The Transport Plane Series of 1941 consisted initially of six different values from 6- through 50-cents. An 8-cent value was issued in 1944, when the domestic airmail rate was raised from sixty-four to eighty-four cents per ounce. This new series of airmail stamps was the culmination of efforts beginning around 1936 to replace a variety of older airmail stamps still in use. Differing only in color and denomination, each stamp featured an identical twin engine airplane design.
Prior to the seven-stamp Transport Plane Series of 1941-1944, airplanes appearing on United States airmail stamps were identifiable, consisting of the Curtiss Jenny, de Havilland DH 4M, Ryan NYP “Spirit of St. Louis,” and the Martin M-130 China Clipper. One exception was the airplane shown on the 1928 5-cent Beacon stamp. The airplane, only 3/16 of an inch in size, was included only to illustrate the beacon's function.
The airplane shown on the Transport Plane stamps is fictional. The Postal Bulletin of May 27, 1941, described the design prior to the first stamp's release as "a representation of a modern transport plane in flight." Much of it resembles a Douglas DC-3, the most widely used airliner of that time. Its tail, which consists of three vertical fins, is a product of the stamp designer’s imagination. Moreover, it appears that the bottoms of the two outboard fins extend below the airplane’s tail wheel. If so, they would have been torn off as the airplane taxied on the runway. Later airplanes such as the Lockheed Constellation had similar tail fins, but its tricycle landing gear kept the tail high off the ground. The history and interesting background surrounding the design is researched and documented in The Transports by G.H. Davis.
Joseph G. Bock, U.S. Transport Airmail Series , Airpost Journal 76-77 (Jan.-March 2005, April- July 2005, Feb.-April 2006).
Thomas H. Boyle Jr., Airmail Operations During World War II (Mineola, N.Y.: American Air Mail Society, 1998).
Henry W. Beecher and Anthony S. Wawrukiewicz, U.S. Domestic Postal Rates, 1872-1999, 2nd ed. (Portland OR: CAMA Publishing Co.,1999).
G.H. Davis, The Transports (Reston, VA: Bureau Issues Association, 1999).
Anthony S. Wawrukiewicz and Henry W. Beecher, U.S. International Postal Rates, 1872-1996 (Portland, OR: CAMA Publishing Co., 1996).