Report presenting analytical estimates of the thrust, efficiency, drag, and weight of the air-turborocket engine. The effects of changes in the engine components on design and off-design performance are emphasized. Results regarding the performance, effect of design parameters, effect of subsonic cruising Mach number, geometry variations, engine weight estimates, and comparison with turbojet engines are provided.

Report presenting an investigation of an all-internal conical compression inlet with annular bleed at the throat at Mach number 5.0 and zero angle of attack. Results regarding the performance of the diffuser alone, a Pitot-pressure survey of the flow leaving the diffuser, total-pressure distribution, and inlet efficiencies are provided.

Memorandum presenting several proposed-high performance aircraft that have been studied analytically and by model flight tests to define some problem areas in dynamic lateral behavior of high-speed aircraft which require specific attention. Aileron control problems and Dutch roll characteristics with and without artificial damping were considered.

From Introduction: "A 12-percent-chord-thick wedge section and a reversed NACA 0012 section were chosen for these tests as they are representative of sections having no boat tailing and appreciable boat tailing (i.e., blunt and rounded trailing edges, respectively), and the results of this investigation are compared with those obtained from a previous investigation of the NACA 0012 section. Conclusions are drawn regarding the relative merits of the two unconventional sections and the conventional section in transonic speed range."

"A fuel-distribution control for continuous-flow manifold injection on reciprocating engines is described. A method is installation of the control on an engine is suggested. The device controlled the flow to four spring-loaded nozzles within 2 percent of perfect distribution over a wide range of fuel-flow rates and the distribution was practically unaffected by uneven discharge-nozzle pressures" (p. 1).

Report presenting results of chordwise pressure-distribution measurements on a 45 degree sweptback wing at transonic speeds. The two stations for measuring were located at the 18 percent chord from the root and the 87 percent chord. The changes in pressure distribution with Mach number did not indicate any appreciable net loss in section lift, but did indicate large increases in the section drag and diving moment.

"It is shown that for velocities slightly in excess of sonic, the position of detached shock wave located in front of a given body at zero angle of attack may be estimated theoretically to a reasonable degree of accuracy. In case of bodies of revolution the result was simple, but for two-dimensional bodies, pressure coefficient varies with Mach number, and slight difficulty appears. Theory developed compares favorably with available experimental data" (p. 1).

Report presenting an investigation of the performance of a turbojet engine equipped with a tail-pipe burner at zero ram over a range of rotor speeds and tail-pipe-burner fuel flows. A thrust augmentation of 40 percent was obtained at zero ram for a tail-pipe-burner fuel-air ratio of 0.043 or a total fuel-air ratio of 0.056. Results with an engine with standard tail pipe, engine with tail pipe burner and no afterburning, and engine with tail pipe burner and afterburning are provided.

Report presenting airspeed and altitude data for nonscheduled cargo operations of a Douglas DC-4 airplane between Seattle, Washington and Alaska during February and March of 1947 to determine the probability of reaching or exceeding given values of airspeed and Mach number. The total probability of exceeding a placard never-exceed speed of 266 mph depends primarily on exceeding the speed in descent. The probability was found to be about once in 100 hours of descent or once in 1000 hours of general flying time.

Report presenting testing of six flutter wings, two swept 45 degrees and four unswept, attached to three freely falling bodies. Flutter frequency and phasing were recorded.

Report presenting flight tests to determine the longitudinal stability and control characteristics of models of the Lark pilotless aircraft. Testing included the standard configuration with the horizontal wing flaps deflected 0 degrees, 15 degrees, and 60 degrees, and a test with the tail surfaces in line with the wings with the wing flaps not deflected. Results regarding time-history records, drag, longitudinal stability, and control effectiveness are provided.

Report presenting a flight investigation in natural icing conditions to determine the effect of ice formations on the performance of an axial-flow turbojet engine. Results regarding the tail-pipe temperature, engine jet thrust, and characteristics of ice formation are provided. No general conclusions can be reached from the data because the icing condition was relatively light.

Contains charts for use in determining preliminary values of the spanwise-load, shear, bending-moment, and accumulated-torque distributions of swept wings. The charts are based on strip theory and include four aerodynamic-load distributions, two section-moment distributions, and two inertia-load distributions. The taper ratios considered cover the range from 1.0 to 0 and the results are applicable to any angle of sweep.

Report presenting the results of a preliminary experimental flutter investigation of widely different unswept cantilever wings at Mach number 1.3. Wings with a variety of mass-density parameters, center-of-gravity positions, and elastic-axis positions were tested.

The third investigation in a series to determine the fundamental characteristics of trailing-edge controls at transonic speeds. This particular report uses a 35 degree sweptback untapered airfoil model with an aspect ratio of 3 and a flap with a bevelled trailing edge with a trailing-edge angle of 23 degrees. Results regarding lift, pitching-moment, and hinge-moment characteristics are provided.

Memorandum presenting an analysis of selected experimental pressure-distribution data at transonic speeds for the purpose of deriving an empirical method which may be used for estimating the trailing-edge loads and bending moments at the design stage. The trailing-edge normal-force and bending-moment coefficients calculated by the derived method follow the general trend of the experimental data and appear to be a guide where specifically applicable chordwise pressure-distribution data at transonic speeds are not available.

Report presenting an experimental investigation of thrust augmentation of a 4000-pound-thrust axial-flow-type turbojet engine by interstage injection of water-alcohol mixtures into the compressor at sea-level, zero-ram conditions. the number, size, and arrangement of interstage nozzles were varied to produce a satisfactory augmentation system of minimum complication. Results regarding the unaugmented performance with and without interstage-injection nozzles, augmented performance with three-stage system, augmented performance with other injection systems, temperature surveys, and engine operation are provided.

From Introduction: "This paper presents the results of the investigation of the wing-alone and wing-fuelage configurations employing a wing with the quarter-chord line swept back 60^o, aspect ratio 4, taper ratio 0.6, and an NACA 65A006 airfoil section parallel to the free stream."

Report presenting a temperature survey made in the wake of two closely located parallel jets emerging into the atmosphere from two types of twin convergent nozzles. Results regarding the twin unshrouded nozzles and twin nozzles with twin geometry-simulated shrouds are provided.

Report presenting an investigation of two sharp-edge annular inlets with conical central bodies at low airspeeds in the propeller research tunnel to obtain information concerning the surface-pressure, drag, and pressure-recovery characteristics of the inlets at subsonic flight. Results regarding the nose and inner surface of the diffuser, inlet lips, minimum surface pressures and critical Mach numbers, pressure surveys in inlets, and pressure surveys in diffusers are provided.

Report presenting measurements made at transonic speeds by the freely-falling-body method to compare the drag of a rectangular plan-form airfoil of aspect ratio 7.6 with an NACA 65-006 airfoil section. Results regarding the velocity measurements, base-pressure measurements, and airfoil drag measurements are provided.

"An investigation has been conducted in the Langley 300 MPH 7- by 10-foot tunnel to determine the effect of negative dihedral, tip droop, and wing-tip shape on the low-speed aerodynamic characteristics of a complete model having a 45 degrees sweptback wing. Longitudinal and lateral stability characteristics were obtained for the model with and without tail surfaces" (p .1).

"Pressure-distribution data of the NACA 64(sub 1)-012 and 64(sub 1)A012 airfoils have been analyzed to determine the effects of increasing the trailing-edge angle from 9 to 14 degrees. The primary effect of increasing the trailing-edge angle was to decrease the loading over the rear portion of the airfoil under lifting conditions. The differences in trailing-edge load increased with Mach number and lift coefficient" (p. 1).

Report presenting a method for the preparation and purification of the intermetallic molybdenum desilicide was developed and its properties were determined. Chemical properties were found to be highly inert, unattacked by boiling hydrochloric acid, sulfuric acid, or aqueous sodium hydroxide, slightly attacked by nitric acid, and dissolved by molten sodium hydroxide. Other mechanical properties of the material were also provided.