Some old Helicopters and Converiplanes Patents

[hesham]

Hi,


from the same report about Lockheed Model-286,there is some old helicopters and convertiplanes
patents;


http://www.dtic.mil/dtic/tr/fulltext/u2/731493.pdf

 

[hesham]

And;

 

[hesham]

And;

 

[hesham]

Hi,

here is a strange helicopter,had a tilt rotor,designed by Mr. Avery Harold in 1943;



https://encrypted.google.com/patents/US2468913