Air defense

This anti-air tower is deadly against flying enemies, but can't target troops on the ground. Place it wisely to cover as much airspace as possible.

Air Defense 

• A powerful defensive building with a very high damaged per second, it capable of defending against flying troops. Air defense can only shoot one target at a time and it cannot shoot a ground unit. Air defense is unlocked at level 4 Town Hall.

Defense 

• Air Defense has an admirable range and a very high damage per shot against each target. As the in-game description states, it's best to position them so that they cover as much area as possible. One common strategy for Town Hall 8 and above is to position them in a wide triangle (or diamond, once the fourth Air Defense is available) around the Town Hall.
• Lava Hounds target air defense first, so make sure that you can defend it well with other defenses building which target air troops. Single-Target Inferno Towers are most effective, if you have them. If not, other point defenses such as Archer Towers and Hidden Tesla’s are recommended for the defense along them.
• Air Defense is a popular first target for armies sporting ground troops, as they are the only defensive structure that cannot target them. Make sure they are defended well, and they will help to keep the skies clear from rampaging Balloons, Dragons, Healers, Lava Hounds, and Minions.
• Air Defenses are there for when Archer Towers and Wizard Towers just won't cut it, or are distracted by ground units such as Giants and Heroes.
• If possible, keep your Air Defenses behind your first lines of defense (e.g. Cannons and Archer Towers), preferably with a Wall in between. This will prevent a large Giant or Golem assault from quickly destroying the Air Defense and allowing a Healer to be deployed early in the battle. The longer it takes the Giants to destroy the Air Defense, the more time your turrets will have to thin out their ranks before a Healer can be safely deployed.

Offense

• Air Defense is a natural target to attack first, as clearing them helps overlay the way for an air assault. Healers are very vulnerable to the Air Defense, destroying this building with Giants before deploying her is recommended.
• They are easily destroyed by any ground-based troop, as they cannot fight back.
• It is advisable to keep Balloons away from Air Defenses, as they are capable of destroying most Balloons in one or two hits from a great distance.
• Air Defenses are quite effective against Dragons, it is possible to keep an Air Defense occupied with a one or two Dragons for a fleet of Balloons to quickly destroy a majority of the ground defenses.
• A great way to overwhelm the Air Defense is use a large group of Minions, since the Air Defense can only target one air unit at a time.

Upgrade Differences 

• Air Defenses undergo significant visual changes at levels 4, 7 and 8.
• When initially constructed, the Air Defense consists of a single wooden launch tube with a single red-and-black rocket. The launch tube is banded with metal.
• Levels 2 and 3, an additional red-and-black rocket is added to the launcher.
• Level 4, a second wooden launch tube is added, with two rockets in each tube. The rockets change from red and black to red and yellow while also acquiring caps that are yellow and black.
• Level 5, Air Defense adds a fifth rocket to one of the launchers.
• Level 6, Air Defense adds a third wooden launch tube with 2 rockets in each tube.
• Level 7, the three launch