Report presenting an investigation with sting-mounted rocket-propelled models in free flight at approximately zero lift to determine the effect of wing flexibility on the damping-in-roll characteristics of a wing-body combination over a range of Mach numbers.

Turbojet thrust augmentation with fuel-rich afterburning of hydrogen, diborane, and hydrazine was computed. Results regarding takeoff thrust augmentation and flight thrust augmentation are provided.

Memorandum presenting the boundary-layer velocity profiles were measured on ten samples of various porous materials and on impervious aluminum plate mounted flush with the inner surface of the side wall of a small wind tunnel. Suction was applied to the back side of the porous test materials through a 4-inch-square opening. Results regarding measurements on the impervious plate and measurements on porous materials without suction and with suction are provided.

Memorandum presenting a theoretical analysis of the effect of aerodynamic hysteresis on stalling flutter. The results were applied to a given airfoil and correlation of the experimental and theoretical results was found possible by assuming that the angle of aerodynamic lag varies as the slope of the static-lift curve. It was shown that the phenomenon of stalling flutter can at least in some cases be explained on the basis of an aerodynamic lag or hysteresis effect.

Report presenting theoretical calculations made by means of semirigid-flutter theory to determine the effect of centrifugal force on the critical flutter speed of a uniform cantilever beam. Calculations are made on airfoils with fundamental bending frequencies up to 2000 radian per second. Centrifugal force can under certain conditions reduce the critical flutter speed.

Memorandum presenting an NACA submerged inlet and an NACA series I nose inlet installed in bodies of 12.4 fineness ratio to determine the drag and pressure-recovery characteristics of each body-inlet configuration. The tests were conducted with large-scale free-fall models released at an altitude of 40,000 feet, for mass-flow ratios of about 0.4 and 0.7 over a Mach number range of about 0.70 to 1.10. Results regarding drag and ram-recovery ratios are provided.

Memorandum presenting a measurement of the mean skin-friction coefficients on a flat-plate model, with and without initial roughness, and on a wind tunnel wall were measured at a nominal Mach number of 5.5 over a range of Reynolds numbers.

The paper presents flight measurements of the dynamic lateral stability of the D-558-II (BuAero No. 37974) research airplane. Data are presented for a range of calibrated airspeed from 167 miles per hour to 474 miles per hour.

Report presenting testing of a rocket-powered cone-cylinder body with a conical boattail to determine the jet interference effects on drag at transonic Mach numbers. If the nozzle was overexpanded, it increased boattail pressure drag at transonic Mach numbers, but an underexpanded nozzle affected boattail drag at 1.59, followed by a drag reduction.

From Introduction: "This report presents net thrusts computed for hydrogen, diborance, and hydrazine with fuel-air ratios form stoichiometric values to 0.5. Net thrusts for fuel-rich afterburning are compared with those for stoichiometric combustion of the turbojet fuel and air augmented with a 220-second specific-impulse rocket."

"An investigation of a 1/24- scale dynamically similar model of the Douglas C-124 airplane was made to determine the ditching characteristics and proper technique for ditching the airplane. Various conditions of damage, landing attitude, flap setting, and speed were investigated. The behavior of the model was determined from visual observations, motion- picture records, and time-history deceleration records. The results of the investigation are presented in table form, photographs, and curves" (p. 1).

"Altitude performance of a YJ71-A-7 turbojet engine, with afterburner inoperative, was determined in the NACA Lewis altitude wind tunnel over a wide range of flight conditions. Engine speed and exhaust-nozzle area were controlled independently during this investigation. The variation of corrected values of air flow, net thrust, and fuel flow with corrected engine speed was not defined by a single curve with changes in altitude at given flight Mach number" (p. 1).

"An investigation to increase the compressor surge-limit pressure ratio of the XJ40-WE-6 turbojet engine at high equivalent speeds was conducted at the NACA Lewis altitude wind tunnel. This report evaluates the compressor modifications which were restricted to (1) twisting rotor blades (in place) to change blade section angles and (2) inserting new stator diaphragms with different blade angles. Such configuration changes could be incorporated quickly and easily in existing engines at overhaul depots" (p. 1).