Why Helicopters Have A Speed Limit

Why Helicopters Have A Speed Limit
Why haven't we built a helicopter that can go supersonic yet? The short answer is physics.

https://www.youtube.com/watch?utm_source=ifttt&v=f72WZwvMTj4 November 24, 2016 at 04:14PM
via Digg https://www.youtube.com/watch?utm_source=ifttt&v=f72WZwvMTj4