Nav Canada - Provides navigation services like air traffic control, weather information and many other services. Flycalc - Flycalc is a web based, navigation tool for New Zealand based flight plans. Royal Institute of Navigation - If you have an interest in navigation in its broadest terms - from aircraft Cat III landings though sailing for pleasure to orientation strategies with young children, then you should consider membership of the RIN. The Institute of Navigation - Non-profit professional society dedicated to the advancement of the art and science of navigation. QuDieM - Provides flying school software, holding pattern and flight plan computers. Product information and company history. AirplaneCharts.Com - Aviation VFR and IFR Charts. Sectional and Terminal Charts. NOS Low Altitude En route Charts and Approach Plates. Canso - Civil Air Navigation Services Organisation - Exists to ensure the provision of air navigation services for civil aviation communities worldwide. Ed Williams' Aviation Page - Formulas and on line calculators for aviation navigation. Aviation Formulary - Introduction to the mathematical processes used in navigation including great circle navigation theory. PocketFMS - Flight planning and moving map software for PCs and mobile pocket PCs using Windows. Includes world-wide VFR maps, bi-hourly updated navigation data, weather integration and an extensive airspace warning system. Density Altitude Calculator - JavaScript calculator for pilots. Determines density altitude from the altitude, air temp, altimeter setting and relative humidity. National Air Traffic Services - Provides aeronautical information services including let down plates and aviation warnings. Free registration required. FlightLogXL - Flight log in Excel. Calculates heading, distance and time based on entered waypoints.