The tunguskas use radar also but can fire independantly of it. However if think that by flying low and fast matching the countour of the terrain is the best way to avoid being hit by ainti aircraft fire. It also protects you from enemy fighters who have a hard time chasing you at such an altitude. I am not sure if this is true or not but i think you can sneak up on the anti air deffenses. I remember on one mission i flew over a sam and AAA hornets nest and got no fire coming up at me untill i had already passed it. I turned for a second run and got creamed. So i think you can catch them by surprise. -+
Fast and low is the way to go