Memorandum presenting an analysis of the two-dimensional, geared, trailing-edge flap-tab combination at supersonic speeds to determine if the combination could be used to reduce the hinge moments to extremely small values while retaining a large part of the lift effectiveness of a plain flap with the same ratio of flap chord to wing chord.

Report presenting an investigation of a basic wing-fuselage combination with several types of external-store installations meant to delay the advent of airplane buffet caused by external stores. Modifications for airplane design in order to minimize the effect of drag are provided. Some of the arrangements tested included the tandem-mounted arrangement, flush-mounted arrangement, store with a fan-shaped tail, and auxiliary airfoil arrangement.

Report presenting an experimental investigation of thrust augmentation of an axial-flow-type turbojet engine with a 4000-pound-thrust rating using a water-alcohol injection at the compressor inlet at sea-level conditions and zero ram. Three injection systems were investigated in order to obtain satisfactory atomization and distribution of the injected liquids. Results regarding engine performance and engine operation are provided.

This paper contains a detailed description of a 2,000-horsepower propeller dynamometer used to make wind-tunnel tests of a two-blade NACA 10-(3)(08)-03 propeller for a range of blade angles from 20 degrees to 55 degrees at airspeeds up to 500 miles per hour. The results of these tests and comparisons with results obtained from a theoretical analysis and from previous tests made in other wind tunnels are presented.

Memorandum presenting an investigation in the high-speed 7- by 10-foot tunnel using the transonic bump method to determine the longitudinal stability and control characteristics of a semispan airplane model at transonic speeds. The results indicated an increase in the maneuvering stability through the transonic range, but regions of instability were indicated by the slope of the curve stabilizer incidence for trim against Mach number at all positions tested.

"A bibliography of NACA papers on rotating-wing aircraft issued up to July 1948 is presented. The list of papers is subdivided for ready reference under appropriate subject headings, and the titles are listed chronologically within each subject" (p. 1).

"A theoretical analysis is presented for obtaining by use of Theodorsen's propeller theory the load distribution along a propeller radius to give the optimum propeller efficiency for any design condition. Examples are included to illustrate the method of obtaining the optimum load distributions for both single-rotating and dual-rotating propellers" (p. 1).

The hydrodynamic characteristics of an aerodynamically refined planing-tail hull were determined from dynamic model tests in Langley tank no. 2. Stable take-off could be made for a wide range of locations of the center of gravity. The lower porpoising limit peak was high, but no upper limit was encountered. Resistance was high, being about the same as that of float seaplanes. A reasonable range of trims for stable landings was available only in the aft range of center-of-gravity locations.

"The production-model 333-A-23 turbojet-engine compressor with a 17-blade impeller was operated at ambient and 0 F inlet temperatures and at inlet pressures of 14 and 5 inches mercury absolute for equivalent impeller speeds from 6000 to 12,750 rpm. The results of this investigation are compared with those of the 533-A-21 compressor. At the design equivalent speed of 11,750 rpm the maximum pressure ratio was 4.39" (p. 1).

"An altitude-test-chamber investigation was conducted to determine the operational characteristics and altitude blow-out limits of a Solar afterburner in a 24C engine. At rated engine speed and maximum permissible turbine-discharge temperature, the altitude limit as determined by combustion blow-out occurred as a band of unstable operation of about 8000 feet altitude in width with maximum altitude limits from 32,000 feet at a Mach number of 0.3 to about 42,000 feet at a Mach number of 1.0. The maximum fuel-air ratio of the afterburner, as limited by maximum permissible turbine-discharge gas temperatures at rated engine speed, varied between 0.0295 and 0.0380 over a range of flight Mach numbers from 0.25 to 1.0 and at altitudes of 20,000 and 30,000 feet" (p. 1).

Based on results of longitudinal trim and tumble tests of a 0.057-scale model of the Chance Vought XF7U-1 airplane, the following conclusions regarding the trim and tumble characteristics of the airplane have been drawn: 1. The airplane will not trim at any unusual or uncontrolled angles of attack. 2. The airplane will not tumble with the center of gravity located forward of 24 percent of the mean aerodynamic chord. When the center of gravity is located at 24 percent of the mean aerodynamic chord and slats are extended and elevators are deflected full up, the airplane may tumble if given an external positive pitching moment.

"A series of calculations of the dynamic response of airplane wings to gusts were made with the purpose of showing the relative response of a reference airplane, the DC-3 airplane, and of newer types of airplanes represented by the DC-4, DC-6, and L-49 airplanes. Additional calculations were made for the DC-6 airplane to show the effects of speed and altitude. On the basis of the method of calculation used and the conditions selected for analysis, it is indicated that: 1) The newer airplanes show appreciably greater dynamic stress in gusts then does the reference airplane; 2) Increasing the forward speed or the operating altitude results in an increase of the dynamic stress ratio for the gust with a gradient distance of 10 chords" (p. 1).

"The compression plane is intended for operation on or close to the surface of the water, and has a hull with a concave bottom which forms the upper surface of a tunnel into which air is forced under pressure to support part of the load. The results of the tests made in Langley tank no. 1 include values of the horizontal forces, trimming moment, and static pressure in the tunnel for a wide range of loads and speeds and two power conditions, and are presented in the form of curves against speed with load as a parameter. The results are scaled up to 10 times the model size for three conditions at which the model is self-propelled at a steady speed" (p. 1).

From Summary: "The performance of an annular combustion chamber from a 24C turbojet engine was investigated over a range of simulated altitudes from 20,000 to 55,000 feet and corrected engine rotor speeds from 6000 to 13,000 rpm at a simulated ram-pressure ratio of 1.04. The purpose of the investigation was to determine the effects on the altitude operational limits, combustor-outlet gas temperature distribution, combustion efficiencies, and combustor inlet-to-outlet total-pressure drops of two changes in the 24C-4B basket air-passage arrangements that were designed to improve combustor-outlet temperature distribution. These changes were: (a) replacement of the downstream secondary air holes with large rectangular slots further upstream (rectangular-slot basket), and (b) enlargement of anticoking holes in the rectangular-slot basket (modified rectangular-slot basket)."

Report presenting aerodynamic characteristics of uncambered symmetrical parabolic and double-wedge airfoils with leading-edge and trailing-edge flaps using the Busemann second-order-approximation theory. Characteristics presented include aileron effectiveness factor, rate of change of hinge-moment coefficient with aileron deflection, rate of change of the pitching-moment coefficient, and the location of the center of pressure of the airfoil-aileron combination.

Report presenting a general analysis that allows the rolling motions of an aircraft using a displacement-response, flicker-type automatic pilot to be determined. The system is not ideal for many stabilization problems due to inherent residual oscillations, but it offers a simple and economical solution in situations in which steady state oscillations are not a problem. Results regarding some general remarks, transient and steady states, stabilization boundaries, amplitude equations, and period equations are provided.

Report presenting the results of pitching-moment and lift measurements on a model of the D-558-1 airplane with no nose-inlet flow at several tail and elevator settings at a range of Mach numbers. Information about the stability, control, and downwash results is provided.

Report presenting testing of a low-acceleration transonic flutter test vehicle to obtain flutter data on two similar sweptback wings which indicated that wing flutter was symmetrical in mode. Results regarding flight and flutter characteristics for the FR-1-B are provided.

Report presenting an investigation using the NACA wing-flow method to determine the longitudinal stability and control characteristics at transonic speeds of a semispan airplane with a 45 degree sweptback wing and tail. Measurements of the lift and angle of attack for trim were made for several stabilizer and elevator settings. Testing was also performed to investigate the effects of transition wires mounted on the wing and tail, the effect of increasing the boundary-layer thickness on the test surface, and the effectiveness of a wing flap with a sweepback of 45 degrees.

Report presenting an investigation of control systems suitable for target-seeking missiles. Testing occurred in the free-flight tunnel of the GB-5 glide bomb equipped with a light-seeker control unit which applied flicker control. Results indicated that good stability could be obtained with the control system, but was somewhat less stable than with a proportional control system.

Report presenting the operational characteristics of a 20-inch ramjet with four different gutter-grid flame holders and a three-gutter flame holder with an adjustable gutter angle. The flame holders were compared on the basis of operating ranges of fuel-air ratio, combustion-chamber-inlet velocity, and the combustion efficiencies obtainable.

Memorandum presenting some pressure-distribution and boundary-layer measurements made in flight in the presence of shock on two modifications of the local contour of the wings of a high-speed airplane. Results regarding the pressure distribution, boundary-layer surveys, and effects on test airplane are provided.

"An investigation of the rolling effectiveness at transonic and supersonic speeds of a wing-aileron configuration simulating the D-558-2 airplane has been made by means of a rocket-propelled test vehicle. The variation of rolling effectiveness with Mach number is similar to that obtained previously for tapered sweptback wings having full-span, 0.2-chord ailerons" (p. 1).

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.