Memorandum presenting the static lateral-directional stability characteristics of several airplane models recently investigated which cover many of the geometric arrangements of high-speed airplane components of current interest. The results are limited to the most pertinent aerodynamic phenomena contributing to the lateral-directional characteristics of each airplane type. Results for five different models are provided.

Report presenting an investigation to determine the aerodynamic characteristics in pitch at a Mach number of 6.8 of hypersonic missile configurations with cruciform trailing-edge flaps and all-movable control surfaces. Testing indicated that all-movable controls on the flared-afterbody model should be capable of producing much larger values of trim lift and of normal acceleration than the trailing-edge-flap configuration. Some of the configurations tested include body alone, body with 5 degree fins and trailing-edge flaps, and body with 10 degree flare and all-movable controls.

Report discussing an experimental investigation to determine the aerodynamic characteristics of the Army Chemical Corps model E112 bomblets. From Summary: "A detailed analysis has not been made; however, the results showed that a gap between model tips and the end plates or increasing the end-plate size for a solid model could result in a spirally stable configuration." A large amount of data collected from testing and photographs of the model are provided.

Report presenting an investigation of a model of the Republic F-105 airplane to determine the static longitudinal aerodynamic characteristics of a revised configuration. The revisions included a lengthened fuselage, a relocated canopy, a contoured fuselage afterbody, a ventral fin, and an enlarged vertical tail. Results regarding the effect of stores, effect of dive-brake flaps, effect of forebody modifications, gun blisters, and duct air bleed, and a comparison of the modified model with the original are provided.

"An investigation was conducted in the NACA Lewis icing research tunnel to determine the characteristics and requirements of cyclic deicing of a 65,2-216 airfoil by use of an external electric heater. The present investigation was limited to an airspeed of 175 miles per hour. Data are presented to show the effects of variations in heat-on and heat-off periods, ambient air temperature, liquid-water content, angle of attack, and. heating distribution on the requirements for cyclic deicing" (p. 1).

The problem of determining the two dimensional potential flow around wing sections of any shape is examined. The problem is condensed into the compact form of an integral equation capable of yielding numerical solutions by a direct process. An attempt is made to analyze and coordinate the results of earlier studies relating to properties of wing sections. The existing approximate theory of thin wing sections and the Joukowski theory with its numerous generalizations are reduced to special cases of the general theory of arbitrary sections, permitting a clearer perspective of the entire field. The method which permits the determination of the velocity at any point of an arbitrary section and the associated lift and moments is described. The method is also discussed in terms for developing new shapes of preassigned aerodynamical properties.

"An investigation has been made of a partial-span model of the tail surface designed for use on the Hughes Falcon (MX-904) missile to determine the aerodynamic characteristics of the tail and elevator including elevator hinge moment. Data obtained at Mach numbers of 1.62 and 1.96 in the Langley 9- by 12-inch supersonic blowdown tunnel are presented for the condition where the tail was attached to a segment of the foreshortened body" (p. 1).

"Flight tests were made to determine the total-pressure recovery of a split-wing ram-jet inlet with a fixed area exit 20 percent larger than the inlet throat over a Mach number range from 1.4 to 3.16. Total-pressure-recovery measurements at the diffuser exist station indicated abrupt pressure changes in the total-pressure profile throughout the Mach number range. Comparisons of average total-pressure recovery with the theoretical total-pressure recovery showed good agreement" (p. 1).

"Characteristic exhaust velocity was measured for a small range of mixture ratios with four different injectors. Performances of parallel-sheet, like-on-like, and triplet injectors were about the same, but a parallel-jet injector had a much lower performance. Performance values for ammonia-oxygen were slightly lower than for heptane-oxygen" (p. 1).

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 lateral stability characteristics of a scale model of the MX-1764 airplane. The addition of the inlet configurations to the model generally had only small effects on the lateral stability.

"The static aeroelastic divergence characteristics of a delta-plan-form model of the canard control surface of a proposed air-to-ground missile have been studied both analytically and experimentally in the Mach number range from 0.6 to 3.0. The experiments indicated that divergence occurred at a nearly constant value of dynamic pressure at Mach numbers up to 1.2. At higher Mach numbers somewhat higher values of dynamic pressure were required to produce divergence" (p. 1).

Memorandum presenting an analysis to determine the feasibility of using a constant diffuser Mach number to position a translating spike for optimum inlet performance. A control system incorporating this concept was investigated on a blunt lip, translating-spike inlet at flight Mach numbers of 1.8 to 2.0 and angles of attack up to 6 degrees. Results regarding inlet characteristics and performance with control are provided.

"An analysis of the effects of compressibility on the longitudinal stability, control, and trim of airplanes flying at high subsonic speeds and a discussion of the causes of and the means for lessening or preventing the diving tendency are presented. Wind-tunnel results for Mach numbers up to 0.90 are included for purposes of illustration and cover several investigations of longitudinal stability and control, airfoil characteristics, dive-recovery aids, and elevator characteristics. Methods are indicated for compensating for the undesirable control tendencies results from the characteristics of the wing at supercritical speeds by the appropriate choice of elevator contour" (p. 1).

Report discussing an investigation to determine the effects of sweepback and low aspect ratio on the aerodynamic characteristics of a wing at high subsonic Mach numbers. Tests were performed at aspect ratios of 2, 3, and 5 and sweepback angles of 0, 30, and 45 degrees. Generally, sweepback and low aspect ratio were found to both delay and lessen the effects of compressibility.

From Introduction: "The present paper presents the scale effect on the longitudinal aerodynamic characteristics, the aerodynamic characteristics in yaw, and the tuft studies for 0^o and 3.7^o yaw. The results of the effect of leading-edge and trailing-edge flaps on the aerodynamic characteristics of the wing will be presented in later reports."

Report presenting a high-speed wind-tunnel investigation of a pitot-static tube to provide information on the effects of compressibility upon the pressure indications of a representative airspeed head at high subsonic speeds. The calibration factor for the instrument has been evaluated for several small angles of pitch and yaw throughout a Mach number range from 0.30 to approximately 0.925. The results indicate that the calibration factor for each combination of pitch and yaw angles tested is almost constant with Mach number up to a Mach number of approximately 0.8.

Report presenting an investigation of an NACA 65A006 airfoil equipped with high-lift devices, including a 0.15-chord drooped-nose flap and a 0.20-chord plain trailing-edge flap. Airfoil section lift, pitching-moment, and drag characteristics obtained at high Reynolds numbers and low Mach numbers with the flaps deflected individually and simultaneously are presented. At Reynolds numbers up to 9.0 x 10(exp 6), the optimum combination of drooped-nose and plain trailing-edge flaps increased the maximum section lift coefficients from 0.78 to 1.89.

Memorandum presenting a wind-tunnel investigation conducted to determine the rotary stability characteristics in yawing flow of a series of untapered wings with angles of sweep of -45, 0, 45, and 60 degrees. The results of the yawing-flow tests indicated that the values of the rotary derivatives agreed fairly well with simple sweep theory for a moderate range of lift coefficients.

Report presenting initial flight tests of two simplified flutter vehicles. Test results were in agreement with the results of the freely-falling-body test in that the wing failures in the transonic range occurred at velocities greater than the flutter velocity calculated from the two-dimensional theory.

Memorandum presenting Mach number histories of the motion experienced by a hypothetical, small, straight-wing aircraft accelerating at various rates through an assumed controls-fixed pitch-down balance change in the transonic range. Two approximate analytical solutions of the longitudinal equations of motion are developed which are based on certain simplifying assumptions indicated by the differential-analyzer results.

Report presenting results of an exploratory free-flight investigation at zero lift of several rocket-powered drag research models equipped wing wing tanks at a range of Mach numbers. The tanks, which were slender bodies of revolution, were mounted on 34 degrees sweptback, nontapered wings of 2.7 aspect ratio. Results regarding drag and trim change are provided.

"A description of the two swept propellers investigated in the Langley 8-foot high-speed tunnel is presented, together with the discussions of the numerous assumptions and analyses on which the designs of these propellers are based. The blades are swept considerably along the entire blade radius and, in order to allow for reductions in the maximum stresses, are swept forward inboard and backward outboard. The blades have been designed on the basis of the blade-element method primarily to have subcritical efficiencies at the highest possible forward speed. The designs have been controlled primarily by the stresses in the blades" (p. 1).

From Introduction: "The investigation covered a range of Mach numbers from 0.66 to 1.12 and included measurements of angle of attack, pitching moment, normal force, and chord force. The drag at zero lift obtained in this investigation was reported in reference 1, but without the correction for tare of the end plate."

Memorandum presenting an investigation to determine the feasibility of a high-performance transonic axial-flow compressor stage with a weight flow of 40 pounds per second per square foot of frontal area. A transonic axial-flow inlet stage with a hub-tip ratio of 0.35 and an axial Mach number of approximately 0.75 was designed and fabricated. Results regarding overall rotor performance, flow parameters, radial matching of blade-element sections, and comparison of blade-element parameters with design rules are provided.