Memorandum presenting the Bell X-5 variable-sweep research airplane tested primarily at 58.7 degrees sweepback to determine the characteristics at transonic speeds of a fighter-type airplane with extreme sweepback. Some of the dynamic and static lateral stability characteristics have been discussed previously. Results regarding the lateral control, roll coupling, lateral problems at high lift, wing dropping, rudder oscillation at supersonic Mach numbers, and some pilots' impressions are also provided.

Report presenting the heat transfer and pressures on the lifting surfaces of a 60 degree delta wing with NACA 65A005 profile at angles of attack up to 9 degrees. Results obtained are compared to values obtained from flat-plate theory.

Report presenting an investigation conducted by means of preflight and flight tests to determine the performance of a 50-percent-magnesium 50-percent JP-4 slurry fuel in a twin-engine ramjet test vehicle. Data were obtained over a range of Mach numbers. Although a successful flight test was carried out, the performance obtained from preflight testing was below theoretical values.

Report summarizing research on the strength and creep of aircraft structural elements and components at elevated temperatures. Experimental data for aluminum alloy columns, plates, stiffened panels, and multiweb box beams are presented for temperatures up to 600 degrees Fahrenheit and compared with results predicted from materials data.

Memorandum presenting the optical transmission characteristics of turbulent boundary layers in air on a flat plate with negligible heat transfer measured photometrically for ranges of Mach number from 0.4 to 2.5. The results indicated that the scattering from a collimated beam of white light which penetrates a turbulent boundary layer depends mainly on the integral across the layer of the difference between the free-stream density and the local boundary-layer density.

"The theoretical performance of pentaborane has been recalculated using recent data on the vapor pressure of boric oxide. Previous calculations were based upon vapor-pressure data obtained some years ago by a method not as accurate as that employed in current investigations. The recalculated performance data for pentaborane differ appreciably from previously published data and are considered more accurate for evaluation of the relative potentialities of boron-containing fuels" (p. 1).

Theoretical calculations of specific impulse to determine the separate effects of increasing the combustion-chamber pressure and the nozzle expansion ratio on the performance of the propellants, hydrogen-fluorine, hydrogen-oxygen, ammonia-fluorine and AN-F-58 fuel - white fuming nitric acid (95 percent). The results indicate that an increase in specific impulse obtainable with an increase in combustion-chamber pressure is almost entirely caused by the increased expansion ratio through the nozzle.

Report presenting an exploratory investigation of the effectiveness of outboard horizontal tails in reducing the static longitudinal stability changes with lift coefficient associated with many sweptback wings. The results indicated that outboard horizontal tails can be a very effective means of counteracting the trend toward longitudinal instability characteristics of many sweptback wings. Results regarding the effects of changes in horizontal-tail position, effects of wing fences, average downwash at the tail, effects of changing tail size, lift, drag, and pitching-moment characteristics, and effects of flaps are provided.

Report presenting several short two-dimensional subsonic diffusers over a range of throat Mach numbers from 0.3 to 0.9. The designs incorporated an effective diffusion angle of approximately 30 degrees and an area ratio of 3. At a throat Mach number of 0.7, the resulting profile distortion of the unmodified 30 degree diffuser was diminished from about 11 to approximately 4 percent by using any of the configurations.

Memorandum describing an investigation using two airplanes, an F6F-3 and F-86A, each fitted with servo equipment for varying in flight the lateral and directional stability and handling characteristics, which have been flown by test pilots to simulate the predicted dynamic behavior of six prototype airplanes. The methods of simulation and the types and ranges of variables considered are presented and the results of the individual programs are discussed.

Report presenting testing of two airplanes, the F6F-3 and F-86A, fitted with servo equipment for varying in flight the lateral and directional stability and handling characteristics and flown by test pilots to simulate the predicted dynamic behavior of six prototype airplanes. Results regarding the aerodynamic characteristics and pilot opinions for each plane are provided.

"Tests have been made in the Langley 4- by 4-foot supersonic pressure tunnel at Mach numbers of 1.41, 1.61, and 2.01 to determine the static longitudinal stability and control characteristics of various arrangements of the Grumman F11F-1 airplane. Tests were made of the complete model and various combinations of its component parts and, in addition, the effects of various body modifications, a revised vertical tail, and wing fences on the longitudinal characteristics were determined" (p. 1).

Report presenting the results of short-time creep-buckling and creep-bending tests of 2024-T4 aluminum-alloy columns of slenderness ratio 111 are presented. Tests were performed at 600 degrees Fahrenheit and strain measurements were taken with high-temperature electric-resistance strain gages.

Report presenting an investigation in the 16-foot transonic tunnel to determine the effects of leading-edge droop on the aerodynamic and loading characteristics of an unswept wing with a taper ratio of 0.5, an aspect ratio of 4, and NACA 65A004 airfoil sections parallel to the plane of symmetry. The results indicate that, below a Mach number of 0.94, leading-edge droop delayed the onset of leading-edge separation and moved the main wing-compression shock rearward.

An investigation of the effects of jet nozzle geometry, size of base annulus, and base bleed upon the base and afterbody pressures of a cylindrical afterbody at transonic speeds has been conducted. Sonic and supersonic conical nozzles with jet-to-base diameter ratios from 0.25 to 0.85 were investigated with a cold jet at jet total-pressure ratios up to approximately 8.0 through a Mach number range from 0.6 to 1.25. Base pressure coefficients of about -0.55 were measured for the sonic nozzles at a Mach number of 1 or greater. The jet-to-base diameter ratio had a substantial effect on the base pressure obtained on the cylindrical afterbody of this investigation. Base bleed was beneficial in increasing the base pressure under certain conditions but had little or no effect at certain other conditions.

Memorandum presenting an aircraft modification involving the incorporation of small canard surfaces into the design, which is meant to compensate for eliminating ailerons. Results of testing in the 20-foot free-spinning tunnel of dynamic models of two sweptback-wing fighter airplanes showed that canard surfaces were very effective in aiding termination of spins of these models. A discussion of the spin tests, catapult and force tests, and effect of jet-engine angular momentum is provided.

Report presenting a blade-vibration and rotating-stall survey on a modified version of a production turbojet engine with a 13-stage axial-flow compressor with a design pressure ratio of 7 and an air flow of 120 pounds per second. This testing was carried out due to the problems rotating stall can cause with both experimental and production axial-flow compressors. Results regarding the rotating-stall patterns, rotor-blade vibrations, radial and axial strength of rotating stall, and maximum rotating-stall speed are provided.

Report presenting the effect of adjusting compressor inlet-guide-vane angle on overall compressor performance, stage performance, engine thrust, and specific fuel consumption in a 7000-pound-thrust turbojet engine. Data was obtained at several angles and demonstrated that increasing the guide-vane angle decreased the weight flow at the higher compressor speeds. It had no effect on stage performance other than at the first stage, where it reduced maximum flow, pressure, and temperature coefficients.

Report discussing methods, advantages, and disadvantages of locating rotating heat exchangers ahead of, within, and behind the main engine compressor. Heat rejection should occur at the compressor discharge for best engine performance. Results regarding turbojet-engine performance, turboprop-engine performance, and a comparison of engine performance with liquid- and air-cooling are provided.

Report presenting a highly loaded transonic rotor which was designed, built, and tested as part of a two-stage counterrotating-compressor research program. The design conditions were chosen to explore the upper limits of loading and Mach number for the transonic unit. The complete rotor design procedure is presented as well as the recorded stall traces and techniques for obtaining the data.

"The transient motion in angles of attack and sideslip during a constant rolling maneuver has been analyzed. Simplified expressions are presented for the determination of the pertinent modes of motion as well as the modal coefficient corresponding to each mode. Calculations made with and without the derivatives for side force due to sideslip and lift-curve slope indicate that although these derivatives increase the total damping of the system they do not markedly affect the transient motion" (p. 131).

Report presenting a J47-25 engine instrumented with thermocouples and operated under steady-state and transient-conditions in an altitude test stand to determine the operating temperatures at altitude in the turbine section of a turbojet engine. Results regarding the temperature effects and transient operation are provided.

A pneumatic proportional-plus -integral shock-positioning control unit was investigated for controlling a ram-jet engine at a flight Mach number of 2.5 and altitudes of 50,000 to 65,000 feet. A satisfactory of attack, the control action was marginal for the same control settings used at zero angle of attack.

Force and moments were measured for the XV-1 convertiplane at 75 to 150 knots. Rotor on and off and propeller powered and off configurations were investigated. The characteristics of the V-tab horizontal tail and its downwash field were studied. Lift interference between fixed wing and rotor and possible means of drag reduction were considered.