"An investigation has been made at large scale of the characteristics of highly swept wings. Data were obtained at several angles of sideslip on wings having angles of sweep of plus or minus 45 degrees, plus or minus 30 degrees, and 0 degrees. The airfoil sections of the wings varied from approximately NACA 0015 at the root to NACA 23009 at the tip. Each wing was investigated with flaps under flection, partial-span split flaps deflected 60 degrees, full-span split flaps defected 60 degrees and split-flap-type ailerons deflected plus or minus 15 degrees" (p. 1).

"Flight tests have been made with a P-51D airplane to determine the effect of chordwise vanes on the amplitude of tail buffeting. The tests made during abrupt pull-ups to the buffeting boundary included strain measurements on wing and tail and tuft studies over the wing. The results indicate that the vanes tested have no appreciable effect on the amplitude of tail buffeting" (p. 1).

Report presenting the application of simple sampling procedures to gust data obtained from P-61 thunderstorm flights in Orlando, Florida. The results demonstrated that the observed values of maximum effective gust velocities tend to be functions of the record distance of cloud survey.

Report presenting a study of the characteristics of a large-scale triangular wing to include the effects of section modifications. The wing in this report is the same as the one in the previous report but features various degrees of rounding of the wing leading edge and wing maximum thickness rather than having sharp edges. Results regarding the effects of airfoil section modifications, visible trailing vortices, and surveys in the extended chord plane are provided.

Report presenting airspeed and altitude data obtained from Lockheed Constellation airplanes flying between New York and San Francisco during May and June of 1946 in order to determine the probability of reaching or exceeding given values of airspeed and Mach number. Analysis indicated that the total probability of exceeding the placard "never extend" speed depends primarily on the probability of exceeding this speed in descent. The probability of exceeding the critical Mach number is very negligible.

From Introduction: "Experimental investigations (reference 1) have shown that in some cases the thrust can be more than doubled by means of tail-pipe burning. A comparison is made of a standard turbojet engine, whose thrust is augmented by tail-pipe burning, and a ram-jet engine. The performance characteristics for the ram-jet engine were computed entirely from theoretical considerations and on the assumption that the burner-inlet velocity was constant."

Report presenting testing of the low-speed aerodynamic characteristics in yaw of a 42 degree sweptback wing of circular-arc airfoil sections in the pressure tunnel. The wing had an aspect ratio of 3.94, taper ratio of 0.625, and no dihedral or twist. Results regarding lateral-stability parameters of plain wing, effect of wing flaps on lateral-stability parameters, effect of fuselage on lateral-stability parameters, a comparison with the NACA 64(sub 1)-112 wing, characteristics in the extended yaw range, and airflow characteristics in the region of a vertical tail are provided.

Report presenting an investigation of the surface pressures of the outer and inner surface of the bubble-type canopy in order to determine their load requirements. Testing was performed on a Grumman F8F-1 airplane. The forces on the canopy was found to be the highest when the airplane is operating at high speed with the canopy closed.

Report presenting an investigation of the mechanism of interaction of compression shock with boundary layer. Shockless pressure distributions at supercritical Mach numbers were found to be accounted for by a marked thickening of the boundary layer for some distance ahead of a shock wave.

A study of the relations existing among pin-point autoignition, homogeneous autoignition, and knock has been made by means of the NACA high-speed camera and the full-view combustion apparatus. High-speed photographic records of combustion, together with corresponding pressure-time traces, of benzene, 2,2,3-trimethylbutane, S-4, and M-4 fuels at various engine conditions have shown the engine conditions under which each of these phenomena occur and the relation of these phenomena to one another.

"A procedure is presented for obtaining the pressure distribution on an arbitrary airfoil section in cascade in a two-dimensional, incompressible, and nonviscous flow. The method considers directly the influence on a given airfoil of the rest of the cascade and evaluates this interference by an iterative process, which appeared to converge rapidly in the cases tried (about unit solidity, stagger angles of 0 degree and 45 degrees). Two variations of the basic interference calculations are described" (p. 1).

"Tests have been conducted in the Langley high-speed 7- by 10-foot tunnel over a Mach number range from 0.40 to 0.91 to determine the stability and control characteristics of an 0.08-scale model of the Chance Vought XF7U-1 airplane. The wing-alone tests and the effect of the various vertical-fin modifications, speed-brake modifications, and fuselage modifications on the aerodynamic characteristics in pitch and yaw are presented in the present paper with a limited analysis of the results. Also included are tuft studies of the flow for some of the modifications tested" (p. 1).

From flight tests of 0.5-scale models of the Fairchild Lark pilotless aircraft conducted at the flight test station of the Pilotless Aircraft Research Division at Wallops Island, Va., some evaluations of the static longitudinal stability were obtained by analysis of the short-period oscillations induced by the abrupt movement of the rudder elevators. The analysis shows that for the Lark configuration with wing flap deflections of 0 degrees and 15 degrees the static longitudinal stability decreases slightly up to the critical Mach number and than as the Mach number increases further the stability increases greatly.

Studies of the stalling characteristics show that the stall begins at the tip and moves inboard with increasing angle of attack at positive sweep; the sta11 begins at root and moves outboard at negative sweep (sweepforward). At +/-45 deg sweep the stall was less sharply defined than at the lower angles of sweep. No effect of Mach number on the.flow patterns as indicated by tufts was found in the speed range of these tests which extended to a Mach number of 0.55.

"A total of 197 hours of time histories of airspeed and altitude have been obtained on Lockheed Constellation airplanes flying between New York, N.Y. and San Francisco, Calif. during May 1946 and June 1946. Data for 130 hours were previously analyzed to determine the probability of attaining excessive airspeeds and Mach numbers and the results have been published. After the publication, data for additional 67 hours became available" (p. 1).

Wind-tunnel investigations were made in pitch and yaw with and without split flaps. Presence of the fuselage had negligible effect on values of maximum lift coefficient and slope of lift curve, but caused a destabilizing shift in the rate of change of pitching moment with lift. Effects of fuselage position on drag characteristics were small for wings without flaps, but were appreciable when split flaps were on.

"An investigation has been conducted on a one-sixth segment of an annular turbojet combustor to determine the effects of modification in air-flow distribution and total-pressure loss on the performance of the segment. The performance features investigated during this series of determinations were the altitude operational limits and the temperature-rise efficiency. Altitude operational limits of the combustor segment, for the 19XB engine using the original combustor-basket design were approximately 38,000 feet at 17,000 rpm and 26,000 feet at 10,000 rpm" (p. 1).

From Summary: "Tests with a dynamically similar model of the Navy XP4M-1 airplane were made to determine the best way to land the airplane in calm and rough water, to determine its probable ditching performance, and to determine practicable modifications which could be incorporated in the design of the airplane that would improve its ditching characteristics. The results were obtained by making visual observations, by recording longitudinal decelerations ,and by taking motion pictures of the landings. A list of conclusions from the test results is included."

"The results obtained from measurements of gust and draft velocities within thunderstorms for the period July 22, 1946 to July 23, 1946 at Orlando, Florida, are presented herein. These data are summarized in tables I and II, respectively, and are of the type presented in reference 1 for previous flights. Inspection of photo-observer records for the flights indicated that no data on ambient air temperature variations within thunderstorms were obtained" (p. 1).

From Summary: "An investigation has been made in the Langley two-dimensional low-turbulence pressure tunnel to develop the optimum configuration of a 0.35-chord slotted flap on an NACA 65(sub 1120)-111 airfoil section modified by removing the trailing-edge cusp. The section pitching-moment characteristics and the effects of standard roughness on the section characteristics were determined for the flap retracted at Reynolds numbers ranging from 3.0 x 10(exp 6) to 9.0 x 10(exp 6)."