The application of unsteady aerodynamic theory to rotor blades is published
Thursday, February 28, 1957
Robert Loewy publishes his paper that laid the foundations for understanding how unsteady aerodynamics affected rotor loads and performance.
The reference to his paper is provided below,
Loewy, R. G.: A Two-Dimensional Approximation to the Unsteady Aerodynamics of Rotary Wings. Journal of the Aeronautical Sciences, vol. 24, no. 2, Feb. 1957, pp. 81–92.
(Note: Only the month and year for the milestone are valid)