33
/
AIzaSyB4mHJ5NPEv-XzF7P6NDYXjlkCWaeKw5bc
November 30, 2025
2150720
179955
2
Public Timelines
FAQ

jun 27, 1931 - First patent for helicopter

Added to timeline:

15 Nov 2018
0
0
440

Date:

jun 27, 1931
Now
~ 94 years ago