Memorandum presenting a supplementary investigation in the 20-foot free-spinning tunnel to determine the effect of external stores and lateral center-of-gravity displacement on the spin and spin-recovery characteristics of a scale model of the McDonnell F2H-3 airplane. Results regarding wing-tip tanks and experimental aerodynamic shapes are provided.

Report presenting a partial-span wing tested to determine the cause of a flutter which had occurred in high-speed flight. Changes were made to the wing stiffness, location of the center of gravity of the wing, and the mass balance of the aileron. Results regarding the effect of wing changes on flutter, effect of aileron changes on flutter, shock-wave study, and static aerodynamic coefficients are provided.

Report presenting an investigation to determine the spin and recovery characteristics of a model of the Douglas AD-2W airplane, which has a large radome installation. Results indicated that the plane has satisfactory erect and inverted spin-recovery characteristics. Information about erect spins, inverted spins, and recommended recovery technique is provided.

Report presenting tests at Mach numbers between 1.36 and 2.01 of a twin-scoop duct inlet that had slots in the walls of the duct contiguous to the forebody and immediately behind the inlet. The mass flow and total-pressure recovery through the diffusor were measured during tests in which the slot length was constant and the slot width and ramp angle were varied. Results regarding mass flow and total-pressure recovery are provided.

From Introduction: "The purpose of the investigation conducted at the NACA Lewis laboratory and reported herein was to determine the improvements possible in full-scale turbojet-engine performance when a single-annular combustor with slotted air-inlet orifices was used."

Performance of the compressor, combustor, and turbine operating as integral parts of the XJ34-WE-32 turbojet engine was determined in the Lewis altitude wind tunnel over a range of altitudes from 5000 to 55,000 feet and flight Mach numbers from 0.28 to 1.05. Data were obtained for each of four exhaust-nozzle areas and are presented in graphical and tabular form.

Memorandum presenting a supplementary investigation conducted in the 20-foot free-spinning tunnel to determine the effect of external stores and lateral center-of-gravity displacement upon the spin and spin-recovery characteristics of a 1/20-scale model of the McDonnell F2H-3 airplane. Results regarding the tests with wing-tip tanks installed and with the experimental aerodynamic shape installed are provided.

From Summary: "This report covers the first part of an experimental investigation of NACA submerged inlets at four locations on the fuselage of a fighter airplane model for Mach numbers from 0.30 to 0.875. Data are presented showing the characteristics of the model without inlets and with inlets 16.7 percent of the root chord forward of the wing-root leading edge and equipped with small boundary-layer deflectors. The data show that variations in the mass of air entering the inlet had a large effect on the ram-recovery ratio."

From Summary: "Three methods for calculating span load distribution, those developed by V.M Falkner, Wm. Mutterperl, and J. Weissinger, have been applied to five swept wings. The angles of sweep ranged from -45 degrees to +45 degrees. These methods were examined to establish their relative accuracy and case of application. Experimentally determined loadings were used as a basis for judging accuracy. For the convenience of the readers the computing forms and all information requisite to their application are included in appendixes. From the analysis it was found that the Weissinger method would be best suited to an over-all study of the effects of plan form on the span loading and associated characteristics of wings."

"This paper presents the results of measurements of longitudinal stability of a 1/50-scale model of the XP-88 airplane by the wing-flow method. Lift, rolling-moment, hinge-moment, and pitching-moment characteristics as well as the downwash at the tail were measured over a Mach number range from approximately 0.5 to 1.05 at Reynolds numbers below 1,000,000. No measurements of drag were obtained" (p. 1).

An investigation was conducted to determine the effects of water injection on the over-all performance of a modified J33-A-27 turbojet-engine compressor at the design equivalent speed of 11,800 rpm. The water-air ratio by weight was 0.05. With water injection the peak pressure ratio increased 9.0 per- cent, the maximum efficiency decreased 15 percent (actual numerical difference 0.12), and. the maximum total weight flow increased 9.3 percent.

"An investigation was conducted to determine the effect of turbine-disk cooling with air on the efficiency and the power output of the radial-flow turbine from the Turbo Engineering Corporation TT13-18 turbosupercharger. The turbine was operated at a constant range of ratios of turbine-inlet total pressure to turbine-outlet static pressure of 1,5 and 2.0, turbine-inlet total pressure of 30 inches mercury absolute, turbine-inlet total temperature of 12000 to 20000 R, and rotor speeds of 6000 to 22,000 rpm, Over the normal operating range of the turbine, varying the corrected cooling-air weight flow from approximately 0,30 to 0.75 pound per second produced no measurable effect on the corrected turbine shaft horsepower or the turbine shaft adiabatic efficiency" (p. 1).