The effect of fuel volatility on altitude starting limits of an axial-flow-compressor-type turbojet engine was investigated using fuels with Reid vapor pressures of 1.1 and 5.4 pounds per square inch. At flight Mach numbers from 0.40 to 0.85, the AN-F-58 fuel allowed consistent windmilling at altitudes 2000 to 8000 feet higher than was obtained with the 1.1-pound Reid vapor pressure fuel. At a flight Mach number of 0.25, ignition could not be established at any altitude with the lower-volatility fuel.

An analog investigation of the power plant for a gas-turbine powered helicopter indicates that currently proposed turbine-propeller engine controls are satisfactory for helicopter application. Power increases from one-half to full rated at altitudes from sea level to 15,000 feet could be made in less than 4 seconds with either the rotor or propellers absorbing the engine power.

Report presenting an investigation in the low-turbulence pressure tunnel at Mach number 1.2 to determine lift, drag, and moment characteristics of a wing with an airfoil section designed for maximum lift at low speeds, 45 degrees of sweepback, aspect ratio 4, and taper ratio 0.6. A similar wing with the NACA 65A006 airfoil section was also investigated and compared to the experimental wing.

Report presenting results from a preliminary flight investigation on a swept-wing airplane of the lateral-control characteristics and wing-dropping tendency encountered at high Mach numbers. Measurements of aileron and rudder-control effectiveness are presented and used with estimated damping-in-roll characteristics and data from steady sideslips to approximate the variation of effective dihedral with Mach number.

Report presenting an investigation on a supersonic scoop inlet derived from a conical spike nose inlet at Mach numbers of 1.3, 1.6, and 1.9. The pressure recoveries of both inlets were similar. Results regarding the pressure drag, amounts of boundary-layer suction, and comparison of the inlets under several conditions are provided.

"A metallographic microscope was developed with provision for heating a specimen to 1800 F in protective atmospheres, that is, vacuum or gas. A special objective was constructed of reflecting elements with an unusually long working distance (7/16 in.) and a high numerical aperture (0.5). Changes in specimen microstructure were observed and recorded on 35-millimeter motion-picture film. The resulting pictures were projected as motion pictures and individual frames were cut and enlargements made for close observation" (p. 1).

"The high-speed photographic investigation of the mechanics of spark-ignition engine knock recorded in three previous reports has been extended with use of the NACA high-speed camera and combustion apparatus with a piezoelectric pressure pickup in the combustion chamber. The motion pictures of knocking combustion were taken at the rate of 40,000 frames per second. Existence of the preknock vibrations in the engine cylinder suggested in Technical Report no.727 has been definitely proved and the vibrations have been analyzed both in the high-speed motion pictures and the pressure traces" (p. 223).

Report presenting the application of the external-compression principle to a cascade of blades in an attempt to achieve a closer approach to isentropic contraction ratios in supersonic compressor blading. Tests of a rotor designed to incorporate the external-compression principle are provided. Results regarding overall performance, performance at design speed and peak efficiency, off-design performance, and some considerations for future designs are provided.

In connection with the general problem of providing air flow to an aircraft power plant located within a fuselage, an investigation was conducted in the Langley 8-foot high-speed tunnel to determine the effect on external drag and pressure distribution of air inlet openings located at the nose of a streamline body. Air outlet openings located at the tail and at the 21-percent and 63-percent stations of the body were also investigated. Boundary layer transition measurements were made and correlated with the force and the pressure data. Individual openings were investigated with the aid of a blower and then practicable combinations of inlet and outlet openings were tested. Various modifications to the internal duct shape near the inlet opening and the aerodynamic effects of a simulated gun in the duct were also studied. The results of the tests suggested that outlet openings should be designed so that the static pressure of the internal flow at the outlet would be the same as the static pressure of the external flow in the vicinity of the opening.

Report presenting a wind-tunnel investigation at low speed to determine the effects of sideslip on the static longitudinal trim characteristics of three fighter-type airplane models. The three models consisted of a 45 degree swept-wing model with a horizontal tail geometrically similar to the wing and mounted slightly below the wing, a clipped-delta-wing model with a horizontal tail mounted in a moderately high position, and a 60 degree delta-wing with no horizontal tail. Results regarding static longitudinal stability, variation of pitching-moment coefficient with sideslip, effect of modifications to Model B on static longitudinal stability and variation of pitching-moment coefficient with sideslip, and static lateral stability are presented.

Report presenting an investigation made in the 7- by 10-foot tunnel of the static lateral and directional stability and some tail-load characteristics of a model with a highly tapered swept wing and two horizontal-tail positions. Testing were made with the horizontal tail located at the tip of the swept vertical tail and with the horizontal tail located in the wing-chord plane extended. Results regarding static lateral and directional stability and vertical-tail loads are provided.

From Introduction: "The primary purpose of the wing instrumentation was to obtain data for use in design of NACA research missiles; however, it is believed that the wing is representative of typical supersonic designs and that the data will be of general use and interest. Only the wing data are reported herein."

From Summary: "An analysis is given of the oscillating motion of a ballistic missile which upon entering the atmosphere is angularly misaligned with respect to the flight path. The history of the motion for some example missiles is discussed from the point of view of the effect of the motion on the aerodynamic heating and loading. The miss distance at the target due to misalignment and to small accidental trim angles is treated. The stability problem is also discussed for the case where the missile is tumbling prior to atmospheric entry."

"The static longitudinal stability characteristics of a 0.15-scale model of the Hermes A-lE2 missile have been determined in the Langley high-speed 7- by 10-foot tunnel over a Mach number range of 0.50 to 0.98, corresponding to Reynolds numbers, based on body length, of 12.3 x 10(exp 6) to 17.1 x 10(exp 6). This paper presents results obtained with body alone and body-fins combinations at 0 degrees (one set of fins vertical and the other set horizontal) and 45 degree angle of roll. The results indicate that the addition of the fins to the body insures static longitudinal stability and provides essentially linear variations of the lift and pitching moment at small angles of attack throughout the Mach number range" (p. 1).

Report presenting an investigation in the transonic tunnel to determine the characteristics of several flap-type spoiler ailerons, lower-surface deflector ailerons, and spoiler-slot-deflector ailerons. Six-component force and moment data were obtained at a range of Mach numbers and angles of attack.

"An investigation of the combustion of gasoline, safety, and diesel fuels was made in the NACA combustion apparatus under conditions of temperature that permitted ignition by spark with direct fuel injection, in spite of the compression ratio of 12.7 employed. The influence of such variables as injection advance angle, jacket temperature, engine speed, and spark position was studied. The most pronounced effect was that an increase in the injection advance angle (beyond a certain minimum value) caused a decrease in the extent and rate of combustion. In almost all cases combustion improved with increased temperature" (p. 125).

"This report presents the results of an investigation to determine the coefficients of discharge of nozzles with small, round orifices of the size used with high-speed compression-ignition engines. The injection pressures and chamber back pressures employed were comparable to those existing in compression-ignition engines during injection. The construction of the nozzles was varied to determine the effect of the nozzle design on the coefficient. Tests were also made with nozzles assembled in an automatic injection valve, both with a plain and with a helically grooved stem" (p. 193).

From Summary: "Signal Corps wind equipment AN/GMQ-1 consisting of a 3-cup anemometer and wind vane was calibrated for wind velocities from 1 to 200 miles per hour. Cup-shaft failure prevented calibration at higher wind velocities. The action of the wind vane was checked and found to have very poor directional accuracy below a velocity of 8 miles per hour. After shaft failure was reported to the Signal Corps, the cup rotors were redesigned by strengthening the shafts for better operation at high velocities. The anemometer with the redesigned cup rotors was recalibrated, but cup-shaft failure occurred again at a wind velocity of approximately 220 miles per hour."