Anti-aircraft weapon

An anti-aircraft weapon is a weapon system designed to counter enemy aircraft, or, in some cases, low-flying spacecraft such as frigates. While human AA weapons most often rely on conventional bullets or missiles, Covenant anti-aircraft weapons are exclusively plasma-based.

UNSC

 * Surface-to-air missile - the basic concept of an anti-air missile.
 * M19-B Surface-to-Air Missile Launcher - a man-portable surface-to-air missile launcher.
 * Anaconda Surface-to-Air Missile - a type of UNSC anti-air missile.
 * Surface-to-air missile launcher - a heavy UNSC SAM emplacement seen in Halo 3.
 * Unidentified UNSC missile battery - another type of SAM battery, seen in Halo: Reach.
 * M71 Anti-Aircraft Gun - a Gatling-style AA gun emplacement featured in Halo: Reach.

Covenant

 * Covenant anti-aircraft battery - The Covenant's heavy anti-air emplacements.
 * Type-38 Anti-Aircraft Cannon - A type of heavy AA cannon featured in Halo: Reach.
 * Heavy Shade - Shade turrets with heavier armament and shielding are also used in anti-aircraft roles.