A system to prevent or limit resonance in a rotocraft. The system comprises an airframe, a rotor system having a natural frequency and including a rotor and a mast attached to the airframe, and a non-linear spring positioned between the rotor system and the airframe. The rotor system and the airframe are operable to move relative to each other as the rotor system begins to oscillate. The non-linear spring is configured to be deformed when the rotor system and the airframe move relative to each other such that the deformation of the non-linear spring causes the natural frequency of the rotor system to change. Also disclosed is a related method for preventing or limiting resonance in a rotorcraft.

An un-manned aerial vehicle including a powered chassis having a top side and a bottom side. The powered chassis includes a fuel powered electricity generator. The vehicle includes a flight system functionally coupled to the powered chassis. The vehicle includes a flood light system functionally coupled to a bottom side of the powered chassis and oriented to project light downward therefrom. The flood light system includes a plurality of modular lights that are able to selectably couple to the bottom side of the powered chassis. The flood light system includes a programmable light control module that controls lighting. The vehicle includes an automated flight control system functionally coupled to the flight system that automatically directs light from the flood light system to a desired region.

A multirotor aircraft that includes a chassis, at least three engines that are equipped with propellers, and one or more axial free wings that are connected to the chassis by axial connections. The leading edges of the one or more axial free wings are designed to face constantly same direction when the multirotor flying, and the attack angles of the one or more axial free wings are designed to be changed relatively to the chassis due to flow of air over the one or more axial free wings.

The invention related to an autogyro (1) comprising a body (2), a mast (3) arranged in the upper region of the body, a rotor (4) which is rotatably arranged in the region of the end of the body (3) and which can be put into autorotation by an air flow, a drivable propeller (6) which is arranged in the region of a rear body end (5) and which generates a propulsion of the autogyro (1), a guide mechanism (7) arranged behind a propeller (1), and at least one brace (8) which extends past the propeller in the longitudinal direction of the autogyro at a radial distance from the propeller (6) in an outwards direction and which connects the guide mechanism (7) to the body (2). According to the invention, the guide mechanism (7) has a guide mechanism protrusion (9) which is arranged coaxially to the rear body end (5) and which extends forwards from the guide mechanism (7) in the direction of the rear body end (5) at a distance therefrom. Furthermore, at least the region of the rear body end (5) of the body (2) and the guide mechanism protrusion (9) together form a streamlined outer contour. The invention further relates to an autogyro in which the mast (3) is designed, in particular the mast is arranged and/or inclined relative to the propeller (6), such that when rotating, the blades (17) of the propeller (6) always only partly overlap with the mast (3) in a respective overlap region (21) when viewing the autogyro (1) from the rear.

The invention related to an autogyro (1) comprising a body (2), a mast (3) arranged in the upper region of the body, a rotor (4) which is rotatably arranged in the region of the end of the body (3) and which can be put into autorotation by an air flow, a drivable propeller (6) which is arranged in the region of a rear body end (5) and which generates a propulsion of the autogyro (1), a guide mechanism (7) arranged behind a propeller (1), and at least one brace (8) which extends past the propeller in the longitudinal direction of the autogyro at a radial distance from the propeller (6) in an outwards direction and which connects the guide mechanism (7) to the body (2). According to the invention, the guide mechanism (7) has a guide mechanism protrusion (9) which is arranged coaxially to the rear body end (5) and which extends forwards from the guide mechanism (7) in the direction of the rear body end (5) at a distance therefrom. Furthermore, at least the region of the rear body end (5) of the body (2) and the guide mechanism protrusion (9) together form a streamlined outer contour. The invention further relates to an autogyro in which the mast (3) is designed, in particular the mast is arranged and/or inclined relative to the propeller (6), such that when rotating, the blades (17) of the propeller (6) always only partly overlap with the mast (3) in a respective overlap region (21) when viewing the autogyro (1) from the rear.

Off-board gyrocopter take-off systems and associated methods are disclosed. A representative method includes restraining a gyrocopter from vertical and lateral movement, pre-rotating a fixed-pitch lift rotor of the gyrocopter via a power source located off the gyrocopter, and releasing the gyrocopter for vertical movement to allow the gyrocopter to lift under a force provided by the lift rotor. Optionally, the method can further include interrupting or reducing power from the power source to the gyrocopter as a way to release the gyrocopter for vertical movement.

Off-board gyrocopter take-off systems and associated methods are disclosed. A representative method includes restraining a gyrocopter from vertical and lateral movement, pre-rotating a fixed-pitch lift rotor of the gyrocopter via a power source located off the gyrocopter, and releasing the gyrocopter for vertical movement to allow the gyrocopter to lift under a force provided by the lift rotor. Optionally, the method can further include interrupting or reducing power from the power source to the gyrocopter as a way to release the gyrocopter for vertical movement.

The invention relates to an autogyro having a rotor (12). According to the invention, a gas pressure spring (32) is provided and is arranged for trimming the rotor (12).

The ‘Air Wheel’ rotor is a rotor with blades of variable pitch and variable twist. The ‘Air Wheel’ rotor comprises one or more hubs connected to the closed axisymmetric wing via flexible blades. There is provided a wide range of combinations of the wing relative width and coning angle typical for a lifting rotor with a thin planar wing attached to the tips of long blades, for a shrouded fan in a wide annular wing, or an impeller in a rotating cylindrical wing is provided.

The ‘Air Wheel’ rotor combines and enhances the advantages of a rotor and a wing. The ‘Air Wheel’ rotor has high aerodynamic properties, and eliminates limitations of the rotor size and flight speed. The ‘Air Wheel’ rotor can be used for designing vertical take-off and landing aircraft.

A power generation apparatus and method comprises at least one gyroglider rotary wing flying at an altitude above the nap of the earth. A strong and flexible tether, connected to the gyroglider frame is pulled with a force generated by the rotary wing. The force is transmitted to a ground station that converts the comparatively linear motion of the tether being pulled upward with a lifting force. The linear motion is transferred to a rotary motion at the ground station to rotate an electrical generator. The tether is retrieved and re-coiled about a drum by controlling the gyroglider to fly down at a speed and lift force that permit recovery of the gyroglider at a substantially reduced amount of retrieval force compared to the lifting force during payout of the tether. Thus, the net difference in force results in a net gain of energy.