NACA instrumentation has been installed in the X-4 airplanes to obtain stability and control data during the acceptance tests conducted by the Northrop Aircraft Corporation. This report presents data obtained on the stalling characteristics of the airplane in the clean and gear- down configurations. The center of gravity was located at approximately 18 percent of the mean aerodynamic chord during the tests. The results indicated that the airplane was not completely stalled when stall was gradually approached during nominally U accelerated flight but that it was completely stalled during a more abruptly approached stall in accelerated flight. The stall in accelerated flight was relatively mild, and this was attributed to the nature of the variation of lift with angle of attack for the 001-614 airfoil section, the plan form of the wing, and to the fact that the initial sideslip at the stall produced (as shown by wind-tunnel tests of a model of the airplane) a more symmetrical stall pattern.

Report presenting an investigation to evaluate the engine service performance of nozzle-diaphragm blades of AISI 321 and AISI 347 stainless steels. Data were obtained from three nozzle diaphragms alternately bladed with each of the two materials. Results regarding a visual inspection, a metallurgical examination, the mechanism of cracking, and the classification of failures are provided.

Memorandum presenting an analysis made to estimate the performance of a direct-air nuclear turbojet-powered airplane using a split-flow reactor and a separated-type shield. The analysis was for flight Mach numbers of 0.9 and 1.5 and covered a range of altitudes, reactor-wall temperatures, turbine-inlet temperatures, compressor pressure ratios, and airplane lift-drag ratios.

Memorandum presenting an analysis made to estimate the performance of a direct-air nuclear turbojet-powered airplane with a split-flow reactor and a separated-type shield. The analysis was for flight Mach numbers of 0.9 and 1.5 and covered a range of altitudes, reactor-wall temperatures, turbine-inlet temperatures, compressor pressure ratios, and airplane lift-drag ratios.

Report presenting a wing-body combination with a plane triangular wing of aspect ratio 2 and NACA 0005-63 sections in streamwise planes has been investigated at subsonic and supersonic Mach numbers. Lift, drag, and pitching moment are presented for a range of Mach and Reynolds numbers.

Report presenting an investigation of a wing-body combination with a plane triangular wing of aspect ratio 2 and NACA 0008-63 sections in streamwise planes at subsonic and supersonic Mach numbers. Lift, drag, and pitching moment are presented for a range of Mach and Reynolds numbers.

Report presenting an investigation in the supersonic tunnel at Mach number 1.85 and angles of attack from 0 to 5 degrees to determine optimum design configurations for a convergent-divergent type of supersonic diffusers with a subsonic diffuser of 5 degrees included divergence angle. Total-pressure recoveries in excess of the theoretical recovery across a normal shock at a free-stream Mach number of 1.85 were obtained with a number of configurations.

Report presenting testing of a wing-body combination with a plane triangular wing of aspect ratio 2 and NACA 0003-63 sections in streamwise planes at subsonic and supersonic Mach numbers. Lift, drag, and pitching moment are presented for a range of Mach and Reynolds numbers.

Report presenting an investigation of a wing-body combination with a plane triangular wing of aspect ratio 4 and NACA 0005-63 sections in streamwise planes at subsonic and supersonic Mach numbers. Lift, drag, and pitching moment are presented for a range of Mach and Reynolds numbers.

"A wing-body combination having a triangular wing of aspect ratio 4 with NACA 0005-63 thickness distribution in streamwise planes, and cambered and twisted for a trapezoidal span distribution has been investigated at both subsonic and supersonic Mach numbers. The lift, drag, and pitching moment of the model are presented for Mach numbers from 0.25 to 0.96 and 1.20 to 1.70 at a Reynolds number of 1.5 million. The variations of the characteristics with Reynolds number are also shown for several Mach numbers" (p. 1).

Memorandum presenting pressure distributions on two wing-body combinations obtained at a Mach number of 1.9 to investigate the wing-body interference. A rectangular wing, a triangular wing, and a cylindrical body with an ogive nose were studied alone and in combination. The pressure distributions over the wing-body combination compared favorably with theoretical calculations based primarily on a generalization of the method of Nielsen and Matteson, except at the root section of the wings where the boundary layer of the body modified the flow.

Report presenting a wing-body combination with a plane triangular wing of aspect ratio 2 with NACA 0005-63 thickness distribution in streamwise planes, which has been twisted and cambered for a trapezoidal span load distribution at subsonic and supersonic Mach numbers.

A wing-body combination having a plane triangular wing of aspect ratio 2 with NACA 0005-63 thickness distribution in streamwise planes, and twisted and cambered for a trapezoidal span load distribution has been investigated at both subsonic and supersonic Mach numbers. The lift, drag, and pitching moment of the model are presented for Mach numbers from 0.60 to 0.90 and 1.30 to 1.70 at a Reynolds number of 3.0 million. The variations of the characteristics with Reynolds number are also shown for several Mach numbers.

From Introduction: "Presented in this paper are the results of an investigation of a semispan model of a delta wing with 60^o sweepback at the leading edge which was equipped with a large triangular control having an overhang balance mounted on a skewed hinge axis. The purpose of this investigation was to determine the aerodynamic characteristics of a delta wing with a control which was designed to provide aerodynamic balance at zero control deflection based on the span load distribution of reference 1."

From Introduction: "The wings were tested in combination with fuselage similar to the one used in the 7- by 10-foot wind-tunnel investigations. The results are reported herein and are compared with results for three similar model wings on the transonic bump (references 1, 2, and 3)."

Report presenting a direct-connect altitude test chamber investigation of the combustion performance of a 28-inch-diameter ramjet engine with a can-type center pilot burner. Combustion-chamber configurations with three different flame holders were investigated at a simulated flight Mach number of 2.0 and several different altitudes.

Report presenting an investigation in the 20-foot free-spinning tunnel to determine the motions and trim conditions from 0 to 90 degrees angle of attack for the X-3 airplane, which is a supersonic airplane with an extremely long nose and s mall wing. Testing was conducted on several scales of models and component parts. Results from dynamic and static tests are provided.

"This report summarizes the effects of fuel volatility and engine design variables on the problem of starting gas-turbine engines at sea-level and altitude conditions. The starting operation for engines with tubular combustors is considered as three steps; namely, (1) ignition of a fuel-air mixture in the combustor, (2) propagation of flame through cross-fire tubes to all combustors, and (3) acceleration of the engine from windmilling or starting speed to the operating speed range. Pertinent data from laboratory researches, single-combustor studies, and full-scale engine investigations are presented on each phase of the starting problem" (p. 1).

Report presenting a wind-tunnel investigation to determine the effects of a section modification on the aerodynamic characteristics of a wing with 35 degrees of sweepback. The wing was modified by increasing the leading-edge radius of the NACA 64A010 section and adding a small amount of camber to the forward portion of the chord. Lift, drag, pitching-moment, and trailing-edge-flap hinge-moment characteristics of the modified wing are compared with results from the original wing.

Memorandum presenting the effects of specimen-axis orientation with respect to forging direction on the true stress-strain curves and the fracturing characteristics at room temperature of forged and subsequently heat-treated billets of alloys 16-25-6, S-816, and Inconel X. Results regarding plastic properties and fracture properties are provided.

Memorandum presenting an investigation conducted in the Lewis 8- by 6-foot supersonic wind tunnel to determine the force and pressure characteristics of an all-external compression inlet with a conical spike and a supersonic cowl lip. Measurements of lift, drag, pitching moment, and internal and external pressures were made at free-stream Mach numbers of 1.59, 1.79, and 1.99 for a range of mass-flow ratios and angles of attack to 10 degrees.

"At the request of the Bureau of Aeronautics, Department of the Navy, an investigation of the Westinghouse XJ34-WE-32 turbojet engine is being conducted in the NACA Lewis altitude wind tunnel to determine the steady-state and transient operating characteristics of the controlled and uncontrolled engine at various altitudes and ram pressure ratios. As part of this program, transient performance data that illustrate the operation of the engine is obtained in the form of oscillographic traces. Similar data for engine operation in the afterburning range, covering a range of throttle settings from the minimum value giving rated speed (throttle position, 72 degrees) to full afterburning (throttle position, 110 degrees), is presented herein" (p. 1).

Memorandum presenting a study using a suspended flat plate to continuously vary the Mach number in the 18- by 18-inch Mach number 1.91 supersonic tunnel. The technique was applied to the determination of pressure recovery and mass-flow characteristics of four supersonic nose inlets over the Mach number range produced. Results regarding the plate calibration and inlet performance are provided.

Report presenting a flight investigation of a ground-launched supersonic twin ram-jet test vehicle using short flame-length burners. Results were obtained for a range of Mach numbers, altitudes, and fuel-air-ratios. Engine performance, gross thrust, fuel rate, total impulse, values of combustion efficiency and impulse, and overall combustion efficiency are also included.