Report presenting a series of outdoor tests to determine the static-thrust and torque characteristics of single- and dual-rotating propellers for use in aircraft propeller design and in take-off performance estimation.

Report presenting testing to determine which of three spinner-diffuser designs on an NACA cowling was the most effective in cooling a Pratt & Whitney R-2800 engine installation. The results of pressure-distribution studies in front of and behind each bank of cylinders are presented for a wide range of propeller-operating conditions.

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.

Tank tests were made of a hull model of the Hughes-Kaiser cargo airplane for estimates of take-off performance and maximum gross load for take-off. At hump speeds, with the model free to trim, the trim and resistance were high, which resulted in a load-resistance ratio of approximately 4.0 for a gross load coefficient of 0.75. With a 4000,000-lb load, the full size craft may take off in 69 sec over a distance of 5600 ft.

Report presenting testing to determine the solubilities in gasoline at low temperatures of 15 aromatic amines from the NACA exploratory program as antiknock additives. The solubility data is summarized in a table by interpolating or extrapolating experimental results to obtain solubility at -60 degrees Celsius.

Report presenting tests made in the LMAL 16-foot high-speed tunnel to determine the aerodynamic characteristics of a 1000-pound AN-M-65-AZON radio-controlled bomb at a Mach number range of 0.2 to 0.6. Over the Mach number range, the hinge-moment coefficients, yawing-moment coefficients, and lateral-force coefficients exhibited no important changes with increasing speed.

Report presenting testing to investigate the effects of 2-percent additions of nine aromatic amines on the knock-limited performance of AN-F-28 (28-R) fuel. The p-toluidine and p-tert-butylaniline gave the best overall improvement in the knock-limited power of the fuel.;

Report presenting drag measurements in the two-dimensional low-turbulence tunnel of an available 100-inch-chord model of the NACA 23016 wing section. Results regarding the curves of section drag coefficient plotted against Reynolds number for various surface conditions and lift coefficients, variation of drag coefficient with lift coefficient, and effects of skin friction are provided.