верхній і нижній співвісні несучі гвинти (про вертоліт)
dual rotors / twin rotors
twin rotors / dual rotors
coaxial rotors
hollow shaft (of lower coaxial shaft)
through shaft (of upper coaxial rotor)
tandem-rotor helicopter (twin rotors mounted longitudinally)
wash from rotors
thrum of the engine (rotors etc.)
coaxial-rotor helicopter
coaxial machine gun
coaxial mounting
coaxial
at lower echelons
Forces of Lower Readiness (FLR)
land-based lower layer (LBLL)
lower deck (the)
lower deck
lower firing saddle
lower layer
lower receiver
lower right margin
lower unit
Sea-Based Lower Layer (SBLL)
lower glacis plate
lower elevating screw
lower bearing
lower torque link
lower explosive limit
wing lower surface
lower stratosphere
lower loop of a gun sling
lower-level intelligent control