"So far, very careful investigations have been made regarding the flight properties, in particular the static and dynamic stability, of engine-propelled aircraft and of untowed gliders. In contrast, almost no investigations exist regarding the stability of airplanes towed by a towline. Thus, the following report will aim at investigating the directional stability of the towed airplane and, particularly, at determining what parameters of the flight attitude and what configuration properties affect the stability" (p. 1).

We have set ourselves the problem of calculating the laminar flow on a body of revolution in an axial flow which simultaneously rotates about its axis. The problem mentioned above, the flow about a rotating disk in a flow, which we solved some time ago, represents the first step in the calculation of the flow on the rotating body of revolution in a flow insofar as, in the case of a round nose, a small region about the front stagnation point of the body of revolution may be replaced by its tangential plane. In our problem regarding the rotating body of revolution in a flow, for laminar flow, one of the limiting cases is known: that of the body which is in an axial approach flow but does not rotate.

A study is made of the advantages that can be realized in compressible-flow research by employing a substitute heavy gas in place of air. The present report is based on the idea that by properly mixing a heavy monatomic gas with a suitable heavy polyatomic gas, it is possible to obtain a heavy gas mixture which has the correct ratio of specific heats and which is nontoxic, nonflammable, thermally stable, chemically inert, and comprised of commercially available components. Calculations were made of wind-tunnel characteristics for 63 gas pairs comprising 21 different polyatomic gases properly mixed with each of three monatomic gases (argon, krypton, and zenon).

The Redox process uses or produces only a very few materials that are hazardous for reasons other than radioactivity. The conditions under which these materials become hazardous were carefully taken into consideration in the development of the process and design of the equipment. A considerable about of information on the hazardous properties of the process materials was obtained so that the pertinent material could be incorporated into the process specifications. Providing the equipment is operating properly and the process is being carried out within specification limits, no hazardous conditions can be created by the process. The purpose of this report is to assemble in a single, readily available document all of the information on the normal concentration limits and safe handling procedures needed to adequately control the use and storage of these materials. This report should be helpful in preparing safety bulletins and provide guidance in case of unusual incidents, malfunctioning of equipment, or contemplated changes in either the process or equipment. It is important to remember that a maximum allowable concentration (MAC) is only a limit on the concentration of a toxic material which cannot be exceeded in the air to which workers are constantly exposed to every working …

Unsteady shock-induced separation of the ramp boundary layer was reduced and stabilized more effectively by external perforations than by external or internal slots. At Mach 2.0 peak total-pressure recovery was increased from 0.802 to 0.89 and stable mass-flow range was increased 185 percent over that for the solid ramp. Peak pressure recovery occurred just before instability. The 7 and one-third-diameter duct ahead of the engine reduced large total-pressure distortions but was not as successful for small distortions as obtained with throat bleed. By removing boundary-layer air the bypass nearly recovered the total-pressure loss due to the long duct.

Summary of trafficability studies conducted by the Waterways Experiment Station. It includes information about phase I tests related to "Soil Classification and Trafficability Data" as a sub-project of "Trafficability of Soils as Related to the Mobility of Military Vehicles" (published 1947-1955). It also includes initial results of phase II, "Soils Trafficability Predictions."

From introduction: In this report the authors have attempted to present a strictly factual account of the birth and development of Paricutin volcano and avoid any interpretive opinions that might break the true narrative of events.