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, please check out my video for that location too... You can find the link at the training zone page of this guide