clean conditioned air system

air conditioned suit

conditioned petroleum product

well-conditioned soldier

clean / dirty fighting

brake clean through

clean element

keep the place clean

clean (hydrogen) bomb

clean break with the enemy

clean side

clean up a penetration

clean weapon

clean-bore ammunition

fire extinguishing system sprinkler system and fire alarm system

Air Force weapons system / AF weapon system

aerial refueling / air refueling / in-flight refueling (IFR) / air-to-air refueling (AAR)

air combat capable helicopter / air-to-air capable helicopter

air support field pack, field pack air support, airborne / para (air support) / Pathfinder Bergen

merchant ship communication system (mercomm system)

multiple launch rocket system (MLRS); multiple rocket launcher system

attitude-and-heading reference system / attitude and heading reference system (AHRS)

selective calling system, SELCAL system

Unmanned Aerial System / Uncrewed Aircraf System (UAS)

system of system common operating environment

air command and control system (ACCS)

air cooling system

air defense artillery system

air defense guided missile system (AD GM sys)

air electronic guidance information system (AEGIS)

air traffic signalling system

air-delivered cluster weapons system

air-ground operations system