Memorandum presenting an investigation in natural icing conditions to determine the effect of ice formations on the performance of an axial-flow turbojet engine. A description of the change over time in tail-pipe temperature, engine jet thrust, fuel flow, ice collection, and acceleration qualities are provided.

Report presenting tests to investigate the use of a simple centering spring, which had no variation of force gradient with impact pressure, as an artificial feel device for the elevator control of a fighter airplane. Testing was conducted using a Chance Vought F4U-4B airplane equipped with power controls. Results regarding the force experienced and effects of the feel system are provided.

The flow fields near a 45 degree swept-wing-fuselage combination at moderate angles of sideslip (plus-or-minus 8 degrees), as determined experimentally at low speed, are presented as variations with chordwise distance for various spanwise and vertical locations and angles of attack. The results indicated that for positions close to the fuselage (on and near the plane of symmetry) changes in the angle of sideslip caused large changes in the flow-field characteristics and particularly in the local angles of sideslip, which in some cases were nearly double the static angle of sideslip.

Memorandum presenting wind-tunnel tests that have been made to determine the aerodynamic characteristics of a model tail plane with modified NACA 65-010 sections and a tapered plan form. Results were obtained with the model tail plane unswept and swept back. The data show the lift, drag, pitching-moment, and hinge-moment coefficient variation with angle of attack and flap deflection at various Mach numbers.

Report presenting an investigation of the lateral stability and control effectiveness of a model of a fighter-type airplane model with a low-aspect-ratio and 3.4-percent-thick wing with negative dihedral at a range of Mach numbers, sideslip angles, and angles of attack. Results regarding the lateral characteristics at zero angle of attack, lifting conditions, and lateral and directional controls are provided.

Report presenting an investigation of water landings in the impact basin with a model with a flat rectangular planing surface, a pulled-up bow, and a simulated landing wheel. Runs were made at several wave conditions, trim ranges, flight-path angles, and beam loadings. The results were found to be applicable in predicting loads and motions exhibited by a flat rectangular ski during impact with a water surface.

Report presenting data showing the effect of a jet on base pressure for a series of conical afterbody-jet-nozzle combinations with a range of boattail angles and base-to-jet diameter ratios. Generally, base pressure increased for increasing values of boattail angle, nozzle angle, jet temperature, and jet total pressure and for decreasing values of base-to-jet diameter ratio, jet Mach number, and free-stream Mach number.

Report presenting an investigation to determine the effect of several chord-extension configurations at low speed on a variable-sweep airplane model with a partially cambered wing. Testing occurred at a designated Reynolds number based on the mean aerodynamic chord of the wing at 50 degrees sweep for average test conditions. Results regarding the effect of chord extensions at 50 degrees, 60 degrees, and 20 degrees sweep, effect of chord extensions on lateral stability, and a comparison with different wing modifications are provided.

"The performance of a 24C-4 combustor was investigated with three different combustor baskets and five modifications of these baskets at conditions simulating static (zero-ram) operation of the 24C jet engine over ranges of altitude and engine speed to determine and improve the altitude operational limits of the 24C combustor. Information was also obtained regarding combustion characteristics, the fuel-flow characteristics of the fuel manifolds, and the combustor total-pressure drop. NACA modifications, which consisted of blocking rows of holes on the baskets, increased the minimum point on the altitude-operational-limit curve, which occurs at low engine speeds, for a narrow-upstream-end basket by 8000 feet (from 23, 000 to 31,000 ft) and for a wide-upstream-end basket by 21,000 feet (from 12, 000 to 34,000 ft)" (p. 1).

Report presenting zero-lift drag data for a flare-stabilized bluff body of fineness ratio 4.4 alone and with conical and flat windshields at a range of Mach and Reynolds numbers. The model with the flat windshield was found to have the lowest drag at Mach numbers up to 1.05, but there was little difference in drag among the models above 1.05.

Report presenting the longitudinal stability characteristics of a simple infrared homing missile determined in flight with a rocket-powered model. Static and dynamic longitudinal stability derivatives of the cruciform, interdigitated, canard-wing missile configuration were determined using the pulse-rocket technique for a range of Mach numbers.

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 the methods and instruments used at a particular lab to illustrate the magnitudes of errors associated with Mach number measurements at supersonic speeds and at high altitudes. Data is presented for two modified methods of the basic radar phototheodolite method of position-error calibration.

"An investigation at medium to high subsonic speeds has been conducted in the Langley low-turbulence pressure tunnel to determine the static stability and control characteristics and to measure the fin normal forces and moments for a model of a wingless fin-controlled missile. With the horizontal-fin deflection limited to a maximum of 6 degrees, longitudinally stable and trimmed flight could not be maintained beyond an angle of attack of 17 degrees for a Mach number of 0.88 and beyond 20 degrees for a Mach number of 0.50 for any center-of-gravity location without the use of some auxiliary stability or control device such as jet vanes" (p. 1).

Report presenting an investigation at subsonic and transonic speeds of the aerodynamic characteristics of a wing-body configuration designated as a swept biplane, which is composed of a sweptback and sweptforward wing joined at the tips. Results indicate that the plan form prevents the abrupt pitch-up normally encountered on monoplane swept wings. Results regarding subsonic tests, transonic tests, and some additional design considerations are provided.

Report presenting measurements of chordwise pressure distribution over the 10-percent-thick wing of the X-1 research airplane at a section near the midspan of the left wing. Results regarding the upper- and lower-surface pressure distributions at a range of Mach numbers and section loads are provided.

Paper presenting a preliminary account of some research conducted on the general problem of flow separation. The research is fundamental in nature, partly theoretical, and partly experimental. Measurements are made of subsonic and supersonic speeds for a variety of two dimensional model shapes involving separation.

Report presenting a temperature survey for two bodies with wings swept 39 and 75 degrees for an angle of attack of 7 degrees, Mach numbers up to 4.86, and a designated Reynolds number. Effects of wing-body interference on heating and the difference in heating on windward and leeward sides at a designated angle of attack are explored. Pressure coefficients are also presented for two different stations on the body.

Report presenting an investigation of wings of aspect ratios of 4, 3, and 2 with a plan-form taper ratio of 0.5 and a thickness taper ratio of 0.33 to determine their transonic longitudinal characteristics and effects of tapering thickness ratio. Results regarding the combined effects of aspect ratio and thickness ratio and effects of tapered thickness ratio are provided.

Report presenting an investigation in the flutter research tunnel to determine the oscillating forces and moments on a two-dimensional wing equipped with an oscillating circular-arc spoiler. The study indicated that force and moment coefficients and their phase angles are affected by Reynolds number, Mach number, and reduced frequency.

Low cowl drag, external compression inlet with subsonic dump diffuser for high Mach number application.

Report presenting an investigation of a zero-cowl-drag, all-external-compression inlet with an abrupt area discontinuity or subsonic dump diffuser for high Mach number application. Results regarding the diffuser performance characteristics, effect of spike retraction, a comparison with other inlets, and some theoretical calculations related to the results are provided.

Experimental side and blade pressure distributions over a series of conical boattails without and with jet flow from the base are presented at a Mach number of 1.91. For the case of no jet flow the methods of characteristics and linearized theory are shown to overpredict the side pressure drag. A semi-empirical theory is presented to predict the effect of boattail angle on base pressure. With the boattail extending to a sharp edge at the nozzle exit, the over-pressure jet is shown to decrease the side pressure drag. Presence of an annular base may eliminate the effect of the jet on the side pressure drag, but the jet effect on the base pressure drag may greatly increase or decrease the total boattail drag.

Memorandum presenting an investigation in the 7- by 10-foot tunnel to determine the effect of wing-root leading-edge and scoop-type jet-engine air-inlet configurations on the static longitudinal stability characteristics and the duct-flow characteristics of a scale model of the MX-1764 airplane. The addition of the inlet configurations to the model generally resulted in slight reductions in longitudinal stability and increases of maximum lift coefficient.