This is an original sketch for the cache used for the October 1, 1946, American Airlines demonstration flight of the Flying Post Office. The sketch includes a set of two initialed approval dates--"E.C.W. 9.17. ‘46" and "MEP 9/20/46." The sketch includes a designation of 2 1/8” in blue below it, measuring its width. Additional numbers--668 over 3, 24, and 162--appear on the sketch. The number S-1168 appears in the bottom far right.
The Post Office Department worked with both American Airlines and United Air Lines to test the feasibility of using clerks to process mail in airplanes while in flight. The American Airlines demonstration flight was from Los Angeles to Boston. Official cachets were used along the route, with different colors designated for each city. The Los Angeles, New York, and Boston cachets were blue. Tucson, Memphis, and Washington, D.C., cachets were green; El Paso, Dallas, and Nashville cachets were purple. Ft. Worth’s cachet was magenta, and Philadelphia’s black.
Reference:
American Air Mail Society, A Priced Catalogue and Reference Listing of the Airposts of the World, American Airmail Catalog, 6th edition. Mineola, New York, Volume 3, 2004.
