1. n S. H. Scher: Effect of 40° Sweepback on The Spin and Recovery Characteristics of a 1/25Scale Model of a Typical Fighter-type Airplane as Determined by Free-spinning-lunnel Tests,NACATN1256, 1947.2)M. Knight:Wind TunnelTests on Autorotation and The "FLAT SPIN", NACA Report No.273, 1927, pp.343-351. "° C. J. Wenzinger and T. A. Hams: The Vertical Wind Tunnel of The National Advisory Committee for Aeronautics, NACA Report No. 387, 1931, pp.449-506.4)M. J. Bamber: Aerodynamic Rolling and Yawing Moments Produced by Floating Wing-tip Ailerons, as Measured by The Spinning Balance, NACA TN 493, 1934.5)N. F. Scudder and M. P. Miller: The Nature of Air Flow about The Tail of an Airplane in a Spin, NACATN421, 1932.6)R. W. Stone, Jr. and S. M. Burk, Jr.:Effect of Horizontal-tail Position on The Hinge Moments of an Unbalanced Rudder in Attitudes Simulating Spin Conditions,NACATN1337, 1947.