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.

"Wind-tunnel tests of a 1/5-scale semispan model of the Republic XF-12 horizontal tail surface equipped with an internally balanced elevator were conducted in the 6- by 6-foot test section of the Langley stability tunnel. The tests included measurements of the aerodynamic characteristics of the horizontal tail with and without a beveled trailing edge and also included measurements of the tab characteristics. The variation of the aerodynamic characteristics with boundary-layer conditions and leakage in the internal-balance chambers, measurements of the boundary-layer displacement thickness near the elevator hinge axis, and pressure distributions at the mean geometric chord were also obtained" (p. 1).

"A 1/6-scale model of the Republic XF-12 vertical tail with stub fuselage, stub horizontal tail, and a de-icing air duct was tested in the Langley stability tunnel. The investigation consisted of a study of the effects of the duct, with and without air flow, on the aerodynamic characteristics of the model. The model tested was a revision of a model previously tested in the Langley stability tunnel" (p. 1).

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.

Report discussing tests of the drag clean-up and stability of the Bell YP-59A jet-propelled airplane. The general stability, static stability, and control characteristics were examined. Specific details are also included about the effects of the exhaust jet on air flow at the tail.

"Flight measurements have been made of the individual aileron hinge moments, aileron rolling effectiveness pb/2V ,and stick-force characteristics in abrupt aileron rolls with a P-40F airplane (AAF No. 41-14119) over an indicated airspeed range from 108 to 304 miles per hour. Three methods for measuring the rate of change of hinge moment with angle of attack were investigated. Presented for comparison with the flight results are data from two-dimensional wind-tunnel tests of the wing-aileron profile as measured at the center aileron hinge" (p. 1).

"An injection system that supplies water to each cylinder of a double-row radial engine was tested...as part of a general investigation of the power-plant installation of a four-engine heavy bomber. The tests were conducted to determine the effectiveness of water injection in cooling the engine during take-off. The injection of 500 pounds of water at the take-off power condition reduced the maximum measured exhaust-valve-seat temperature 64 degrees Fahrenheit and the maximum spark-plug-gasket temperature 55 degrees Fahrenheit" (p. 1).

Report presenting the cooling characteristics of a 14-cylinder double-row radial air-cooled engines in a test stand and in flight. Three types of cooling tests were made for both engines: variable charge-air flow, variable cooling-air pressure drop, and variable fuel-air ratio. For the same operating conditions, the test-stand engine was found to run consistently cooler than the flight engine.

Report discussing an investigation into the stalling characteristics, aileron effectiveness, and longitudinal stability of a scale model of the XB-36 airplane. The model was tested with the original configuration as well as with several modifications to the outboard panels and flap arrangement.

"An investigation was conducted to determine the knock-limited blending characteristics of leaded fuels containing selected aromatic fuel components (benzene, toluene, mixed xylenes, and cumene). Each of the aromatics was blended with an alkylate blending agent and with a virgin base stock. The blending characteristics of the resulting fuels were determined in a full-scale aircraft-engine cylinder" (p. 1).

Report discussing the knock-limited performance of blends of 2,3-dimethylpentane and 23-R fuel in an F-4 engine at three sets of conditions and three compression ratios. The knock-limited performance of 2,3-dimethylpentane has about the same sensitivity to compression ratio and inlet-air temperature as 28-R fuel.

Report discussing flight measurements of the handling qualities of an F6F-3 obtained over the course of thirty flights and under a variety of conditions. The longitudinal stability and control of the plane were found to be satisfactory by the test pilots. Information about the elevator control, flaps, and the longitudinal trimming device is provided in greater detail.

Report discussing the lateral and directional stability and control of the F6F-3 airplane in a variety of flying conditions. Information about the control-free lateral oscillations, aileron control characteristics, maximum sideslip, dihedral effect, blow-up characteristics of the landing flaps, rudder, pitching moment, and power of the rudder trim tab and aileron trim tab is included.

Report discussing the stalling characteristics of the F6F-3 under a variety of flight conditions. Stall warnings, initial roll-off, and effects of stall are described.

Report discusses the thrust and power characteristics of several single- and dual-rotating propellers with differing blade width and number of blades for negative-thrust operation from -45 degrees to 145 degrees blade angle. From Summary: "The tests indicate that it is possible to predict for a given propeller design characteristics in the negative-thrust range from known characteristics at a different activity factor. Adequate negative thrusts were indicated for extremely high positive as well as negative blade angles."

Report discussing the effects of supercharging on the take-off thrust and useful load for a typical helicopter. Performance of the engine with the supercharger and on the rotor thrust is detailed.

Report discussing testing on an F6F-3 with a spring-tab rudder to determine the directional stability and control characteristics. Using the spring-tab rudder was found to result in lower trim-force change with speed and lower pedal forces in sideslips than the original rudder. Pilots were found to prefer the maneuverability of this configuration.

"Results of performance measurements made in level fight with the HNS-1 (Army YR-4B) helicopter are presented. These data include torquemeter measurements of shaft power for both the main rotor and the tail rotor. The power data, in conjunction with full-scale-tunnel date on the lift and drag of the fuselage, are used to calculate the drag-lift ratio for the main rotor" (p. 1).

Report discussing tests of a Sikorsky YR-4B helicopter, including photography of a rotor blade in forward-flight conditions at several azimuth angles for several tip-speed ratios. Fabric deformation in the form of sagging and bulging was noted. A reversal in the bending curve near the blade tip was also noted, which was hypothesized to come from losses of lift and high centrifugal force.