In multiplayer, an attack helicopter (the AH-1W Super Cobra for SAS/Marines and the Mi-24 for OpFor/Spetsnaz) can be summoned to provide fire support for the player's team with a seven kill streak. Once summoned, the helicopter follows a pattern circling around the map once, looping back to where it started, and then leaves. Helicopters search for and kill any enemies with machine guns and (contrary to popular belief) very rarely, utilize rockets (it is possible, albeit extremely rare, to be team killed by a friendly helicopter in hardcore game modes).
Helicopter support does not stack; players who has achieved seven kill streaks have to wait until the current helicopter leaves or is shot down to call in a new helicopter. Lower tier air support (i.e. UAV and airstrike) can be activated at same time a helicopter is active, however. The helicopter leaves after approximately two minutes at most, but can leave earlier.
Helicopters have 1100 hit points. They take 30% damage from bullets until they have lost 500 hit points, at which point they take full damage from bullets. Helicopters also use evasive maneuvers after losing 500 hit points, and attack and move faster during evasive maneuvers. Shooting down a helicopter is an option, with the RPG and light machine guns being the most effective weapons. One hit from an RPG rocket deals 1000 damage, 91% of a helicopter's hit points. The Sonic Boom perk (which increases the lethal radius of the RPG by 25%) does not affect the damage done to a helicopter. Mounted M249 machine guns are also effective, often more so than RPGs, as they can easily take down a helicopter in around five seconds. Although helicopters never open fire without line of sight, they often continue firing at a player who has taken cover, and its bullets penetrate many surfaces.
While the AH-1 SuperCobra and the Mi-24 Hind helicopters are identical in performance, the Mi-24 is much larger than the AH-1, making it a much easier target for RPGs. It is harder to hit the AH-1 unless it's very close to the RPG user.
Helicopters assess certain factors when deciding which players to engage (factors not listed in any particular order):
- Distance between the enemy and the helicopter; helicopters attack closer targets first.
- Whether the player has attacked the helicopter before; helicopters prefer to attack the player who most recently attacked them.
- The weapon an enemy player is using; a helicopter is more likely to attack an enemy player with a LMG-Sniper Rifle-Assault Rifle-SMG-Shotgun. Contrary to popular belief, carrying an RPG does not increase the chance of a helicopter shooting the player.
- Player stats for the current game, such as kill-to-death ratio; helicopters likely attack enemy players with high kill-to-death ratios.
- The helicopter usually does not finish off someone it puts into Last Stand.
The kill-to-death ratio and the number of points seem to be the most important factors in deciding who will be attacked.
- In multiplayer, if shot down (either with an RPG or automatic weapon), the helicopter's tail explodes, causing the chopper to spin out of control, eventually exploding just outside the map, always in the same place, regardless of where it was destroyed.
- If the player dies and calls in a support chopper, the chopper's kills still count for the next life's killstreak.
- Although extremely rare, helicopters sometimes fire rockets at players.
- In a private match, changing the radar to "always on" makes the Airstrike and helicopter require three and five kills respectively. This also applies to Split-Screen matches.