[Goose]

The Su-35S shot down and publicized few days ago (as per Twitter) was equipped with L-265M10P/R electronic countermeasures pods that should be of interest to US intelligence.

https://theaviationist.com/2022/04/03/fi...n-ukraine/

I am sure they will be. Even if damaged they are useful.
One area that has kind of been a "black hole" is what Russia is using for IFF. Supposedly they designed an entire new system in 2014 or so, but whether it was ever actually fielded I don't know. That may mean Russia and Ukraine are actually using the same IFF hardware if the Russians didn't actually replace theirs. Obviously they would be using different codes, but the long history of Russian IFF being compromised may make people nervous. That may account for the Russians not doing as well as expected in the air. Both sides may not trust their IFF that much.
If indeed the Ukrainians have used helicopters to attack oil facilities in Russia, the Russians not using their IFF may account for their lack of prompt response. It may be they assume everything inside Russian airspace is friendly because they really can't tell without IFF, and visually inspecting every aircraft is impossible. Granted the helicopters were probably flying low, but they still should have been detected.

[Goose]

The Su-35S shot down and publicized few days ago (as per Twitter) was equipped with L-265M10P/R electronic countermeasures pods that should be of interest to US intelligence.

https://theaviationist.com/2022/04/03/fi...n-ukraine/

I am sure they will be. Even if damaged they are useful.
One area that has kind of been a "black hole" is what Russia is using for IFF. Supposedly they designed an entire new system in 2014 or so, but whether it was ever actually fielded I don't know. That may mean Russia and Ukraine are actually using the same IFF hardware if the Russians didn't actually replace theirs. Obviously they would be using different codes, but the long history of Russian IFF being compromised may make people nervous. That may account for the Russians not doing as well as expected in the air. Both sides may not trust their IFF that much.
If indeed the Ukrainians have used helicopters to attack oil facilities in Russia, the Russians not using their IFF may account for their lack of prompt response. It may be they assume everything inside Russian airspace is friendly because they really can't tell without IFF, and visually inspecting every aircraft is impossible. Granted the helicopters were probably flying low, but they still should have been detected.