An aircraft has an ethanol fuel storage, an ethanol-fueled fuel cell selectively connected to the ethanol fuel storage, and a power management unit configured to receive electrical power from the ethanol-fueled fuel cell.

A vehicle includes a tilt rotor that is aft of a fixed wing and that is attached to the fixed wing via a pylon. A flight computer configured to instruct the tilt rotor to produce a maximum downward angle including by updating an actuator authority database associated with the flight computer to reflect the maximum downward angle, and generating a rotor control signal for the tilt rotor using the updated actuator authority database that reflects the maximum downward angle, wherein the maximum downward angle is adjustable.

An aircraft includes an airframe with an upper portion and an extending tail, a counter-rotating, coaxial main rotor assembly disposed at the upper portion of the airframe, a translational thrust system, including a propeller, disposed at the extending tail of the airframe and a flight control system configured to control at least one of revolutions-per-minute (RPM) and pitch of the propeller of the translational thrust system in response to an input speed or acceleration command.

A rotorcraft capable of a hover mode and a forward cruise mode including a fuselage, a first electric propulsion system, a second electric propulsion system, and an electric power control unit to control power to the first and second electric propulsion systems in the hover and forward cruise modes. The first electric propulsion system is a tip jet cold flow system that imparts rotation on a pair of rotor blades disposed above a top surface of the fuselage, and a first electric motor configured to drive the tip jet cold flow system. The second electric propulsion system includes a propeller disposed in the rear of the fuselage and a second electric motor configured to drive the propeller.

A first power source includes a high discharge rate battery and a second power source includes a high energy battery. An electronically activated switch switches between the first power source and the second power source in response to a control signal from a power controller. If the electronically activated switch fails, it fails with one of the first power source and the second power source in an open circuit position and with the other one of the first power source and the second power source in a closed circuit position. The power controller generates the control signal, including by: during a vertical landing associated with a vertical takeoff and landing (VTOL) vehicle, generating the control signal to switch from the high energy battery to the high discharge rate battery independent of a measured current.

Various implementations directed to an aircraft thermal management system are provided. In one implementation, an aircraft may include a fuselage having one or more fuselage sections. The aircraft may also include one or more electric motors configured to drive one or more propulsion systems of the aircraft, where the one or more electric motors are configured to generate thermal energy. The aircraft may further include an aircraft thermal management system configured to transfer the thermal energy generated by the one or more electric motors to the one or more fuselage sections.

A rotorcraft having an electric drive for driving a main rotor of a rotorcraft, more particularly a helicopter, the electric drive comprising: a coupler for coupling the electric drive to a rotor mast, which can be coupled for conjoint rotation with a drive unit of a helicopter rotor transmission, for coupling for conjoint rotation with the main rotor or tail rotor. A rotorcraft with an electric drive is provided with which the space requirement is reduced, the construction is simplified and the maintenance requirement is reduced. This problem is solved in that the electric drive is designed as an electric ring motor, with the electric ring motor being arranged and attached coaxially with the rotor mast.

A drive system of at least one rotor of an aircraft via electrical energy in addition to or as a replacement of a mechanical system. The electrical energy is provided at least in part by at least one device for recovering thermal energy from hot gases of an internal combustion engine of the aircraft.

An aircraft includes an airframe having an empennage, a counter rotating, coaxial main rotor assembly located at the airframe including an upper rotor assembly and a lower rotor assembly, and a translational thrust system positioned at the empennage and providing translational thrust to the airframe. At least two control surfaces located at the empennage are independently operable via commands from one or more flight control computers. A method of operating an aircraft includes transmitting a first signal from one or more flight control computers to a first control surface located at a first lateral side of a translational thrust system, and actuating the first control surface to a first position via the first signal. A second signal is transmitted to a second control surface located at a second lateral side opposite the first lateral side, and the second control surface is actuated to a second position via the second signal

An aircraft includes an airframe having an extending tail, a counter rotating, coaxial main rotor assembly disposed at the airframe including an upper rotor assembly and a lower rotor assembly, and a translational thrust system positioned at the extending tail and providing translational thrust to the airframe. A fly by wire control system for the aircraft includes a flight control system configured to receive a plurality of inputs and a flight control computer to translate the inputs into commands and issue the commands to one or more controlled elements of the aircraft. A fly by wire control system for a dual coaxial rotor rotorcraft with auxiliary propulsor includes a flight control system configured to receive a plurality of inputs and a flight control computer to translate the inputs into commands and issue the commands to one or more controlled elements of the rotorcraft.