Covenant Point Defense Laser
The 50mm Point-Defense Gun (also known as the Helix AAA) functions much like the CIWS designs created during the 20th Century, firing 50mm projectiles. Unlike Archer missiles and the MAC weapon systems mounted on capital ships, the Point-Defense Guns are not used to engage Covenant capital ships, instead meant to intercept smaller threats like Seraph fighters or Boarding Craft to prevent (or at least lessen) the damage inflicted to a warship.
Because Human operators lack the reflexive responses necessary to operate the Point Defense Guns to maximum effect, the autocannons are computer controlled and, if an AI is available, control is diverted to it. "Smart" AI's seem better able to operate the Point-Defense Guns than standard computers and even lesser "dumb" AI's.
During the Human occupation of Alpha Halo, the ODST's that recaptured and secured the wreckage of the UNSC Pillar of Autumn from the Covenant managed to scavenge several dual barreled  50mm turrets, using them as anti-air defensive emplacements at Alpha Base. These were not fitted to the Pelicans for use, but were carried underneath the dropships for transport to Alpha Base.
|List of UNSC Vehicle Weapons and Explosives|
|Artillery||102mm SC-HE Rocket Turret | 440 mm Heavy Artillery | KG Mk 34 Antipersonnel Flame Mortar Launcher|
|Autocannons||50mm Point Defense Gun | 110mm Rotary Cannon | 120mm Ventral Gun | GUA-23/AW/Linkless Feed Autocannon | M247 GPMGT Autocannon | M247T MMG | M41 Light Anti-Aircraft Gun | X23 NNEMP Cannon | AAA Helix Gun|
|Chemical weapons||Narcozine Gas | VX 7 Nerve Gas|
|Magnetic Acceleration weapons||LRG Rail Gun | M68 Gauss Cannon | Magnetic Accelerator Cannon|
|Land mines||Antlion Anti-Personnel Mine | Asteroidea Anti-personnel Mine | Lotus Anti-Tank Mine | Trip Mine | Type 14 Magnetic/Anti-Tank Mine|
|Missiles||Anaconda Surface-to-Air Missile | ANVIL-II ASM | ANVIL-IV ASM | A-74 Sylver Vertical Missile Launcher | Archer Missile | Ares Missile | Argent V Missile | ASGM-10 Missile | Scorpion Missile|
|Nuclear weapons||FENRIS Nuclear Warhead | Fury Tactical Nuclear Weapon | HAVOK Nuclear Warhead | NOVA Bomb | Shiva-class Nuclear Missile|
|Space mines||HORNET Mine | Moray Space Mine|
|Tank guns||90mm High Velocity Cannon | 120mm High-Velocity Gun|