A propeller guard (200) according to the present disclosure is a propeller guard (200) for an unmanned aerial vehicle including a main body part (1) and a propeller part (2) and includes: an encircling part (210) that extends around the propeller part (2) and protects the propeller part (2); and a connection part (220) that connects the main body part (1) and the encircling part (210), wherein the encircling part (210) has a buoyant force for maintaining at least a part of the main body part (1) and the propeller part (2) above water.

Devices and methods for activating a flight-enable beacon configured to provide a light beacon or data signal comprising capability to establish and maintain a fixed set of coordinates. The flight-enabled beacon is configured with a processor, memory, motor, gimbal or swashplate and light emitting source and can be configured to attain and maintain a target altitude and emit a light over a fixed period of time. The flight-enabled beacon is configured to be light and with small form factor for easy portable transport in cases of emergency or to provide a signal easily locatable by parties located a distance from the activated light-enabled beacon.

A buoyancy method for deploying a plurality of floats of a buoyancy system of an aircraft. The plurality of floats comprises a plurality of main floats and a plurality of secondary floats that are folded in flight. The method comprises a step of deploying the main floats in flight prior to ditching, and a step of deploying the secondary floats after ditching.

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 multicopter aircraft with a wide span rotor configuration is disclosed. In various embodiments, a multicopter as disclosed herein includes a fuselage and a plurality of rotors. The plurality of rotors includes inner rotors and outer rotors, with the inner rotors being substantially surrounded by the outer rotors or the fuselage. The inner rotors and the outer rotors may be tilted based at least in part on their arrangement in relation to the fuselage.

An aircraft includes a fuselage which includes an unenclosed cockpit, a left arm where the proximal end is attached to the fuselage, a right arm where the proximal end is attached to the fuselage, a left float which is attached to the left arm between the proximal and distal ends, a right float which is attached to the right arm between the proximal and distal ends, and a plurality of rotors which includes a left inner rotor that is attached at a fixed angle to a top surface of the left float, a right inner rotor that is attached at a fixed angle to a top surface of the right float, a left outer rotor that is attached at a fixed angle to a top surface of the distal end of the left arm, and a right outer rotor that is attached at a fixed angle to a top surface of the distal end of the right arm.

An aircraft includes a fuselage which includes an unenclosed cockpit, a left arm where the proximal end is attached to the fuselage, a right arm where the proximal end is attached to the fuselage, a left float which is attached to the left arm between the proximal and distal ends, a right float which is attached to the right arm between the proximal and distal ends, and a plurality of rotors which includes a left inner rotor that is attached at a fixed angle to a top surface of the left float, a right inner rotor that is attached at a fixed angle to a top surface of the right float, a left outer rotor that is attached at a fixed angle to a top surface of the distal end of the left arm, and a right outer rotor that is attached at a fixed angle to a top surface of the distal end of the right arm.

A robust amphibious air vehicle incorporates a fuselage with buoyant stabilizers and wings extending from the fuselage. At least one lift fan is mounted in the fuselage. Movable propulsion units carried by the wings are rotatable through a range of angles adapted for vertical and horizontal flight operations.

A robust amphibious air vehicle incorporates a fuselage with buoyant stabilizers and wings extending from the fuselage. At least one lift fan is mounted in the fuselage. Movable propulsion units carried by the wings are rotatable through a range of angles adapted for vertical and horizontal flight operations.