AV-8B Harrier II

The Boeing AV-8B Harrier II is a V/STOL (Vertical/Short Take Off and Landing) fighter jet designed and used by the British Military and is also used by the United States Marine Corps, as well as the Italian and Spanish navies. The British Military use the Harrier GR7 and GR9 whilst other nations use the AV-8B version. It appears in Call of Duty 4: Modern Warfare and Call of Duty: Modern Warfare 2. The Harrier is used by the Royal Navy and USMC to support their amphibious landing operations. They usually carry out Airstrikes against enemy fortifications and units in support of friendlies. As a VTOL aircraft, it is capable of hovering in place like a helicopter, though it mostly relies on its speed to avoid enemy fire. It is slower than most attack fighters, which is why it is more useful in a Ground Support role rather than an Air Superiority role.

Call of Duty 4: Modern Warfare
A flight of USMC AV-8B Harrier IIs appear in the mission Heat, callsign Falcon One. They provide close air support to the S.A.S. team using cluster bombs. Additionally the player can see Harriers bombing targets in the mission Shock and Awe ahead of the Marine assault, thereby reducing resistance to a ground assault by the Marines. Two of the jets fly right over the player's position in the mission Charlie Don't Surf when they are on the roof of the TV station.

Call of Duty: Modern Warfare 2
The Harrier II also makes a handful of appearances in Campaign, though they are seen far less often than in Call of Duty 4, with the F-15E Strike Eagle replacing them in the role of Close-Air Support. In the level Exodus, prior to reaching the HVI's house, a pair of Harriers can be seen using their VTOL capability to take off from a driving range near the C-130 crash site.

The Harrier strike is an unlockable killstreak reward in Call of Duty: Modern Warfare 2. Requiring a killstreak of 7 (6 with the Hardline perk), the Harrier Airstrike calls in three harrier jets: two to bomb the target location, and the third hovers in place over the selected area, and will attempt to kill enemy targets with its undermounted gun. The third jet will also fire missiles at an enemy Attack Helicopter, Pave Lows, or Chopper Gunner if seen in the air and destroy them.

The Harrier Strike is an inaccurate representation of the AV-8B's abilities. Harriers are not designed to use their vector thrust nozzles to hover over an area for extended periods of time, only for take off and landing. While hovering, the Harrier uses immense amounts of fuel, overheats the engines and is very difficult to maneuver. Nonetheless, this hover mode is the main attack method used in multiplayer, where it can easily suppress large areas of the map. Also, real harriers are not fitted with turreted machine guns, instead they are usually fitted with forward fixed 20mm or 25mm gun pods.

Unlike a Pave Low Helicopter, Harrier kills from both the Airstrike and strafing runs extend the user's killstreak. This makes the Harrier very useful for achieving higher ranked killstreaks such as Chopper Gunner or AC130. Because of the lengthy duration of the Harrier killstreak, players will often use it in conjunction with another killstreak to gain quick access to the Tactical Nuke killstreak reward.

Harriers do not deploy flares and remain relatively still, making an easy target for Stinger missiles and Javelin missiles.

Harrier vs Attack Helicopter

 * The Harrier has to rotate towards the direction of its intended target before firing, giving players a warning if they're about to be targeted, and players can also 'circle strafe' a Harrier by staying underneath it and move around every time the Harrier starts rotating. The Attack Helicopter can seemingly attack enemies from all directions.
 * Harriers target enemies that it is facing regardless. Helicopters are more selective in picking targets and tend to attack the more dangerous players or those who attempt to shoot it down.
 * The Harrier arrives and strikes within 4 seconds of calling it in, the helicopter takes about 15 seconds to arrive and start killing.
 * Harriers will hover making them an easier target, helicopters move around to get a better view of enemies.
 * Harriers can shoot down helicopters while the Attack Helicopter can't attack air targets.
 * The Harrier remains in the air for 45 seconds after coming to a complete stop; the Attack Helicopter stays around for one minute upon reaching the battlefield.
 * Harriers can be devastating if deployed in the right place and has a huge presence in the match. However because of it's high presence, it's more likely to get shot down straight away. Helicopters circle the map, has a lower profile and is very good for getting the odd kill.
 * Harriers can sometimes be confused with the Airstrike by their similar function and appearance on the radar, Helicopters are easily exploited by their thin line on radar.
 * Harriers have an Airstrike, making splash damage an advantage.
 * Multiple Harriers can be called in at the same time (doesn't matter if enemy or friendly). Helicopters can only be called in as long as no other helicopters are in the air (Care Package Little Birds don't count).
 * Harriers are considered more deadly as they kill players quicker with their short controlled powerful bursts of fire while players can escape a Helicopter shooting at them by running indoors.
 * The Harrier doesn't have a flare, making for an easy shoot-down, but the Attack Helicopter moves around buildings so it can be harder to lock-on.
 * You get more points for destroying a Harrier than a Helicopter.
 * Calling in a Harrier requires you to mark an area on the map, and you are vulnerable to enemy fire during this process. Marking an area with lots of enemies can greatly increase the Harrier's effectiveness; conversely, marking an area devoid of enemies can greatly reduce the effectiveness of the Harrier. Managing to mark the ideal area without the aid of a UAV is usually difficult. The Helicopter does not require the player to mark an area, making it easier to use than the Harrier.
 * You can easily avoid the harrier on small maps, as standing directly below it and moving around underneath it will stop it from targeting you.

Trivia

 * In the level Exodus it is inaccurate that the Harrier is taking off in VTOL (Vertical Take Off and Landing) configuration, since when it is fully loaded for close air support it is too heavy to take off vertically, and would use the STOL (Short Take Off and Landing) configuration.
 * It is unlikely that the Harrier would still be in service at the time that Modern Warfare 2 takes place, due to the Marine Corps transitioning from the AV-8B to the F-35B. However, the Harrier may still serve along side the F-35 until it is completely phased out, similar to how the F-14 remained in service with the US Navy for many years along side its replacement, the F/A-18.
 * The fact that the multiplayer Harrier has a thermal-targeting machine gun is inaccurate, as no variation of the Harrier has a ventral gun. Also, the gun appears to be somewhat larger than the landing gear, making landing the Harrier impossible without causing damage. Furthermore, having a bulky machine gun on the bottom would make it heavier and disrupt its air flow, as well as being pointless in air-to-air combat due to the Harrier being equipped with a GAU-12U Equalizer 25mm cannon pod.
 * 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 or other air support (this applies to all killstreak rewards that 'stay' on the map for a short time).
 * 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.
 * The Harrier never uses its VTOL ability in combat, due to the massive amount of fuel used by the engines, it only uses it for Carrier landings, and sometimes for airfield landings.
 * In MP, a player can use the Riot Shield the player can look at a diagonal angle to trick the Harrier into focusing all of its firepower on a single person. The user also gets +50 EXP from every burst from the Harrier. (+500 in S&D). Of course in real combat, the Harrier's rounds would demolish the shield if not crush the users legs from the pure force of the rounds.
 * If you get kills during the Airstrike portion of the Harrier strike, it counts as Precision Airstrike kills.