fred pleitgen is out front tonight in ukraine with more. reporter: ukrainian su-25 attack aircraft given the go to assault russian positions. against all odds, ukraine s air force is still very much in the fight. are you helping the ground forces now a lot in the south with the counteroffensive operation? yep, yep. reporter: the mission is extremely dangerous, especially for front line attack aircraft. ukraine s aces trying to keep russian air defenses off balance. we lost many young pilots from our brigade. this taught us to change something. day by day we tried to fly not the same as yesterday. reporter: while kyiv says its counteroffensive is progressing, the battles are tough and gains