All the World's Rotorcraft - http://avia.russian.ee/
Provides pictures and background from the first designs to current machines. Also offers dictionary and links to related resources. |
Helicopter History Site - http://www.helis.com
This site traces the evolution of rotary wing aircraft back to Leonardo Da Vinci. |
Helicopters and Autogiros 1939 to 1945 - http://www.luftfahrtmuseum.com/htmi/itk/h4.htm
Aviation history in the WWW: Index of aircraft by category and time period. |
Igor I. Sikorsky Historical Archives, Inc. - http://www.sikorskyarchives.com/
Dedicated to acquiring, preserving and protecting the historical materials that chronicle the aviation careers of Igor Sikorsky, the companies he founded and the accomplishments of its employees. |