A landing gear provided with at least two first rollers mounted on two first free-wheels respectively connected to a first skid and configured, during a landing phase, to lock in the elastic return direction when the first skid moves in a first direction from the first skid towards a second skid and to be free in the sink direction during movement in a second direction, at least two second rollers being mounted on two respective second free-wheels connected to a second skid and configured, during a landing phase, to lock when the second skid moves in the second direction and to be free during movement in the first direction.

A landing gear provided with at least two first rollers mounted on two first free-wheels respectively connected to a first skid and configured, during a landing phase, to lock in the elastic return direction when the first skid moves in a first direction from the first skid towards a second skid and to be free in the sink direction during movement in a second direction, at least two second rollers being mounted on two respective second free-wheels connected to a second skid and configured, during a landing phase, to lock when the second skid moves in the second direction and to be free during movement in the first direction.

A multi-rotor UAV (unmanned aerial vehicle) includes a fuselage, four aircraft wings and a landing stand, wherein the landing stand comprises four landing support legs, every landing support leg is installed below an outermost end of a corresponding aircraft wing to form a landing support structure of the UAV, every landing support leg comprises a main pole and a base soft rubber, wherein the base soft rubber enwraps a base of the main pole for buffering. The multi-rotor UAV of the present invention is stable while taking off or landing, and is light in weight.

A multi-rotor UAV (unmanned aerial vehicle) includes a fuselage, four aircraft wings and a landing stand, wherein the landing stand comprises four landing support legs, every landing support leg is installed below an outermost end of a corresponding aircraft wing to form a landing support structure of the UAV, every landing support leg comprises a main pole and a base soft rubber, wherein the base soft rubber enwraps a base of the main pole for buffering. The multi-rotor UAV of the present invention is stable while taking off or landing, and is light in weight.

A vertical take-off and loading (VTOL) rotary aircraft or helicopter has eight propellers in a quad propeller arm configuration where each propeller arm has two counter-rotating propellers. Folding propeller arms are designed to allow storage in a single car sized garage. Each propeller may be powered by a three-phase alternating current motor. The main power plant for the aircraft is a gas combustion engine that generates electricity. If the gas engine fails, a battery backup system will safely bring the aircraft down for a controlled landing. The direct current bus is redundant in that even with a gas combustion engine failure the direct current bus battery pack will safely bring down the aircraft. Various embodiments of this invention may also include a landing gear crumple zone designed to soften a hard landing.

A vertical take-off and loading (VTOL) rotary aircraft or helicopter has eight propellers in a quad propeller arm configuration where each propeller arm has two counter-rotating propellers. Folding propeller arms are designed to allow storage in a single car sized garage. Each propeller may be powered by a three-phase alternating current motor. The main power plant for the aircraft is a gas combustion engine that generates electricity. If the gas engine fails, a battery backup system will safely bring the aircraft down for a controlled landing. The direct current bus is redundant in that even with a gas combustion engine failure the direct current bus battery pack will safely bring down the aircraft. Various embodiments of this invention may also include a landing gear crumple zone designed to soften a hard landing.

A landing gear includes a pair of skids, a cross tube and a stiffening portion. The pair of skids is arranged in parallel with a front-rear axis of an airframe of a rotary wing aircraft. The cross tube is attached to the airframe and coupling the pair of skids to each other. The cross tube includes curved portions located closer to end portions of the cross tube than to portions of the cross tube attached to the airframe. The stiffening portion suppresses flattening of the cross tube and is arranged in at least one of internal spaces of the curved portions or a stiffened portion located between a pair of curved portions. The stiffening portion includes an enlarged diameter portion which increases in diameter by an axial fastening power acting in an axial direction of the cross tube, and a fastening portion configured to generate the axial fastening power.

A landing gear includes a pair of skids, a cross tube and a stiffening portion. The pair of skids is arranged in parallel with a front-rear axis of an airframe of a rotary wing aircraft. The cross tube is attached to the airframe and coupling the pair of skids to each other. The cross tube includes curved portions located closer to end portions of the cross tube than to portions of the cross tube attached to the airframe. The stiffening portion suppresses flattening of the cross tube and is arranged in at least one of internal spaces of the curved portions or a stiffened portion located between a pair of curved portions. The stiffening portion includes an enlarged diameter portion which increases in diameter by an axial fastening power acting in an axial direction of the cross tube, and a fastening portion configured to generate the axial fastening power.

This disclosure describes a configuration of an unmanned aerial vehicle (UAV) landing gear assembly that includes adjustable landing gear extension that may be extended or contracted so that the body of the UAV is contained in a horizontal plane when the UAV is landed, even on sloping surfaces. For example, when a UAV is landing, the slope of the surface may be determined and the landing gear extensions adjusted based on the slope so that the body of the UAV remains approximately horizontal when the UAV lands and is supported by the landing gear extensions.

This disclosure describes a configuration of an unmanned aerial vehicle (UAV) landing gear assembly that includes adjustable landing gear extension that may be extended or contracted so that the body of the UAV is contained in a horizontal plane when the UAV is landed, even on sloping surfaces. For example, when a UAV is landing, the slope of the surface may be determined and the landing gear extensions adjusted based on the slope so that the body of the UAV remains approximately horizontal when the UAV lands and is supported by the landing gear extensions.