(ав.) головний редуктор
main gear box / main rotor transmission
main-rotor head / main-rotor hub
main-rotor hub / main-rotor head
transmission / gear box
rotor (system) gear box
tail rotor gear box
main gear box oil temperature indicator
gear reduction transmission
helical gear transmission
lateral dual rotor system / side-by-side rotor helicopter
main transmission oil temperature gauge
gearbox / gear box
aircraft accessory gear box
engine accessory gear box
intermediate gear box
rotor gear pump
intermediate reduction gear box
aft main rotor
main rotor brake
main rotor hub
blade tip light / main-rotor blade tip light
five-blade main rotor
forward main rotor
main rotor noise
main-rotor (hydraulic) collective pitch actuator
main-rotor axis
main-rotor blade
main-rotor blade durability
main-rotor blade tip light blade tip light
main-rotor brake
main-rotor collective pitch control rod
main-rotor diameter