"An additional series of high-speed wind-tunnel tests of a modified 0.17-scale model of the McDonnell XF2H-1 airplane was conducted to evaluate the effects of a reduction in the thickness-to-chord ratios of the tail planes, the displacement of the horizontal tail relative to the vertical tail, and the extension of the trailing edge of the wing. Two tail-intersection fairings designed to improve the flow at the tail were also tested. The pitching-moment characteristics of the model were improved slightly by the use of the thinner tail sections" (p. 1).

Report presenting a low-speed investigation in the stability tunnel to determine the static longitudinal stability and control characteristics of a 60 degree triangular-wing model with various triangular-all-movable horizontal tails. An all-movable trail of 10 percent of the wing area and aspect ratio 2.31 was investigated in 17 tail positions, including positions above, below, and to the rear of the assumed center of gravity.

Report presenting a wind-tunnel investigation to determine the effects of leading-edge radius and maximum thickness-chord ratio on the variation with Mach number of the aerodynamic characteristics of several thin symmetrical NACA 4-digit-series airfoil sections. The variations with Mach number of the lift, drag, and pitching moment for a 4-percent-chord-thick airfoil section are not significantly affected by a change of leading-edge radius from 0.18 to 0.53 percent of the chord.

Report presenting an investigation to determine the effects of several leading-edge modifications on the maximum lift and pitching-moment characteristics on a large-scale 45 degree swept-forward wing. A full-span leading-edge flap deflected 30 degrees down tended to give the largest gain of maximum lift. Results regarding the plain leading-edge flaps and cambered nose are explored.

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.

Report presenting tests using the NACA wing-flow method to determine the effect of sweepback angle on the longitudinal characteristics of a scale semispan model of the Bell X-5 variable-sweep airplane at a range of Mach numbers. Lift, drag, and pitching moments were obtained for a range of angles of attack.

"A study has been made of the variation of seaplane hull weight with length-beam ratio in a systematic series of hulls designed for constant gross weight and similar spray characteristics. It is found that increases in the length-beam ratio bring about small reductions in the hull weight if it is assumed that seaplanes having the same weight and bottom shape will be designed for the same load factor. A short discussion is also given to show the reduction in load factor that may occur with high length-beam ratios" (p. 1).

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.

The results obtained from measurements of gust velocities, draft velocities, and ambient-air temperature within thunderstorms for the period September 17, 1946 to September 18, 1946 at Orlando, Fla. are presented herein. These data are summarized in tables I, II, and III, respectively, and are of the type presented in reference 1 for previous flights.

"A method of distributing fuel equally to a plurality of spray nozzles in a gas-turbine engine by means of balanced-diaphragm fuel distributors is presented. The experimental performance of three of eight possible distributor arrangements are discussed. An analysis of all eight arrangements is included. Criterions are given for choosing a fuel-distributor arrangement to meet specific fuel-system requirements of fuel-distribution accuracy, spray-nozzle pressure variations, and fuel-system pressures" (p. 1).

Report presenting experimental flutter testing at Mach numbers up to 3.0 using cantilever-wing models with 0 to 60 degree sweepback and 60 degree delta-wing models. The main variables explored were the high Mach number and center-of-gravity location on flutter trends. The theoretical results for flutter analyses were noted to be lower than the experimental results.

Report presenting testing of a series of single and double unswept, lateral-support struts at a Mach number of 1.9 on a cone-cylinder body at zero angle of attack. The struts consisted of a rectangular box section with identical wedge fairings fore and aft. Results regarding the shock-wave intersections and pressure distributions are provided.

Memorandum presenting the pressure recovery, mass flow, and drag of a twin-scoop inlet-body combination measured at Mach numbers 1.4 and 1.7 at zero angle of attack. Tests were made of the inlet-body combination with an ogival forebody, an ogival forebody with a small amount of bluntness near the tip, and two forebodies of elliptical longitudinal section. Results regarding the effect of forebody bluntness on pressure recovery, effect of forebody bluntness on mass-flow ratio, and the effects of forebody bluntness on drag are provided.

Report presenting an experimental investigation at zero flight speed and sea-level conditions on a 4000-pound-thrust centrifugal-flow-type turbojet engine to determine the amount of thrust augmentation obtainable at maximum rotor speed by the injection of water, alcohol, and water-alcohol mixtures at the compressor inlets. A maximum thrust augmentation of 26 percent was obtained by the injection of 4.5 pounds per second of water and 2.0 pounds per second of alcohol. Results regarding the tail-pipe gas temperature, air-flow and compressor-outlet pressure, fuel flow, specific liquid consumption, and thrust augmentation are provided.

Report presenting an investigation of the internal-flow characteristics of two novel designs of internal-compression air inlets in the supersonic blowdown tunnel. A longitudinally slotted contracting channel and effective contracting channel formed by the natural thickening of the boundary layer in a confined channel can be used to obtain pressure recoveries at a satisfactory level.

Report presenting an investigation at high subsonic speeds to determine the static aerodynamic forces and moments on a canard missile model during simulated launching from the midsemispan location of a 45 degree sweptback wing-fuselage-pylon combination. Significant variations in all the aerodynamic components were noted with changes in chordwise location of the missile. Results regarding force and moment characteristics and effects of angle of attack and Mach number are provided.

An analysis has been made of available data on vee tail surfaces. Previously published theoretical studies of vee tails have been extended to include the control effectiveness and control forces in addition to the stability. Tests of two isolated tail surfaces with various amounts of dihedral provided a check of the theory. Methods for designing vee tails were also developed and are given in the present paper.

Report presenting an investigation to determine if thin airfoils with increased values of low-speed maximum lift coefficient but also retain the basic advantages of thin sections at high Mach numbers can be developed. Several experimental thin airfoil sections were developed from an analysis of airfoil data and two of them were investigated at high and low subsonic Mach numbers. Results regarding the low-speed characteristics and high-speed characteristics are provided.

Report presenting testing of the effectiveness of transpiration cooling of an 8 degree total angle conical body with water removed onto the surface through a porous section near the nose. Results regarding a reference test without cooling, a cooling test with 0.010 pound of water per second, a cooling test with 0.0025 pound of water per second, a hypothesis of the phenomena of liquid transpiration cooling, water consumption are provided.

Flight and ground investigations have been made to compare an exhaust-ejector installation with a standard exhaust-collector-ring installation on air-cooled aircraft engines in a twin-engine airplane. The ground investigation allowed that, whereas the standard engine would have overheated above 600 horsepower, the engine with exhaust ejectors cooled at take-off operating conditions at zero ram. The exhaust ejectors provided as much cooling with cowl flaps closed as the conventional cowl flaps induced when full open at low airspeeds. The propulsive thrust of the exhaust-ejector installation was calculated to be slightly less than the thrust of the collector-ring-installation.

Report presenting testing using a Douglas D-558-I airplane to determine the effect of wing vortex generators on some of the undesirable handling characteristics of aircraft flying at hypercritical speeds. The effects on buffeting, lateral unsteadiness, change in trim, and loss of control effectiveness were the primary objectives.

Report presenting an investigation of the F9F-4 airplane to evaluate a high-energy blowing boundary-layer-system in flight in order to improve the maximum lift characteristics of airplane wings. A high-energy blowing-boundary-layer control system was installed by the Grumman Aircraft Engineering Corporation. A series of test flights were made to measure the lift and drag variations with changes in angle of attack for the flap and gear both up and down and for blowing on and off.

Memorandum presenting a flight investigation conducted on a 20-inch-diameter steady-flow ramjet at a range of altitudes and free-stream Mach numbers. Results regarding the variation of combustion efficiency with fuel-air ratio and pressure altitude, effects of combustion-chamber-inlet velocity, and altitude on the operating range of fuel-air ratio are provided. The ramjet unit operated smoothly over the entire range of velocities and altitudes with the exception of occasional rough operation at excessively rich mixtures.

Report presenting an investigation of the handling qualities of a fighter airplane that is controlled by a pilot supplying signals to a rate type of automatic control system. The handling qualities were investigated in pull-ups, aileron rolls, aerobatics, rough-air flying, and precision tasks.