Report presenting tests in the 8-foot high-speed wind tunnel to determine the loads and the load distributions at high speeds for a number of windshields of the cockpit-canopy type. Ten windshields of various designs similar to those in general use were included in these tests. Results regarding drag, loads, and design considerations are provided.

Report presenting knock-limited performance tests made with eight representative fuels rated at 100-octane number using the CFR aviation method. All eight fuels were mixtures of representative blending agents and bases. Results regarding the effect of inlet-temperature air changes, effect of octane numbers in a full-scale single-cylinder engine, effect of addition of aromatics to the fuels, and type of spark plug used are provided.

From Introduction: "The present report, therefore, may be considered a supplement to reference 1. The combined scope of the stall charts of reference 1, designated A, and of the present work, designated B, is summarized in the following table: For the wing with root thickness ratio to 18 was also investigated.

From Introduction: "The results of the load tests and some additional aerodynamic characteristics of perforated double split flaps on a rectangular NACA 23012 airfoil are given in the present report."

"This paper studies the effect of altitude on the ratings of rotating electric machines and after determining the fundamental principles involved, discusses these in relation to the application of such machines in modern aircraft" (p. 1).

"Methods are given for making the necessary corrections to the strains indicated by multiple-strand resistance-type wire strain gages used singly or as rosettes to measure strains at an angle to the principal strain. The results of tests to determine the validity of the methods of correction are reported" (p. 1).

"The various equations for computing profile drag by the momentum method are examined, and the errors arising from complete or partial neglect of compressibility effects in the Jones equation and the Bicknell equation are evaluated. The integrating method of Silverstein and Katzoff is shown to be accurate over a wide range of Mach number and wake shapes" (p. 1).

Report presenting an experimental survey of the details of the flow of fluids across banks of streamline tubes as a continuation of previous work. Information that clarifies the picture of flow has been obtained by surveys of total, dynamic, and static pressure, and hot-wire cooling surveys of the unheated tubes.

Report presenting results from a series of flight tests of the maximum speed and cooling characteristics in full-throttle level flight of the XP-42 airplane equipped with a short-nose high-inlet velocity cowling. The results of the tests indicated a maximum speed of 336 miles per hour at 960 horsepower at 25,000 feet. Results regarding maximum speed and pressure and temperatures are provided.

Report presenting results from a series of flight tests of the performance and cooling characteristics in high-speed level flight and in climb of the XP-42 airplane equipped with a short-nose low-inlet-velocity cowling and an axial-flow fan mounted on the spinner. Results regarding maximum speed and pressures and temperatures are provided.

Report presenting the results of flight measurements of performance and cooling characteristics of the XP-42 airplane equipped with a short-nose low-inlet-velocity cowling. Testing included measurements in level flight and climb of the effects of a spinner-mounted axial-flow fan without propeller cuffs, no fan or cuffs, and two different sets of propeller cuffs.

Report presenting flight measurements of the performance and cooling characteristics of a short-nose high-inlet-velocity cowling on the XP-42 for conditions of climb with and without propeller cuffs and for high speed without cuffs. The speed of the airplane was approximately 1 mile per hour greater without propeller cuffs than the previously measured value with cuffs. Results regarding maximum speed, pressures and temperatures, and ground cooling are provided.

Report presenting a procedure for the shear-lag analysis of box beams, such as wing structures. It is based off of a previous method but allows for the separation of the most essential part of the shear-lag analysis.

Report presenting an experimental technique developed by means of which the variables affecting the time element in the detonation process in a spark-ignition engine can be controlled and approximately measured. Results indicated that higher maximum permissible pressures can be used if the rate of compression of the end gas is increased. Suggestions for future study are provided.

Report presenting flight testing of an improved type of all-movable tail surface. The particular arrangement tested provides control-free stability and a stable variation of the control forces during maneuvers. Results regarding rudder effectiveness, directional stability, rudder-free lateral motion, and rudder-free turns are provided.

Aerodynamics data are obtained for the design of linked balancing tabs and effect of varied tab span and location to produce suitable lateral control characteristics with reasonable stick pressures for high-speed aircraft. Simple and spring-linked balancing tabs may considerably reduce control pressures if aileron system is designed for low maximum aileron deflection. Spring-linked tabs also decrease variation of stick pressure with speed and impart better controlllability at low speeds.

Report presenting force-test measurements in two-dimensional flow in the 4- by 6-foot vertical tunnel to determine the characteristics of several different shaped overhang-type aerodynamic balances applied to a straight-contour flap mounted on an NACA 0015 airfoil. The flap with blunt-nose overhang was overbalanced throughout certain ranges of flap deflection. Results regarding precision, lift, flap hinge moments, pitching moment, and drag are provided.

Report presenting force-test measurements in two-dimensional flow made in the 4- by 6-foot vertical tunnel to determine the aerodynamic effects of changing the alignment of the cover plates on a sealed internally balanced flap. Manufacturing imperfections in the alignment of the cover plates with the airfoil contour may have serious effects on the resultant hinge moment of a flap with a sealed internal balance. Results regarding lift, flap hinge moments, pitching moment, and drag are provided.

Report presenting tests made in the 7- by 10-foot tunnel to determine the effect of direction of propeller rotation on the static longitudinal and lateral stability characteristics of the scale model of the North American B-28 airplanes. The results of the present investigation indicate that the mode of propeller operation has a considerable effect upon lateral and longitudinal stability and may have an effect upon propulsive efficiency.

From Introduction: "A typical ice formation on a wing leading-edge-type light installation is shown in figure 1. Although the primary purpose of this analytic investigation was to determine the practicability of providing a landing-light thermal ice-prevention system which could be incorporated with the wing leading-edge thermal ice-prevention system of the B-17 F airplane, the analysis has been developed in a general form for future application to similar deigns. "

Report presenting comparisons between the approximate substitute single-stringer method of shear-lag analysis and the exact solutions, which indicate that for beams of practical proportions the approximate method yields a value for the maximum root stress that exceeds the value obtained by use of the exact solution by less than 10 percent.

Report presenting the potential function for flow, with circulation, of a compressible fluid about a circular cylinder, which is obtained in series form including terms of the order of M(exp 4) where M is the Mach number of the free stream. The equations are used to obtain pressure coefficient as a function of Mach number at a point on the surface of the cylinder for different values of circulation.

Report presenting an analysis which shows that, when account is taken of sideslip and wing flexibility, the calculated rolling maneuverability of an airplane is in good agreement with the results obtained from flight tests. The method used avoids the complications of successive approximations but is nevertheless believed to be more nearly accurate than other methods based on semirigid-wing assumptions. The method is applied to a wing of tubular shell construction and the procedure is illustrated for a modern pursuit airplane.

Report presenting an investigation of the existence of energy dissipations in gas dynamics, which must be attributed to a lag in the vibrational heat capacity of the gas, and most specifically the flow about a very small impact tube. A new method of measuring the relaxation time of gases is introduced in which the total-head defects observed with a specially shaped impact tube are compared with theoretical considerations.