BACKGROUND

1. Field

The present disclosure relates to aircraft data systems, more specifically to air temperature correction for example.

2. Description of Related Art

Air temperature measurements (AT), e.g., total air temperature (TAT) measurements, are currently not corrected for all environmental effects, resulting in reduced accuracy of both AT and its dependent parameters (e.g., True Airspeed, and Static Air Temperature). These reduced accuracies force aircraft to operate with sub-optimal engine settings (reduced takeoff margin and increased fuel burn in cruise) and with decreased margin on their range calculations (reduced aircraft range to provide calculation margin).

Such conventional methods and systems have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for improved AT accuracy. The present disclosure provides a solution for this need.

SUMMARY

A system for correcting an air temperature (AT) reading, e.g., a total air temperature (TAT) reading, can include a water content sensor configured to measure a water content in an airflow and to output a water content signal indicative thereof, an AT sensor configured to measure an air temperature and output an AT signal indicative thereof, and a correction module operatively connected to the water content sensor and the AT sensor. The correction module can be configured to receive the water content signal and the AT signal and to correct the AT signal based on the water content to output a corrected AT signal.

The correction module can be configured to use known correlation data to correct the AT signal based on the water content. The correction module can be configured to output the corrected AT signal to one or more aircraft systems.

The correction module can be included in an air data probe operatively connected to an air data computer to output the corrected AT signal to the air data computer to correct an airspeed value using the corrected AT. In certain embodiments, the correction module can be further configured to receive at least one of an altitude value, a dynamic pressure value, a total pressure value, or a static pressure value (e.g., from any suitable aircraft system(s), e.g., an air data probe) to correct the AT. In certain embodiments, the correction module can be included in an air data air data computer operatively connected to an air data probe. The air data probe can be configured to locally correct an airspeed value using the corrected AT. In certain embodiments, the air data probe can be configured to locally correct the AT signal based on at least one of an altitude value, a dynamic pressure value, a total pressure value, or a static pressure.

The correction module can be included in an air data computer. The air data computer can also be operatively connected to at least one pitot probe, at least one static port, and at least one angle of attack indicator.

The water content sensor can be a liquid water content sensor configured to sense at least liquid water content. In certain embodiments, the water content sensor may be configured to sense ice water content. In certain embodiments, the correction module can be configured to correct the AT signal based on one or more other characterization factors (e.g., location of sensors).

In certain embodiments, the water content sensor can be configured to indirectly or directly sense a second AT. The system can include a comparison module configured to receive the second AT and the AT from the AT sensor and to compare the second AT to the AT from the AT sensor to determine if there is a fault in the AT sensor.

In certain embodiments, the AT sensor can be a first AT sensor and the AT signal is a first AT signal, and the system can include at least a second AT sensor to output a second AT signal. The system can include a comparison module configured to receive the second AT and the first AT to compare the second AT to the first AT from the AT sensor and/or to select the first AT sensor or the second AT sensor as an AT source based on the water content.

The correction module can be configured to use the water content sensor to determine a reversionary AT if the AT sensor is determined to have faulted. The correction module can be configured to ignore the water content signal to if the water content sensor is determined to have failed. In certain embodiments, the correction module can be configured to output a notification of reduced AT accuracy to alert a crew member that the AT used by one or more aircraft systems is uncorrected for water content.

In certain embodiments, the system can include a heater controller operatively connected to the correction module configured to control at least one heater system based on liquid water content (LWC), ice water content (IWC), or corrected AT (and/or any other suitable parameters, e.g., airspeed, altitude, etc.). The heater system can be at least one of a pitot tube heater or an AT sensor heater, for example. In certain embodiments, if the IWC is greater than zero, and if LWC is greater than an LWC threshold, and the AT is less than an AT threshold, the heater controller causes the at least one heater system to operate at maximum heat.

A method can include receiving a water content signal from a water content sensor that is configured to measure a water content in an airflow, receiving an air temperature (AT) signal from an AT sensor that is configured to measure an air temperature, correcting the AT based on the water content, outputting a corrected AT signal to be used by one or more aircraft systems. Correcting the AT can include using correlation data stored in the non-transitory computer readable medium to correct the AT signal based on the water content. Outputting a corrected AT signal can include outputting the AT signal to an air data computer.

A non-transitory computer readable medium having computer executable instructions configured to cause a computer to perform any method and or any portion(s) thereof disclosed herein.

These and other features of the systems and methods of the subject disclosure will become more readily apparent to those skilled in the art from the following detailed description taken in conjunction with the drawings.

