An engine system of an aircraft includes a gas turbine engine comprising at least one spool and at least one electric machine operably coupled with the at least one spool. A controller is configured to detect if the at least one spool of the gas turbine engine is in or is approaching an overspeed condition and apply a load to the at least one spool via the at least one electric machine.

A concealed office fan lamp is provided, which includes a stop device, a support and a fan blade. A lamp is arranged at the bottom of the support, a cavity is arranged in the support, the fan blade is electrically connected with a driving mechanism to make it rotatably arranged in the cavity, and the stop device is arranged on the support and/or the fan blade to detect the motion state of the fan blade. According to the motion state, the fan blade is stopped and hidden in the cavity. By providing a stop device on the fan lamp, the fan blade can be accurately stopped and hidden in the cavity, the person under the fan lamp cannot see the fan blade when the fan lamp stops working, making the fan lamp more beautiful as a whole.

Methods and systems for controlling windmilling in an engine are described. An electric starter motor is coupled to the engine, a circuit element is coupled to the electric starter engine and to a DC signal source, and a control system coupled to the engine and to the circuit element. The control system is configured for: determining whether the engine is in a windmilling state; when the engine is in a windmilling state, commanding the circuit element to apply a DC signal to the electric starter motor; and modulating the DC signal applied to the electric starter motor to control a level of rotational motion of the engine.

An improved HVAC vent is disclosed. The vent may include an air turbine positioned within a passageway for selectively enabling and preventing airflow. In use, the air turbine is selectively operable between first and second states. In the first state, the air turbine may be freely rotatable, via the airflow, so that the received airflow can move through the passageway. In the second state, rotation of the air turbine is controlled or prevented so that the received airflow is inhibited or substantially inhibited from moving through the passageway. The vent may also include a motor. In use, the motor may act an energy generator and as an active brake so that in the first state, rotation of the air turbine is used to charge a power storage unit, and in the second state, the motor limits rotation of the air turbine.

A bidirectional thrust assembly comprises a motor, a selective power transfer mechanism, and a plurality of fans; wherein a change in direction of rotation of the motor causes the selective power transfer mechanism to change a torque transfer among the plurality of fans, wherein the fans may be opposing, and wherein the fans may be unidirectional. The bidirectional thrust assembly may be used in or by a plurality of craft or with respect to other objects which may need to be maneuvered, included suspended load control systems, vertical takeoff and landing craft, watercraft.

This supercharging device is provided with an impeller having a shaft, a motor generator configured so as to rotate the impeller to perform supercharging, a planetary gear mechanism, and a restricting mechanism configured so as to restrict the rotation of the impeller. The planetary gear mechanism has a sun gear to which the shaft is linked, a ring gear configured so as to rotate by means of motive power from an engine, a plurality of planetary gears, and a carrier linked to the plurality of planetary gears. The carrier has a cylinder part through which the shaft passes. The motor generator has a rotor integrated with the outer peripheral surface of the cylinder part, and a stator disposed on the radially outward side of the rotor.

A bidirectional thrust assembly comprises a motor, a selective power transfer mechanism, and a plurality of fans; wherein a change in direction of rotation of the motor causes the selective power transfer mechanism to change a torque transfer among the plurality of fans, wherein the fans may be opposing, and wherein the fans may be unidirectional. The bidirectional thrust assembly may be used in or by a plurality of craft or with respect to other objects which may need to be maneuvered, included suspended load control systems, vertical takeoff and landing craft, watercraft.

A gas turbine engine for an aircraft, comprises a high-pressure (HP) spool comprising an HP compressor and a first electric machine driven by an HP turbine; a low-pressure (LP) spool comprising an LP compressor and a second electric machine driven by an LP turbine; an engine controller configured to identify a condition to the effect that the HP spool has reached or exceeded an HP speed limit whilst the LP spool has not reached an LP speed limit, and to operate the first electric machine in a generator mode of operation to reduce the HP spool speed below the HP speed limit.

A braking system for the low pressure spool of a gas turbine engine includes a braking assembly connected to the low pressure spool and reversibly configurable between an actuated state and an unactuated state. The braking assembly in the unactuated state allows rotation of the low pressure spool without interference. The braking assembly in the actuated state applies a force opposing the rotation of the low pressure spool. A method of controlling the speed of rotation of a low pressure spool and a method of controlling the speed of rotation of low and high pressure spools are also discussed.

A gas turbine engine has an engine static structure and at least one component rotatable relative to the engine static structure about an engine axis of rotation. A fan is coupled to at least one component for rotation about the engine axis of rotation. An actuator is mounted to the engine static structure, wherein the actuator is activated to prevent the fan from rotation and is inactivated to allow the fan to rotate. A method for preventing rotation of a fan in a gas turbine engine is also disclosed.