From Summary: "These properties compare favorably with those of the strongest similar alloys previously investigated. However, compared with a 60Cr-25Fe-15Mo alloy, the three cobalt-chronium-nickel cast alloys are inferior. A correlation of NACA and OSRD (Project NRC-8) data is presented, showing the variation of rupture strengths with temperature in the range of 1350^o to 2000^o for alloys."

Report discussing about 400 references pertaining to the hydrodynamic design of seaplanes have been compiled, and the information is presented in the form of abstracts classified under six main headings.

From Summary: "Qualitative investigations have shown that use of the NACA injection impeller with the R-3350 engine increases the inertia of the fuel-injection system and, when the standard fuel-metering system is used, this increase in inertia results in poor engine acceleration characteristics. This investigation was therefore undertaken to determine whether satisfactory acceleration characteristics of the engine equipped with the injection impeller could be obtained by simple modifications to the fuel-monitoring system. The engine was operated with two types of carburetor; namely, a hydraulic-metering carburetor incorporating a vacuum-operated accelerating pump and a direct-metering carburetor having a throttle-actuated accelerating pump."

From Summary: "Tests of a 1/7 size model of the Grumman XJR2F-1 amphibian were made in Langley tank no.1 to examine the landing behavior in rough water and to measure the normal and angular accelerations experienced by the model during these landings. All landings were made normal to the direction of wave advance, a condition assumed to produce the greatest accelerations. Wave heights of 4.4 and 8.0 inches (2.5 and 4.7 ft, full size) were used in the tests and the wave lengths were varied between 10 and 50 feet (70 and 350 ft, full size)."

A 1/5.5-size powered dynamic model of the Columbia XJL-1 amphibian was landed in Langley tank no. 1 in smooth water and in oncoming waves of heights from 2.1 feet to 6.4 feet (full-size) and lengths from 50 feet to 264 feet (full-size). The motions and the vertical accelerations of the model were continuously recorded. The greatest vertical acceleration measured during the smooth-water landings was 3.1g.

From Introduction: "This report presents only that portion of the data from the first ditching which was to be used roughly establish the accelerations experienced by the pilot and the amount of water pressure to which the fuselage structure was subjected during the ditching."

Report presenting measurements of a Consolidated B-24D airplane of accelerations at various points on the wing during landing impacts. landings were made with the wheels initially stationary but free to rotate, with the brakes set before contact, and with the main wheels rotating prior to contact.

From Summary: "The sources of error that may enter into the measurement of airspeed by pitot-static methods are reviewed in detail together with methods of flight calibration of airspeed installations. Special attention is given to the problem of accurate measurements of airspeed under conditions of high speed and maneuverability required of military airplanes." (author).

Report discussing an adapter which uses three Tuckerman optical strain gages to measure the displacement of the three vortices of an equilateral triangle along lines 120 degrees apart. These displacements are substituted in well-known equations in order to compute the magnitude and direction of the principal strains. Tests of the adaptor indicate that principal strains over a gage length of 1.42 inch may be measured with a systematic error not exceeding 4 percent and a mean observational error of the order of + or minus 0.000006. The maximum observed error in strain was of the order of 0.00006. The directions of principal strains for unidirectional stress were measured with the adaptor with an average error of the order of 1 degree.

From Introduction: "The purpose of this report is to summarize, without extended proofs, the results of a study of a simplified model of nonadiabiatic, compressible fluid flow, both subsonic and supersonic, and to state these results in a form that will make them immediately useful in providing a theoretical background for current technical problems of high-speed combustion.

"About 500 additional references pertaining to hydrodynamic design of seaplanes have been compiled, and the information is presented in the form of abstracts classified under six main headings:GENERAL INFORMATION, HYDROSTATICS, HYDRODYNAMICS, AERODYNAMICS, OPERATION, and RESEARCH. The compilation is an extension of NACA RM No. L6I13, entitled "Abstracts Pertaining to Seaplanes," by Jerold M. Bidwell and Douglas A. King. An author index and a subject index are included" (p. 1).

From Introduction: "The present report, therefore, may be considered a supplement to reference 1. The combined scope of the stall charts of reference 1, designated A, and of the present work, designated B, is summarized in the following table: For the wing with root thickness ratio to 18 was also investigated.

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 an investigation of the characteristics of partial-span spoilers located at 0.75 of the chord on an NACA 66-series tapered wing, especially at high speeds. The effect of small spoiler projections was found to increase with an increase in speed until the critical Mach number was exceeded.

From Introduction: "The apparent increase in the inertia properties of a body moving in a fluid medium has been called the additional-mass effect. This report presents a resume of test procedures and results of experimental determinations of the additional-mass effect of flat plates. In addition to data obtained from various foreign sources and from a NACA investigation in 1933, the results of tests recently conducted by the National Advisory Committee for Aeronautics are included."

"Additional tests as recommended in reference 1 were made in the 7- by 10-foot wind tunnel of the 1/8-scale model of the Brewster F2A airplane to determine the angle of attack of horizontal tail and the elevator angles required for trim with flaps down" (p. 1).

Report discussing an aerodynamic control effectiveness study using free-flight, rocket-propelled test vehicles. Information about the effects of wing sweepback, aspect ratio, taper ratio, and section thickness ratio on the rolling effectiveness of full-span, sealed ailerons is provided.

Report presenting an application of the principle of aileron-stick forces and mechanical advantage to an aileron installation in which the stick forces are small over the low-deflection range and excessively large at full deflection.

"The purpose of this report is to show by analysis of existing data, pending direct experimental determination, the extent to which nonuniform distribution of fuel to cylinders of a multicylinder engine can produce temperature deviation and the benefits to be anticipated from attainment of uniform fuel distribution" (p. 1).

Report presenting a series of related flying-boat hull forms with various combinations of aerodynamic and hydrodynamic requirements that were tested in an NACA tank and high-speed tunnel. Effects explored included varying the height of the bow, varying the height of the stern, increasing the angle of dead rise at the bow, decreasing the angle of dead rise on the afterbody, increasing the depth of step, increasing the angle of afterbody keel, adding chine flare, adding a third planing surface, and rounded chines at the bow.

Report discussing a series of related forms of flying-boat hulls representing various degrees of compromise between aerodynamic and hydrodynamic requirements was tested in Langley Tank No. 1 and in the Langley 8-foot high-speed tunnel. The purpose of the investigation was to provide information regarding the penalties in water performance resulting from further aerodynamic refinement and, as a corollary, to provide information regarding the penalties in range or payload resulting from the retention of certain desirable hydrodynamic characteristics. The information should form a basis for over-all improvements in hull form.

From Introduction: "The results of the load tests and some additional aerodynamic characteristics of perforated double split flaps on a rectangular NACA 23012 airfoil are given in the present report."

"The data are presented in coefficient form and include lift, drag, and pitching-moment coefficients of the airfoil-flap comoinations and the normal-force, chord-force, and hinge-moment coefficients of the upper (perforated split) flap and lower (slotted) flap" (p. 1).

From Introduction: "The aerodynamic characteristics of a series of 10-foot-diameter propellers are being investigated in the Langley 16-foot high-speed tunnel in a comprehensive propeller research program. Using high-critical-speed NACA 16-series airfoil sections (reference 1), these propellers are designed to have Betz minimum induced-energy loss loading (reference 2) for a blade angle of 45^o at the 0.7 radius, when used as a four-blade propeller operating at an advance ratio of approximately 2.1 The ultimate purpose of the program is to determine the influence upon propeller design factors and of compressiblity; the propeller tests reported herein form part of the investigation of the effects of blade-section thickness ratio."