Abstract: A propeller device for aircraft, spacecraft or watercraft comprising two or more blades and a spinner. The blades are arranged on a hub so that they can be in a deployed or a retracted position. The spinner comprises first, second and third movable portions configured for allowing deploying or retracting the blades and for keeping the blades deployed or retracted.

Abstract: A propeller device for aircraft, spacecraft or watercraft comprising two or more blades and a spinner. The blades are arranged on a hub so that they can be in a deployed or a retracted position. The spinner comprises first, second and third movable portions configured for allowing deploying or retracting the blades and for keeping the blades deployed or retracted.

Abstract: The invention relates to a double wall duct system (1) suitable for carrying fluids to at least other system comprising an internal duct (3) for conveying the fluid and an external duct (2) for conveying a potential leakage in the system (1), the double wall duct system (1) also comprising a clearance (8) between the ducts (2, 3) and at least one bend, the system (1) also comprising at least one bushing (4, 5) that connects the system (1) to at least other system, the bushing (4, 5) being slidable in the system (1) before being connected to the system (1) and to other systems, the inner duct (3) being connectable at its ends to other systems and the outer duct (2) being connectable to one end of the bushing (4, 5), the bushing (4, 5) providing a closed structural integrity of the system (1) therefore allowing a potential leakage in the double wall system (1) to be detected and evacuated in a controlled manner. The invention also relates to a method of manufacturing such a double wall duct system (1).