Sikorsky S-72 experimental compound helicopter developed in the 1970s.
Fullsize image: https://diqn32j8nouaz.cloudfront.net...2_fullsize.jpg
https://diqn32j8nouaz.cloudfront.net..._nasa_7402.jpg
Fullsize image: https://diqn32j8nouaz.cloudfront.net...1_fullsize.jpg
https://diqn32j8nouaz.cloudfront.net..._nasa_7401.jpg
Fullsize image: https://diqn32j8nouaz.cloudfront.net...0_fullsize.jpg
https://diqn32j8nouaz.cloudfront.net...2_nasa_740.jpg
Previously:
https://www.homemadetools.net/forum/...384#post204560
https://www.homemadetools.net/forum/...906#post190921
https://www.homemadetools.net/forum/...381#post181482
https://www.homemadetools.net/forum/...142#post165164
https://www.homemadetools.net/forum/...219#post149989
