Abstract: A thrust producing unit for producing thrust in a predetermined direction, comprising at least two rotor assemblies and a shrouding that accommodates at most one of the at least two rotor assemblies, wherein the shrouding defines a cylindrical air duct that is axially delimited by an air inlet region and an air outlet region, and wherein the air inlet region exhibits in circumferential direction of the cylindrical air duct an undulated geometry.

Abstract: An aircraft with an airframe and at least one thrust producing unit the at least one thrust producing unit being electrically powered by an associated electrical engine that is electrically connected to an electrical energy source via an electrical energy distribution system, wherein the airframe comprises at least one load carrying section and at least one propulsion system carrying section, wherein the at least one load carrying section and the at least one propulsion system carrying section are segregated from each other, wherein the at least one load carrying section is provided for transportation of passengers and/or cargo, and wherein the at least one propulsion system carrying section is provided for carrying at least essentially the electrical energy source and the electrical energy distribution system.

Abstract: A multirotor aircraft with at least two thrust producing units, the multirotor aircraft being adapted for transportation of passengers and comprising an aircraft operating structure that is adapted for operation of the multirotor aircraft in failure-free operating mode, and a redundant security architecture that is at least adapted for operation of the multirotor aircraft in case of a failure of the aircraft operating structure in operation, the redundant security architecture being provided to comply with applicable authority regulations and certification requirements regarding passenger transportation.

Abstract: A multirotor aircraft with an airframe and a thrust producing units arrangement, wherein the thrust producing units arrangement comprises a predetermined number of thrust producing units for producing thrust in a predetermined direction, and wherein a flexible suspension unit is rigidly mounted to the airframe, wherein the flexible suspension unit comprises at least one bearing that mechanically couples the thrust producing units arrangement to the airframe such that the thrust producing units of the predetermined number of thrust producing units are inclinable in relation to the airframe.

Abstract: A multirotor aircraft with an airframe and at least one wing that is mounted to the airframe, the at least one wing being provided with at least four thrust producing units that are arranged in spanwise direction of the at least one wing, wherein each one of the at least four thrust producing units comprises at least one rotor assembly that is accommodated in an associated shrouding, the associated shrouding being integrated into the at least one wing, wherein the associated shrouding defines an air duct that is axially delimited by an air inlet region and an air outlet region, wherein the air inlet region exhibits in circumferential direction of the air duct at least two different aerodynamic profiles.

Abstract: A multirotor aircraft with at least two thrust producing units, the multirotor aircraft being adapted for transportation of passengers and comprising an aircraft operating structure that is adapted for operation of the multirotor aircraft in failure-free operating mode, and a redundant security architecture that is at least adapted for operation of the multirotor aircraft in case of a failure of the aircraft operating structure in operation, the redundant security architecture being provided to comply with applicable authority regulations and certification requirements regarding passenger transportation.

Abstract: A thrust producing unit for producing thrust in a predetermined direction, comprising a shrouding and at least two rotor assemblies, wherein the shrouding defines an internal volume, and wherein a first rotor assembly of the at least two rotor assemblies defines a first rotor axis and a second rotor assembly of the at least two rotor assemblies defines a second rotor axis, the first and second rotor axes being one of: (i) coaxially arranged, and (ii) inclined by associated inclination angles with respect to the predetermined direction, the associated inclination angles being comprised in a range between ?60° and +60°, and preferably amounting to 0°, and wherein the first rotor assembly is arranged outside of the internal volume of the shrouding.

Abstract: A propeller assembly with at least two propeller blades that are interconnected by associated connection means, the associated connection means defining a common pitch axis for the at least two propeller blades in operation, each one of the at least two propeller blades comprising associated leading and trailing edges that define a respective chord and quarter chord line thereof, wherein the common pitch axis is arranged with a predetermined offset relative to the quarter chord line of each one of the at least two propeller blades, and wherein the associated connection means is adapted to enable, at least in operation in a non-axial inflow field, a passive pitch adjustment of the at least two propeller blades around the common pitch axis.

Abstract: A multirotor aircraft with an airframe and at least one wing that is mounted to the airframe, the at least one wing being provided with at least four thrust producing units that are arranged in spanwise direction of the at least one wing, wherein each one of the at least four thrust producing units comprises at least one rotor assembly that is accommodated in an associated shrouding, the associated shrouding being integrated into the at least one wing, wherein the associated shrouding defines an air duct that is axially delimited by an air inlet region and an air outlet region, wherein the air inlet region exhibits in circumferential direction of the air duct at least two different aerodynamic profiles.

Abstract: A multirotor aircraft with an airframe and a thrust producing units arrangement, wherein the thrust producing units arrangement comprises a predetermined number of thrust producing units for producing thrust in a predetermined direction, and wherein a flexible suspension unit is rigidly mounted to the airframe, wherein the flexible suspension unit comprises at least one bearing that mechanically couples the thrust producing units arrangement to the airframe such that the thrust producing units of the predetermined number of thrust producing units are inclinable in relation to the airframe.

Abstract: A thrust producing unit for producing thrust in a predetermined direction, comprising at least two rotor assemblies and a shrouding that accommodates at most one of the at least two rotor assemblies, wherein the shrouding defines a cylindrical air duct that is axially delimited by an air inlet region and an air outlet region, and wherein the air inlet region exhibits in circumferential direction of the cylindrical air duct an undulated geometry.

Abstract: A thrust producing unit for producing thrust in a predetermined direction, comprising a shrouding and at least two rotor assemblies, wherein the shrouding defines an internal volume, and wherein a first rotor assembly of the at least two rotor assemblies defines a first rotor axis and a second rotor assembly of the at least two rotor assemblies defines a second rotor axis, the first and second rotor axes being one of: (i) coaxially arranged, and (ii) inclined by associated inclination angles with respect to the predetermined direction, the associated inclination angles being comprised in a range between ?60° and +60°, and preferably amounting to 0°, and wherein the first rotor assembly is arranged outside of the internal volume of the shrouding.

Abstract: A thrust producing unit for producing thrust in a predetermined direction, comprising at least two rotor assemblies and a shrouding, each one of the at least two rotor assemblies, defining an associated rotor plane, wherein a first rotor assembly of the at least two rotor assemblies is provided for operating in a failure-free operating mode of the thrust producing unit and a second rotor assembly of the at least two rotor assemblies is provided for operating at least in case of a failure of the first rotor assembly, and wherein the shrouding accommodates at most one of the at least two rotor assemblies.

Abstract: An aircraft with a modular airframe. The modular airframe has a load carrying framework and at least one exchangeable covering item that exhibits a first predetermined shaping. The at least one exchangeable covering item is detachably mounted to the load carrying framework. The modular airframe is customizable by exchanging the at least one exchangeable covering item with a substitute exchangeable covering item that exhibits a second predetermined shaping.

Abstract: An aircraft with an airframe and at least one thrust producing unit the at least one thrust producing unit being electrically powered by an associated electrical engine that is electrically connected to an electrical energy source via an electrical energy distribution system, wherein the airframe comprises at least one load carrying section and at least one propulsion system carrying section, wherein the at least one load carrying section and the at least one propulsion system carrying section are segregated from each other, wherein the at least one load carrying section is provided for transportation of passengers and/or cargo, and wherein the at least one propulsion system carrying section is provided for carrying at least essentially the electrical energy source and the electrical energy distribution system.

Abstract: A propeller assembly with at least two propeller blades that are interconnected by associated connection means, the associated connection means defining a common pitch axis for the at least two propeller blades in operation, each one of the at least two propeller blades comprising associated leading and trailing edges that define a respective chord and quarter chord line thereof, wherein the common pitch axis is arranged with a predetermined offset relative to the quarter chord line of each one of the at least two propeller blades, and wherein the associated connection means is adapted to enable, at least in operation in a non-axial inflow field, a passive pitch adjustment of the at least two propeller blades around the common pitch axis.

Abstract: A helicopter with a fuselage (4), at least one engine, a roll axis, at least one main rotor, and at least one housing (2) mounted to said fuselage (4). An air inlet (8) and an air outlet (7) are provided along at least a part of a circumference of the at least one housing (2), said air inlet (8) and said air outlet (7) being formed by angularly offset and separate gaps between an inside segment (33) and an outside segment (34) essentially extending respectively longitudinally in direction of said roll axis. At least one rotatable compressor (1) with a plurality of airfoil blades (6) is provided radial inside said at least one housing (2) between said air inlet (8) and said air outlet (7), said at least one rotatable compressor (1) being drivable by said at least one engine about a fan axis (5) and each chord of said airfoil blades (6) is essentially radial oriented with regard to said fan axis (5).

Abstract: A pitch stabilizer with box configuration suitable for providing stability to a rotorcraft comprising a vertical mid-plane and a fuselage; the pitch stabilizer comprising one or two pitch stabilizing assemblies, with no more than one pitch stabilizing assembly on each side of the vertical mid-plane, wherein each pitch stabilizing assembly comprises upper pitch stabilizing means, lower pitch stabilizing means and a wing tip element.

Abstract: An aerodynamic blunt aft body (10) of a helicopter fuselage with two strakes (7, 8) along an aft surface (9) and/or respective left hand and right hand side fuselage surfaces (5, 6). Each strake (7, 8) is defined by first and second intersection lines (3, 4) resulting from intersections of horizontal planes (z) with the surface of the aft surface (9) or the respective left hand and right hand side fuselage surfaces (7, 8). The strakes are defined by a two or three dimensional spline (12) from the surface (2) towards the aft surface (9) inside said first and second intersection lines (3, 4) and inside the bounding box (15).

Abstract: A pitch stabilizer with box configuration suitable for providing stability to a rotorcraft comprising a vertical mid-plane and a fuselage; the pitch stabilizer comprising one or two pitch stabilizing assemblies, with no more than one pitch stabilizing assembly on each side of the vertical mid-plane, wherein each pitch stabilizing assembly comprises upper pitch stabilizing means, lower pitch stabilizing means and a wing tip element.