[hoplitis]

Did they "lock on" a target and conduct a bombing/strafing run?
Was the target to the "right" side of the map?
Could the plane do a "low left entry - hit target - high left exit" in a simple path? Planes seem to follow a straight path up to a point, do one turn (or none at all) and exit (straight path). This maybe an "if I'm to hit the target then I won't be able to turn" thing. Maybe hitting an aquired target gets priority over following the preplanned route?
There were issues with the entry/exit hexes in the past. I think it was fixed. Personallly it has not bothered me recently.