An aircraft has a small high-speed propeller used during take-off, climbing and landing maneuvers, and a large collapsible or foldable propeller used for loitering. The large collapsible or foldable propeller is kept in a folded configuration during take-offs and landings to minimize drag and to avoid ground strikes. During loitering operations, the large collapsible propeller is unfolded and used at a lower rotational speed than the smaller high-speed propeller to permit efficient and quite loitering. During loitering operations, the smaller high-speed propeller may be disengaged so as to spin freely or held in a non-rotational position. One or more foldable propellers may be paired with at least one conventional propeller. The propellers may be arranged as twin tractor, tractor-pusher, or nearly any other type of layout on the fuselage or wings, or on pods of the fuselage or wings.
Collapsible large diameter propeller for quiet aircraft
2020-01-07
Patent
Electronic Resource
English
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