Examples described herein provide a method for overspeed protection of a motor of a gate crossing mechanism. The method includes monitoring, by an overspeed protection circuit, a voltage across a first Zener diode and a second Zener diode. An anode of the first Zener diode is connected to an anode of the second Zener diode. The method further includes, responsive to determining that a Zener voltage threshold is exceeded, allowing a current to flow into a gate pin of a triac. The triac controls the motor of the gate crossing mechanism.

A system includes one or more sensors to detect unintended forward and reverse rotation of rotating machinery. The system also includes a monitoring system consisting of a processor, memory, display and communication interface. The processor receives signals from the sensors. The processor determines unintended rotation when the pattern of received signals match with the conditions defined in the processor. The processor generates a notification signal of “Unintended Rotation” on the display. The notification signal is also sent to the operator workstation to alert the operating personnel. The notification history is also stored in the system memory. The system is also configured to initiate automatic action to stop the unintended rotation and protect the machinery components from unintended rotation. The action may include closing the suction and discharge valve and starting the lubrication system to lube the bearings of the rotating machinery and the motor.

In accordance with at least one aspect of this disclosure, there is provided a system for an aircraft engine. In embodiments, the system includes an accessory box and a fuel accessory located in an interior space within the accessory box, where a vent is defined through a wall of the accessory box. In embodiments, the vent includes a plurality of holes or slots in an outer wall of the accessory box for passage of gaseous fuel from the interior space. In embodiments, the vent is configured for passive ventilation of the interior space.

Fuel systems of gas turbine engines of aircraft, and associated methods are provided. The fuel systems and methods can permit reverse purging of one or more fuel manifolds of a gas turbine engine to prevent coking in some modes of operation. A fuel system includes first and second fuel manifolds fluidly connectable to a combustor of the gas turbine engine. A valve is operatively disposed between the second fuel manifold and a fuel supply line for controlling fuel supply to the second fuel manifold. A reservoir includes a movable piston disposed therein and dividing the reservoir into a first chamber and a second chamber. The first chamber is fluidly connectable to the fuel supply line or to a fuel purge line via the valve. The second chamber is in fluid communication with the second fuel manifold to receive residual fuel from the second fuel manifold.

Fuel systems of gas turbine engines of aircraft, and associated methods are provided. The fuel systems and methods can permit reverse purging of one or more fuel manifolds of a gas turbine engine to prevent coking in some modes of operation. A fuel system includes first and second fuel manifolds fluidly connectable to a combustor of the gas turbine engine. A valve is operatively disposed between the second fuel manifold and a fuel supply line for controlling fuel supply to the second fuel manifold. A reservoir includes a movable piston disposed therein and dividing the reservoir into a first chamber and a second chamber. The first chamber is fluidly connectable to the fuel supply line or to a fuel purge line via the valve. The second chamber is in fluid communication with the second fuel manifold to receive residual fuel from the second fuel manifold.

A method for monitoring the torsion of a rotary shaft on an aircraft turbomachine based on the measurements from at least three sensors distributed along the rotary shaft to divide the shaft into at least two shaft segments, the method comprising: a step of measuring, for each sensor, a parameter dependent on the rotation of the shaft, a step of calculating, for each achievable pair of sensors, a parameter related to the torsion of the shaft, a step of comparing the different calculated parameters related to the torsion of the shaft with references, a step of detecting damage on a shaft segment at the end of the comparison step, and a step of indicating the localization of the damage on the shaft from the shaft segment for which damage has been detected.

A mounting member for a sensor for a turbomachine having an axis is disclosed. The mounting member includes a body configured to mount to a portion of a circumferential interior surface of a casing of the turbomachine. An opening extends through a radially inner surface of the body, and is configured to position the sensor facing radially inward relative to the axis. A passage in the body extends longitudinally through the body to route a communications lead of the sensor circumferentially relative to the circumferential interior surface of the casing.

A probe adapter includes an adapter body including a probe aperture and a slot. The probe adapter further includes a driver slidably mounted within the slot and slidable between a first position and a second position. The driver includes a first end and a second end opposite the first end. The first end includes a ramped recess extending in a direction from the first end toward the second end. The probe adapter further includes a threaded fastener configured to contact the second end of the driver so as to retain the driver in the first position.

An electric power dissipater assembly for an electrically-actuated turbocharger that includes: a power switch configured to be electrically connected to an electric power output of an electrically-actuated turbocharger; at least one resistor that is electrically connected to the power switch such that, when the power switch is in a closed position and connected to the electric power output, the at least one resistor is electrically coupled to the electric power output so that electric power provided by the electrical power output is received at and dissipated by the at least one resistor; a controller that controls whether the power switch is in the closed position or an open position; and a substrate that is physically coupled to the at least one resistor and that includes a coolant path that is used to cool the at least one resistor when coolant is received within the coolant path.

An electric power dissipater assembly for an electrically-actuated turbocharger that includes: a power switch configured to be electrically connected to an electric power output of an electrically-actuated turbocharger; at least one resistor that is electrically connected to the power switch such that, when the power switch is in a closed position and connected to the electric power output, the at least one resistor is electrically coupled to the electric power output so that electric power provided by the electrical power output is received at and dissipated by the at least one resistor; a controller that controls whether the power switch is in the closed position or an open position; and a substrate that is physically coupled to the at least one resistor and that includes a coolant path that is used to cool the at least one resistor when coolant is received within the coolant path.