Report presenting an experimental study of the pressure fluctuations at the combustion-chamber inlets of a ramjet operating a Mach number of 1.92 in the supersonic tunnel. Results are presented for two burner configurations of different operating characteristics to indicate trends in pressure magnitude, frequency, and wave form. Results regarding the perforated conical flame holder, regenerative-type burner, and diffuser total-pressure recovery are provided.

Report presenting transonic speed testing utilizing a rocket-powered Bell XS-1 airplane with 10-percent-thick wing and 8-percent-thick horizontal tail. Information is provided for flights up to Mach number 1.06 and altitudes of about 40,000 feet. Results regarding the variation of control-surface positions and forces and sideslip angle with Mach number, time history, rudder effectiveness, and lateral oscillations are provided.

Ignition characteristics of AN-F-32 and two AN-F-58a fuels were studied in a single can-type turbojet combustor under air-flow conditions representing engine speeds of 1600, 2500, and 4000 rpm, altitudes from sea level to 30,000 feet, ambient temperatures at sea level from 90 degrees to minus 36 degrees F, and flight Mach numbers of 0 and 0.6. Critical fuel-flow rates for ignition increased with increase in preignition engine speed, with increase in altitude, or with decrease in sea-level ambient temperature. This flow rate appears to increase in a direct relation to decrease in fuel volatility as indicated by the 10-percent-evaporated temperature.

A preliminary study was made of the feasibility of three cycles for nuclear propulsion of aircraft: a direct-air-turbojet, a binary liquid-metal turbojet, and a helium compressor jet. All three cycles appeared feasible for flight at a Mach number of 0.9 and altitudes up to 50,000 feet; the liquid-metal cycle appeared feasible for flight at a Mach number of 1.5. The air and helium cycles resulted in heavier aircraft than did the liquid-metal cycle, particularly at a Mach number of 1.5. The relative advantage of the liquid-metal cycle became greater as the flight speed and altitude increased, and as the reactor wall temperature decreased.

Report presenting engine evaluation tests of twelve sets of cermet turbine blades. The first five runs were similar to previous engine tests, but the remaining ones were modified based on information gained during the first runs.

"Spin tests have been conducted in the Langley free-spinning tunnel on a 1/16-scale model of the McDonnell XP-85 airplane with the normal X-tail replaced with a short-coupled conventional tail arrangement. The effect of the conventional tail arrangement and the effects of various modifications upon the spin and recovery characteristics of the model were determined. The results of the tests indicated that installation of the conventional tail arrangement will not provide satisfactory recoveries from spins of the airplane" (p. 1).

From Summary: "The hottest part of a turbine blade is likely to be the trailing portion. When the blades are cooled and when water is used as the coolant, the cooling passages are placed as close as possible to the trailing edge in order to cool this portion. In some cases, however, the trailing portion of the blade is so narrow, for aerodynamic reasons, that water passages cannot be located very near the trailing edge. Because ceramic coatings offer the possibility of protection for the trailing part of such narrow blades, a theoretical study has been made of the cooling effect of a ceramic coating on: (1) the blade-metal temperature when the gas temperature is unchanged, and (2) the gas temperature when the metal temperature is unchanged."

Memorandum presenting surveys made at the exit of a radial-flow centrifugal impeller to obtain instantaneous values of velocity from blade to blade and at various positions between the front and rear diffuser walls. Surveys were also made at several radial stations midway between the walls of the diffuser to observe the radial change in the flow pattern through the vaneless diffuser. Results regarding typical trace, hub-shroud surveys, and radial surveys are provided.

From Summary: "This paper presents the results of an investigation of the dynamic stability and controllability of a model which approximately represents the Lockheed XFV-1 airplane to a 1/8 scale. The investigation consisted of hovering flights in still air at a considerable height above the ground, hovering flights very close to the ground, vertical take-offs and landings, flights through the transition range from hovering to normal forward flight, and sideways translational flights."

"A critical study was made of the operation of a type of back-fire arrester used to reduce the fire hazard of aircraft engines. A flame arrester consisting of a pack or plug of alternate flat and corrugated plates of thin metal was installed in the intake pipe of a gasoline engines; an auxiliary spark plug inserted in the intake manifold permitted the production of artificial back fires at will. It was found possible to design a plug which prevented all back fires from reaching the carburetor" (p. 211).