A sensor includes an airfoil body, a heater element, and a temperature probe. The airfoil body defines a sensor axis and having a leading edge, a trailing edge, and an ice accretion feature. The heater element extends axially through the airfoil body between the leading edge and the trailing edge of the airfoil body. The temperature probe extends axially through the airfoil body between the heater element and the trailing edge of the airfoil body. The heater element is axially overlapped by the ice accretion feature to accrete ice chordwise forward of a tip surface aperture. Gas turbine engines, methods of making sensors, and methods of accreting ice on sensors are also described.

A sensor includes an airfoil body, a heater element, and a temperature probe. The airfoil body defines a sensor axis, an insulating cavity, and extends between a leading edge and a trailing edge of the airfoil body. The heater element extends axially within the airfoil body and is positioned between the leading edge and the trailing edge of the airfoil body. The temperature probe extends axially within the airfoil body, is positioned between the heater element and the trailing edge of the airfoil body, and is separated from the heater element by the insulating cavity to limit thermal communication between the temperature probe and the heater element. Gas turbine engines, methods of making sensors, and methods of thermally separating temperature probes and heater elements in sensors are also described.

An air data system for an aircraft includes a multi-function probe (MFP) and an inertial reference unit (IRU). The MFP is positioned to sense a pressure of airflow about an exterior of the aircraft. A first electronics channel of the MFP is electrically coupled to the IRU to generate air data parameter outputs based on the pressure sensed by the MFP and inertial data sensed by the IRU.

A circuit that produces an output signal having a frequency that is proportional to absolute temperature (PTAT) is disclosed. In one embodiment, the circuit includes a ring oscillator and a bias current circuit coupled thereto. The ring oscillator and the bias current circuit are implemented in close proximity to one another. During operation, the bias current circuit generates a bias current that is provided to the ring oscillator. The amount of bias current generated is dependent upon the temperature of the circuit. In turn, the frequency of an output signal provided by the ring oscillator is dependent on the amount of bias current received from the bias current circuit. Accordingly, the frequency of the ring oscillator output signal is dependent on the temperature of the circuit.

A system and method for an aircraft includes a probe, first and second current sensors, and a control circuit. The probe includes a heater that includes a resistive heating element routed through the probe, wherein an operational current is provided to the resistive heating element to provide heating for the probe. The first current sensor is configured to sense a first current through the resistive heating element, and the second current sensor is configured to sense a second current through the resistive heating element. The control circuit is configured to determine a leakage current based on the first and second currents and determine a remaining useful life the probe based on the leakage current over time.

An air data probe includes a probe body including a probe wall. The probe body is formed from a first material by direct energy metal deposition. An insert is positioned in the probe wall. The insert is formed from a second material different from the first material. The insert is encapsulated in the probe wall via the direct energy metal deposition.

A probe system includes a heater and a control circuit. The heater includes a resistive heating element routed through the probe. An operational voltage is provided to the resistive heating element to provide heating for the probe. The control circuit is configured to provide a test voltage different than the operational voltage and monitor a test current generated in the resistive heating element while providing the test voltage. The control circuit is further configured to detect micro fractures in the resistive heating element based on the test current.

A probe system configured to receive a radio-frequency (RF) signal from a radio-frequency (RF) antenna includes a heater and a control circuit. The heater includes a resistive heating element routed through the probe system. An operational voltage is provided to the resistive heating element to provide heating for the probe system and the resistive heating element has an element capacitance. The control circuit is configured to determine an antenna response of the resistive heating element and determine a remaining useful life of the probe system based on the antenna response over time.

A total air temperature probe includes a housing including an inlet scoop, an outlet, a main airflow passage extending from the inlet scoop to the outlet, an exit that extends through the housing, and a total air temperature sensor flow passage and a sensor assembly positioned in the total air temperature sensor flow passage. The main airflow passage includes an upper inlet surface extending from the inlet scoop, a lower inlet surface opposite the upper inlet surface and extending from the inlet scoop, an upper outlet surface extending from the upper inlet surface to the outlet, and a lower outlet surface opposite the upper outlet surface and extending from a split point in the housing to the outlet. The total air temperature sensor flow passage branches off from the main airflow passage and extends to the exit. The upper outlet surface is consistently concave toward the outlet.

An air data system with a digital interface includes least one air data component, a receiving system and at least one digital connection. The at least one digital connection is between the receiving system and the air data component. A method for transmitting data in an air data system with a digital interface includes measuring at least one air data parameter with at least one air data component. The method includes generating a digital signal representative of the at least one air data parameter with the at least one air data component, sending the digital signal to a receiving system, and processing the at least one air data parameter with the receiving system.