Abstract: A self-adjusting variable-pitch propeller has a drive shaft rotatable about a shaft axis in a predetermined forward rotational sense, a hub carried on the drive shaft and limitedly rotatable relative thereto about the shaft axis both in the forward rotational sense and in an opposite backward rotational sense, and a spring operatively braced between the hub and the shaft for rotationally urging the hub on the shaft in the forward rotational sense. A plurality of blades projecting radially from the hub are each rotatable about a respective blade axis generally perpendicular to the shaft axis. Respective rods extending axially in the hub each have an inner end at a respective one of the blades and an outer end. Respective linkages connecting the inner ends of the rods to the respective blades angular displace the blades about the respective axes on relative displacement of the rods and hub.