Salute!
Good question and good basic common sense, Brain.
The 15 n.m. distance might be great if tracking parallel to the coast or known defense facilities or..... But heading straight in is asking for trouble ( that was the Vincennes delimma). Some of these SAM systems can reach out and touch you at much further ranges than 15 n.m. if you are at medium or high altitude at 0.8M or slower. In this tragedy case, the "target" was heading straight for the missile battery and associated "research" or military site.
The fog of war and poor integrated air defense comm was a definite player.
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