Russian air defense system

Azerbaijan Airlines says plane crashed after 'external interference'
as questions mount over possible Russian involvement
...
...
 Miles O'Brien, a CNN aerospace analyst, told Jim Sciutto on Thursday
that the fact that the metal around the holes is bent inwards shows
that there was "an explosion in proximity to the tail of that
aircraft."

That is "quite literally smoking gun evidence of a surface-to-air
missile," O'Brien said, adding that the plane was flying over Chechnya
"in the midst of heightened military activity."

"You might conclude a hair trigger approach to things," he suggested.

https://www.cnn.com/2024/12/27/asia/azerbaijan-airlines-crash-intl/index.html