Night flying commercial airmail by air did not develop until after "the Great War to end all wars." Before World War I, however, the US Post Office Department did make serious efforts to establish airmail in areas where it would be more economical to deliver mail by air than other means.
If this effort had succeeded, it probably would have encouraged airplane development. But Congress did consent, and no funds were made available for an airmail service at that time.
After the United States entered World War I, the Army decided that a very good way to train pilots in cross-country flying and to test the planes under all kinds of flight conditions would be to establish a schedule of flights to carry mail. On 15 May 1918, a line was opened to carry mail between Washington, Philadelphia, and New York. This was the beginning of continuously scheduled airmail service for the public.
A War I era machine gunner and pilot in their Dehaviland DH-4 biplane
Army pilots, then, became the first flying mailmen. Every day some of these young men piloted their Curtiss “Jennies” over the 238-mile stretch.
The military demonstration in 1918 proved that a scheduled airmail service was feasible. On 12 August 1918, the Post Office Department took over the service, employing its own pilots.
The Post Office Department used a few De Haviland DH-4s with liberty engines for testing mail hops, but the first plane it purchased was the Standard JR-1B—the first plane specifically designed for carrying mail. This biplane was powered by a 185-horsepower engine and carried the pilot and about 200 pounds of mail at 90 miles an hour.
The United States airmail service was proving successful so larger planes began to be used, and service was extended from the eastern cities to the West Coast.
However, for timely airmail delivery, night flying was required, which called for marking and lighting up airfields with powerful lights—carbon arc searchlights.
By 1923, searchlights, mounted on brackets to be lifted from their wheels, were being manufactured specifically to use as rotating airfield beacons.
An edition of the Cleveland Sunday News-Leader included the illustration below and reported: "Hazards of 'Flying the Mail' at night on non-stop coast-to-coast flights will be lessened soon by five huge beacon lights, 36 inches in diameter and of 500,000,000 candlepower each, which will guide the way in the dark zone between Chicago and Cheyenne, Wyo.
The aviators will fly in the daytime east of Chicago and west of Cheyenne."
Carbon arc searchlights of the type illustrated above and below were also used to spread their light out and over landing fields.
A 1925 article in Everybody's magazine aptly described the brilliant effect of these airport lights: "Through most seasons of the year the relay from Omaha to Cheyenne is covered at night, but the half-billion candle-power flood lights illuminate the terminal fields as brilliantly as the sun," wrote Samuel Taylor Moore.
"Even those powerful lights are sometimes obscured by snow drifts by the fierce winds that sweep over the plains from the Rocky Mountains."
In the same year, a bill was introduced in Congress to transfer the mail routes to private contractors. This was put into effect the following year.
Those airmail contracts may have been the key to the survival of many of the struggling young air transport companies.
Airmail contracts were what gave these companies steady work and permitted them to purchase new planes—like the Boeing above and the Douglas illustrated in the 1927 advertisement from U. S. Air Services magazine below—and earn something for their services.
Without earnings of some kind, they could never have expanded and finally become the great commercial airlines in the United States today.
“The carbon arc has the greatest brightness per unit area of any artificial light source known, rivaling that of the sun, states a 1932 book titled National Projector Carbons, published by the National Carbon Company—a popular U. S. manufacturer of carbons for carbon arc lights. “It is not surprising, then, that it has been adapted to the projection of motion pictures, to the projection of stereopticon slides, to spot and flood lighting in theatres, to the lighting of photographer’s studios, to photo-engraving, to the large powerful searchlights used by the Army and Navy, and last, but not least, to the modified type of searchlights used to illuminate the Air Mail Fields being established throughout the country.”
Note: For more information on this subject, read AIRMAIL, how it all began by Carroll V. Glines, which the covers the pioneering efforts of early American high flyers delivering the mail in much more detail.
This page was last modified on Tuesday, March 09, 2010