Recently calculations based on the ICAO RNP AR document 9905 were added as an RNP Class to the SDK; click here for further details. To start with this includes the FAP and temperature calculations. As a demo and for testing purposes, an RNP AR page has been added to the app along with a map that shows geographic data calculated. i.e. FAP coordinate
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ICAO RNP Calculations
This is now available in the Microsoft store and please give any feedback especially for improvements you would like to see.