From Summary: "The experimental investigation of damping screens described herein was undertaken primarily to test theories of the effects of damping screens and to obtain information on the performance of screens in oblique flow. The characteristics investigated include the damping of longitudinal and lateral components of turbulence, the effect of screens on scale, the conditions for the production of turbulence and eddies by screens, and the damping of spatial variations of mean speed."

From Introduction: "Since these results were not applicable to the present problem, a theoretical analysis of the aerodynamic properties of slender wing-body combinations was undertaken. The results of this investigation were first reported in reference 5 and were later extended in reference 6 to include cruciform-wing and body combinations. The present report summarizes and extends the theory and results previously presented in these references."

Report includes the National Advisory Committee for Aeronautics letter of submittal to the President, summaries of the committee's activities and research accomplished, bibliographies, and financial report.

Note presenting the application of the Laplace transformation to the solution of the lateral and longitudinal stability equations. The expressions for the time history of the motion in response to a sinusoidal control motion are derived for the general case in which all initial measurements are assumed different from zero.

"Theoretical blockage corrections are presented for a body of revolution and for a three-dimensional, unswept wing in a circular or rectangular wind tunnel. The theory takes account of the effects of the wake and of the compressibility of the fluid, and is based on the assumption that the dimensions of the model are small in comparison with those of the tunnel throat. Formulas are given for correcting a number of the quantities, such as dynamic pressure and Mach number, measured in wind tunnel tests" (p. 771).

"Theoretical blockage corrections are presented for a body of revolution and for a three-dimensional unswept wing in a circular or rectangular wind tunnel. The theory takes account of the effects of the wake and of the compressibility of the fluid, and is based on the assumption that the dimensions of the model are small in comparison with those of the tunnel throat. Formulas are given for correcting a number of the quantities, such as dynamic pressure and Mach number, measured in wing-tunnel tests. The report presents a summary and unification of the existing literature on the subject" (p. 771).

Report presenting the results of several years of experience of operation of a small water channel, which has shown that the hydraulic analogy can be used successfully to demonstrate many two-dimensional compressible-flow phenomena.

The results of local-instability tests of h-section plate assemblies and compressive stress-strain tests of extruded 75s-t6 aluminum alloy, obtained to determine flat-plate compressive strength under stabilized elevated temperature conditions, are given for temperatures up to 600 degrees F. The results show that methods available for calculating the critical compressive stress at room temperature can also be used at elevated temperatures if the applicable compressive stress-strain curve for the material is given.

An investigation was made of a 1/10-scale dynamically similar model of the Grumman FgF-2 airplane to study its behavior when ditched. The model was landed in calm water at the Langley Tank No. 2 monorail. Various landing attitudes, speeds, and configurations were investigated. The behavior of the model was determined from visual observations, acceleration records, and motion-picture records of the ditchings. Data are presented in tabular form, sequence photographs, time-history acceleration curves, and plots of attitude and speed against distance after contact.

"An investigation of a 1/14-scale dynamically similar model of the Northrop C-125 airplane was made to determine the ditching characteristics and proper ditching technique for the airplane. Various conditions of damage, landing attitude, flap setting, and speed were investigated. The behavior of the model was determined from visual observations, motion-picture records, and time-history deceleration records" (p. 1).

A ditching investigation of a model of the Convair-Liner airplane was made to observe the behavior and determine the safest procedure for making an emergency water landing. The ditching model was designed and constructed by the National Advisory Committee for Aeronautics. Design information on the airplane was furnished by the Consolidated Vultee Aircraft Corporation. A three-view drawing of the airplane is shown. The investigation was made in calm water at the Langley tank no. 2 monorail.

Report presenting an investigation in the stability tunnel to determine the effects of changes in horizontal-tail size and location on the static lateral stability characteristics of a complete model with wing and tail surfaces having the quarter-chord line swept back 45 degrees. Available procedures for predicting the effect of the horizontal tail on directional stability were found to be unreliable when applied to swept-tail configurations.

Results are presented of an investigation made to determine the two-dimensional lift and drag characteristics of nine NACA 6-series airfoil section at Reynolds numbers of 15.0 x 10sub6, 20.0 x 10sub6, and 25.0 x 10sub6. Also presented are data from NACA Technical Report 824 for the same airfoils at Reynolds numbers of 3.0 x 10sub6, 6.0 x 10sub6, and 9.0 x 10sub6. The airfoils selected represent sections having variations in the airfoil thickness, thickness form, and camber. The characteristics of an airfoil with a split flap were determined in one instance, as was the effect of surface roughness. Qualitative explanations in terms of flow behavior are advanced for the observed types of scale effect.

From Summary: "A solution is presented for the problem of the compressive buckling of simply supported, flat, rectangular, solid-core sandwich plates stressed either in the elastic range or in the plastic range. Charts for the analysis of long sandwich plates are presented for plates having face materials of 24S-T3 aluminum alloy, 76S-T6 Alclad aluminum alloy, and stainless steel. A comparison of computed and experimental buckling stresses of square solid-core sandwich plates indicates fair agreement between theory and experiment."

Memorandum presenting the flight tests of two airplanes with boundary-layer control are reviewed. The results for take-off and flight test measurements are reported. Suction proved to be an effective means of obtaining high lifts during flights.

Report presenting a study of the available rudder and elevator hinge-moment-coefficient data in order to determine the floating characteristics of various types of rudders and elevators in spinning attitudes. Results regarding the rudder floating characteristics, elevator floating characteristics, and a comparison of several types of rudders and elevators are provided.

A method is presented for the calculation of the flutter speed of a uniform wing carrying an arbitrarily placed concentrated mass. The method, an extension of recently published work by Goland and Luke, involves the solution of the differential equations of motion of the wing at flutter speed and therefore does not require the assumption of specific normal modes of vibration. The order of the flutter determinant to be solved by this method depends upon the order of the system of differential equations and not upon the number of modes of vibration involved. The differential equations are solved by operational methods, and a brief discussion of operational methods as applied to boundary-value problems is included in one of two appendixes. A comparison is made with experiment for a wing with a large eccentrically mounted weight and good agreement is obtained. Sample calculations are presented to illustrate the method; and curves of amplitudes of displacement, torque, and shear for a particular case are compared with corresponding curves computed from the first uncoupled normal modes.

"The theory is given for calculating the free-space oscillating pressures associated with a rotating propeller, at any point in space. Because of its complexity this analysis is convenient only for use in the critical region near the propeller tips where the assumptions used by Gutin to simplify his final equations are not valid. Good agreement was found between analytical and experimental results in the tip Mach number range 0.45 to two, three, four, five, six, on eight-blade propellers and for a range of tip clearances from 0.04 to 0.30 times the propeller diameter" (p. 785).

"An investigation has been made in the Langley gust tunnel with two identical airplane models approximating 1/40-scale models of the B-29, coupled in tandem with a boom so that the individual centers of gravity were equidistant from the single coupling joint at the tail of the lead airplane. Time histories of the boom joint load were obtained as the models were flown through a gust. The results indicate that on a similar configuration involving airplanes the size of B-29 airplanes a load on the boom joint of 10,000 to 14,000 pounds could be induced by encountering a gust of 50 feet per second and having a gradient distance of 17 chords, at a forward speed of 380 feet per second and that the total load is extremely sensitive to the steadiness of flight that can be maintained with or without a gust" (p. 1).

Report presenting an investigation of the icing of aircraft-engine induction systems. Criterions for safe operation and for the design of new induction system are established through the investigation. The results were obtained from laboratory investigations of carburetor-supercharger combinations, wind-tunnel investigations of air scoops, multicylinder-engine studies, and flight investigations.

Report presenting an investigation of a strain-gage torquemeter employing a circuit to minimize effects of contact resistance, which was evaluated under static and dynamic conditions. Effects of temperature, axial stress, slip-ring contact resistance, and speed on the operation of the torquemeter were investigated. Results regarding the torsion-shaft static calibration, axial-stress effects, and dynamic operation are provided.

"A rocket-propelled model of the MX-656 configuration has been flown through the Mach number range from 0.65 to 1.25. An analysis of the response of the model to rapid deflections of the horizontal tail gave information on the lift, drag, longitudinal stability and control, and longitudinal-trim change. The lift-coefficient range covered by the test was from -0.2 to 0,3 throughout most of the Mach number range" (p. 1).

Report presenting the theory of conical flow and its application to conical aircraft wings. Following an explanation of the theory, several types of wings are analyzed and compared with each other.

"Expressions are presented for the load distribution on a representative group of plan forms in sideslip at supersonic speeds. These expressions were obtained by the application of lifting-surface theories based on the linearized equation for compressible flow. Sketches of the load distributions are included" (p. 1).