main-rotor speed

main-rotor head / main-rotor hub

main-rotor hub / main-rotor head

Nr gauge (Nr = speed of rotation) / rotor speed sensor

main gear box / main rotor transmission

main rotor transmission / main gear box

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

rotor speed / Nr

rotor speed sensor / Nr gauge

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

main-rotor head casing

main-rotor rate

main-rotor rotation direction

main-rotor rpm

main-rotor slip ring assembly

main-rotor vertical hinge pin

main rotor

supersonic speed (exceeds speed of sound / Mach 1)

variable-speed with speed control