rotor (system) gear box

main gear box / main rotor transmission

main rotor transmission / main gear box

tail rotor gear box

lateral dual rotor system / side-by-side rotor helicopter

main-rotor head / main-rotor hub

main-rotor hub / main-rotor head

gearbox / gear box

aircraft accessory gear box

engine accessory gear box

intermediate gear box

rotor gear pump

intermediate reduction gear box

main gear box oil temperature indicator

transmission / gear box

camshaft gear (timing gear)

gear reduction unit / gear-reduction unit

rotor system

lateral dual rotor system

tandem-rotor system

fire extinguishing system sprinkler system and fire alarm system

air box handhole cover

ammunition box

axle box

battery box

box formation

box freight car

box magazine

box trail

brain box

brake rotor

control box / console / desk

dead letter-box