Flight tests of the Sikorsky HNS-1 (Army YR-4B) helicopter ; Part 2: Hovering and vertical-flight performance with the original and an alternate set of main-rotor blades, including a comparison with hovering performance theory
Wartime report ; L-596
1945
15 S., [11] Bl
Ill., graph. Darst
Originally issued April 1945 as Memorandum report L5D09a
Book
English