Report discussing the effects of internal coolants injected with fuel on the icing characteristics of a twin-barrel injection carburetor mounted on an engine-stage supercharger assembly. The tests were made at conditions that simulated war emergency power and at a variety of water-fuel ratios, carburetor-air temperatures, and carburetor-air relative humidities.

Report presenting aerodynamic and hydrodynamic tests of a 1/10-scale wing-hull model and a 1/10-scale float-strut model of the proposed arrangement of the Hughes-Kaiser cargo airplane. The aerodynamic tests were made primarily to study the drag characteristics of these models as originally designed and to determine how the design could be improved. Results regarding the wing-hull model and float-strut model are provided.

Report presenting testing of a Pratt & Whitney R-1830-43 engine mounted in a B-24D nacelle in the full-scale wind tunnel in order to investigation the potential improvements of fuel economy. Suggestions for improving the cruising power and cruising range by operating at specified fuel-air ratios are provided.

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.

Report presenting climb and high-speed tests of a Hamilton Standard No. 6507A-2 three-blade propeller, which have been made to determine the effect of blade loading on propeller efficiency. The normal and military power climb efficiencies were found to be about equal at altitudes below 16,000 feet.

Report discussing the results of testing on a flying boat model with an afterbody length-beam ratio of 4.7 to determine its takeoff and landing stability and resistance characteristics.The range of stable trims was smaller than models with a conventional afterbody, but the range of stable positions for the center of gravity was about the same. Landing stability was satisfactory, and the hump resistance and trim is less than a boat with a smaller ratio.

Report discussing testing to determine the cooling effect of modified baffles and auxiliary-cooling ducts on the rear-row cylinders of a double-row radial engine. The modified baffles were found to reduce the temperatures of the exhaust-valve seats, but did not have an effect on the valve-guide temperatures. The auxiliary-cooling ducts reduced temperatures of the exhaust-valve seats and rear spark plug gaskets.

Report presenting an investigation of carburetor-air scoops designed for the XTB2D-1 airplane in the NACA propeller-research tunnel. The purpose of the investigation was to determine the performance of several scoops and to make modifications necessary to improve the pressure recovery without adversely affecting the drag of the airplane. The investigation included tests of nine carburetor-air scoops with numerous boundary-layer-bypass and ducting modifications, the original engine cowl, and two canopies.

Report presenting a study of the performance of bombers powered by one, two, four, and six 2000-horsepower engines supercharged to 25,000 feet. The performances are computed and are based on drag coefficients equal to the best obtained on modern airplanes and on weight estimates obtained from modern Army Air Forces airplanes. A chart is provided with the coordinates of power loading and wing loading noted so that all performances can be compared.

Report discusses the results of testing conducted to determine the performance of automatic, internal-coolant valves actuated by cylinder temperatures.The performance of the valves with respect to temperature sensitivity, rapidity of response, and hunting characteristics is described. The relative effects on cylinder performance obtained by internally supplying water and additional fuel were also examined.

Availability data obtained on SNB-1 trainer-class airplanes were analyzed and results presented as flight envelopes which predict occurrences of large values of air speed and acceleration. Comparison is made with SNJ-4 trainer-class airplane data analyzed by the same method. It is concluded that flight envelopes are satisfactory; that the two types show large differences in flight loads and speeds experience; and that SNB-1 will seldom, if ever, exceed design limit load factor and restricted speed, which SNJ-4 can be expected to exceed design-limit load factor and restricted speed in a very small number of flight hours.

Report presenting testing to determine the effect of xylidines of the corrosiveness of aircraft-engine oil toward engine bearings as part of an investigation on the suitability of xylidines as an antiknock component in aviation gasoline. Results regarding the loss in bearing weight, corrosion losses, temperature characteristics, and types of corrosion 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 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 of a steel cylinder barrel with aluminum fins of the optimum spacing of 0.090 inch. The primary purpose is to determine the excellence of the thermal bonds between the aluminum fins and the aluminum base and between the aluminum base and the steel and to compare the heat transfer of the barrel with that of barrels with a fin space of 0.052 inch.

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.

Report discussing modifications to the spray nozzle to prevent the formation of refrigeration icing in the induction system of an aircraft engine. Two fuel-injection systems, a spinner type and a drilled-inducer type, that prevent the formation of refrigerator icing satisfactorily were created.

Report discussing the effects of Mach number on the aerodynamic characteristics of an Allison powered single-engine pursuit airplane. Information about the lift, drag, pitching-moment characteristics, stability, tail effectiveness, and elevator effectiveness with Mach number is provided.

Report discussing tests on the PBN-1 airplane to determine the effects of modifications on spray characteristics and take-off and landing stability. Spray strips were found to reduce the spray over the bow at low speeds. The effects of changing the main step location and altering the elevator position are described.

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 discussing a study of automatic nonreturn air valves for use in an intermittent-jet engine. Four valve-spring materials, three valve-grill materials, and five types of valves were used. Valve A, which was made out of aluminum, was found to perform the best and last the longest.

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 to determine the effect of the location of the diffuser vanes with respect to the supercharger outlets and the effect of flow conditions at the impeller inlet on the air-flow distribution in the outlets of the engine-stage supercharger of an 18-cylinder double-row radial aircraft engine. The effect of flow conditions at the impeller inlet was investigated by distorting the flow at the inlet and noting the effect in the supercharger outlets. Results regarding the diffuser effect and inlet effect are provided.

Report discussing an investigation to determine the effect of omitting some of the fuel constituents in AN-F-28 Amendment 2 fuel that are normally lost in flight on fuel-vapor loss. Removing the components was found to decrease the fuel-vapor loss and increase the critical altitudes.