Report presenting the results of an experimental wind-tunnel investigation of the damping in pitch of two triangular wings having leading edges swept back 45 degrees are presented. The wings differed only in airfoil section. Results regarding the damping coefficients, aeroelastic effects at supersonic speeds, Reynolds number effects, and application of the results to the prediction of the dynamic behavior of full-scale aircraft are provided.

"An investigation was conducted to determine the electric power requirements necessary for ice protection of inlet guide vanes by continuous heating and by cyclical de-icing. Data are presented to show the effect of ambient-air temperature, liquid-water content, air velocity, heat-on period, and cycle times on the power requirements for these two methods of ice protection. The results showed that for a hypothetical engine using 28 inlet guide vanes under similar icing conditions, cyclical de-icing can provide a total power saving as high as 79 percent over that required for continuous heating" (p. 1).

Report presenting a rocket-powered model of the X-3 configuration flown through a range of Mach numbers to determine the response of the model to rapid deflections of the horizontal tail and its effects on lift, drag, longitudinal stability and control, and longitudinal-trim change. The model was found to remain statically and dynamically stable through the lift-coefficient and Mach number range of the test.

Report presenting testing of a centrifugal compressor from a production-type turbojet engine, which was successfully operated as a centripetal refrigeration turbine over a range of rotor speed, inlet pressure, and pressure ratio for full admission. The performance results indicated that partial admission was found to be the most efficient method of turbine control, but throttling at the turbine inlet was easy to apply. When nozzles are used, they should have erosion-resistant surfaces to minimize erosion effects.

"A two-dimensional inlet-guide-vane cascade was investigated to determine the effects of ice formations on the pressure losses across the guide vanes and to evaluate the heated gas flow and temperature required to prevent Icing at various conditions. A gas flow of approximately 0.4 percent of the inlet-air flow was necessary for anti-icing a hollow guide-vane stage at an inlet-gas temperature of 500 F under the following icing conditions: air velocity, 280 miles per hour; water content, 0.9 gram per cubic meter; and Inlet-air static temperature, 00 F. Also presented are the anti-icing gas flows required with modifications of the hollow Internal gas passage, which show heat input savings greater than 50 percent" (p. 1).

Memorandum presenting an investigation of the dynamics of a turbine-propeller engine in the altitude wind tunnel employing the frequency-response technique for a range of pressure altitudes form 10,000 to 30,000 feet. The investigation showed that the dynamic responses generalized for pressure altitude over the range of frequencies investigated. Results regarding steady-state characteristics, the linearity investigation, and dynamic characteristics are provided.

Memorandum presenting the results of a theoretical investigation of the lateral response and stability characteristics of the X-3 research airplane (Douglas Model No. 499D). Included are time histories calculated by a computer showing the effect of various disturbances on the lateral response of the airplane with 0 degrees geometric dihedral and -5 degrees dihedral.

Report presenting an investigation of the low-speed lateral characteristics of a 47.5 degree sweptback-wing-fuselage combination with several flap and spoiler aileron arrangements. Results regarding aileron control characteristics, spoiler-control characteristics, and a comparison of the two are provided.

Memorandum presenting flight tests made on the Bell X-1 airplane with the 10-percent-thick wing and the 8-percent-thick tail to evaluate the effects of fixing the rudder and changing the inclination of the principal axes of inertia. The data were obtained during power-off glides at altitudes between 32,000 and 16,000 feet.

Report presenting flight measurements of the dynamic longitudinal-stability characteristics of a 35 degree swept-wing airplane. The results indicated that a sharp reduction in damping at a Mach number of 0.92 with maximum damping occurred at Mach number of 0.88 and 0.94. Results regarding oscillation periods, damping coefficients, scatter, and number of cycles required for oscillations to damp to a certain amplitude are provided.

Report presenting an investigation of a model of the Bumblebee XPM missile to determine the causes of booster-fin failures for a range of Mach numbers and Reynolds numbers. The cause of fin failure was determined to be the launching shoes that caused the missiles to trim at increasingly negative angles of attack. Additional testing with wing spoilers and alternate booster fins was also conducted.

Report presenting the results of an investigation of a model of the Bumblebee XPM missile to determine the causes of booster-fin failures on full-scale missiles. Results indicated that failures of the fins were due to launching shoes which caused the missile to try at increasingly negative angles of attack as the Mach number increased.

Report presenting an analysis of the force distribution on a slender pointed body of revolution at angle of attack utilizing pressure-distribution data and balance measurements. The data were obtained in the supersonic tunnel at a variety of Mach numbers and angles of attack. Results regarding normal forces and axial force are provided.

Report presenting the effects of Mach number between 0.50 and 0.95 and between 1.09 and 1.29 on the characteristics of the downwash and on the location of the wake behind a triangular wing of aspect ratio 4 as determined from semispan model tests.

Report presenting results during demonstration flight tests of the Northrop X-4 No. 1 and No. 2 airplanes. Results regarding the static and dynamic longitudinal- and lateral-stability characteristics, the stalling characteristics, and the buffet boundary.

Report presenting aerodynamic characteristics of an unswept wing with an aspect ratio of 2.67, a taper ratio of 0.5, and employing full-span, 25-percent chord, plain, trailing-edge flaps using wind-tunnel testing of a semispan model. The trailing-edge flap was generally effective in changing the lift coefficient at each angle of attack and Mach number of the investigation. Results regarding lift characteristics, hinge-moment characteristics, drag characteristics, and pitching-moment characteristics are provided.

Report presenting the damping-in-roll characteristics of three wings with an aspect ratio of 4, a taper ratio of 0.6, an NACA 65A006 airfoil section, and three different sweep angles at a range of Mach numbers and angles of attack. The data were obtained in the 7- by 10-foot tunnel transonic bump by utilizing the twisted-wing technique. Results regarding the damping-in-roll parameter, angle of attack, and lift-curve slope are provided.

From Introduction: "Results are presented to indicate the effect of altitude, flight Mach number, and exhaust-nozzle-outlet area on the combustion efficiency, the losses in total pressure occurring in the combustion chamber, and the fractional loss in engine cycle efficiency resulting from combustion-chamber pressure losses. The engine cycle efficiency is also presented.These results are shown graphically as a fraction of corrected engine speed and in tabular form."

"Tabulated pressure coefficients and aerodynamic characteristics are presented unanalyzed for six spanwise stations on the right wing of the Douglas D-558-I research airplane (BuAero No. 37972). The data were obtained in a 1 g stall at subcritical Mach numbers, in a speed run to a Mach number of 0.90 and in a wind-up turn at a Mach number of 0.86" (p. 1).

"An investigation has been conducted in the Langley 20-foot free-spinning tunnel on a 1/30 - scale model of the Grumman XFlOF-1 airplane to determine its spin and recovery characteristics. The investigation included erect and inverted spins for both the straight-wing and swept-wing configurations. Tests to determine the optimum size spin-recovery parachutes and the rudder forces required for recovery were also made" (p. 1).

Report presenting an investigation of the static stability and control characteristics of a scale model of a preliminary Bell X-5 airplane design in the landing configuration with and without dive brakes. Results regarding the effects of slats, flaps, landing gear, gear doors, dive brakes and gap at the wing root are provided.

From Introduction: "The effect of flame-holder and fuel-system design on the burner performance and the effect of altitude and flight Mach number on over-all performance with a fixed-area exhaust nozzle are reported in reference 1 to 4. Altitude performance characteristics of a tail-pipe burner having a converging conical burner section are presented in this report. Tail-pipe burner performance at several flight conditions is given in both tabular and graphical forms and compared with performance of the standard engine and of the tail-pipe burner reported in reference 2."

Memorandum presenting a determination of the external-shock drags of supersonic inlets with circular cross sections from shadow photographs at a Mach number of 2.70 for a low-external-compression and a high-external-compression inlet. The calculated mass flow for both types of inlets showed reasonably good agreement with the measured values. Results as determined by the characteristics method and the approximate method are provided.

Report presenting the results of a wind-tunnel investigation of the lift and moment characteristics of four 10-percent-thick circular-arc airfoil sections. Increases in the trailing-edge thickness were found to result in increases in maximum lift coefficient and lift-curve slope at all Mach numbers as well as increases in lift-divergence Mach number at all lift coefficients.