US Patent 11465737 Conformal pylon/boom prop-rotors

A vertical lift rotor propulsor assembly comprises a boom having a casing with a casing profile and a first propeller blade having a blade profile that corresponds substantially to at least a portion of the casing profile of the casing of the boom. A drive mechanism is at least partially housed within the boom and at the first propeller blade is rotatably mounted to the drive mechanism to be driven thereby. The drive mechanism is to operationally move the first propeller blade between a stowed position in which the first propeller blade is substantially flush with the casing of the boom, and a deployed position in which the first propeller blade is extended a determined distance from the casing of the boom.