Pilot’s Directions

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Commercial aviation in the United States was launched on August 12, 1918, with the initiation of regular airmail service between Washington and New York. Pilots were forced to use railroad and road maps, or pages from atlases. As late as 1921, with transcontinental airmail operations day and night, no aeronautical charts existed. Pilots noted times and courses between prominent landmarks. If they were lucky, they flew two trips behind veteran pilots: if not two trips, just one. Notes from various pilots were assembled and published by the Post Office Department. These Pilot’s Directions contained distances, landmarks, compass courses, and emergency landing fields, with services and communications facilities at principal points along the route in a narrative form:

Hazelhurst Field, Long Island.—Follow the tracks of the Long Island Railroad past Belmont Park racetrack, keeping Jamaica on the left. Cross New York over the lower end of Central Park.

Newark, N.J.—Heller field is located in Newark and may be identified as follows: The field is 1 1/4 miles west of the Passaic River and lies in the V formed by the Greenwood Lake Division and Orange branch of the New York, Lake Erie and Western Railroad. The Morris Canal bounds the western edge of the field. The roof of the large steel hanger is painted an orange color.

These narrative checkpoints covered the routes at 10- to 25-mile intervals. With the passage of the Air Commerce Act in 1926, the Department of Commerce became responsible for the production of aeronautical charts for the nation’s airways. The first chart published in 1927 was a strip map that covered the air route from Kansas City to Moline, Illinois. These early charts depicted prominent topographical features for visual flying and contained the locations of the newly installed airway-lighted beacon system for night operations. The strip map concept was extended throughout the late 1920s to other lighted airways between major airports.

The original airway beacon was a 24-inch rotating searchlight containing a parabolic mirror. It was powered by a 110-volt, 1000-watt lamp that produced approximately 1,000,000 candlepower. Beacons were established at intervals of 10 to 15 miles along the airway. Rotating at six revolutions per minute, they produced a clear flash every 10 seconds. Beacons were supplemented by green or red coded flashes; green for beacons at landing fields (sites were numbered from west to east, or south to north, depending upon the direction of the airway); red or green course lights pointed in the direction of the airway.

Lights flashed a Morse-code letter that identified the site. For simplicity, letters that contained fewer elements, dots and dashes, than numbers, were used. A sequence of letters evolved: W-U-V-H-R-KD-B-G-M. These letters formed the popular mnemonic, “When Undertaking Very Hard Routes, Keep Direction By Good Methods.” This sequence was repeated every 100 miles. Figure shows a strip map for the Los Angeles-to-Las Vegas route in March 1931 with the airway beacons.

The strip map had a scale of 1:500,000, the same as today’s sectional charts. Topography was shown as contours and color tints. Cultural features included railroads, highways, cities, and towns, and prominent electric transmission lines. Airports were shown by type: military or civilian. The lighted airways and new low-frequency radio ranges were depicted.

Supplemental aeronautical information was published in the Domestic Air News until 1929, when it was replaced by Air Commerce Bulletins. These publications contained official aviation information assembled and distributed by the Department of Commerce. These were the forerunners of today’s Airport/Facility Directory and Notice to Airmen publications. In 1932, the free bulletin series described airports, intermediate landing fields, and meteorological conditions in the various states, along with the low-frequency A/N radio ranges for air navigation. By 1940, bulletins contained notices to airmen, air navigation radio aids, danger areas in air navigation, and a directory of airports. They were prepunched notebook size and included airway radio facility charts.

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