Assertion: helicopter | /r/CapableOf | obtain its lifting power
Facets:
value: by means of a rotating airfoil
type: MANNER
Source sentences:
text: The fact that the helicopter obtains its lifting power by means of a rotating airfoil (the rotor) greatly complicates the factors affecting its flight, for not only does the rotor turn but it also moves up and down in a flapping motion and is affected by the horizontal or vertical movement of the helicopter itself.