Report discusses measurements of gust size and intensity during the spring and summer of 1941 and 1942 under a variety of weather conditions and various altitudes up to 34,000 feet. Information about average gust-gradient distance, gust velocities, and gust frequency is included.

Report describes exploratory testing to determine the feasibility of using a hydrofoil with a type of flying boat afterbody called a planing tail. Several hydrofoil locations were examined, including no hydrofoil, and the effects of resistance characteristics were charted. The researchers concluded that it is possible to add a single hydrofoil to that type of afterbody to provide additional hydrodynamic lift without introducing instability.

"A model of a flying boat was tested to determine the landing characteristics when the depth of the step was reduced to zero by means of a retractable planing flap on the forebody" (p. 4). The results of stability and resistance testing are presented.

Report discusses methods of determining the iron contamination of used lubricating oil in order to study wear rates of piston rings and cylinder barrels of aircraft engines. Two methods of separating iron from used lubricating oil are presented. The results of the analyses of the oil are presented and the methods are evaluated.

Report discusses the "effects of oil introduced into the combustion chamber and of oil-spray piston cooling on the knock-limited performance of aircraft engines" (from Summary). A CFR engine and Allison V-1710 cylinder were used to test the rate of oil consumption, knock, and knock-limited brake mean effective pressure.

"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 describes a balanced-diaphragm device for measuring dynamometer torque of single-cylinder or multicylinder engines that was developed for laboratory use. Design variables are described, included desired torque-measuring device characteristics, diaphragm design, pilot valve, the torque-indicating instrument, the capacity range, ability of reversed operation, and double-acting operation. The accuracy is described as satisfactory and effects of other variables are negligible.

Report discusses an investigation into the relation between the effects of cylinder-head temperature and inlet-mixture temperature on the knock limits of fuels. The tests were run at a constant fuel-air ratio and the decrease in cylinder-head temperature required to offset the effect of increasing the inlet-mixture temperature on knock-limited power was determined. The apparatus and testing procedure are described and the effect of changes in cylinder-head temperature on the knock limit of any fuel are plotted.

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 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.

"Strength tests were made on two sets of beams having webs with large circular lightening holes. The main conclusion drawn from the tests is that allowable web stressed derived from pure shear tests and allowable flange stresses derived from compression tests cannot be applied in the design of beams without making corrections for interaction" (p. 1). Pure shear tests and beam tests were performed and the circumstances of failure were investigated.

Report discusses the problem of large airplanes spinning and the fact that they should not be intentionally spun because they are not designed for the loads and speeds that may be encountered in spin and recovery. Stall and spin characteristics for large airplanes are described. Recommended piloting procedures in case of a large airplane spinning event are also provided.

Report discusses an apparatus that may be used for indicating the formation of fatigue cracks or for following the progress of cracks. Details of the experiment and discussion of the way in which the deflection-crack area relationship may be used to monitor fatigue cracks are included.

Report discusses measurements of the relaxation time of steam and nitrogen due to their importance as turbine-working fluids. Additional calculations regarding different nozzle lengths are included.

Report discusses the results of tensile and compressive tests of two types of plastic-bonded glass cloth and their potential use in aircraft construction. The ultimate tensile stress and compressive yield stresses for the different materials are provided.

From Summary: "Local-instability tests of 24S-T aluminum-alloy formed Z- and channel-section columns were made in order to determine a length of test specimen that would avoid the increased strength associated with short lengths and also permit the occurrence of a convenient buckling pattern. The effect of column length on the critical compressive stress, on the average stress at maximum load, and on the number of half-waves of the buckling pattern is shown."

Report discusses the results of testing of 10-inch 24S-T aluminum alloy shear panels with 1.5 inch holes with notched edges to determine if a notch decreases the strength of the panel and if reinforcements can overcome the negative effects of the notch. The notch did appear to increase the stress concentration around the holes, but the lack of applicability to real-world scenarios is discussed.

"Thirty-nine Z-sections formed from 24S-T aluminum-alloy sheet with the angle of bend between the flanges and the web varying from 5 degrees to 120 degrees were tested as columns. Angles of bend from 30 degrees to 120 degrees had little or no effect on the critical stress or on the average stress at maximum load for local instability of the columns. The lengths of the columns were such that at angles of bend below 30 degrees they failed by Euler buckling" (p. 1).