Excerpt:
Although fixed-wing aircraft receive all the attention by most historians, helicopter flight was the first flight envisioned by man. In fact, the ancient Chinese were playing with a hand-spun toy that rose upward when revolved rapidly and as early as the mid 1500's, the great Italian inventor Leonardo Da Vinci had used his fertile mind to make drawings of a machine that we now know as the helicopter.
Annotation:
This remarkably deep site describes the history of helicopters from Leonardo Da Vinci to the present. A drop down menu at the top of the screen provides menus of links to essays describing helicopter companies, chronologies of six periods in the history of helicopters, essays on the mechanics of helicopter flight and the military uses of helicopters. Images accompany the essays throughout and the site also includes a section devoted to sound, video and 3D clips. This site also creates a virtual community with chat rooms and a listserve, and provides a search engine for quick access to the large amount of information in this site. It is an Argentinian site, however, thus English grammar is not always perfect here.