Watch "Russian Telegram channels report a Russian aircraft crash near Mariupol. According to them, the aircraft was shot down by Russian air defense." on Streamable.
I figure they may be able to compare flight plans with actual course and tell when a pilot is diverging from the planned route. Based on how they are diverging, it may suggest that they are trying to book it to Ukraine? Not sure if this is actually possible, but it’s the best way I can imagine them being able to tell, other than the pilot just disobeying immediate orders and heading for the border, which would be pretty obvious.
I figure they may be able to compare flight plans with actual course and tell when a pilot is diverging from the planned route. Based on how they are diverging, it may suggest that they are trying to book it to Ukraine? Not sure if this is actually possible, but it’s the best way I can imagine them being able to tell, other than the pilot just disobeying immediate orders and heading for the border, which would be pretty obvious.