Flying Sectional Charts

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With more flying conducted away from established airways, it became apparent that a system of charts was needed to provide complete coverage. Recommendations of the Committee on Aerial Navigation Maps in 1929 prompted the Coast and Geodetic Survey to develop a series of 92 sectional aeronautical charts for the United States. Sectionals were perhaps the best topographic maps; however, strip maps continued to be published until 1932 when the initial series of 31 sectionals was completed.

Figure shows the June 1932 Los Angeles Sectional Chart. Sectionals contained the same general information as strip maps. Lighted airways as well as the low-frequency radio ranges were shown. This chart refers the user to see Airway Bulletin No. 2, “Descriptions of Airports and Landing Fields in the United States,” for detailed information on airports and landing fields. The Air Corps used strip maps until 1935 when the maps were officially discontinued in favor of the new sectional aeronautical charts. Aeronautical charts for Alaska were nearly completed by the beginning of World War II.

New charts were required as aircraft became more reliable and instruments for blind flying with ground navigational systems were developed. A pioneer of instrument charts was E. B. Jeppesen, founder of today’s Jeppesen Sanderson Company.

Jeppesen joined Boeing Air Transport, the predecessor of United Airlines, as an airmail pilot in 1930. He worked his way up to the route between Cheyenne, Wyoming, and Salt Lake City, one of the more dangerous because of terrain and changeable weather conditions.

Appalled by the lack of navigational information for pilots, Jeppesen began making notes about every bit of navigational information, compiling data on airports, slopes, obstacles, and drainage patterns. (Drainage patterns pertain to the overall appearance of features associated with water, such as shorelines, rivers, lakes, and marshes, or any similar feature.) He developed data for the routes between airports and in 1934 published his first Airway Manual. The manual included routes via the new radio navigation aids plus the individual airport flight patterns.

The Air Corps also recognized the need for specialized air charts with the advent of instrument flying and radio navigation. In 1937, the Army issued its first radio facility charts, which were used through the end of World War II.

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