Circular presenting a description of the Fiat T.R.1 airplane, which has been created for training and long-distance touring. Information regarding the fuel tanks, aircraft design, controls, tail characteristics, and flight characteristics is provided.

Circular describing the De Havilland "Leopard Moth", which is a three-seat cabin high-wing monoplane with a good cruising speed and fuel efficiency. Details of the components, controls, characteristics, performance, drawings, and photographs are provided.

Circular presenting a description of the Short "Empire" flying boat, which is an all-metal, four-engine, cantilever monoplane with a two-step hull.

Circular describing the Dewoitine D.332, which is a commercial three-engine all-metal low-wing monoplane form France. Details of the construction history, wing, fuselage, power plant, landing gear, characteristics, performance, drawings, and photographs are provided.

Circular presenting a description of the Handley Page 42, which is an all-metal sesquiplane. Details are provided of the cockpit, wings, fuselage, tail, power plant, landing gear, controls, and flying qualities.

"Although all constructors in Germany use duralumin quite frequently, and prefer cold riveting exclusively for permanent (nondetachable) connections of individual structural components, their methods and equipment are very diversified. The differences are due to a great extent to the diversity of structural types and to the special shapes of the individual subassemblies. The results is that different manufacturers have developed totally different riveting methods, as well as entirely different working methods" (p. 1).

Report issued by the U.S. Bureau of Mines covering the crude oils from different regions of Texas. Analysis of the properties of each oil sample from the different regions of the state are presented. This report includes tables, and a map.

Report issued by the U.S. Bureau of Mines on the issues of disposal of crude oil and natural gas brine. Disposal methods are studied and presented. This report includes tables, maps, and illustrations.

Report issued by the U.S. Bureau of Mines on the fatalities of coal miners in November, 1930. The common causes of death, and the location of the mines that the fatalities occurred in are listed. This report includes tables.

Report issued by the U.S. Bureau of Mines on the effects of different operating conditions on high-pressure natural gas pipelines. Analysis of past and current studies on natural gas transmission are presented. This report includes tables, graphs, and an illustration.

This report presents a method for solving the problem of liquid cooling at high temperatures, which is an intermediate method between water and air cooling, by experiments on a test-stand and on an airplane. A utilizable cooling medium was found in ethylene glycol, which has only one disadvantage, namely, that of combustibility. The danger, however is very slight. It has one decided advantage, that it simultaneously serves as protection against freezing.

English airplane construction is presented with a particular emphasis on metal construction techniques. Steel rib and fuselage construction are discussed as well as the use of duralumin in construction.

Report presenting an investigation of the drag and power cost associated with the changing of the nose of a nacelle from a streamline shape to a conventional cowling shape. Full-scale propellers and nacelles were used. The results of the tests showed that the streamline afterbody drag approached that of an airship form and that the added drag due to the open-nose cowling was only a quarter of the drag increase obtained with the other afterbody.

Report presenting testing of rectangular Clark-Y biplane cellules with zero and -0.25 stagger, the gap equal to the chord, and 0 degrees decalage were tested on the NACA spinning balance in the 5-foot vertical tunnel.

Four models of outboard floats (N.A.C.A. models 51-A, 51-B, 51-C, and 51-D) were tested in the N.A.C.A. tank to determine their hydrodynamic characteristics and in the 20-foot wind tunnel to determine their aerodynamic drag. The results of the tests, together with comparisons of them, are presented in the form of charts. From the comparisons, the order of merit of the models is estimated for each factor considered. The best compromise between the various factors seems to be given by model 51-D. This model is the only one in the series with a transverse step.

"Preliminary results are given of drag tests of streamline wires. Full-size wires were tested over a wide range of speeds in the N.A.C.A. high speed tunnel. The results are thus directly applicable to full-scale problems and include any compressibility effects encountered at the higher speeds. The results show how protuberances may be employed on conventional streamline wires to reduce the drag, and also show how the conventional wires compare with others having sections more like strut or symmetrical airfoil sections" (p. 1).

"This paper gives results of a short investigation of the drag of a forward-sloping closed-cabin windshield. The drag of the windshield in both the original and a final modified form was determined from tests in the variable-density wind tunnel. The final form of the windshield was arrived at by modifying the original as the result of flow observations in the N.A.C.A. smoke tunnel. The investigation studied the utility of the N.A.C.A. smoke tunnel as applied to reducing the drag of objects for which the full dynamic scale could not be approached in the smoke tunnel, but designers should find the results of the flow observations and drag measurements of value" (p. 1).

"It is shown that the control force of ordinary ailerons may be reduced to zero over a range of deflections and at a given flight condition by the use of an appropriate differential movement. Approximations to the ideal motion obtainable with a simple linkage are discussed and a chart that enables the selection of an appropriate crank arrangement is presented. Various aspects of the practical application of the system are discussed and it is concluded that a small fixed tab, deflected to trim both ailerons upward, would be advantageous" (p. 1).

This note presents the results of a series of tests made in the N.A.C.A. tank on a one-sixth full-size model of the hull and side floats of the Navy P3M-1 flying boat for the purpose of finding a method of reducing the amount of spray thrown into the propellers of this craft when taking off and landing. The model was tested without spray strips and with five different spray-strip arrangements. The best arrangement was an improvement over the bare hull with no spray strips, but the improvement was not sufficient to be satisfactory with the propellers in the designed position.

"A resume of the equations and formulas for the forces and moments on an aircraft-engine mount is presented. In addition, available experimental data have been included to permit the computation of these forces and moments. A sample calculation is made and compared with present design conditions for engine mounts" (p. 1).

"Pressure-distribution tests were made on the 32-foot whirling arm of the Daniel Guggenheim Airship Institute of a rectangular wing of NACA 23012 section to determine the rolling and the yawing moment due to angular velocity in yaw. The model was tested at 0 and 5 degree pitch; 0, +/- 5, and +/- 10 degrees yaw; and with no flap and with split flaps 25, 50 and 75 percent of the wing span and deflected 60 degrees. The results are given in the form of span load distributions and as calculated moment coefficients" (p. 1).

From Summary: "Charts are presented for the coefficients in the formulas for the critical compressive stress at which cross-sectional distortion begins in thin-wall columns of I-, Z-, channel, and rectangular-tube sections. The energy method of Timoshenko was used in the theoretical calculations required for the construction of the charts. The deflection equations were carefully selected to give good accuracy. The calculation of the critical compressive stress at stresses above the elastic range is briefly discussed in order to demonstrate the use of the formulas and the charts in engineering calculations. Two illustrative problems are included."

"The analysis of the bending action in box beams with appreciable shear deformation of the flanges becomes very difficult in the general case of variable cross section and loading. This paper presents a convenient method of solving the problem by the familiar method of dividing the beam into a number of bays that can be assumed to have constant cross section and loading. Application of formerly derived shear-lag formulas leads to a general equation closely analogous in form to the well-known three-moment equation" (p. 1).

"An aluminum-alloy plate containing an open circular hole of diameter large compared with the thickness of the plate was subjected to bending forces normal to the plane of the plate. Deflection and strain measurements were taken for two different loads. Stress concentrations occurred at the edge of the hole and the maximum stresses were tangential to the hole at the ends of the transverse diameter. The maximum stress at the edge of the hole was 1.59 times the computed stress on the net section and 1.85 times the computed stress in a solid plate of the same dimensions subjected to the same bending forces" (p. 1).