Report presenting an investigation of an NACA 65A006 airfoil equipped with high-lift devices, including a 0.15-chord drooped-nose flap and a 0.20-chord plain trailing-edge flap. Airfoil section lift, pitching-moment, and drag characteristics obtained at high Reynolds numbers and low Mach numbers with the flaps deflected individually and simultaneously are presented. At Reynolds numbers up to 9.0 x 10(exp 6), the optimum combination of drooped-nose and plain trailing-edge flaps increased the maximum section lift coefficients from 0.78 to 1.89.

Memorandum presenting a wind-tunnel investigation conducted to determine the rotary stability characteristics in yawing flow of a series of untapered wings with angles of sweep of -45, 0, 45, and 60 degrees. The results of the yawing-flow tests indicated that the values of the rotary derivatives agreed fairly well with simple sweep theory for a moderate range of lift coefficients.

Report presenting initial flight tests of two simplified flutter vehicles. Test results were in agreement with the results of the freely-falling-body test in that the wing failures in the transonic range occurred at velocities greater than the flutter velocity calculated from the two-dimensional theory.

Memorandum presenting Mach number histories of the motion experienced by a hypothetical, small, straight-wing aircraft accelerating at various rates through an assumed controls-fixed pitch-down balance change in the transonic range. Two approximate analytical solutions of the longitudinal equations of motion are developed which are based on certain simplifying assumptions indicated by the differential-analyzer results.

Report presenting results of an exploratory free-flight investigation at zero lift of several rocket-powered drag research models equipped wing wing tanks at a range of Mach numbers. The tanks, which were slender bodies of revolution, were mounted on 34 degrees sweptback, nontapered wings of 2.7 aspect ratio. Results regarding drag and trim change are provided.

"A description of the two swept propellers investigated in the Langley 8-foot high-speed tunnel is presented, together with the discussions of the numerous assumptions and analyses on which the designs of these propellers are based. The blades are swept considerably along the entire blade radius and, in order to allow for reductions in the maximum stresses, are swept forward inboard and backward outboard. The blades have been designed on the basis of the blade-element method primarily to have subcritical efficiencies at the highest possible forward speed. The designs have been controlled primarily by the stresses in the blades" (p. 1).

From Introduction: "The investigation covered a range of Mach numbers from 0.66 to 1.12 and included measurements of angle of attack, pitching moment, normal force, and chord force. The drag at zero lift obtained in this investigation was reported in reference 1, but without the correction for tare of the end plate."

This report contains a selected list of Government sponsored research projects on related aircraft materials in effect during the calendar year 1947. Information is contained on titles, description, sponsoring and conducting agencies.

"An investigation has been made in the Langley full-scale tunnel of a 47.5 degree sweptback wing-fuselage combination equipped for boundary-layer control by suction. The wing aspect ratio was 3.5, the taper ratio was 0.5, and the airfoil sections normal to the quarter-chord line were NACA 64(sub 1)-A112. The wing configurations tested included the wing with various combinations of extensible leading-edge and split flaps" (p. 1).

Memorandum presenting an investigation to determine the feasibility of a high-performance transonic axial-flow compressor stage with a weight flow of 40 pounds per second per square foot of frontal area. A transonic axial-flow inlet stage with a hub-tip ratio of 0.35 and an axial Mach number of approximately 0.75 was designed and fabricated. Results regarding overall rotor performance, flow parameters, radial matching of blade-element sections, and comparison of blade-element parameters with design rules are provided.

This report presents an analysis of a compound engine operating with manifold pressures ranging from 60 to 110 lb/sq in. absolute and discusses the effects of engine limits (peak cylinder pressure and turbine-inlet temperature) and component efficiency.

Report discussing the point downwash angles and dynamic pressure at the horizontal-tail location of the D-558-1 airplane at a range of Mach numbers and lift coefficients. Results regarding the effective downwash with the tail-on and tail-off configuration, flow direction at the tail, rate of change, and dynamic pressure changes are provided.

Report presenting an investigation of the performance and general operating characteristics of a small single-cylinder, two-stroke-cycle, loop-scavenged engine using compression ignition at low compression ratios, high inlet-manifold temperatures and high inlet-manifold and exhaust-gas pressures. Results regarding the scavenging characteristics, power output, cylinder pressures, thermal efficiency, and exhaust measurements are provided.

Report presenting measurements of the chordwise pressure distributions over the 8-percent-thick wing of the XS-1 research airplane at a section near the midspan of the left wing. Data are presented for a Mach number range and a normal-force coefficient of about 0.33. Results regarding the upper-surface pressure distribution, lower-surface pressure distributions, and total section loads are provided.

"Abrupt rudder-fixed aileron rolls have been made with the Bell X-1 airplane in powered flight at Mach numbers between 0.90 and 1.06 at about 40,000 feet pressure altitude. These aileron rolls indicate that the aileron effectiveness for large deflections at Mach number 0.94 is only one-fourth the value at Mach number 0.82, and the effectiveness at Mach number 1.06 is slightly greater than at Mach number 0.94" (p. 1).

"NACA instrumentation has been installed in the Northrop X-4 airplane to obtain stability and control data during the Northrop conducted acceptance tests. The results of the fourth and fifth flights of the Northrop X-4 number 1 airplane are presented in this paper. These data were obtained for a center-of-gravity position of approximately 19.5 percent of the mean aerodynamic chord. The results of this flight showed that the directional stability as measured in steadily increasing sideslips was positive and high and that the effective dihedral was positive. The results also show the airplane to be longitudinally stable, stick fixed, with the center of gravity at 19.5 percent of the mean aerodynamic chord" (p. 1).

From Introduction: "Some experimental data on flame-holder pressure losses have been presented (reference 1 to 4). A theoretical analysis that assume a sudden enlargement of flow area was made at the NACA Lewis laboratory to determine the effect of flame-holder open area and combustion-chamber-inlet Mach number on the pressure losses across flame holders. The results of this analysis were then compared with experimental data obtained with several different flame-holder designs."

Report presenting aerodynamic and icing investigations in the icing research tunnel on a model of a turbojet-engine nacelle with a short straight air inlet. The hot-gas blowback system consisted of several orifices peripherally located around the inlet and was investigated in both dry-air and icing conditions. Results regarding the aerodynamic investigation without bleedback, aerodynamic investigation with cold-gas bleedback, aerodynamic investigation with hot-gas bleedback, and icing with bleedback are provided.

From Introduction: "The purpose of this report is to present the results of the analytical investigation of the turbine of reference 1 to indicate the extent to which the various turbine losses affect the turbine efficiency over the range of performance."

Report presenting an investigation to determine the performance of twin-scoop side inlets mounted on the fuselage of a proposed supersonic aircraft. The inlets had half of a conical spike as the compression surface and a ram-type boundary-layer-removal system. Results regarding the first inlet and redesigned inlet are provided.

Report presenting an experimental investigation of the downwash and sidewash flow angles in a transverse plane behind a cruciform-wing and body combination. The wing-body combination had a cruciform arrangement of two identical triangular wings of aspect ratio 2.31 corresponding to a leading-edge sweep angle of 60 degrees placed on a body of fineness ratio of 16. The investigation was conducted at a specified Mach and Reynolds number and a range of angles of bank and attack.

Report presenting testing of a centrifugal compressor from a production-type turbojet engine, which was successfully operated as a centripetal refrigeration turbine over a range of rotor speed, inlet pressure, and pressure ratio for full admission. The performance results indicated that partial admission was found to be the most efficient method of turbine control, but throttling at the turbine inlet was easy to apply. When nozzles are used, they should have erosion-resistant surfaces to minimize erosion effects.

"Pressure-distribution measurements and load-coefficient data at low speeds obtained in flight for a conventional front and rear sliding canopy are presented. The load-coefficient data indicate that the highest net aerodynamic load for the front canopy was in the exploding direction and occurred with the front and rear canopies closed. The highest net load for the rear canopy was in the crushing direction with the front canopy open and the rear canopy closed" (p. 1).

Report presenting a comparison of the high-speed aerodynamic characteristics of a family of four wing-fuselage configurations with four different degrees of sweepback as determined from transonic-bump model tests in the 7- by 10-foot tunnel, sting-supported model tests in the 8-foot tunnel, and the 7-foot by 10-foot tunnel.