Editing Airlock

{{Era|Forerunner|Human|UNSC|HCW|RW}}
[[File:1208375252 Airlock-floorsign.gif|thumb|UNSC airlock floor sign]]
An '''airlock''' is a device which allows passage between two areas of drastically different pressures and/or atmospheric composition, while preventing the exchange of gases and pressure. An airlock consists of a small chamber with two airtight doors in series, which do not open simultaneously. They are most commonly used on spacecraft, where they allow safe passage between the pressurized interior of the ship and the vacuum of space, though they can also be found in enclosed habitats on worlds with toxic atmospheres, for example.<ref>'''Halo: Fractures''', "A Necessary Truth"</ref>

On [[United Nations Space Command|UNSC]] spacecraft, [[hangar bay]]s, [[Class-3 Enclosed Heavy Lifeboat|lifepod]] or [[Single Occupant Exoatmospheric Insertion Vehicle|HEV]] launch areas are typically equipped with airlocks, used to prevent pressure loss from exposure to vacuum either due to a hull breach or the deployment of a lifepod or HEV.<ref>'''[[Halo: The Flood]]'''</ref> {{Class|Halcyon|cruiser}}s, in particular, employ them as redundancy features for survivability during combat with [[Covenant]] warships. The {{UNSCShip|Hopeful}} had an airlock large enough to cycle a fleet of dropships simultaneously.<ref>'''Halo: Ghosts of Onyx''', ''page 99''</ref>

The Covenant typically employs [[energy barrier]]s in place of physical airlocks. Certain UNSC facilities also employ energy barriers for this purpose, presumably having reverse-engineered Covenant or Forerunner versions.

==Identified airlocks==
*[[UNSC Pillar of Autumn#Airlocks|Airlocks on the ''Pillar of Autumn'']]
*[[Umbilical|Cairo Station umbilical locks]]

==Gallery==
<gallery>
File:Frigate ext airlock.jpg|An external airlock/docking collar on the side of a [[UNSC frigate]]'s [[bridge]].
File:PoA ext airlock.jpg|An external airlock on the {{UNSCShip|Pillar of Autumn}}.
</gallery>

==List of appearances==
*''[[Halo: The Fall of Reach]]'' {{1st}}
*''[[Halo: Combat Evolved]]''
*''[[Halo: The Flood]]''
*''[[Halo 2]]''
*''[[Halo: Ghosts of Onyx]]''
*''[[Halo: Uprising]]''
*''[[Halo: Glasslands]]''
*''[[Halo: Combat Evolved Anniversary]]''
*''[[Halo 4]]''
*''[[Halo 2: Anniversary]]''
*''[[Halo 5: Guardians]]''
*''[[Halo: Fractures]]''
**''[[Breaking Strain]]'' {{Mo}}
**''[[A Necessary Truth]]'' {{Mo}}
**''[[Into the Fire]]''

==Sources==
{{Ref/Sources}}

{{Halcyon Locations}}