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Tests of an attack-type airplane in the Ames 40- by 80-foot wind tunnel to improve the high-speed maneuvering control-force characteristics

Description: Report discussing testing on a twin-engine airplane to determine which modifications would make it suitable for ground-support attack operations. Some of the suggested modifications include replacing fabric-covered elevators with metal-covered elevators with a balance tab, replacing fabric-covered ailerons with metal-covered ailerons with a balance tab, sealing the airplane, fairing the nose guns, removing the lower-periscope deflector, and fairing the bomb racks. The results of other types of configurations are included in the report.
Date: November 1945
Creator: McCormack, Gerald M.
Partner: UNT Libraries Government Documents Department

Aerodynamic study of a wing-fuselage combination employing a wing swept back 63 degrees: Aerodynamic characteristics in sideslip of a large-scale model having a 63 degree swept-back vertical tail

Description: Report presenting an investigation to determine the effects of a vertical tail with the leading edge swept back 63 degrees on the aerodynamic characteristics of a wing-fuselage combination with a wing with the leading edge swept back 63 degrees. The aerodynamic characteristics in sideslip with and without the vertical tail are also presented. Results regarding the directional stability, rudder effectiveness, and rudder hinge moments are described.
Date: October 7, 1949
Creator: McCormack, Gerald M.
Partner: UNT Libraries Government Documents Department

An investigation of the low-speed stability and control characteristics of swept-forward and swept-back wing in the Ames 40- by 80-foot wind tunnel

Description: An investigation has been made at large scale of the characteristics of highly swept wings. Data were obtained at several angles of sideslip on wings having angles of sweep of plus or minus 45 degrees, plus or minus 30 degrees, and 0 degrees. The airfoil sections of the wings varied from approximately NACA 0015 at the root to NACA 23009 at the tip. Each wing was investigated with flaps under flection, partial-span split flaps deflected 60 degrees, full-span split flaps defected 60 degrees and split-flap-type ailerons deflected plus or minus 15 degrees. Values of maximum lift were obtained at Reynolds numbers raging from 5.7 to 9.2 times 10 to the 6th power. In this report the summarized results are compared with the predictions made by use of the simplified theory for the effect of sweep and with existing small-scale data. The basic wind-tunnel results from which these summary data were taken are included in an appendix. The primary problems accompanying the use of weep as revealed by this investigation are the loss in maximum lift, the high effective dihedral, and the sharp reduction in lateral-control effectiveness. In general, simple theory enables good predictions to be made of the gross effects of sweep but further refinements are necessary to obtain the accuracy required for design purposes. In cases where comparisons can be made, the indications are that, as sweep increases, scale effects diminish and large-scale results approach small-scale results.
Date: June 10, 1947
Creator: McCormack, Gerald M. & Stevens, Victor I., Jr.
Partner: UNT Libraries Government Documents Department

Effects of boundary-layer control on the longitudinal characteristics of a 45 degrees swept-forward wing-fuselage combination

Description: Report presenting an investigation to determine the benefits obtainable by applying boundary-layer control to a 45 degree swept-forward wing-fuselage combination. Force and pressure-distribution data were obtained with and without boundary-layer control with various combinations of leading-edge and trailing-edge flaps.
Date: February 2, 1950
Creator: McCormack, Gerald M. & Cook, Woodrow L.
Partner: UNT Libraries Government Documents Department

Effects of several leading-edge modifications on the stalling characteristics of a 45 degree swept-forward wing

Description: Report presenting an investigation to determine the effects of several leading-edge modifications on the maximum lift and pitching-moment characteristics on a large-scale 45 degree swept-forward wing. A full-span leading-edge flap deflected 30 degrees down tended to give the largest gain of maximum lift. Results regarding the plain leading-edge flaps and cambered nose are explored.
Date: June 14, 1949
Creator: McCormack, Gerald M. & Cook, Woodrow L.
Partner: UNT Libraries Government Documents Department

A study of stall phenomena on a 45 degree swept-forward wing

Description: Report presenting an investigation to determine the underlying causes of the undesirable longitudinal characteristics of a 45 degree swept-forward wing in the moderate and high lift-coefficient range. Several methods were used to create a detailed correlation between separation phenomena and longitudinal characteristics of the wing. Both turbulent and leading-edge separation need to be postponed in order to improve the longitudinal characteristics of this wing.
Date: January 1949
Creator: McCormack, Gerald M. & Cook, Woodrow L.
Partner: UNT Libraries Government Documents Department

The use of area suction for the purpose of delaying separation of air flow at the leading edge of a 63 degree swept-back wing

Description: From Summary: "An investigation was conducted to determine the effectiveness of area suction used to delay the separation of air flow at the leading edge of a 63 degree swept-back wing. Changes in lift, drag, and pitching-moment data were correlated with the occurrence of the separation of the air flow by means of pressure-distribution data. It was found that the spanwise and the chordwise extent of area suction required to control leading-edge separation were in general agreement with that predicted by theory, but the quantity of flow required was considerably higher than predicted by theory."
Date: November 22, 1950
Creator: Cook, Woodrow L.; Griffin, Roy N., Jr. & McCormack, Gerald M., Jr.
Partner: UNT Libraries Government Documents Department

Power-off tests of the Northrop N9M-2 tailless airplane in the 40- by 80-foot wind tunnel

Description: Report discussing tests on the N9M-2 airplane to evaluate the airplane efficiency factor and to investigate the characteristics of the aeroboost in the elevon control system. The efficiency factor compared reasonably well to conventional airplanes and the aeroboost system and valve-chatter tests were satisfactory.
Date: December 14, 1944
Creator: Stevens, Victor I., Jr. & McCormack, Gerald M.
Partner: UNT Libraries Government Documents Department

The effects of boundary-layer control on the longitudinal characteristics of a swept-back wing using suction through streamwise slots in the outboard portion of the wing

Description: Report presenting an investigation to determine the effects of a simplified form of boundary-layer control on the low-speed longitudinal characteristics of a sweptback wing. The primary objective was to improve the longitudinal characteristics of the sweptback wing at lift coefficients below the maximum. Results regarding the characteristics of the wing without boundary-layer control and effects of boundary-layer control are provided.
Date: January 5, 1951
Creator: McCormack, Gerald M. & Tolhurst, William H., Jr.
Partner: UNT Libraries Government Documents Department