Aviation History Helicopters

• Helis.com  - Narrative of the beginning of the air vehicle's creation as well as developments through time and technology.
• Rotorcraft and Helicopter Directory  - Compilation of relevant data sources on various types of air vehicles including autogyros, tilt-wings and other references.
• Sikorsky Historical Archives  - Reference for the different types of pioneering aviation vehicles. Provides an archive of pictures and related data.
• Virtual Aviation Museum - Helicopters 1939 to 1945  - Showcases various types of air vehicles produced during the inclusive time. Includes description and illustrations.