The russian equivalent of the global positionning system (gps) is called glonass and it's not fully operationnel yet so it's very possible that the pilots of those plane where not aware they were in other countries air space when they were doing their military exercices.
Bet reminder: I bet with Tboned51 that Splatoon won't reach the 1 million shipped mark by the end of 2015. I win if he loses and I lose if I lost.