The helicopter (attack chopper) is a killstreak which takes 5 kills to get. It can be purchased at level 19 by medics and assassins, and it applies to all soldiers in the "Big Brother" challenge (10th challenge) on the speeding train where you have no weapons, but permanent air support. Unfortunately, it cannot be used in indoor maps (ex. facility). Due to a recent update, however, the attack chopper deals 2x damage as it previuously did. The attack chopper fires bullets quickly and aims automaticly at the nearest enemy, but it uses up time for its gun to rotate and only lasts 10 seconds.