Report presenting an investigation to determine the flow losses that occur as a result of locating the axis of an intercooler at various angles with respect to the supply-duct axis and also to determine the flow pattern throughout the intercooler. The flow losses were found to be small for angles of inclination up to about 70 degrees. The distribution of flow through the intercooler also appeared to be fairly uniform up to about this angle.

Report discusses the results of an investigation into the oscillations performed by suspended bodies like trailing airspeed heads and other towed devices. The most violent types of instability observed were found to be caused by unsteady or nonuniform air flow where the cable was lowered from the airplane. No method was found for reducing cable oscillations in short cable lengths, but the degree of stability present was considered satisfactory as long as the suspended body is lowered into a uniform air stream.

Report presenting calculations to determine the effects of spring and gravity moments in the control system on the longitudinal-stability characteristics of the Brewster XSBA-1 airplane, and the computed results have been verified by flight tests.

Report presenting an analysis of the power losses in airplane flight of cross-flow plate and tubular intercoolers to determine the cooling-air weight flow and pressure drop that give minimum total power loss for any given cooling effectiveness. The investigation covers a range of flight conditions of altitude, airspeed, lift-drag ratio, supercharger-pressure ratio, and adiabatic efficiency.

Report presenting a study of the design of an air-heated wing and the results of tests performed on a model air-heated leading edge, which were made to determine the validity of the proposed wing design.

Report presenting testing of an airplane in icing conditions to determine the effect of exhaust heat applied to the wings as a means of preventing ice formations. Other ice-prevention equipment, including an exhaust gas-heated pitot-static head, hot-air-heated windshield, and an inflatable de-icer were also tested.

"Two stress-strain curves are presented for both tension and compression. In addition, the results of a number of flat-end column tests are presented. The more apparent conclusions regarding extruded magnesium alloy J-1 are: it has a very low proportional limit in relation to the yield and ultimate strengths and it has a very low yield point for compression as compared with tension" (p. 1).

Report presenting an investigation using tight-fitting baffles on the cooling fins of several modern air-cooled engine cylinders in order to maintain a constant free-flow area from the front to the rear of each interfin air passage. Results regarding the effect of restriction in cooling-air flow paths on cylinder temperature and effect of restrictions in cooling-air flow paths on cooling-air mass flow are provided.

Report presenting a series of 25-hour accelerated high-output tests run on a single-cylinder aircraft-type spark-ignition engine to determine the effect of coaxial lapping of piston rings prior to engine operation. Standard cast-iron rings were used and tested with all rings lapped and with only the oil-control rings lapped. The results indicated that coaxial lapping with loose abrasive reduced both wear and scuffing.

Report presenting tests in the free-flight tunnel to determine the effect of the fuselage length and the aspect ratio and size of the vertical tail on lateral stability and control. Fuselages of two different lengths and various vertical tail surfaces were used on a powered model in the investigation. Results regarding the test conditions, flight tests, and force tests are provided.

Tests were made to determine whether spring-tab ailerons tended to oscillate or flutter in speed ranges up to 400 mph. Flight tests showed spring-tab ailerons had desirable light stick forces and no tendency to overbalance. No flutter tendencies were indicated up to 400 mph, and any oscillations following abrupt control deflections were heavily damped.