Rare early Air Navigation Map showing the air route between San Diego, California and Phoenix, Arizona, published by the Airways Section of the US Corps of Engineers.
The map consists of a color coded topographical map, with what amounts to compass and visual flight recognition instructions for a flight from San Diego to Phoenix, via Yuma, Arizona and Gila Bend.
In 1921, the United States Army Air Corps initiated a compressive evaluation of aeronautical charts in an effort to develop a standardized map for aerial navigation. Based upon this study, the Air Corps issued 63 air navigation maps covering most of the military routes in the United States. Prior to 1926, these maps were jointly compiled by the Geological Survey and U. S. Army Engineer Reproduction Plant. By 1926, the preparation of air maps shifted to the U.S. Coast and Geodetic Survey (under the Commerce Department) with the passage of the Air Commerce Act. Maps from this point on were intended to merge the growing commercial airways system with the military network.
This map covers the area from Phoenix west to San Diego and shows elevation and contours, cities and towns, rivers, roads and railroads. Airfield classifications are shown with different symbols including seaplane landings. True north and magnetic north are depicted. On a scale of 8 miles per inch. Dissected into two panels and backed in linen.
These early air navigation maps are very rare, this being only the second example we have seen in over 20 years.