Leonardo da Vinci had a vision for a helicopter 400 years before it was made. Click to read the full
Leonardo da Vinci had a vision for a helicopter 400 years before it was made. Click to read the full fact. -- source link
Tumblr Blog : wtf-fun-factss.tumblr.com
#aerial screw#aviation#awesome#flying machine#fun fact#ge hong#genuis#helicopter#history#invention#people#random fact#random facts#renaissance#science#vertical flight