Preliminary results at high speeds indicate lower bearing temperatures, less internal bearing wear, and greater reliability of the conventional, cage-type cylindrical roller bearings than of either full-complement or special cageless roller bearings of the types investigated, although the latter bearing types have been operated successfully to DN values of 1.0 X 10 superscript 6.

Report presenting an investigation at a Mach number of 1.61 to determine the control effectiveness characteristics of seven tip controls on a 60 degree delta wing. Pressure distribution measurements were made for a range of angles of attack and control deflections. Results regarding the effect of control deflection, effect of wing angle of attack, effect of hinge-line location, effect of fences, and effect of control size and location are provided.

From Summary: "The loitering and range performance of airplanes equipped with several different turbojet engines was analytically investigated by applying the results of off-design cycle analyses to specific airplane characteristics. The method of off-design cycle analysis is presented herein and is verified by a check with experimental data. For all engines considered, the loitering and the range fuel flows obtained with rated tail-pipe nozzle area, variable engine speed operations were within 2 or 3 percent of the optimum fuel flow obtainable with any method of engines operation. The optimum loitering altitude generally occurred between approximately 25,000 and 35,000 feet with corresponding optimum flight Mach numbers of 0.4 to 0.65. In general, the optimum range fuel flows occurred at 3000 to 5000 feet higher altitude and at approximately 0.15 higher flight Mach numbers than the optimum loitering fuel flow."

"The explosion limits of five alkylsilanes were determined as a function of temperature and composition at a pressure of 1 atmosphere. Over a fuel concentration range of 2 to 10 percent, the lowest temperatures (zero C) below which explosion did not occur for the five fuels studied were: tetramethylsilane (CHsub3)sub4Si, 450 degrees; trimethlysilane (CHsub3)sub3SiH, 310 degrees;dimethylsilane (CHsub3)sub2SiHsub2, 220 degrees; methylsilane CHsub3SiHsub3, 130 degrees; and vinylsilane Hsub2C=CH-SiHsub3, 90 degrees. Explosion limits for hydrocarbons analogous to these silanes fall in a temperature range of 500 degrees to 600 degrees C" (p. 1).

Report presenting an investigation in the 16-foot transonic tunnel to determine the effects of leading-edge slats on the aerodynamic and longitudinal stability characteristics of a model of a swept-wing fighter-type airplane. Two different spanwise extents of leading-edge slats were tested, from 35 to 95 percent semispan and from 46 to 95 percent semispan. Results regarding the lift characteristics, drag characteristics and lift-drag ratios, stability characteristics, and flow-study pictures are provided.

Report presenting load measurements using the swept-wing Bell X-5 and Douglas D-558-II research airplanes during flights in which reductions of longitudinal stability were experienced when pilots attempted to perform routine test maneuvers at moderate values of lift. Results regarding the maximum angles of attack and sideslip measured, pitching accelerations, horizontal-tail loads, wing loads, and stability deficiencies are provided.

Memorandum compiling summaries from NACA reports on fuel that were published between July 1945 and 1952. The summaries are intended to be detailed enough to eliminate the need to obtain the complete report.

Report presenting an investigation of a model of the Douglas X-3 to determine some methods to improve the low-speed longitudinal stability and control characteristics. Some of the components tested included plain and slotted leading-edge flaps and plain, split, and slotted trailing-edge flaps. Results regarding the effect of various factors on longitudinal stability and flap characteristics are presented.

Report presenting an investigation in the full-scale tunnel to determine the effects of a Fowler type slotted flap on the aerodynamic characteristics of a semispan 49.1 degree sweptback wing with NACA 65A006 airfoil sections streamwise, an aspect ratio of 3.78, and a taper ratio of 0.59. Results regarding the pitching-moment curve, effect of flap deflection, and lift increments are provided.

"During the course of an investigation by the Langley Pilotless Aircraft Research Division regarding the effectiveness of spoilers and ailerons on sweptback tapered wings, it was necessary to test a given control configuration on wings of varying degrees of stiffness. In the process of conducting these tests, repeated wing failure was experienced with the weaker wing-spoiler configurations, whereas no failure occurred with any of the wing-aileron models. An investigation which was conducted by means of rocket-propelled test vehicles in free flight showed that the cause of the repeated failures was flutter of the bending-torsion type" (p. 1).

Report presenting a transonic investigation made by the free-fall technique of a plane wing and a cambered and twisted wing, each with an aspect ratio 6, taper ratio of 0.5, and a sweepback of 45 degrees. Measurements were made of the loads on the exposed wings, pressures on the fuselage in the vicinity of the wing, and acceleration and angle of attack of the complete model.

"The over-all performance of a 16-stage axial-flow compressor was determined with various stator-blade resettings and a reduction in solidity of the rotor blades in the last three stages. It was shown that little control over the sudden change in slope of the surge-limit line at intermediate speeds was obtained with the blade modifications attempted, except that some change in speed at which the change in slope occurred could be effected by stator-blade resettings" (p. 1).

Report presenting an investigation to determine the effects of horizontal-tail location and plan form on the longitudinal stability and control characteristics of a fuselage and thin delta wing with extended double slotted flaps. Several configurations of the aircraft, including flaps with the tail off, extended double slotted flaps, and canard with extended double slotted flap and delta tail are explored.

Report presenting zero-lift drag data obtained on a series of eight fin-stabilized bodies with noses of fineness ratio 3 and differing nose shape by launching them from a helium gun. The nose shapes explored included a cone, x exp(3/4), x exp(1/2), parabolic, (3/4)P, (1/2)P, L-V Haack, and Von Karman. The results are compared with theoretical calculations and wind-tunnel measurements.

"An investigation of the effect on transonic and supersonic drag of a fuselage protuberance designed to improve the overall longitudinal distribution of cross-sectional area of an essentially unswept wing-fuselage combination has been made with free-flight rocket models. The wing-fuselage configuration was tested with and without a fuselage protuberance designed to relieve the steep area gradient over the rear portion of the wing" (p. 1).

Report of an investigation to determine the effects of inboard plan-form modifications on two unswept wings at Mach numbers 1.61 and 2.01. The only difference between the two wings was the spanwise thickness distribution. The modifications were performed by means of inserting sections that linearly extended the local chord from the 40 percent semispan station to the model center line.

Report presenting an investigation of a reduced-chord multistage turbine at design speed and various turbine-inlet pressures from 12 to 40 inches of mercury absolute. At each inlet pressure, the turbine was operated over a range of overall turbine total-pressure ratios; turbine-inlet temperature was maintained at 700 degrees R. The results indicated that no appreciable effect on turbine overall performance was observed over the range of turbine-inlet total pressures investigated.

Report presenting an investigation on a full-scale afterburner test rig and two turbojet-engine afterburner configurations to determine criteria for the design of fuel systems for afterburners. The effect of fuel-air ratio distributions at the flame holder on combustion performance was obtained along with the effects of variation in design variables on the ratio distributions.

An analysis is made of the factors affecting the weight-flow rate per unit frontal area of centrifugal compressors with axial-flow vaned diffusers preceded by mixed-flow vaneless sections. It is shown that, for specified inlet conditions to the impeller and vaned diffuser, the weight-flow rate is increased at the expense of pressure ratio and vice versa. Charts are presented to help the designer make a satisfactory compromise between weight-flow rate and pressure ratio. Some conclusions of the investigation are : (1) Prewhirl is of negligible value in centrifugal compressors designed for high weight-flow rates.

Report presenting an experimental investigation performed to determine the effect on base and forebody pressures of using a sting modified with varying length splitter plates and fins instead of a conventional sting to support a cone-cylinder body of revolution.

Report presenting an investigation to evaluate the effects of nacelles and extended split flaps on the longitudinal characteristics of a wing-fuselage-tail combination of a type believed to be suitable for long-range high-speed airplanes. Wind tunnel tests to study the effects of the nacelles and flaps were conducted at a range of Mach and Reynolds numbers. Results regarding the effects of the nacelles with the tail off, effects of tail height, effects of nacelles with the tail on, and effects of flaps are provided.

From Introduction: "The airfoil sections tested, which differ only in thickness ratio, were the NACA 64-006, 64-008, 64-010, and 641-012. Lift, drag, and pitching-moment data were obtained for Mach numbers of 0.3 to that for tunnel choke at angles of attack of -2^o to 31^o. The results of this investigation are reported herein."

From Introduction: "The investigation is discussed in the present report is an analysis of the turbojet engine as the power plant for bombers capable of supersonic flight speeds. A similar analysis, in which the turbojet engine is considered for the propulsion of supersonic fighter aircraft, is presented in reference 1. Two plans are considered in this report."

From Introduction: "The ram-jet missile studied in the present report is one type of shieldless which has the advantage of employing the simplest type of propulsion system."