Heli Attack 3/Zone 3-3

Helicopters to destroy: 8 Bomber Helis 5 respawning Gunned Robots

Tactics
Again, same as 2-4, and don't forget my warnings at the zone 3-2.... And lastly, the third and last secret free weapon is in this zone, to reach this one, drow down twice thile you're on the second metal bridge you see and destroy the walls on the right, than go right into the space left from this walls and destroy the walls above you. jump up there, and you will see a flakcannon... You can find the link at the training zone page of this guide