main defense (line) area

main defense area (line) / main defensive position

main line of defense (resistance)

outline the main line of defense (of the enemy)

deployment line; line of deployment (LD); line of departure

main tank/ main fuel tank

main gear box / main rotor transmission

main rotor transmission / main gear box

main-rotor head / main-rotor hub

main-rotor hub / main-rotor head

main defense forces

main defense zone (defence)

main zone of defense

main fighting line

main line of advance

main battle line

main battle area (MBA)

main fighting area / zone

main support area

perimeter defense (all-around defense)

beach defense mine / beach-defense mine

back line defense

observer-target line (OT line)

scheme trail line (tag line)

air defense area

area air defense

area air defense commander (AADC)

area defense

ballistic missile defense area

battalion defense area

defense area

forward defense area

rear area protection and defense