A heater that inhibits the formation of ice in an air gap separating a stationary stator and a rotatable rotor of a rotating machine. The heater includes a plurality of stringers configured to be arranged in associated winding slots of the associated stator adjacent the air gap, and extending between two ends of the heater. Each of the stringers includes two electrical resistance heating traces arranged between two electrical insulation layers that are arranged between two thermal conduction layers. The traces extend along an entire length of each of the stringers between the two ends of the heater. The traces are electrically isolated from each other.

A spring compression device comprises a spring sleeve configured to receive a spring; a spring adjustment member provided on and engaged with the spring sleeve and configured to abut a spring mounted on the spring sleeve, wherein the spring sleeve and spring adjustment member define an operating length (L) of the spring compression device, and the spring adjustment member is configured to be moved relative to the spring sleeve to adjust the operating length of the spring compression device; and at least one blocking component for blocking movement between the spring sleeve and the spring adjustment member.

A system includes a first AC bus configured to supply power from a first AC power source. A second AC bus is configured to supply power from a second AC power source. A first transformer rectifier unit (TRU) connects a first DC bus to the first AC bus through a first TRU contactor (TRUC). A second TRU connects a second DC bus to the second AC bus through a second TRUC. A ram air turbine (RAT) automatic deployment controller is operatively connected to the first TRUC and to the second TRUC to automatically deploy a RAT based on the combined status of the first TRUC and the second TRUC.

A system includes a first AC bus configured to supply power from a first generator. A first generator line contactor (GLC) selectively connects the first AC bus to the first generator. A second AC bus is configured to supply power from a second generator. A second GLC selectively connecting the second AC bus to the second generator. An auxiliary generator line contactor (ALC) is connected to selectively supply power to the first and second AC buses from an auxiliary generator. A first bus tie contactor (BTC) electrically connects between the first GLC and the ALC. A second BTC electrically connects between the ALC and the second GLC. A ram air turbine (RAT) automatic deployment controller is operatively connected to automatically deploy a RAT based on the combined status of the first GLC, the second GLC, the ALC, the first BTC, and the second BTC.

A boundary layer ingestion-open rotor system for use with an aircraft having a fuselage, wings, and an empennage includes an open rotor assembly, one or more energy storage systems, and an electronic control unit (ECU). The open rotor assembly includes fan blades connected to and extending radially from a rotor hub, and a linkage assembly connecting the hub to the fuselage aft of the empennage within a predefined boundary layer of airflow around the fuselage. The energy storage systems are connectable to the rotor hub. In response to an electronic control signal, the system(s) selectively energize the open rotor assembly to cause rotation of the hub to occur within the boundary layer. The ECU selectively generates the electronic control signals to energize the open rotor assembly during one or more predetermined flight operating phases of the aircraft, e.g., cruise, takeoff, landing, and descent.

A toggle assembly includes a first joint member having a first lug and a second lug, a second joint member, and a third joint member. The second joint member has a first arm that receives a first rolling element, a second arm that receives a second rolling element, a third arm, and a fourth arm. The second joint member is pivotally connected to the first joint member via a first pin that extends through the first lug, the first rolling element, the second rolling element, and the second lug. The third joint member has a third lug and a fourth lug disposed opposite the third lug. The third joint member is pivotally connected to the second joint member via a cross rod pin that extends through the third lug, the third arm and the fourth arm.

A system includes a first AC bus configured to supply power from a first generator. A second AC bus is configured to supply power from a second generator. An AC essential bus tie contactor (AETC) selectively connects between an AC essential bus and the first and second AC busses. An AETC controller is connected to switch the AETC between a first state connecting the AC essential bus to the first AC bus and a second state connecting the AC essential bus to the second AC bus. A sensor system is configured to detect at least one of delta current and overcurrent in the AC essential bus and in at least one of the first AC bus and the second AC bus. The sensor system is operatively connected to the AETC controller for switching the AETC between the first state and the second state based on input from the sensor system.

A ram air turbine (RAT) system can include a generator configured to be turned by a RAT and to output an alternating current (AC) power, a generator control unit (GCU) configured to control an output of the generator, a rectifying module configured to rectify the AC power into a direct current (DC) power, and a DC load configured to receive the DC power from the rectifying module. The DC load can be operatively connected to the GCU to provide feedback from the DC load to the GCU. The GCU can be configured to control the output of the generator as a function of the feedback to prevent stalling of the RAT and/or doorbelling current and/or voltage in the system caused by disconnecting the generator from the DC load.

An air management system with a set of compressed air sources for supplying pressurized air to air consumer equipment. In particular, either an air bleed system, electrical compressors, or a combination thereof may perform such supplying of compressed air depending on the aircraft operation condition.

A wireless autopilot system includes a mounting plate for securement onto a flight control surface of an aircraft, an airfoil, and a flight control device. The flight control device is connected to the mounting plate, and an elongated bracket functions as an anti-flutter counterbalance. A servomotor is connected to the airfoil by the elongated bracket, and a controller having a wireless transceiver for communicating with an application on an externally located processor enabled device is located within the main body. Changes in the position of the servomotor during flight are instructed by the application, and result in a change to the orientation of the aircraft.