The Harrier Strike is available after seven kills in a row are attained (six, with Hardline). It consists of two airstrikes, similar to the Precision Airstrike in terms of power, but the third jet that flies over the map hovers with a turret, which targets enemy players - users of Cold-Blooded are not affected by the turret but can be killed by the airstrikes.
The killstreak itself adds kills to the user's streak, making the Harrier very useful for obtaining higher rewards, most commonly the Pave Low, Chopper Gunner or the AC-130.
Before the actual hovering harrier, there's a small precision airstrike; unlike the normal precision airstrike, where 3 planes bomb the selected area, only 2 planes do this, with the third Harrier simply flying to the selected area and hovering over it. The hovering jet, while attacking infantry on the ground, is also aggressive towards enemy helicopters as it is armed with missiles (if there are no hostile killstreaks nearby, it will not use the rockets as an anti-infantry measure) - the Attack Helicopter, Pave Low and Chopper Gunner are quickly destroyed by a hovering Harrier, meaning it is inadvisable to call in such air support when enemies have a Harrier in the air, however this is not true in some cases, since a heavily damaged harrier may be destroyed by a less-frequent missile, fired from the Attack Helicopter. Note though that enemy Harriers will not engage each other. Harriers will also not engage AC-130s and are an easy target for their 105mm howitzer. A Harrier can be taken down with one shot from a Javelin or Stinger.
Two Harriers near each other can easily be destroyed by one Stinger or Javelin missile; the Harrier can also be targeted as a means to destroy a Pave Low or other helicopter as well, when they fly nearby.
For a Game/Round Winning Killcam gained by the hovering Harrier earns the TitleTrue Liar. Attaining such a kill with the airstrike portion earns Finishing Touch instead.
On large maps the Harrier will sometimes get stuck firing long range at someone and missing. This is because Harrier bullets fire in a deterministic spread left then right of the target. At range, this bracketing is large enough to allow a person to squeeze between shots. In these cases, as long as the target doesn't move the Harrier will waste the rest of its flight time firing at one target and do no damage.
Harriers have 3000 health, take 0.5x base damage from bullets, are destroyed instantly by Stingers, Javelins and Predator missiles/AC-130 guns, and take 2100 damage from RPG-7's and AT4-HS's.
The Harrier was originally set to appear in Call of Duty: Modern Warfare 3, but was cut before the game's final release, the only proof that it exists are cut quotes of the Multiplayer announcers. Also, two HUD icons can be found.
When the Airstrike is in effect, the first two Harriers making the Airstrike are smaller than the hovering Harrier attacking the other players.
Harrier jets do not collide with buildings.
The Harrier makes two references to the movie True Lies: when the player gets the game-winning kill, they receive the title "True Liar", and the prestige challenge for getting Harrier kills is called "You're fired!", a reference to the line Arnold Schwarzenegger says to the head terrorist before killing him.
If the player gets kills with the Airstrike portion of the Harrier strike, they count as airstrike kills, like those of the Precision Airstrike and Stealth Bomber. These kills are recognized by the picture of three bombs on the killfeed.
Many players who attempt to shoot down the Harrier prefer using the Stinger more than the Javelin as Stingers have two missiles compared to the Javelin's only one. Also a Stinger seems more accurate than the Javelin even when fired straight up.
When the Javelin is fired while aiming straight up the Harrier, the missile can sometimes miss and fly down on the player, killing him instead of destroying the Harrier.
When a Stinger is fired, it can occasionally miss, usually because the Harrier moves excessively while it's hovering. To prevent this from happening again, move to a different place some distance away and fire again.
If a Harrier shoots down an enemy Attack Helicopter, Pave Low, or Chopper Gunner, the player will not be awarded the Flyswatter challenge or count towards Cold Blooded challenges.
If a Harrier is shot down as it is departing the map, the sound of it leaving will still be played, although it was destroyed.
When firing against other killstreaks, Harrier jets will use missiles rather than the mounted gun. This is the only time these are seen using missiles.
In game, the killstreak's kill icon points to left as a result of wrongly defined "flip" parameter.
In Highrise (confirmed only in splitscreen), if a Cold-Blooded player jumps off of the map by the south-east spawn, the Harrier will slowly float down to a distance from which a player can knife the Harrier.
It appears that the Harrier will only fire its turret at targets that are directly in front of the Harrier. If an enemy Harrier is not facing the player, they can run around freely while keeping an eye on it.
Unused sound files from Modern Warfare 3 indicate that this killstreak was supposed to appear in the game, but was cancelled for unknown reasons.
Friendly factions' (TF 141, Navy SEALS, etc.) harriers have a grey camouflage scheme commonly seen on most U.S. fighter jets as well as well as a U.S. Airforce logo on the side of the nose and the number 8 on both of the wings (topside). Enemy factions' (Militia, Spetsnaz, etc.) harriers have a jet black color scheme as well as a Russian flag on the tail rudder of the jet (both left and right).
In the Content Collection 1 Trailer for Call of Duty: Modern Warfare 3, a Harrier Strike is seen being called in on the multiplayer map Black Box, even though it doesn't appear as a killstreak in the actual game.