not intended to destroy radar but to force operators to turn it off.
So if Ukraine received AGM-88 HARM then it is capable of using it in that mode which requires only the LAU-118 launcher, some cables and a simple switch in the cockpit with a light indicating that the missile has locked on an emission source. This kind of work can be easily done in the facilities that repair Ukraine's fighters and could be installed on any aircraft that is capable of carrying 500kg payload on a pylon.
The resulting tactic would be very crude but when used in conjunction with a GMLRS strike it can be timed to give Russian air defenses an impossible choice - continue using radar to shoot down GMLRS and risk being destroyed or switch off the radar and allow GMLRS to strike target.
From what I've heard this has been the case in the recent attacks that allegedly resulted in 14 Russian SAM systems or radars destroyed. However this data is not confirmed.
But that's just the simplest manner in which HARM can be integrated. I also learnt that in the past Poland has explored the options to integrate NATO munitions onto MiG-29 - specifically AIM-120, AIM-9 and AGM-65 that would be shared with F-16s. That requires adapting the internal system to MIL-STD-1553 but
allegedly such documentation has been prepared. This means that all Ukrainian MiG-29s - including those assembled from parts donated by Poland and Slovakia - can be converted to MIL-STD-1553 and use HARM not only in passive acquisition mode but with onboard INS or even GPS input as well - thus ensuring that the trajectory doesn't deviate as much once the radar is turned off.
Considering that Ukraine had to assemble the planes from parts - it would be very easy to modify them to launch HARM during that process. Integration of other NATO munitions - apart from perhaps WVR IR missiles for the same reason - is however a much bigger problem because unlike HARM they require data input from the aircraft's sensors and that would be too complicated in current conditions.
So to sum it up:
1. basic HARM integration with launching the missile "blind" in the general direction of the source - any Ukrainian aircraft capable of 500kg payload per pylon.
2. basic HARM integration with INS correction and
perhaps GPS - MiG-29s modified following the documentation from Poland.
Anti-radiation missiles seem like an advanced system that can't easily by installed on another aircraft but they are really not. In many ways they are the easiest thing to add.
Finally a general note on how to interpret the reporting:
The impact of HARMs is not so much the consequence of HARM being some incredible weapon but the lack of long-range ARM in Ukraine's inventory at the beginning of the invasion. Ukraine had only old Soviet ARMs which weren't very effective. HARMs simply restore that capability and after five months of fighting Russians have adapted to lack of threats.
The same thing was true for GMLRS. Ukraine had only fifty (50) Vilkha rockets (Ukrainian-made GPS-guided BM-30 munitions) and very low stocks of unguided BM-30 munitions at the beginning of the invasion. Therefore when GMLRS strikes began Russia has already assumed that Ukraine lacks the means to strike at those ranges as this was the case during the four preceding months of fighting. They laid out their logistics accordingly which allowed Ukraine to strike targets identified by NATO satellite recon.
Consider that the most impactful GMLRS stirkes come near Kherson where the very geographical position of Russian forces is a problem. Everywhere else they play their part, but it's a minor one in the general picture.
In both cases the illusion of a "Wunderwaffe" is really the result of media over-reporting on individual strikes and saturating your attention with them which combined with lack of such reports previously created the distortion.
And now a similar thing will happen with what might be the first ATACMS strike at Novofedorovka in Crimea. Ukraine launched multiple Tochka-U missiles but they were rarely reported. Conversely any use of NATO - especially US - weapon will be disproportionally reported.
