"Because the results of preliminary flight tests had indicated the P-63A-1 airplane possessed insufficient directional stability, the NACA and the manufacturer (Bell Aircraft Corporation) suggested three vertical-tail modifications to remedy the deficiencies in the directional characteristics. These modifications included an enlarged vertical tail formed by adding a tip extension to the original vertical tail, a large sharp-edge ventral fin, and a small dorsal fin. The enlarged vertical tail involved only a slight increase in total vertical-tail area from 23.73 to 26.58 square feet but a relatively much larger increase in geometric aspect ratio from 1.24 to 1.73 based on height and area above the horizontal tail" (p. 1).

"An investigation was conducted to correlate the engine service performance of cast Vitallium turbine buckets with standard laboratory metallurgical data. Data were obtained from four I-40 turbine wheels of Timken alloy with cast Vitallium buckets. In order to accelerate bucket deterioration, the turbine wheels were subjected to 20-minute cycles consisting of 5 minutes at idle and 15 minutes at rated speed" (p. 1).

Report discussing testing to determine the drag characteristics at zero lift of a wing with a circular-arc airfoil section with a maximum thickness of 9 percent chord. The results were compared to previous testing on an NACA 65-009 airfoil. It was found that the NACA airfoil had lower drag coefficients than the circular-arc airfoil tested in this experiment.

Report presenting the results of flight tests conducted to determine the effect of number of fins on the drag of a pointed body moving at low supersonic velocities. The data indicated that the interference drag increased with increased number of ins up to a Mach number of 1.35, but above that value, the effect is reversed to the end of the test Mach number.

Powered models of three different flying boats were landed in oncoming wave of various heights and lengths. The resulting motions and acceleration were recorded to survey the effects of varying the trim at landing, the deceleration after landing, and the size of the waves. One of the models had an unusually long afterbody. The data for landing with normal rates of deceleration indicated that the most severe motions and accelerations were likely to occur at some period of the landing run subsequent to the initial impact.

Report presenting a test-stand investigation conducted on a rectangular ramjet engine design for installation in an aircraft wing. The engine operated without excessive engine noise or vibration over the entire range of operating conditions. Results regarding inlet velocity, exhaust flame characteristics, fuel-air ratio, and total-temperature rise are provided.

Characteristics of NACA submerged duct entries and wing leading-edge inlets designed for a 1/4 scale flow model of a fighter-type airplane powered by a jet engine in the fuselage are presented.

An investigation is in progress at the Langley Laboratory of the NACA to explore the possibilities of axial-flow compressors operating with supersonic velocities relative to the blade rows. The first phase of this investigation, a study of supersonic diffusers, has been reported. The second phase, an analysis of supersonic compressors, has also been reported. Preliminary calculations have shown that very high pressure ratios across a stage, together with somewhat increased mass flows, are possible with compressors which decelerate air through the speed of sound in their rotor blading. These performance characteristics are desirable in compressors for aircraft jet propulsion units, gas turbines, or superchargers. The third phase, presented here, is a preliminary experimental investigation of a supersonic compressor designed to produce a high pressure ratio in a single stage.

"Efficiency investigations have been made on a single-stage modification of the turbine of a Mark 25 aerial torpedo to determine the performance of the unit with five different turbine nozzles. The output of the turbine blades was computed by analyzing the windage and mechanical-friction losses of the unit. The turbine was found to be most efficient with a cast nozzle having sharp-edged inlets to the nine nozzle ports" (p. 1).

Testing was conducting to evaluate the effects of support interference on the drag characteristics of two bodies of revolution at zero angle of attack at Mach number 1.5. Drag and base-pressure measurements are made for a variety of Reynolds numbers to determine the effect of varying the length or diameter of the rear support.

Report presenting an investigation of combustion occurring downstream of various turbulence promoters in a 20-inch length of a 1 7/8-inch inside-diameter, water-jacketed tubing using premixed vaporized fuel and air. Among the turbulence promoters investigated were flat plates perforated with 1/8-inch diameter holes, 1/4-inch diameter holes, and a single large hole to give 12.4, 17.2, and 21.5 percent open area respectively.

Report presenting a general analysis that allows the rolling motions of an aircraft using a displacement-response, flicker-type automatic pilot to be determined. The system is not ideal for many stabilization problems due to inherent residual oscillations, but it offers a simple and economical solution in situations in which steady state oscillations are not a problem. Results regarding some general remarks, transient and steady states, stabilization boundaries, amplitude equations, and period equations are provided.

Report presenting an investigation at transonic speeds in the high speed tunnel to determine the rolling-effectiveness characteristics of several aileron arrangements for use on a 42 degree sweptback wing. Results regarding the rolling-moment coefficients, variation of coefficient with Mach number, outboard cusp aileron, and use of the leading-edge flaps are provided.

"Results of an investigation by the free-fall method are presented herein for a configuration having a body of revolution of fineness ratio 12 and 45 degrees sweptback wing mounted aft of the maximum diameter of the body. The fillets were designed to provide large increases in the sweep of the leading edge and the line of maximum thickness as the wing root was approached. Comparison of these results with those for the same configuration without fillets shows that the addition of wing fillets increased the total drag of the configuration by about 35 percent at Mach numbers near 1.0 and about 15 percent at Mach numbers near 1.2" (p. 1).

Report presenting a comparison of the performance of a German Jumo 004 can-type combustor and the performance of two contemporary United States turbojet combustors to determine whether the Jumo 004 was more advanced and to determine whether there are basic, inherent differences in the performance achieved with the can or annular combustor type. Results regarding altitude operational limits, combustion efficiency, pressure loss, and temperature profile at combustor outlet are provided.

Given here are results of tests made in calm water at various landing attitudes, speeds, and simulated conditions of damage. It was concluded that the best ditching could be made by contacting the water as near the stall angle as possible without losing adequate control. The landing flaps should be full down. If the paratainer hatch and aft-cargo doors fail as expected in a ditching, there will be a large inrush of water into the cargo compartment which makes this location a very hazardous ditching station. The airplane will settle in the water rapidly to the level of the wings with only gradual changes in attitude. The maximum longitudinal deceleration will be between 1.2g and 1.7g in a calm-water ditching.

Memorandum presenting preliminary tests in order to determine the effect of forced ventilation on the hydrodynamic characteristics of a scale model of a streamline fuselage of a hypothetical transonic airplane. The forced ventilation consisted of air ejected at about 300 feet per second through small orifices distributed over the fuselage bottom in a series of patterns simulating chines or multiple steps. Results regarding resistance, effective hydrodynamic lift, trim, spray, and air flow are provided.

Memorandum presenting stability and control data from the X-4 airplane during the Northrop conducted acceptance tests. The data were obtained for a center-of-gravity position of about 22 percent of the mean aerodynamic chord. Results of the flight indicated that the airplane is slightly unstable, stick fixed, in gear-up, flaps-up configuration for a center-of-gravity position at 21.4 percent of the mean aerodynamic chord.

The use of ceramic material for rocket nozzles and the effectiveness of preventing oxidation and erosion of graphite nozzles by chrome-plating the internal surface were investigated. A supported ceramic nozzle, cracked by initial operation, was operated a second time without further cracking or damage. Chrome-plating the internal surface of graphite nozzles effectively prevented oxidation and erosion that occurred during operation with unprotected graphite.

Report presenting an investigation of the pressure distribution over a leading-edge flap in the 19-foot pressure tunnel. Testing occurred on 42 degree and 52 degree sweptback wings of NACA 64(sub 1)-112 sections, with the 42 degree wing being used in conjunction with a circular cross-section fuselage in a high-wing combination.

Report presenting a flight investigation to determine the comparative performance of AN-F-58 and AN-F-32 fuels in a 4000-pound-thrust turbojet engine. The fuels were equivalent over the range of conditions investigated. Results regarding corrected net thrust, corrected jet-fuel consumption, variation of corrected tail-pipe temperature, combustor blow-out speeds, and visual observations of the jet exhaust are provided.

Report presenting the results of a preliminary investigation of a scale model of a convertible-type airplane in the full-scale tunnel. The maximum lift and stalling characteristics of several configurations, the longitudinal stability characteristics, and the effectiveness of the control surfaces with the propellers removed are provided. Results regarding the propulsive characteristics, and effect of propeller operation on the lift and static thrust of the model propellers are also provided.

Report presenting a wind-tunnel investigation through a speed range from Mach number 0.30 to 0.90 to determine the lateral-control characteristics of a 20-percent-chord by 39-percent-semispan aileron and a 60-percent-semispan stepped spoilers on a semispan-wing model with aspect ratio of 3.06 with 51.3 degrees sweepback of the wing leading edge. The aileron rolling effectiveness decreased as the Mach number increased, while the spoiler rolling-moment effectiveness decreased with Mach number.

From Summary: "Results of wind-tunnel tests are presented for a wing with the leading edge swept back 63^o and of symmetrical section in combination with a body at Mach numbers from 0.5 to 0.95 and from 1.09 to 1.51."