The American Helicopter Museum and Education Center has an extensive library and archives with over 18,000 items in our collection that are associated with rotary wing aviation. This includes books, technical papers, operating and maintenance manuals, photographs, videos, drawings, hardware, and important historical artifacts. Along with other design-associated items are the slide rules of Pioneers Juan De La Cierva and Igor Sikorsky that were used in the design process for their historic aircraft of the 1930's and 1940's. Two decades later these were classified as "Beginners Slide Rules". We show the contrast with more complex "Log-Log Duplex" slide rules. These, in turn were made obsolete by pocket calculators and computers.
The material in the archives help to give an understanding of the design challenges of the aircraft. As one example, we have a Bell Helicopter Model 47 D, familiarly known as the "MASH" helicopter on display. If you look at this closely you will see the battery is located on a platform in the tail boom. Our operating manual for the pilot shows that, for two person occupancy the battery should be in this location, but for a single pilot the battery should be moved to a platform located in front of the instrument panel; this compensates for the change in center of gravity of the aircraft. A study of the documents in the AHMEC library and archives allows one to see how helicopters have evolved over time and the thinking that went into their increasing capabilities.
Although we are a non-circulating library, access to our holdings is available by appointment on Monday - Wednesday 10:00am - 3:00pm excluding holidays. Inquiries are invited via our e-mail address.