An unmanned aerial vehicle (UAV) for gas transport is disclosed. The UAV includes a fuselage enclosing a volume, and a gas reservoir enclosed within the fuselage, filling at least a majority of the volume. The gas reservoir is configured to receive and store a gas at a pressure no greater than 100 bar. The UAV also includes a propulsion system having at least one engine, each of the at least one engine coupled to a prop that is driven by the at least one engine using energy derived from the gas stored in the gas reservoir. The UAV also includes a control system communicatively coupled to the propulsion system and configured to operate the unmanned aerial vehicle to autonomously transport the gas. The UAV may have a footprint while on the ground, and the footprint of the UAV may be no larger than three standard parking spaces.

A wing assembly include at least one fuel tank having a tank outboard end. In addition, the wing assembly includes a stout wing rib located proximate the tank outboard end and extending between a front spar and a rear spar. The wing assembly also includes at least one outboard wing rib located outboard of the stout wing rib and defining an outboard wing bay. The wing assembly also includes an upper skin panel and a lower skin panel each coupled to the front spar, the rear spar, the stout wing rib, and the outboard wing rib. A plurality of bead stiffeners are coupled to the upper skin panel and/or the lower skin panel and are spaced apart from each other within the outboard wing bay.

An integral hybrid electric aircraft system including a fuselage including an electrical energy source, wherein the electrical energy source includes a plurality of batteries and a fuel tank, and wherein the fuel tank contains fuel. The fuselage also including a generator in fluid communication with the fuel tank. The generator generates electricity using the fuel from the fuel tank. The system including a set of propulsors, wherein each propulsor of the set of propulsors is electrically connected to the electrical energy source and the generator and wherein the set of propulsors is configured to be powered by the generator during fixed-wing flight. The set of propulsors including at least a pusher propulsor configured to provide forward thrust and at least a lift propulsor configured to provide lift.

An integral hybrid electric aircraft system including a fuselage including an electrical energy source, wherein the electrical energy source includes a plurality of batteries and a fuel tank, and wherein the fuel tank contains fuel. The fuselage also including a generator in fluid communication with the fuel tank. The generator generates electricity using the fuel from the fuel tank. The system including a set of propulsors, wherein each propulsor of the set of propulsors is electrically connected to the electrical energy source and the generator and wherein the set of propulsors is configured to be powered by the generator during fixed-wing flight. The set of propulsors including at least a pusher propulsor configured to provide forward thrust and at least a lift propulsor configured to provide lift.

A fuel gauging sensing device for a fuel tank for aircrafts includes an optical fiber harness along the internal surface of the tank, a master optical controller connected to a first terminal of the optical fiber harness, a slave optical controller connected to a second terminal of the optical fiber harness, wherein the optical fiber harness includes Fiber Bragg Grating (FBG) sensors spaced in the optical fiber harness between 1 mm and 25 mm to provide temperature gradients inside the tank and wherein the master and slave optical controllers are configured to obtain the fuel gauging of the tank based on the output from the FBG sensors.

A fuel gauging sensing device for a fuel tank for aircrafts includes an optical fiber harness along the internal surface of the tank, a master optical controller connected to a first terminal of the optical fiber harness, a slave optical controller connected to a second terminal of the optical fiber harness, wherein the optical fiber harness includes Fiber Bragg Grating (FBG) sensors spaced in the optical fiber harness between 1 mm and 25 mm to provide temperature gradients inside the tank and wherein the master and slave optical controllers are configured to obtain the fuel gauging of the tank based on the output from the FBG sensors.

A rotary wing aircraft with a fuselage and a non-retractable skid-type landing gear that is mounted to the fuselage, the non-retractable skid-type landing gear comprising at least one landing box, the at least one landing box being provided with a skid-type landing base member and an associated box shell that delimits an internal volume of the at least one landing box.

An aircraft includes an airframe having at least one wing. A distributed propulsion system is attached to the airframe and includes first and second pluralities of propulsion assemblies. In a vertical takeoff and landing flight mode, each of the propulsion assemblies generates vertical thrust with rotor assemblies of the first plurality of propulsion assemblies rotating in a horizontal plane and rotor assemblies of the second plurality of propulsion assemblies rotating in a parallel horizontal plane. In a forward flight mode, each of the propulsion assemblies generates forward thrust with the rotor assemblies of the first plurality of propulsion assemblies rotating in a vertical plane and the rotor assemblies of the second plurality of propulsion assemblies rotating in a parallel vertical plane. In both the vertical takeoff and landing flight mode and the forward flight mode, a pod assembly coupled to the airframe remains in a generally horizontal attitude.

A method of operating an aircraft including a gas turbine engine and a plurality of fuel tanks arranged to provide fuel to the gas turbine engine, where at least two of the fuel tanks contain fuels with different fuel characteristics. The method includes obtaining a flight profile for a flight of the aircraft; and determining a fuelling schedule for the flight based on the flight profile and the fuel characteristics. The fuelling schedule governs the variation with time of how much fuel is drawn from each tank. Fuel input to the gas turbine engine may then be controlled in operation in accordance with the fuelling schedule.

A method of operating an aircraft including a gas turbine engine and a plurality of fuel tanks arranged to provide fuel to the gas turbine engine, where at least two of the fuel tanks contain fuels with different fuel characteristics. The method includes obtaining a flight profile for a flight of the aircraft; and determining a fuelling schedule for the flight based on the flight profile and the fuel characteristics. The fuelling schedule governs the variation with time of how much fuel is drawn from each tank. Fuel input to the gas turbine engine may then be controlled in operation in accordance with the fuelling schedule.