In the third tutorial misison of the L39, on radio navigation, i think i noticed a bug and didn't find any mention of it around the forum.
When flying runway heading for a while, the voice over (and text) ask you to turn around and fly back to Mozdok, where you come from.
But shortly after, and long before you're back over the airport, the next text/voice event is triggered, asking you to fly heading 280 for 70km, but cue you to do that once you see the rsbn needle turning around because overflying the beacon.
So my understanding is that last event comes too soon, and should be trigered only above mozdok, not 30km from it.
folowing this idea, i managed to complete this comprehensive tutorial which get you to fly with the IFR hood down :). the remaining triggers work well.