"A spin-tunnel investigation has been made to determine the probability of external fuel tanks striking an airplane after being jettisoned in a spin. The investigation showed that for straight-wing fighter-type designs in any case in which jettisoning of tanks in a spin might aid spin recovery the tanks would probably clear all parts of the airplane" (p. 1).

From Introduction: "Water injection at the compressor inlet has been successfully used to increase the thrust of turbojet engines. References 1 and 2 indicate that the sea-level static thrust of a centrifugal-flow-type turbojet engine may be increased about 25 percent by use of liquid injection. Reference 3 indicates that greater thrust augmentation is possible at a compressor pressure ratio of 11 than of 4."

From experience gained by NACA test pilots in flying at high subsonic Mach numbers and from interpretation of the data obtained, some general precautionary rules for test flying near sonic Mach numbers have been formulated. The reasons for these rules are discussed and observations are made with respect to the hazards arising from undesirable stability and control characteristics which have been noted in test flights of various airplanes. This paper, although written primarily for the attention of test pilots, contains general information of interest to those who are concerned with various phases of flight testing near sonic Mach numbers.

Report presenting an analysis of the spanwise loading using two different methods on the wing of an airplane for which pressure-distribution measurements were available from flight tests up to a Mach number of 0.866. A comparison between measured and calculated distributions was made on the basis of equal wing-panel normal-force coefficients.

Report presenting an investigation of the problem of applying controls to low-aspect-ratio wings of triangular plan form by using the NACA wing-flow method with parallel-sided models with sharp leading and trailing edges. Results regarding the data analysis, Reynolds number and separation effects, flap effectiveness, plan-form characteristics, angle of zero lift, and triangular plan-form flying-wing characteristics are provided.

"An investigation has been made in the Langley full-scale tunnel of a 47.5 degree sweptback wing-fuselage combination equipped for boundary-layer control by suction. The wing aspect ratio was 3.5, the taper ratio was 0.5, and the airfoil sections normal to the quarter-chord line were NACA 64(sub 1)-A112. The wing configurations tested included the wing with various combinations of extensible leading-edge and split flaps" (p. 1).

Report presenting an investigation to determine the cause for a discrepancy between theoretical and experimental pressure distributions found during a two-dimensional investigation of flapped airfoils in a 2- by 8-inch supersonic tunnel. The results indicated that a tunnel-boundary-layer and model-flow interaction effect on the flow over models mounted directly from the walls in supersonic wind tunnels exists.

Report presenting an experimental and analytical investigation of the flutter of uniform sweptback cantilever wings. The experiments used groups of wings sweptback by rotating and by shearing with angles of sweep ranging from 0 to 60 degrees. Results regarding the experimental investigation and a discussion and comparison of the analytical and experimental results are provided.

Two low-acceleration transonic-flutter vehicles were launched and flown. The first carried two test wings, one of which fluttered at M = 0.92 at a frequency of 61.4 cycles per second. The reference flutter speed determined from two-dimensional theory for an unswept wing in incompressible flow is conservative when compared to the experimental flutter speed. The second vehicle carried two test wings, one of which failed at M = 0.71 because of low-frequency divergent oscillation. Since this failure was not caused by conventional flexure-torsion flutter, no comparison with a reference flutter speed can be made.

Report presenting the effects of changes in Reynolds number on the longitudinal aerodynamic characteristics of a 52 degree sweptback wing with an aspect ratio of 2.88 and NACA 64(sub 1)-112 airfoil sections. The model was tested with the leading edge both smooth and rough. Results regarding force and pitching-moment results, flow observations, and discussion of force and moment characteristics are provided.

Report presenting the ditching characteristics of the Douglas DC-4 and DC-6 in a water tank. Dynamically similar models of 1/16 scale were used for the investigation, which was conducted in calm and rough water. The ditching characteristics and safest ditching procedures were determined by testing at various landing attitudes, speeds, and simulated conditions of damage.

Report presenting tests in a pressure tunnel to determine the low-speed pitch characteristics of a 42 degree sweptback wing with circular-arc airfoil sections. Information regarding the characteristics of basic wing, leading-edge flap investigation, and effects of fuselage are provided.

Report presenting a preliminary theoretical and experimental investigation of the supersonic characteristics of blunt-trailing-edge airfoils. Results regarding the drag measurements at zero lift, measurements at angle of attack, and a general discussion of the theoretical and experimental results is provided.

Report presenting an investigation of pressure distributions and flow characteristics at low speed through a range of yaw and angle of attack through the stall for three small-scale low-aspect-ratio pointed wings with varying degrees of trailing-edge sweep. An effort was made to correlate pressure distributions with the strong conical vortex flow observed. Results regarding chordwise pressure distributions and flow characteristics, section lift characteristics at zero yaw, spanwise-load distributions, centers of pressure at zero yaw, and wing force and moment characteristics are provided.

From Introduction: "The effects of variations in altitude, flight Mach number, and exhaust-nozzle-outlet area on the compressor performance characteristics are graphically presented. A complete tabulation of the compressor performance data is also presented."

Report presenting an experimental investigation to determine the vibration characteristics of loosely mounted turbine blades during service operation of a turbojet engine. High-temperature strain gages were used to measure turbine-blade vibrations. Results regarding oscillograph records, critical speeds and frequencies, vibratory-stress levels, and effect of tightening the blade mount are provided.

Report discussing a wing-alone and wing-fuselage configuration with particular characteristics as part of a series of tests of wings using the transonic-bump test technique. Lift, drag, pitching moment, and root bending moment were obtained for the configurations. The effective downwash angles and dynamic-pressure characteristics in the tail region are also described.

Report presenting a discussion of the aerodynamic forces and moments on inclined bodies of revolution. An approximate theory to allow for the effects of viscosity is developed and applied. Results regarding the variation of lift and pitching moment, and center of gravity are provided.

Memorandum presenting a bibliography of unclassified aircraft fire literature consisting of reports from a 20-year period ending January 1, 1949. The reports are separated into the following categories: aircraft fire accidents and statistics, combustibles, ignition sources, fire protection, fire prevention, fire resistance of materials, fire detecting, fire extinguishing, and passenger protection or rescue.

From Introduction: "The purpose of the present paper is to present results obtained recently relating to the characteristics of a full-span sharp-edge spoiler with an 0.02-chord projection above the wing surface at several chordwise positions and also to the relative effectiveness of the sharp-edge spoiler and a wedge-type spoiler located at the 80-percent-chord line."

Report presenting the results of an investigation on a rectangular ram jet to determine the effect of variation in fuel pressure on the starting characteristics, minimum blow-out limits, combustion efficiencies, gas total-temperature ratio, and net-thrust coefficient. Testing occurred using three different fuel nozzles and over a range of pressure altitudes, airspeeds, and fuel-air ratios.

Memorandum presenting limited data covering extension of the transonic-flight tests of the XS-1 airplane. The data show that successful flight to a Mach number of 1.35 has been achieved at altitudes up to 40,000 feet.

Report presenting a study of the flight characteristics of the canard configuration at transonic and supersonic speeds. Known problems concerning the low-speed characteristics of the canard are also investigated.

Report discussing testing on a series of tapered swept wings under conditions simulating rolling flight. The lift, longitudinal-force, and pitching-moment characteristics for three swept wings are provided. The results indicated that a decrease in taper ratio on a swept wing caused a small decrease in damping in roll at low and moderate lift coefficients.