I remember it well.
A lot of Russian generals lost their jobs that day. There were foreign media all over Red Square for some big propaganda fluff promotion of the Soviet Union, when all of a sudden, some dude just lands there, with all the cameras to see.
When their chief general of air defense was called, he thought someone was pulling his leg.
One of the things that supposedly allowed him to pull it off was that there were two major search and rescue operations going on for downed aircraft, so there was a lot of flight activity in the corridor he chose.
Somehow, it all worked out in his favor, until he was arrested.