An actuator includes a brushless DC motor, an output device, a reduction system coupled between the brushless DC motor and the output device, and a contactless position sensor configured to sense a position of the output device.

An aircraft has a pilot compartment and a power source, apparatus adapted to control attitude and direction, apparatus adapted to vary power of the power source, sensors sensing at least altitude, airspeed, power level, and aircraft attitude, a CPU coupled to a data repository, to the sensors and to actuators adapted to change the flight attitude and direction and to vary power, and safe flight envelope data and conditions stored in the data repository defining flight conditions at boundaries of safe and unsafe operation. The CPU monitors the sensors while the aircraft is in operation, determines if flight status is outside the safe flight envelope, and if so, drives appropriate actuators to manipulate the apparats adapted to control flight attitude and direction and/or the apparatus adapted to vary power of the power source in a programmed manner until the flight status is within the safe flight envelope.

An aircraft has a pilot compartment and a power source, apparatus adapted to control attitude and direction, apparatus adapted to vary power of the power source, sensors sensing at least altitude, airspeed, power level, and aircraft attitude, a CPU coupled to a data repository, to the sensors and to actuators adapted to change the flight attitude and direction and to vary power, and safe flight envelope data and conditions stored in the data repository defining flight conditions at boundaries of safe and unsafe operation. The CPU monitors the sensors while the aircraft is in operation, determines if flight status is outside the safe flight envelope, and if so, drives appropriate actuators to manipulate the apparats adapted to control flight attitude and direction and/or the apparatus adapted to vary power of the power source in a programmed manner until the flight status is within the safe flight envelope.

An aft pivot assembly can include a mount device securable to an aft portion of a payload of an aircraft for facilitating release of the payload. The aft pivot assembly can include a shaft operable with the mount device and a release component, the shaft being rotatable about multiple shaft axes relative to the mount device so as to either minimize or eliminate carriage loads about the aft portion, while reacting jettison loads during a jettison event or phase. The rotation of the shaft about its shaft axes can further be limited via a limit device. As the payload transitions from a carriage phase to a jettison phase, the shaft moves in multiple degrees of freedom and in multiple axes relative to the mount device.

An aft pivot assembly can include a mount device securable to an aft portion of a payload of an aircraft for facilitating release of the payload. The aft pivot assembly can include a shaft operable with the mount device and a release component, the shaft being rotatable about multiple shaft axes relative to the mount device so as to either minimize or eliminate carriage loads about the aft portion, while reacting jettison loads during a jettison event or phase. The rotation of the shaft about its shaft axes can further be limited via a limit device. As the payload transitions from a carriage phase to a jettison phase, the shaft moves in multiple degrees of freedom and in multiple axes relative to the mount device.

A flexible fuel bladder assembly for an aircraft includes a flexible fuel bladder positioned at an airframe and having an opening to allow a flow of fuel into and/or out of the fuel bladder. A breakaway valve is operably connected to the fuel bladder at the opening to control a flow of fuel therethrough. A non-contacting or loose fitting reaction feature is affixed to the airframe and is interactive with the breakaway valve such that movement of the breakaway valve relative to the reaction feature results in breakage of a valve body of the breakaway valve and closure of the breakaway valve to prevent flow of fuel therethrough while also allowing for a second reaction mode to cause breakage of a valve body should the connecting hose be pulled relative to the breakaway valve.

A flexible fuel bladder assembly for an aircraft includes a flexible fuel bladder positioned at an airframe and having an opening to allow a flow of fuel into and/or out of the fuel bladder. A breakaway valve is operably connected to the fuel bladder at the opening to control a flow of fuel therethrough. A non-contacting or loose fitting reaction feature is affixed to the airframe and is interactive with the breakaway valve such that movement of the breakaway valve relative to the reaction feature results in breakage of a valve body of the breakaway valve and closure of the breakaway valve to prevent flow of fuel therethrough while also allowing for a second reaction mode to cause breakage of a valve body should the connecting hose be pulled relative to the breakaway valve.

A method of operating an aircraft includes, prior to an in-flight refueling operation, operating the aircraft using fuel from a first fuel tank connected to a fuel delivery system. Subsequently, the in-flight refueling operation is performed over a refueling area while operating the aircraft from another fuel tank, including (1) disconnecting the first fuel tank from the fuel delivery system, (2) jettisoning the first fuel tank, and (3) taking on a replacement fuel tank by (a) capturing the replacement fuel tank from the refueling area and (b) bringing the captured replacement fuel tank onboard the aircraft. The replacement fuel tank is then connected to the fuel delivery system and the aircraft is operated using fuel from the replacement fuel tank.

A method of operating an aircraft includes, prior to an in-flight refueling operation, operating the aircraft using fuel from a first fuel tank connected to a fuel delivery system. Subsequently, the in-flight refueling operation is performed over a refueling area while operating the aircraft from another fuel tank, including (1) disconnecting the first fuel tank from the fuel delivery system, (2) jettisoning the first fuel tank, and (3) taking on a replacement fuel tank by (a) capturing the replacement fuel tank from the refueling area and (b) bringing the captured replacement fuel tank onboard the aircraft. The replacement fuel tank is then connected to the fuel delivery system and the aircraft is operated using fuel from the replacement fuel tank.

A cryogenic fuel tank for retrofitting a conventional fossil-fuel-powered aircraft, or for a purposely built aircraft to run on hydrogen has an aerodynamically shaped outer surface including an ogive shaped nose cone, and a tapered tail cone, wherein the tapered tail cone includes actively adjustable elements for adjusting aerodynamic characteristics of the cryogenic fuel tank. The cryogenic fuel tank is configured to be attached below wings of the aircraft, through support pylons, which include sensors configured to measure forces applied by the cryogenic fuel tank to the airframe. The cryogenic fuel tank includes a nozzle and valve configured to vent gas from the cryogenic fuel tank by expansion through the nozzle in the event that the cryogenic fuel tank is jettisoned from the aircraft.