Report presenting measurements of a Consolidated B-24D airplane of accelerations at various points on the wing during landing impacts. landings were made with the wheels initially stationary but free to rotate, with the brakes set before contact, and with the main wheels rotating prior to contact.

Bulletin presenting an analysis of the vertical-tail loads to be expected as a result of abrupt aileron action in accelerated flight, as in rolls from turns or pull-outs, for example. Critical tail loads may occur in rolling pull-out maneuvers, particularly on airplanes with good ailerons and low directional stability.

From Introduction: "Flight tests with electricity heated propeller-blade shoes reported in references 1 and 2 have establish the practicability of protecting propeller blades from ice formations by thermal-electric means."

From Introduction: "The purpose of this report is to show that it is practical to apply a least-squares method to the correlation of engine-cooling data."

Report discussing some calculations made for the effects of water in cooling the inlet air of aircraft-engine cylinders. From Summary: "The estimates indicate that the cooling effect of the water on the inlet air can be more extensive than the cooling now obtained with the intercoolers or aftercoolers in the air-induction system. In connection with water recovery from the exhaust gas, the estimates indicate that sufficient water can be recovered from 50 percent of the exhaust gas to provide an inducted water-fuel ratio of 0.5."

"Charts are presented for the calculation of the critical compressive stress - the stress at which local instability occurs - for idealized web- and T-stiffened panels, and examples of the use of the charts are given" (p. 1).

Report presenting charts showing the rotor profile drag-lift ratio for a helicopter rotor operating in forward flight and having hinged rectangular untwisted blades. The charts are given for a range of power input covering glides, level flight, and moderate rates of climb. A drag curve was used for preparing the charts, and the curve is compared with experimental curves for typical airfoils.

Report presenting an investigation of the possibility of using internal cooling instead of fuel enrichment to suppress knock and to estimate the fuel savings that will result. Data from four different sources was examined and an analysis of the fuel consumption was conducted. Four different types of coolants were explored.

Report presenting tests made with a dynamic model of the Army B-26 airplane to determine its behavior when landed on water. Results regarding the general behavior, effect of flaps, effect of landing attitude and speed, tests with undamaged model, tests with simulated damage, tests with propellers, vertical decelerations, and effect of weight are provided.

Rough conventional, smooth conventional, and laminar-flow or low-drag sections were tested. The items covered are rotor thrust for fixed power in hovering, range and endurance at cruising speed, and power required at high-forward speed. Calculations indicated that a smooth conventional section gives marked performance gains. Smaller gains are obtainable by using a low-drag section. At high speeds or loads the low-drag section is inferior to the smooth conventional section.

Report presenting an analysis of the effect of power on the variation of stick-fixed neutral point with lift coefficient for several single-engine monoplanes. Testing occurred with the power off and with rated, climbing, or wave-off power and with flaps neutral and deflected. Results for these different conditions are provided.

"In connection with studies of airfoils applicable to large high-speed aircraft, the effects of roughness on three 22-percent-thick airfoils were investigated. The tests were made over a range of Reynolds number from about 6 to 26 x 10(exp 6) for the airfoils smooth and with roughness strips applied to the surfaces. The results indicated that for the roughened models the scale effect was generally favorable" (p. 1).

"An electronic circuit for instantaneously indicating angular velocity and acceleration, both positive and negative, of rotating masses is described; readings are taken on electrical indicating meters. The indicator is described in terms of general application. A circuit diagram, calibration curves, and a mathematical analysis of the differentiation circuit are included" (p. 1).

Report presenting an investigation of the suitability of methyl tert-butyl ether as a component of aviation fuel from considerations of knock-limited performance tests and laboratory inspection tests. Data were obtained from testing on the 17.6 engine under supercharged conditions with fuel blends containing 10 and 20 percent methyl tert-butyl ether. Results regarding small-scale-engine data, full-scale-engine data, and inspection data are provided.

Report presenting the results of a wind-tunnel investigation of propellers operating at negative thrust. Negative-thrust characteristics of two- and four-blade single propellers and four- and eight-blade dual propellers were determined. The results indicate that the constant-speed reversed-pitch propellers posses aerodynamic characteristics that should make them excellent aerodynamic brakes.

Report presenting an investigation of the suitability of 27 aromatic amines for overwater storage of their gasoline blends. The program is also meant to determine the antiknock effectiveness and low-temperature solubility in gasoline.

Report presenting data on the thermal performance and the static pressure drop characteristics of two finned-type exhaust gas and air heat exchangers. One heater was constructed of copper and stainless steel while the other was constructed from aluminum alloy. The measured thermal outputs and static pressure drops are compared with predicted magnitudes.

Report divided into two sections. One discusses a correction that must be applied to a heat meter when it is used at temperatures other than temperatures at which it was calibrated. The other section contains the results of an application of the two methods of correcting the heat-transfer rates for contact and heat-meter resistance to experimental data.

Report presenting tests to investigate the effect of 2-percent additions of nine aromatic amines on the knock-limited performance of AN-N-28 (28-R) fuel. The results of the testing of antiknock effectivneess of the 27 aromatic amines obtained to date in the program are also summarized.

Report presenting data obtained when a float with both horizontal and vertical velocity contact on a water surface. The report is confined to a presentation of the relationship between resultant velocity and impact normal acceleration for various float weights when all other parameters are constant.

Report discusses some unusual velocity-acceleration records on transport airplanes, which the report defines as "records of accelerations experienced in flight that resulted from causes other than atmospheric gusts" (from Summary). The analysis of the records, which is required for determining proper classification, is described, and the sorting of the records into gust- or maneuver-related is described. The report also discusses the importance of receiving this data from flight operators in addition to the routine information they provide.

"Friction and heat-dissipation data are presented for use in determining the load-carrying capacity of 2- by 1.25-inch bearings with the following types of lining: copper-lead, lead-indium-coated silver, and lead-coated copper-lead. The tests were made in a four-bearing friction machine and covered operation with three clearances using three oils of different viscosity at three oil-inlet temperatures. Values are computed to indicate the safe loads at various speeds for bearings lined with each of the three types of material" (p. 1).

Report presenting tests to determine the thermal and pressure-drop performance and durability of a cross-flow, internally finned, tubular exhaust-heat exchanger. The test covered a range of exhaust-gas flows, cooling-air flows, and exhaust-gas temperatures.

Report investigating the theoretical sea-level performance of an explosion jet-propulsion engine similar to the German flying bomb to show the effects on performance of heat added and supercharging and a comparison was drawn between the performance of the explosion engine and the constant-pressure engine. The explosion engine was found to be more efficient than the constant-pressure engine at compressor pressure ratios below 3.0 when the maximum gas temperature of the constant-pressure engine is 1600 degrees Fahrenheit.