From Introduction: "This report presents only that portion of the data from the first ditching which was to be used roughly establish the accelerations experienced by the pilot and the amount of water pressure to which the fuselage structure was subjected during the ditching."

Report presenting testing in the two-dimensional low-turbulence tunnels on a 24-inch-chord model of the NACA 66(215)-116 a = 0.6 airfoil with a 0.25-chord slotted flap. The optimum flap pivot positions were found for three different conditions. The conditions were determined from a consideration of the landing, take-off, and strafing requirements of the airplane.

Report discusses an investigation into the behavior of a cantilever beam in transverse motion with a mass at its tip when the root is suddenly brought to rest. Equations for determining the stresses, deflections, and accelerations that arise in the beam are also provided. This testing can be applied to the shock created in an airplane when landing and the vibrations that result.

Report presenting a theoretical and experimental investigation of the behavior of a cantilever beam in transverse motion when its root is suddenly brought to rest. The results of both types of investigations are compared.

Report presenting a determination of the effectiveness of a charged condenser for breaking oil foams and to obtain data on which to base the design of such a device for mounting at the oil-tank inlet of an airplane. Results regarding the condenser-plate area and arrangement, wet-plate design, condenser voltage, oil temperature, water in oil, and some safety considerations are provided.

Report presenting a cascade investigation in two-dimensional flow in the 5-inch cascade tunnel and the 1-inch turbine-element testing apparatus to obtain a satisfactory bucket design for use in a modern aircraft turbosupercharger. Results regarding the root sections, pitch sections, and tip sections are provided.

Testing of a dynamically similar model of an Army A-20A airplane to determine the best way to land the airplane in calm and rough water and to determine its probable ditching performance. Results regarding the effect of speed and attitude, effect of flap setting, effect of wind and seaway, effect of simulated damage, effect of sinking speed, effect of propellers, effect of gun blisters, and effect of weight are provided.

Report presenting compression tests on six 24S-T aluminum alloy curved sheet-stringer panels 12 inches in length and 24 inches in width, reinforced by six Zeo stringers spaced 4 inches between centers. The increase in developed width had no significant effect on the strain for buckling of sheet between stringers, the strain for buckling of sheet between rivets, the load carried per sheet bay, or the stress at failure.

Report presenting an investigation into the importance of stick force as a criterion of longitudinal stability with special reference to transient effects for maneuvers of short duration. The analysis showed that different combinations of elevator parameters which give the same stick force per unit acceleration in turns give widely different force variations during the entries into and recoveries from steady turns and during maneuvers of short duration such as abrupt pull-ups.

Report discusses the results of testing of rudder deflection for trim at low speeds in the critical wave-off condition. Depending on the lateral center-of-gravity location on the airplane, the useful load in the wings will change and the ability of the rudder to trim the airplane may be greatly improved.

Report presenting the results of tests of a model of a single-engine airplane with two different tilts of the propeller axis. The results indicate that on a typical design, a 5 degree downward tilt of the propeller axis will considerably reduce the destabilizing effects of power.

Report discusses a method developed to estimate the quantities of internal coolants required to prevent overheating of the aircraft cylinder when oxygen boost is applied. The formula and calculations related to inlet-air pressure, added oxygen, added water, added nitrogen, and total fluid weight are detailed.

Report presenting cast-iron piston rings that were run in nitrided-steel cylinder barrels under scuffing conditions and showed a coating material on the scuffed areas. Only a few of the 14 etching reagents that were tried attacked the coating chemically, indicating good corrosion resistance. Results regarding the occurrence of coating, metallurgical characteristics, and chemical characteristics are provided.

"An investigation has been made in the Langley free-flight tunnel to obtain an experimental verification of the theoretical rudder-free stability characteristics of an airplane model equipped with conventional rudders having negative floating tendencies and negligible friction. The model used in the tests was equipped with a conventional single vertical tail having rudder area 40 percent of the vertical tail area. The model was tested both in free flight and mounted on a strut that allowed freedom only in yaw" (p. 1).

Report discusses an investigation into static pressures in subsonic and supersonic flow over an airplane wing as measured by static-pressure tubes, a static-pressure belt, and orifices flush with the wing surface. The results obtained from the three types of measuring devices and a comparison to theoretical calculations are presented.

Report presenting an evaluation of a number of samples of flight acceleration data under a variety of operating conditions to determine the total frequencies and the frequency distribution of atmospheric gusts. The samples include 1748 hours of operation by several airplanes of the domestic airlines of the United States, a Martin M-130 airplane, and a Boeing B-15 airplane. The results indicated that the distribution of gusts within turbulent regions of the earth's atmosphere follows a substantially fixed pattern regardless of the source of the turbine.

Report presenting an investigation of the flow downstream from a two-dimensional grid formed of parallel rods. The nature of the flow was determined primarily by means of total-head measurements. Preliminary tests were made in both the closed-duct and open, two-dimensional configurations, but it was found that the same phenomenon occurred in both cases.

Report discussing the results of testing conducted to determine the knock-limited performance of fuel blends containing 80 percent of S-2 reference fuel and 20 percent of several exploratory fuels. Butyl acetate, sec-butyl acetate, isopropyl acetate, sec-butyl alcohol, tert-butyl alcohol, isopropyl alcohol, cyclohexanol, methylcyclohexanol, isobutylcarbinol, sec-butylcarbinol, triethyl borate, and dimethylfuran were examined.

Report presenting the utilization of the differential equation of Chaplygin's jet problem to give a systematic development of particular solutions of the hodograph flow equations, which extends the treatment of Chaplygin into the supersonic range and completes the set of particular solutions. The solutions serve to place on a reasonable basis the use of velocity correction formulas for the comparison of incompressible and compressible flows.

Report discusses the results of compressive testing of 24S-T aluminum-alloy sheet-stiffener panels with five ratios of stiffener thickness to sheet thickness. For each ratio, rivets of five different diameters were used to attach the stiffeners to the sheets. The compressive strengths were found to increase with an increase in the diameter of the rivets until the ratio of rivet diameter to over-all thickness reached a certain point.

In open box beams subjected to torsion, secondary stresses arise owing to lateral bending of the spar caps. The present paper outlines a simple method for estimating the magnitude of these stresses and gives the results of tests of an open box beam in the neighborhood of a discontinuity where the cover changed from the top to the bottom of the box.

Report discusses an investigation into piston and ring friction as compared to total engine friction under natural operating conditions. Several test conditions were explored, including the effect of scuffing and excess cylinder-wall lubrication on friction. A device for measuring ring tensions and an apparatus for transforming pressure-crank angle indicator diagrams into pressure-volume indicator diagrams are also described.

Report presents the results of experiments on the resistance and porpoising characteristics of flying-boat hulls equipped with rectractable planing flaps. The ideal flap-hull combination would have hump-resistance characteristics at least equal to the XPB2M-1 flying boat and much better upper-limit porpoising characteristics with the flap retracted. Three ways that the flaps can be applied to a practical design are discussed.

Report presenting the magnitude of slipstream contraction, which provides information about the conditions of the ultimate wake. Curves and tables are given for the contraction coefficient of two-blade and four-blade propellers for various values of the advance ratio; the contraction coefficient is defined as the contraction in the diameter of the wake helix in terms of the wake diameter at infinity.