Abstract: A thermal sensor for an aircraft includes a first electrode, a second electrode, a support layer disposed between the first electrode and the second electrode, and a state changing material is configured to disposed within the support layer, wherein the state changing material transitions between a non-conductive state to a conductive state at a threshold temperature to electrically connect the first and second electrodes.

Abstract: A method of actuating an extinguisher system may comprise retaining a broadhead cutter in close proximity to a burst disc surface, receiving an impulse signal, actuating a spring release mechanism in response to receiving the impulse signal, driving a cutter shaft towards the burst disc surface in response to actuation, and piercing the burst disc surface via the broadhead cutter coupled to the cutter shaft.

Abstract: A multi-condition sensor, comprising a housing defining a component cavity, a pressure input tube disposed through the housing, a fault actuator disposed within the component cavity of the housing and in pressure communication with the pressure input tube through the housing, wherein the fault actuator is configured to extend and contract as a function of pressure from the pressure input tube, an alarm actuator disposed within the component cavity of the housing opposite the fault actuator and configured to be actuated by the fault actuator and to extend to a maximum fault position, and an adjustable alarm contact disposed on an opposite side of the alarm actuator within the component cavity and configured to be adjusted to a predetermined extension length from the housing to provide a predetermined alarm contact position.

Abstract: A eutectic sensing element includes an electrically conductive core extending along a first axis to define a length. The core is coated with a coated with a eutectic material formulated to provide desirable thermal response characteristics. The eutectic sensing element further includes an insulating fiber layer disposed on an external surface of the electrically conductive. The insulating fiber layer includes a strand that extends along the length of the electrically conductive core.

Abstract: A fire suppression system may comprise a shape memory actuation system. The shape memory actuation system may be configured as a retainer that retains a plug and/or a disk. The shape memory actuation system may be a shape memory plug that is configured to discharge from a vessel exhaust port. The shape memory actuation system may be deployable in response to an electrical stimulus (e.g., resistive heating causing the shape memory alloy to have a temperature exceeding a transition temperature).

Abstract: The present disclosure relates to a broadhead cutter activation mechanism and system inside of a fire extinguisher. The broadhead cutter device may be attached to a cutter shaft which is driven downward when the elastic potential energy is released form a spring system. The broadhead cutter device may be configured to pierce and open a burst disc to release the flow of an extinguishing agent under pressure.

Abstract: According to one aspect, a fire extinguisher includes a fire extinguisher reservoir and a fire extinguisher outlet burst disc that forms a discharge barrier between the fire extinguisher reservoir and a discharge head to retain a pressurized fire extinguishing agent within the fire extinguisher reservoir. The fire extinguisher actuator assembly includes a cutter positioned within the fire extinguisher proximate the fire extinguisher outlet burst disc. The fire extinguisher actuator assembly also includes a motorized activation device having a drive shaft. The motorized activation device is operable to rotate the drive shaft and push the cutter to pierce the fire extinguisher outlet burst disc, thereby releasing the pressurized fire extinguishing agent through the discharge head.

Abstract: A method and apparatus for testing a duct leak detection system of an aircraft is disclosed. A sensor of the duct leak detection system is selected at an interface of the duct leak detection system. An alternating current is sent through the selected sensor and a resistance of the selected sensor is measured using the alternating current. An indicative signal is generated at the interface when the measured resistance of the selected sensor is outside of a specification of the selected sensor.

Abstract: A method of suppressing a fire includes the steps of dispensing a first inert gas in a suppression area at an initial rate, detecting an undesired temperature in the suppression area, dispensing a second inert gas at a subsequent rate in the suppression area in response to the undesired temperature and displacing a volume from the suppression area with the inert gas to achieve a temperature below the undesired temperature.

Abstract: A method of manufacturing an overheat or fire alarm detection system, comprises the steps of micromachining a pressure sensor and securing a sensor tube in fluid communication with the pressure sensor. The sensor tube may comprise a hollow tube containing a material that evolves gas upon heating. The micromachining step may comprise doping at least a portion of a first layer, forming a cavity at least partially within the doped portion and forming a deformable diaphragm over the cavity.

Abstract: A thermal event detection and notification system detects a thermal event, a control unit receives information from, the information being indicative of the detected thermal event. The control unit determines, based on the information received, a location of said thermal event.

Abstract: A method for preventing chaffing between a linear detector cable and a protective outer sheath including the steps of preparing an elongated polymer tube having a predetermined length and outer diameter, wrapping heat resistant tape having a given width around a distal end portion of the tube to locally enlarge the outer diameter of the tube, and inserting a proximal end portion of the tube into an open end of a metallic protective sheath having a predetermined inner diameter that is slightly greater than or equal to the outer diameter of the tube, so that the heat resistant tape wrapped around the distal end portion of the tube abuts against the end of the sheath to acts as a stop surface.

Abstract: A pneumatic sensing apparatus for use in an overheat or fire alarm system includes a sensor tube containing a pressurized gas in communication with a pressure sensor configured to sense a temperature variation based on changes of the pressurized gas. A pressure switch is coupled to the pressure sensor. The pressure switch includes a signal transducer configured to provide an output indicative of an overheat or fire alarm condition.

Abstract: A pneumatic detection system and a method of forming the pneumatic detection system are described. The system includes a sealed tube, a refrigerant disposed within the sealed tube, and a switch configured to be activated based on a specified pressure being reached within the sealed tube.

Abstract: In various embodiments, a fire suppression system includes a high rate discharge system and a low rate discharge system. The low rate discharge system may comprise components that are capable of varying mass flow of a fire suppression agent in term of the ambient conditions of the aircraft structure. In this regard, the low rate discharge system may comprise a valve that is configured to sense at least one of the ambient pressure and ambient temperature of an aircraft structure.

Abstract: According to one aspect, a fire extinguisher actuator assembly for a fire extinguisher is provided. The fire extinguisher includes a fire extinguisher reservoir and a burst disc that forms a discharge barrier between the fire extinguisher reservoir and a discharge head to retain a pressurized fire extinguishing agent within the fire extinguisher reservoir. The fire extinguisher actuator assembly includes a cutter shuttle assembly having a cutter coupled to a shuttle body. The cutter shuttle assembly is detained within the fire extinguisher proximate the burst disc and biased to form a pressure equalization region between the shuttle body and the burst disc. The fire extinguisher actuator assembly also includes an activation device having a piercing member operable to pierce the burst disc and release pressure from the pressure equalization region, thereby driving the cutter through the burst disc to release the pressurized fire extinguishing agent through the discharge head.

Abstract: A fire suppression system according to an exemplary aspect of the present disclosure includes, among other things, a high pressure inert gas source configured to provide a first inert gas output and a low pressure inert gas source configured to provide a second inert gas output. A distribution network is connected with the high pressure inert gas source and the low pressure inert gas source to distribute the first inert gas output and the second inert gas output throughout a confined space. A volume reduction system is positioned within the confined space and includes a seal member. The seal member is selectively deployable between a first position and a second position to isolate a first volume of the confined space from a second volume of the confined space and reduce an amount of the first inert gas output and the second inert gas output required to respond to a fire threat within the confined space.

Abstract: An embodiment of a cable assembly includes a cable including at least a shielded conductor, a mating connector mounted to a first assembly end, and an elongated strain relief grommet disposed longitudinally between the cable and the mating connector. The strain relief grommet includes a grommet body formed from a compressible material. The body includes a first grommet end portion disposed proximate to the mating connector, and a second grommet end portion disposed distal to the mating connector.

Abstract: According to one aspect, a fire extinguisher includes a fire extinguisher reservoir and a fire extinguisher outlet burst disc that forms a discharge barrier between the fire extinguisher reservoir and a discharge head to retain a pressurized fire extinguishing agent at an internal fire extinguisher pressure within the fire extinguisher reservoir. A cutter is detained within the fire extinguisher proximate the fire extinguisher outlet burst disc. An interior container within the fire extinguisher reservoir has a container pressure and is sealed with a container burst disc. An activation device having a piercing member is operable to pierce the container burst disc and diffuse the container pressure to create a pressure differential relative to the internal fire extinguisher pressure at the cutter, thereby driving the cutter through the fire extinguisher outlet burst disc to release the pressurized fire extinguishing agent through the discharge head.

Abstract: A temperature sensing system comprises a conductive tube, a shape memory alloy (SMA) element, and a detector. The SMA element is disposed to create an electrical contact with the electrical tube when subjected to at least a critical temperature, and the detector is configured to identify an alarm condition when the conductive tube and the SMA element form a closed electrical circuit.