Wing pressure distribution diagrams for several angles of attack and flap deflections of 0 degrees, 20 degrees, and 40 degrees are presented. The normal force coefficients agree with lift coefficients obtained in previous test of the same model, except for the maximum lifts with flap deflection. Pressure distribution measurements were made at Reynolds Number of about 6,000,000.

Report presenting pressure distribution measurements on two 24-inch chord models equipped with Fowler flaps in the two-dimensional low-turbulence pressure tunnel. Results regarding pressure-distribution diagrams and normal-force and moment coefficients are provided.

Tests were made in 8-ft high-speed wind tunnel to determine the drag reduction possible by eliminating the barrel jacket of a protruding 50-caliber aircraft gun. It was found that the drag of a standard aircraft gun protruding into the air stream at right angles to the flow can be reduced by 23% by discarding the barrel jacket. At 300 mph and sea-level conditions, this amounts to a decrease in drag of from 83 to 64 pounds. A rough surface finish on the barrel was found to have no adverse effects on the drag of the barrel, the drag being actually less at high Mach Numbers.

Report presenting testing in the full-scale tunnel to provide data for estimating the longitudinal stability and control characteristics of the Curtis XP-55 airplane. Testing included lift, drag, pitching-moment, hinge-moment, and elevator pressure measurements for various combinations of angle of attack, elevator deflection, and elevator tab settings. The results of the force tests and some correlation of the results of the force tests and the pressure measurements are presented in the report.

Report presenting tests of representative models of flying boat hulls to determine the resistance at low speeds. Results regarding the effect of load coefficients, resistance coefficients, and towing and drifting calculations are provided.

Supplement using data from a previous report to show the cargo that can be carried at various ranges, pounds of cargo that can be carried per pound of fuel, and other graphs to simplify the problem of determining which cargo can be carried at any range. The assumptions, parameters, and equations from the original report are carried over in the supplement.

Report presenting an investigation of the effect of spray strips on the low-speed spray characteristics on a model of the Consolidated PB2Y-3 flying boat. The main purpose of the investigation was to determine what form the strips should be fitted to give the most practicable answer to the problem of controlling the spray at heavy loads.

Report presenting tests in the full-scale tunnel to determine the longitudinal- and lateral-stability and control characteristics of a scale model of the XP-69 airplane. The data include measurements of the forces and moments on the model at various angles of attack and angles of yaw. The effects of elevator, rudder, and aileron deflection on control-surface effectiveness and on hinge moments were determined.

Report presenting testing in the two-dimensional low-turbulence pressure tunnel and the two-dimensional low-turbulence tunnel of two models made by the Consolidated Aircraft Corporation, one of the outboard section and one of the inboard section.

Report presenting the results of flight investigations showing that a beveled trailing-edge aileron gives as low or a lower profile drag than a contour aileron. Section profile drag and lift coefficients with two different types of ailerons were obtained at 3 different Reynolds numbers.

Report presenting power-off wind tunnel tests of a scale model of a twin-engine cargo airplane equipped with amphibious floats. Longitudinal and lateral stability and control characteristics were investigated for three flap positions.

Report presenting stability, maximum lift, and high-speed tests of an observation airplane fitted with Maxwell leading-edge slots. The static and dynamic longitudinal and lateral stability was generally satisfactory and not affected much by the slots.

"Compression tests were made of 63 panels stiffened with corrugated sheet. The specimens were constructed from artificially aged alclad 24S-T aluminum alloy with minimum guaranteed yield strengths of 57 and 48 kips per square inch for the flat- and corrugated-sheet materials, respectively. Results of the tests are presented in charts which show the average stresses at the maximum load and at buckling of the sheet" (p. 1).

Report presenting tests of airplane models that included investigations to determine the longitudinal stability and control, effects of various constituent parts or their modification on longitudinal stability and control, critical speed, and distribution of wing load. Some of the changes made in attempts to improve longitudinal control and to increase critical speed included auxiliary control flaps on the lower surface of the wing, revision of the windshield, increase in dimensions of outboard nacelles, and alteration in profile of wing leading edge.

Report presenting tests made in order to determine the differences in high-speed aerodynamic characteristics between models of a four-engine transport airplane and a similar bomber airplane. The main conclusion found is that the critical Mach number of the transport model is about 0.05 less than that of the bomber model.

"An analysis of the irregular vertical displacement of the wake from the trailing edge of a tailless airplane is presented, which shows the existence of an effective aerodynamic wing twist that causes an induced drag coefficient of 0.0004. The analysis explains most of the discrepancy between the drag determined from the momentum surveys an the drag measured on the wind-tunnel balance" (p. 1).

Report presenting tests of the Northrop MX-334 airplane in the full-scale tunnel. The results are of particular interest since the MX-334 is an all-wing glider-type airplane without a conventional fuselage or vertical surfaces. The primary purpose was to obtain sufficient data with which to determine the longitudinal and lateral stability and control characteristics of the airplane.

Report discusses a method of correlating engine-cooling data and its application to a representative engine-cooling test. Considerations for the correlation method are given, but the application to specific engine-cooling problems should be simple and direct. Information about experimental procedure and an example with specific values are included.

Report presenting an investigation of planing devices like hydroflaps and hydrofoils on several dynamically scaled models of military airplanes and their effectiveness in improving ditching characteristics. The ditching aids were generally found to be of value. Results regarding the hydroflap test in the impact basin, dynamic model tests at the outdoor catapult, and effect of ditching aids on ditching performance and rough water are provided.

"The knock-limited performance of blends of 0,50; and 100 percent by volume of 2,2,3-trimethylpentane in 28-R fuel determined with a modified F-4 engine at three sets of conditions varying from severe to mild at each of three compression ratios (6.0, 8.0, and 10.0). A comparison of the knock-limited performance of 2,2,3-trimethylpentane with that of triptane (2,2,3-trimethylbutane) is included. The knock-Limited performance of 2,2,3-trimethylpontane was usually more sensitive to either compression ratio or inlet-air temperature than 28-R fuel, but the ratio of the knock-limited indicated mean effective pressure of a given blend containing 2,2,3-trimethypentane and 28-R to the indicated mean effective pressure of 28-R alone was not greatly affected by compression ratio if the engine operating conditions were mild" (p. 1).

Report providing charts to assist with estimating F-3 and F-4 knock-limited performance ratings for several ternary and quaternary fuel blends. Several unusual behaviors were noted in the F-3 engines using the aromatic-paraffinic blends, so the charts for them may not be as accurate. General trends observed in different types of fuel are also described.

Report discussing testing of the Douglas A-26B to determine the lateral and directional stability and control characteristics. Information about the control-free lateral and directional oscillations, sideslip due to full aileron deflection, control-fixed and control-free directional stability, effective dihedral, side force due to sideslip, rudder control characteristics, variation of rudder and aileron force with speed, and response to abrupt aileron deflection are described.

Report discussing testing on the Douglas A-26B airplane to determine the stalling characteristics, variation of maximum normal-force coefficient with flap position, and a calibration of the service airspeed installation.

Report discussing testing on two types of single cylinders to determine the effect of the relation of exhaust pressure to inlet-air pressure on knock-limited performance. Variables explored included exhaust pressure, fuel-air ratio, and engine speed. Three types of fuels were also used to explore the effect of exhaust pressure on fuel ratings.