Report presenting an investigation on canopy pressures and canopy-fuselage forces and moments under conditions of combined pitch and sideslip. The canopy configurations tested varied in windshield shape (flat, vee, and round) and were tested at two Mach numbers and Reynolds numbers.

Report presenting zero-lift drag results for two 60 degree delta-wing configurations with air inlets. One had twin conical-shock semi-circular scoops just ahead of the wing-body juncture and one had a modified wing section over the inboard portion to allow installation of modified triangular inlets in the wing leading edge. Results regarding the drag coefficients and mass-flow ratios are provided.

Report presenting an investigation of a configuration with a body of fineness ratio 16.9, a 52.5 degree sweptback wing of aspect ratio 3, taper ratio 0.2, and NACA 65A004 airfoil section, and an incline tail which was aeropulsed continuously in pitching during free flight with and without a sustainer rocket motor operating. The Mach number range covered was from 1.4 to 2.3. Results regarding drag, total normal force and pitching moment, wing normal-force-curve slope, flow conditions at the horizontal tail, and cross coupling are provided.

Report discussing testing of a multijet 60 degree delta-wing airplane configuration with twin-engine exhausts at specified locations under the wing. Data was obtained for jet-on and jet-off conditions between a range of Mach numbers. Results are presented for the effect of jet on drag, jet effect on lift, static longitudinal stability, and dynamic longitudinal stability.

Memorandum presenting an experimental investigation of a two-dimensional, 6.6-percent-thick, 6-foot-chord airfoil section equipped with suction slots for laminar-boundary-layer control. The section was designed to have favorable pressure gradients between the suction slots. The laminar boundary layer on the airfoil had the same extreme sensitivity to minute details of the model surface condition as has been found in other investigations.

"Tabulated pressure coefficients and aerodynamic characteristics are presented unanalyzed for six spanwise stations on the right wing of the Douglas D-558-I research airplane (BuAero No. 37972). The data were obtained in a 1 g stall at subcritical Mach numbers, in a speed run to a Mach number of 0.90 and in a wind-up turn at a Mach number of 0.86" (p. 1).

Memorandum presenting a supersonic wind-tunnel investigation of the origin and distribution of store interference performed in the 4- by 4-foot supersonic pressure tunnel at a Mach number of 1.6 in which separate forces on a store and on a 60 degree delta-wing-fuselage combination were measured. The configuration in this report simulates a heavy-bomber delta-wing airplane and has a large external symmetrical store that represents a nacelle with a frontal area equivalent to a twin-engine nacelle.

Memorandum presenting an investigation conducted in the supersonic pressure tunnel on canopy pressures and canopy-fuselage forces and moments under conditions of combined pitch and sideslip. The canopy configurations tested varied in windshield shape, location on the fuselage, and fineness ratio. Results regarding force and moment data, pressure data, and force and pressure correlation are provided.

"An experimental investigation was made of a preloaded spring-tab flutter model to determine the effects on flutter speed of aspect ratio, tab frequency, and preloaded spring constant. The rudder was mass-balanced, and the flutter mode studied was essentially one of three degrees of freedom (fin bending coupled with rudder and tab oscillations). Inasmuch as the spring was preloaded, the tab-spring system was a nonlinear one" (p. 1).

From Introduction: "Results are presented to indicate the effect of altitude, flight Mach number, and exhaust-nozzle-outlet area on the combustion efficiency, the losses in total pressure occurring in the combustion chamber, and the fractional loss in engine cycle efficiency resulting from combustion-chamber pressure losses. The engine cycle efficiency is also presented.These results are shown graphically as a fraction of corrected engine speed and in tabular form."

Memorandum presenting a calculation of the amount of possible correction for coordinated turns with limited bank angle and level sideslips for a large transport airplane, the C-54D. The results indicate that for all instances from the end of the runway, coordinated turns are the more effective maneuver.

"The drag and pressure recovery of a scoop-inlet model have been investigated at transonic speeds by the free-fall testing technique over a Mach number range from about 0.8 to 1.12. Tests were conducted at zero angle of attack, using both rounded and sharp lips at mass-flow ratios from about 0.6 to 0.9. The results indicate that the Mach number of drag divergence of the scoop-inlet model was about the same as that of the basic model without inlets which was tested previously" (p. 1).

Report presenting an investigation of the accuracy of a currently used method for predicting the dynamic lateral oscillatory characteristics of airplanes. The study involved the comparison of controls-fixed flight-test data from several current fighter-type jet airplanes with the calculated values of period and damping for the airplanes.

From Summary: "A matrix method is presented for determining the longitudinal-stability coefficients and frequency response of an aircraft from arbitrary maneuvers. The method is devised so that it can be applied to time-history measurements of combinations of such simple quantities as angle of attack, pitching velocity, load factor, elevator angle, and hinge moment to obtain the over-all coefficients. Although the method has been devised primarily for the evaluation of stability coefficients which are of primary interest in most aircraft loads and stability studies, it can be used also, with a simple additional computation, to determine the frequency-response characteristics. The entire procedure can be applied or extended to other problems which can be expressed by linear differential equations."

"Low-speed wind-tunnel tests of a l/8 scale model of the Republic XP-91 airplane were made to determine its low-speed characteristics and the relative merits of a vee and a conventional tail on the model. The results of the tests showed that for the same amount of longitudinal and directional stability the conventional tail gave less roll due to sideslip than did the vee tail. The directional stability of the model was considered inadequate for both the vee and conventional tails; however, increasing the area and aspect ratio of the conventional vertical tail provided adequate directional stability" (p. 1).

The Allison model 400-C6 compressor was operated at an inlet pressure of 12 inches of mercury absolute ana ambient inlet temperature at equivalent impeller speeds of 6000, 7000, and 8500 rpm. Additional runs at an equivalent speed of 7000 rpm and ambient inlet temperature were made at inlet pressures from 7 to 22 inches of mercury absolute. The results of this investigation are compared with those of the 533-A-23 compressors. For the speeds investigated, the Allison model 400-C6 compressor had a maximum adiabatic temperature-rise efficiency of 0.768 at an equivalent speed of 7000 rpm; the corresponding equivalent weight flow was 45.0 pounds per second and the pressure ratio was 1.83. At an equivalent impeller speed of 8500 rpm, the maximum equivalent weight flow was 61.6 pounds per second and the peak pressure ratio of 2.38 occurred at an equivalent weight flow of 52.2 pounds per 1 second and an adiabatic temperature-rise efficiency of 0.714. At an equivalent speed of 7000 rpm, increasing the compressor- inlet pressure increased the maximum equivalent weight flow and the pressure ratio.

Report presenting an experimental investigation of a two-dimensional, 6.6-percent-thick, 6-foot-chord airfoil section equipped with suction slots for laminar-boundary-layer control. The airfoil section was designed to have favorable pressure gradients between the suction slots. Results indicated that the laminar boundary layer on the airfoil had the same extreme sensitivity to minute details of the surface condition as has been observed in other similar investigations.

Electrical thermometers commonly used on aircraft are the thermoelectric type for measuring engine-cylinder temperatures, the resistance type for measuring air temperatures, and the superheat meters of thermoelectric and resistance types for use on airships. These instruments are described and their advantages and disadvantages enumerated. Methods of testing these instruments and the performance to be expected from each are discussed. The field testing of engine-cylinder thermometers is treated in detail.

A large number of photomicrographs of fuel sprays were taken for the purpose of studying the spray structure and the process of spray formation. They were taken at magnifying powers of 2.5, 3.25, and 10, using a spark discharge of very short duration for illumination. Several types and sizes of nozzles were investigated, different liquids were used, and a wide range of injection pressures was employed. The sprays were photographed as they were injected into a glass-walled chamber in which the air density was varied from 14 atmospheres to 0.0013 atmosphere.