Apr 20 1939
From The Space Library
The free-flight tunnel placed into operation at Langley Aeronautical Laboratory.
April 20-21: Experiments with four-bladed controllable propeller on Curtiss P-36 begun at Wright Field.
The free-flight tunnel placed into operation at Langley Aeronautical Laboratory.
April 20-21: Experiments with four-bladed controllable propeller on Curtiss P-36 begun at Wright Field.
