A method of monitoring an ice protection system of a rotorcraft or an aircraft includes applying heat to rotating blades of the rotorcraft or the aircraft according to a heater duty cycle and determining an anticipated ice shed time for ice to shed from the rotating blades. Torque of the rotating blades is sensed, and an actual ice shed time for ice to shed from the rotating blades is determined based on the sensed torque. A status of the ice protection system is determined based on the anticipated ice shed time and the actual ice shed time, and the status of the ice protection system is output for consumption by a consuming system.

On an aircraft, a multi-mode power generator is operated in a variable voltage mode to power an electric Wng Ice Prevention System (eWIPS), and is operated in a fixed voltage mode to provide backup power. When atmospheric conditions are conducive to the formation of ice (and main generators are operative), the multi-mode power generator is operated in variable voltage mode to power the eWIPS with a first or second variable voltage. The first variable voltage, the value of which depends on atmospheric conditions, is for anti-ice operation. The second variable voltage, which can be the maximum output voltage, is for de-ice operation. Transitions between different variable voltage levels are not instantaneous which eliminates fatigue damage due to transients. If a main generator fails (or when atmospheric conditions are not conducive to the formation of ice), the multi-mode power generator is operated in fixed voltage mode to provide backup power.

On an aircraft, a multi-mode power generator is operated in a variable voltage mode to power an electric Wng Ice Prevention System (eWIPS), and is operated in a fixed voltage mode to provide backup power. When atmospheric conditions are conducive to the formation of ice (and main generators are operative), the multi-mode power generator is operated in variable voltage mode to power the eWIPS with a first or second variable voltage. The first variable voltage, the value of which depends on atmospheric conditions, is for anti-ice operation. The second variable voltage, which can be the maximum output voltage, is for de-ice operation. Transitions between different variable voltage levels are not instantaneous which eliminates fatigue damage due to transients. If a main generator fails (or when atmospheric conditions are not conducive to the formation of ice), the multi-mode power generator is operated in fixed voltage mode to provide backup power.

A number of devices are provided for detecting presence of ice in an airstream. In some examples such device includes a housing defining a first chamber and a second chamber, and a partition wall separating the first chamber and the second chamber. The first chamber has at least one inlet opening on a front housing wall facing the airstream, and at least one outlet opening, smaller than the at least one inlet opening. The second chamber is configured for being operatively coupled to at least one electromagnetic (EM) system that is configured for transmitting EM energy to the first chamber at least via the partition wall, which is transparent and/or translucent with respect to the EM energy, the EM energy being configured for melting ice that can accrete with respect to the inlet opening. The device is configured for being operatively coupled to at least one air pressure sensor in fluid communication with the first chamber for detecting at least pressure changes in the first chamber responsive to ice accretion on the inlet opening.

A number of devices are provided for detecting presence of ice in an airstream. In some examples such device includes a housing defining a first chamber and a second chamber, and a partition wall separating the first chamber and the second chamber. The first chamber has at least one inlet opening on a front housing wall facing the airstream, and at least one outlet opening, smaller than the at least one inlet opening. The second chamber is configured for being operatively coupled to at least one electromagnetic (EM) system that is configured for transmitting EM energy to the first chamber at least via the partition wall, which is transparent and/or translucent with respect to the EM energy, the EM energy being configured for melting ice that can accrete with respect to the inlet opening. The device is configured for being operatively coupled to at least one air pressure sensor in fluid communication with the first chamber for detecting at least pressure changes in the first chamber responsive to ice accretion on the inlet opening.

A method, system and apparatus are provided for reducing or eliminating contrails formed by an aircraft as it travels through the sky, and more particularly, to disrupting formation of contrails and altering the electromagnetic properties of already-formed contrails through use of one or more lasers. Methods include: positioning at least one laser such that at least one beam from the at least one laser is directed to a position at which contrails form aft of a wing of the aircraft; detecting contrail formation in the position at which contrails form aft of the wing of the aircraft; activating the at least one laser source in response to detecting contrail formation; and reducing or eliminating the contrail in response to activating the at least one laser source.

A method, system and apparatus are provided for reducing or eliminating contrails formed by an aircraft as it travels through the sky, and more particularly, to disrupting formation of contrails and altering the electromagnetic properties of already-formed contrails through use of one or more lasers. Methods include: positioning at least one laser such that at least one beam from the at least one laser is directed to a position at which contrails form aft of a wing of the aircraft; detecting contrail formation in the position at which contrails form aft of the wing of the aircraft; activating the at least one laser source in response to detecting contrail formation; and reducing or eliminating the contrail in response to activating the at least one laser source.

Disclosed herein is a system and method for determining a thickness of ice on Radio Frequency (RF) systems The system includes a sensor unit for use in determining the thickness of ice on a surface of a RADAR system having a RADAR antenna, the sensor unit including a sensor unit antenna tunable to a harmonic of a RADAR antenna signal, the harmonic having a frequency within an ice absorption band, wherein the sensor unit antenna emits the harmonic at a first signal strength; and, a sensor unit receiver communicatively coupled to the sensor unit antenna and configured to detect a second signal strength of the harmonic received by the sensor unit antenna.

An ice detector apparatus for an aircraft includes a heater strip and a temperature sensor. The heater strip is configured to be mounted to an external surface of an aircraft and the temperature sensor is coupled to the heater strip. The temperature sensor is configured to detect a temperature profile of the heater strip, wherein the temperature profile is indicative of an extent of icing. The temperature profile may be indicative of whether the aircraft is operating in an appendix C icing-envelope or an appendix O icing-envelope. The temperature sensor may include a plurality of temperature sensors coupled along a length of the heater strip, such that the temperature profile comprises a spatial temperature map of the heater strip.

A system includes a device having a first surface configured to be exposed to airflow about an exterior of an aircraft, the device including a first self-compensating heater configured to heat the first surface, a first current monitor configured to sense a first measurement value representing electrical current flow through the first self-compensating heater, one or more processors, and computer-readable memory encoded with instructions that, when executed by the one or more processors, cause the system to receive aircraft flight condition data and produce an icing condition signal based upon the first measurement value and the aircraft flight condition data.