Assertion: hovercraft's propeller | /r/HasProperty | derived
Facets:
value: during world war ii
type: TEMPORAL
Source sentences:
text: JEFF B had two ducted rear propellers similar to the proposed SK-10 which was derived from the previous Bell SK-5 / SR.N5 hovercraft tested in Vietnam.
text: However, electrically controlled propellers were developed during World War II and saw extensive use on military aircraft, and have recently seen a revival in use on homebuilt aircraft.[citation needed]