Report details the development of design equations for double-panel, air-heated windshields with ice prevention properties. The application of the equations and suggestions for experimental flight testing are described.

Report summarizes the available hinge-moment data for unshielded horn-balanced control surfaces. The purpose is to correlate the available data to assist with estimating the balance characteristics for use in the design and alteration of control surfaces with horn balances. Plan forms and variation of incremental hinge-moment-coefficient slopes with balance coefficients are presented.

Report presenting hinge-moment, lift, pressure difference across the balance, and pressure-distribution measurements in the two-dimensional test section of the stability tunnel on a 0.60 aileron-chord sealed internal-balance aileron on a specified NACA airfoil. The primary test objective was to determine the effect of speed on the action of the aileron.

"Hinge-moment, lift, and pressure-distribution measurements were made in the two-dimensional test section of the NACA stability tunnel on a blunt-nose balance-type aileron on an NACA 66,2-216 airfoil at speeds up to 360 miles per hour corresponding to a Mach number of 0.475. The tests were made primarily to determine the effect of speed on the action of this type of aileron. The balance-nose radii of the aileron were varied from 0 to 0.02 of the airfoil chord and the gap width was varied from 0.0005 to 0.0107 of the airfoil chord. Tests were also made with the gap sealed" (p. 1).

Report discusses the results of force testing of the aerodynamic characteristics of an NACA 0009 airfoil with a double plain flap; it consisted of a plain forward flap with a chord 20 percent of the airfoil chord and a plan rearward flap with a chord 15 percent of the airfoil chord. Comparisons were made to the characteristics of a 0.50c single plain flap. The lift, hinge moments, drag, and pitching moments are described.

Report presenting a series of tests of the Brewster XSBA-1 airplane conducted to determine the effect of various tail modifications. The current report describes an investigation of flying qualities of the airplanes with its original tail surfaces. Testing regarding longitudinal stability and control and stalling characteristics are provided.

Report presenting flight tests of an all-movable vertical tail of reduced area of the Fairchild XR2K-1 airplane. Results are in agreement with previously obtained data on a larger all-movable tail. Results regarding rudder effectiveness, directional stability, rudder-free lateral motion, rudder hinge moments, and areas of future research are provided.

Report presenting values of the lateral-stability derivative, the rate of change of yawing-moment coefficient with yawing angular velocity, contributed by the wing, the fuselage, and the vertical tail, which have been determined for a midwing airplane model by the free-oscillation method.

Report presenting vibration tests of a four-blade single-rotating propeller operating in a simulated pusher condition performed because the combination of wake and downwash behind a wing might provide serious excitation for reactionless vibrations of propellers with four or more blades. Measurements of propeller vibratory stress were made for various airspeeds, engine speeds, and engine powers.

Report describes a procedure for instrumenting, testing, and presenting the overall characteristics of any engine turbosupercharger installation. The preflight analysis of the system, required testing, importance of accurate data recording, measurements to record, methods of measuring, and presentation of results are also included.

Report discussing an adapter which uses three Tuckerman optical strain gages to measure the displacement of the three vortices of an equilateral triangle along lines 120 degrees apart. These displacements are substituted in well-known equations in order to compute the magnitude and direction of the principal strains. Tests of the adaptor indicate that principal strains over a gage length of 1.42 inch may be measured with a systematic error not exceeding 4 percent and a mean observational error of the order of + or minus 0.000006. The maximum observed error in strain was of the order of 0.00006. The directions of principal strains for unidirectional stress were measured with the adaptor with an average error of the order of 1 degree.

"A mathematical procedure is herein developed for obtaining exact solutions of shear-lag problems in flat panels and box beams: the method is based on the assumption that the amount of stretching of the sheets in the direction perpendicular to the direction of essential normal stresses is negligible. Explicit solutions, including the treatment of cut-outs, are given for several cases and numerical results are presented in graphic and tabular form. The general theory is presented in a from which further solutions can be readily obtained" (p. 1).

From Summary: "Bearing tests of AM-3S, AM-52S, and AM-C57S magnesium-alloy sheet in various thicknesses and tempers were made. Bearing yield and ultimate strengths were determined and compared for various edge distances and for various ratios of loading-pin diameter to sheet thickness. Tensile strengths were determined and ratios of average bearing yield and ultimate strength to tensile strength are given."

Report discusses data obtained from testing shear of joints riveted with round-head and brazier-head rivets. The tightness of the rivets is also compared for one value of rivet diameter. The load-displacement curves and comparison of load at various values of permanent displacement are presented for both types of rivets.

Report presenting data on the effect of exhaust back pressure on engine power for 14 aircraft engines. The data showed that the effect of exhaust back pressure on engine power varies with engine speed, range of back pressure and manifold pressure involved, and engine type. The only method of accurately determining the effect of back pressure on engine power than can currently be recommended is to test the specific engine type at the engine speed for which data are desired.

Report presenting an investigation to determine the loci of possible positions of a heavy bomber in space following a 12-second interval.

Report presenting an investigation to determine the effects of wing loading and altitude on lateral stability and control in the free-flight tunnel. The results of flight tests of the model were correlated with calculated stability boundaries, and an effort was made to determine for each loading condition the airplane configuration that gave the best flight characteristics. Results regarding the lateral stability, lateral control, and general flight behavior are provided.

Report discussing testing to determine the effect of a horizontal tail on the lateral-stability characteristics of a high-wing, a midwing, and a low-wing monoplane. The model was created from a circular fuselage, an NACA 23012 tapered wing, and an NACA 0009 horizontal tail surface. Information about the effective aspect ratio of the tail, restoring moment of yaw, and vertical-tail effectiveness as compared to the wing position is provided.

Report presenting porpoising tests of three rudimentary models composed of two V-bottom planing surfaces in tandem and fitted with a tail plane. The upper and lower branches of the upper trim limit of stability were determined for three angles of dead rise and two depths of step.

Report presenting force tests and measurements of the pressure distribution over the elevator and forward part of the fuselage on a flying model of the Curtiss XP-55 airplane in the full-scale tunnel. The results of the elevator pressure measurements are given in this paper. Results regarding chordwise pressure distributions, span-load distribution, and normal-force coefficients are provided.

Report presenting a study of the installation of 1800-horsepower engines in the PB2Y-3 airplane in place of the current 1200-horsepower engines. Stability and spray tests were made to determine the performance of the model on the water when tested at both the present and projected conditions of gross load and engine power. Results regarding aerodynamic tests and hydrodynamic tests are provided.

Report presenting an investigation to determine the effect of jet motors on the stability of the PB2Y-3 airplane at a gross load of 76,000 pounds. Results regarding Model 131J, Model 131J-1, and Model 131J-2 are provided.

Report presenting testing made with simplified models of two types of hulls that differ considerably from conventional types. Both have a single main planing surface that is combined with after-planing surfaces placed directly below the aerodynamic tail surfaces. Results regarding an investigation of twin planing tails, a single-planing tail, and potentialities indicated by tests are provided.

Report presenting experimental data on the distribution coefficients of technical xylidines for the system gasoline-water. The distribution coefficient is defined as the ratio of the concentration of xylidines in the gasoline layer to that in the water layer. Results regarding the effect of concentration of xylidines, effect of aromatic content of fuel, effect of sea water, and effect of temperature are provided.