Airframes configured for stable in-flight transition between forward flight and vertical takeoff and landing are described herein. In one embodiment, an aircraft can include a fuselage, opposed wings extending from opposed sides of the fuselage, and a plurality of engines. At least one engine can be mounted to each of the opposed wings and at least a portion of each opposed wing including at least one of the plurality of engines can rotate relative to the fuselage around a rotation axis that is non-perpendicular and transverse to a longitudinal axis of the fuselage. Rotating portions of the wings including at least one of the plurality of engines in the described manner can provide a stable and smooth transition between vertical and forward flight.

Airframes configured for stable in-flight transition between forward flight and vertical takeoff and landing are described herein. In one embodiment, an aircraft can include a fuselage, opposed wings extending from opposed sides of the fuselage, and a plurality of engines. At least one engine can be mounted to each of the opposed wings and at least a portion of each opposed wing including at least one of the plurality of engines can rotate relative to the fuselage around a rotation axis that is non-perpendicular and transverse to a longitudinal axis of the fuselage. Rotating portions of the wings including at least one of the plurality of engines in the described manner can provide a stable and smooth transition between vertical and forward flight.

A water sampling method includes acquiring, by an unmanned aerial vehicle, a sampling depth at which a water sample is to be taken. The sampling depth is sent by a portable electronic device or is a preset default depth. The method further includes calculating a descending distance based on the sampling depth and a distance between the unmanned aerial vehicle and a water surface, controlling the water sampler to descend for the descending distance, sampling, by the water sampler, a water sample, and sending a sampling result to a ground station or the portable electronic device.

A water sampling method includes acquiring, by an unmanned aerial vehicle, a sampling depth at which a water sample is to be taken. The sampling depth is sent by a portable electronic device or is a preset default depth. The method further includes calculating a descending distance based on the sampling depth and a distance between the unmanned aerial vehicle and a water surface, controlling the water sampler to descend for the descending distance, sampling, by the water sampler, a water sample, and sending a sampling result to a ground station or the portable electronic device.

An unmanned aerial vehicle is capable of keeping the airframe level on the water surface and is capable of taking off from and landing on water smoothly. The problem is solved by an unmanned aerial vehicle that includes: a plurality of rotary wings; and a plurality of arms radially extending from an airframe center portion of the unmanned aerial vehicle. The arms include floating portions extending downward from the respective arms. The floating portions include air chambers in the respective floating portions, the air chambers each including a hollow and hermetic space.

An unmanned aerial vehicle is capable of keeping the airframe level on the water surface and is capable of taking off from and landing on water smoothly. The problem is solved by an unmanned aerial vehicle that includes: a plurality of rotary wings; and a plurality of arms radially extending from an airframe center portion of the unmanned aerial vehicle. The arms include floating portions extending downward from the respective arms. The floating portions include air chambers in the respective floating portions, the air chambers each including a hollow and hermetic space.

The invention provides a firefighting float plane having a fuselage and two floats mounted to the fuselage. The fuselage has a water tank with open and closed configurations. In some embodiments, the water tank is integrated into the fuselage, and/or both the water tank and the fuselage have a generally triangular cross-sectional configuration. The water tank has a closed bottom in its closed configuration and an open bottom in its open configuration. In some embodiments, the plane has specified ratio of water tank holding capacity to total power of two engine assemblies. It can optionally also have the above-noted fuselage configuration, tank configuration, or both. In some embodiments, the plane has dual propellers, two engine assemblies, and two tail booms, optionally together with specified ratio of water tank holding capacity to total power of two engine assemblies. It may also have the above-noted fuselage configuration, tank configuration, or both.

A retrofittable float with an underwater camera attachment for unmanned aerial vehicles allows an unmanned aerial vehicle (UAV) to traverse over a body of water while recording images and/or video of the underwater environment. The retrofittable float with an underwater camera attachment includes a flotation device, a plurality of mounting brackets, an underwater scope, and at least one underwater illumination light. The flotation device attaches to the UAV via the plurality of mounting brackets. The plurality of mounting brackets is configured to align the center of gravity of the UAV with the center of buoyancy of the flotation device, thereby reducing the risk of capsizing. Once securely mounted, the camera of the UAV is positioned pointing into the underwater scope. The underwater scope allows the camera to record images and/or videos of the underwater environment. Finally, the at least one underwater illumination light is used to increase visibility.

A retrofittable float with an underwater camera attachment for unmanned aerial vehicles allows an unmanned aerial vehicle (UAV) to traverse over a body of water while recording images and/or video of the underwater environment. The retrofittable float with an underwater camera attachment includes a flotation device, a plurality of mounting brackets, an underwater scope, and at least one underwater illumination light. The flotation device attaches to the UAV via the plurality of mounting brackets. The plurality of mounting brackets is configured to align the center of gravity of the UAV with the center of buoyancy of the flotation device, thereby reducing the risk of capsizing. Once securely mounted, the camera of the UAV is positioned pointing into the underwater scope. The underwater scope allows the camera to record images and/or videos of the underwater environment. Finally, the at least one underwater illumination light is used to increase visibility.

A multicopter with boom mounted rotors is disclosed. In various embodiments, a multicopter includes multiple rotors, each mounted substantially horizontally on a distal end of a boom. The multicopter further includes a plurality of boom extensions, each boom extension being associated with a corresponding boom and each boom extension being configured to extend an associated distal end of said corresponding boom by an amount determined based at least in part on a swept area associated with a rotor mounted at or near said associated distal end. The multicopter includes a material, such as netting, secured to the aircraft and of a size sufficient to reach a far end of one or more of said boom extensions.