During World War II, the US War and Navy departments published a number of visual guides on the recognition of aircraft, ships and armored vehicles. At the time, these Recognition Pictorial Manuals were used as a training tool throughout the services. "The first requirement in warfare is the ability to distinguish friend from foe." Today these shoe string bound guide books provide a visual history of WW II hardware allowing the reader to uncover fascinating technology and compare the weapons deployed by all the major combatants.
For aircraft, the US government published a recognition manual (and a number of addendums) that combined aircraft from both the Army and the Navy (the independent US Air Force was founded after the war in September 1947) as well as aircraft from the UK, USSR, Germany, Japan, and Italy. The guide contains pictures and silhouettes from three angles for almost all the airplanes that saw action during the war. The most fascinating part of the manual are the few silhouette collections that summarize the aircraft by country, an example is provided above.
From this aircraft map we see that the giant six-engine German transport plane, Messerchmitt ME 323, dwarfed most other planes. The aircraft provided a key role in supplying Rommel's Afrika Korps in Northern Africa during 1943. Just below and to the right we see the unsymmetrical silhouette of the Blohm und Voss BV 141. When I first saw this chart I thought the artist had made a mistake. The three person crew were located in a separate crew cabin located on the starboard side. The main fuselage held the engine and tail.
I consolidated four of the silhouette maps into one graphic (see below) in order to provide a more complete visual snapshot. It is available in our space and military collection.
Main source for this post: Recognition Pictorial Manual, June 1943 (along with late 1943 and 1944 addendums, U.S. War and Navy Depts. FM30-30.