"Icing data collected on routine operations by four DC-4-type aircraft equipped with NACA pressure-type icing-rate meters are presented as preliminary information obtained from a statistical icing data program sponsored by the NACA with the cooperation of many airline companies and the United States Air Force. The program is continuing on a much greater scale to provide large quantities of data from many air routes in the United States and overseas. Areas not covered by established air routes are also being included in the survey. The four aircraft which collected the data presented in this report were operated by United Air Lines over a transcontinental route from January through May, 1951" (p. 1).

Report presenting the results of a study of the movement of shocks on a three-dimensional wing with and without aileron flutter occurring. The studies include a number of changes and variations to the wing and control. Results for the standard wing and aileron, spoilers at 50 percent chord, upper and lower surface, faired bumps at the 50-percent-chord and 70-percent-chord positions, variations of thickness ratio along the span, vent holes between upper and lower surface, aileron-contour change, aileron mass overbalance, dampers, wing flutter, buffeting forces on fixed controls, and static characteristics are provided.

Report presenting flight testing on two propeller-driven airplanes with wings of NACA 66-series and NACA 230-series airfoil sections to determine the effect of deflecting the landing flaps upward on the high-speed longitudinal-control characteristics.

Memorandum presenting the results of a wind-tunnel investigation of the low-speed aerodynamic characteristics of a horizontal-tail model of aspect ratio 2 with an unswept plan form and of a two-dimensional model. The two-dimensional model provides data which can be used as the basis for computing the three-dimensional lift and hinge-moment parameters by the lifting-surface-theory procedure. Results regarding the effectiveness and hinge-moment parameters, static longitudinal stability, scale effect, effect of standard roughness, and effect of removing the elevator nose seal are provided.

This paper presents a continuation of the work published in Technical Report no. 496. The results of that paper have been extended to include the effect of aerodynamic balance and the effect of a tab added to the aileron. The aerodynamic coefficients are presented in a form convenient for application to the flutter problem.

An investigation was undertaken to determine the characteristics of several basic types of thrust-reverser. Models of three types, target, tailpipe cascade, and ring cascade, were tested with unheated air. The effects of design variables on reverse-thrust performance, reversed-flow boundaries, and thrust modulation characteristics were determined.

A report about thermodynamic properties of several minerals which have been constructed in a form convenient for calculation of chemical equilibria of minerals and of problems related to the heat content of rocks.

"This report presents the results of experiments designed to determine the response of selected military high-range radiacs to extended gamma radiation fields with and without a phantom (simulated operator)." (from Abstract)

The program KRUDE, which solves the slowing down and adjoint equations for a mixture of resonance and nonresonance isotopes in an infinite homogeneous medium, was used to evaluate some resonance capture approximations (variational and successive) that use linear combinations of narrow and wide resonance fluxes. Results obtained for resonance capture in the 291-ev resonance of Zr/sup 91/ and the 192-ev resonance of U/sup 238/ are compared, and three methods for including Doppler effects in the variational method are considered.

The variational method is applied to the monoenergetic time dependent transport equation to obtain a simple relation for the asymptotic decay constant in small pulsed assemblies. The results indicate that flat trial functions may be a reasonable representation of the flux distributions in the thin slab limit. This approach is superior to many of the usual transport approximations.

Report documenting ongoing research and development undertaken by the Metallurgy Division of the Oak Ridge National Laboratory.

Report of the annual conference on weights and measures, hosted by the U.S. National Bureau of Standards in Washington D.C. It includes conference proceedings, a list of attendees, information about committees and officers, and other reports or commentaries discussed at the meetings.

From Introduction: "This report is concerned with the presentation of planning data in a form that facilities direct application to the initial stage of design."

"A theoretical method for evaluating the stability characteristics and the amplitude and the frequency of pulsation of ram-jet engines without heat addition is presented herein. Experimental verification of the theoretical results are included where data were available. Theory and experiment show that the pulsation amplitude of a high mass-flow-ratio diffuser having no cone surface flow separation increases with decreasing mass flow" (p. 1).

"The transonic aerodynamic characteristics of wings of finite span are discussed from the point of view of a unified small perturbation theory for subsonic, transonic, and supersonic flows about thin wings. This approach avoids certain ambiguities which appear if one studies transonic flows by means of equations derived under the more restrictive assumption that the local velocities are everywhere close to sonic velocity. The relation between the two methods of analysis of transonic flow is examined, the similarity rules and known solutions of transonic flow theory are reviewed, and the asymptotic behavior of the lift, drag, and pitching-moment characteristics of wings of large and small aspect ratio is discussed" (p. 1055).

A presentation of the values for the Pu²³⁹ fission cross section f factor extended into a higher energy range than previously reported in BNL-250. The values were obtained by integrating the standard expression defining the f factor on the Hanford IBM-CPC equipment. The un-fit experimental data of Leonard, as corrected for resolution and doppler effect, was used above 0.03 ev being attached to an analytic fit applicable below this point. Results are shown on the accompanying graph.

Monthly letter report on the research on the development of a beta-ray particle size analyzer (BPSA).

The purpose of the test was to determine the radiation levels in a Reactor Plant Boiler Compartment with the respective loop shut down and the remainder of the plant operating at power. The highest radiation levels recorded in the IC Boiler Compartment were located in the vicinity of the reactor coolant loop pipe penetrations of the Compartment. Except for the above mentioned areas, personnel could continuously occupy the IC Boiler Compartment without exceeding the maximum dose rate of 300 mr per week. The areas in the vicinity of the reactor coolant pipe penetrations, however, could be occupied only 1 to 2 hours per person per week because of the high radiation levers (200-250 mr/hr) present at these locations.

The ORNL analog computer was used to examine one aspect of a safety system for the EGCR. The thermal behavior of the fuel as a result of increases in reactivity at various power levels and gas flows was examined. Safety actions initiated by wither a flux-minus-flow signal or a reactor outlet gas temperature signal were included in simulation.