The Impact of the Implementation of The North American Datum of 1983 (NAD 83) on Aeronautical Navigation in the United States

Abstract

On October 15, 1992, the horizontal geodetic reference system used for all aeronautical charts and chart-related products published by National Oceanic and Atmospheric Administration (NOAA)/National Ocean Service (NOS) changed from the North American Datum of 1927 (NAO 27) to the North American Datum of 1983 (NAO 83). The Global Positioning System (GPS) now allows satellites to define much more accurately geographic locations in terms of latitude and longitude, utilizing an earth centered reference system; the NAO 83 is based on this new technology. As a result, the latitude and longitude of almost all points in the National Airspace System (NAS) were revised. The greatest coordinate s hifts were in Hawaii and Alaska where latitude moved by as much as 1200 feet and longitude by up to 950 feet. In the conterminous U.S., the largest changes were approximately 165 feet in latitude and 345 feet in longitude. The impact to aeronautical navigation in the C.S. of the datum shift from NAO 27 to NAO 83 was not limited to aeronautical charts and related publications. All Flight Management Systems (FMSs) and Air Traffic Control Systems (ATCs) had to be modified to accept and utilize the NAO 83 coordinates. The impact of the implementation of NAO 83 on aeronautical navigation in the United States was s gnificant.