"This report presents the results of tests made on three sizes of roots type aircraft engine superchargers. The impeller contours and diameters of these machines were the same, but the length were 11, 8 1/4, and 4 inches, giving displacements of 0.509, 0.382, and 0.185 cubic foot per impeller revolution. The information obtained serves as a basis for the examination of the individual effects of impeller speed and displacement on performance and of the comparative performance when speed and displacement are altered simultaneously to meet definite service requirements" (p. 3).

"The pressure distribution tests described in this report, covering angles of attack up to 90 degrees, were made on a rectangular monoplane wing model in the atmospheric wind tunnel of the Langley Memorial Aeronautical Laboratory. These tests indicate that a rectangular wing, by reason of its large tip loads, is uneconomical aerodynamically and structurally, has pronounced lateral instability above maximum lift, and is not adaptable to accurate calculation based on the classical wing theory" (p. 197).

The investigation presented in this report was conducted for the purpose of determining the distribution and magnitude of water pressures likely to be experienced on seaplane hulls in service. It consisted of the development and construction of apparatus for recording water pressures lasting one one-hundredth second or longer and of flight tests to determine the water pressures on a UO-1 seaplane float under various conditions of taxiing, taking off, and landing. The apparatus developed was found to operate with satisfactory accuracy and is suitable for flight tests on other seaplanes. The tests on the UO-1 showed that maximum pressures of about 6.5 pounds per square inch occur at the step for the full width of the float bottom. Proceeding forward from the step the maximum pressures decrease in magnitude uniformly toward the bow, and the region of highest pressures narrows toward the keel. Immediately abaft the step the maximum pressures are very small, but increase in magnitude toward the stern and there once reached a value of about 5 pounds per square inch. (author).

"This investigation was made for the purpose of determining the characteristics of five full-scale propellers in flight. The equipment consisted of five propellers in conjunction with a VE-7 airplane and a Wright E-2 engine. The propellers were of the same diameter and aspect ratio. Four of them differed uniformly in thickness and pitch and the fifth propeller was identical with one of the other four with exception of a change of the airfoil section" (p. 267).

Different applications of the slotted-wing principle are discussed as well as the advantages of using them. Slotted-wings are provided as a promising solution to the problem of needing to increase flight speed for aircraft while also decreasing landing speed.

The endeavor to draw a strict line between gliders and soarers as been recently abandoned and the following classification adopted: 1) gliders controlled by shifting the weight of the body; 2) gliders controlled by rudders; 3) gliders controlled by wings. The different classes are discussed as well as materials and parts used in construction.

The investigation was limited chiefly to the region of high angles of attack since it is only in this region that any considerable change in the character of the flow can be expected from such artificial aids. The slot, through which compressed air was blown, was formed by two pieces of sheet steel connected by screws at intervals of about 5 cm. It was intended to regulate the width of the slot by means of these screws. Much more compressed air was required than was originally supposed, hence all the delivery pipes were much too small. This experiment, therefore, is to be regarded as only a preliminary one.

I am now proposing a method for the preliminary approximate calculation of the thrust distribution and efficiency of air propellers under any operating conditions. Our task becomes the following, namely, to determine the speed relations and the forces developed on a section with a given direction and velocity of the air current, a problem which can be solved with the aid of the momentum theory.

This report contains descriptions of construction techniques at the Vickers plant including the building of the "wandering web," the spar flange, and the Vickers spars.

This report presents methods to reduce the incidence of aviation accidents. Some of the methods discussed include enlistment and training of aviators, improvement of controls and control surfaces, and upgrading of power plants.

"The main object of these wings was to obtain a high lift without increasing the total drag, and the idea was conceived that, by using a deep high-lift section for the top wing and a medium section for the bottom wing, the mutual interference between the two would be such as to give greater efficiency of the combination as compared with two wings of equal section" (p. 1).

It is proposed in this paper to identify some of the defects and failures in duralumin most frequently encountered by the aircraft industry with a view to indicate their importance. The defects and failures in duralumin may be classified into the following groups: 1) defects produced during manufacture; 2) defects produced during fabrication; 3) corrosion and erosion; and 4) fatigue failures. Only the first two will be covered in this report.

The present report contains the results of a few experiments on three airfoils to which the rear portions, having chords respectively 1/4, 1/3, and 2/5 of the total chords, are hinged so as to form ailerons, especial attention being given to the shape of the slot between the aileron and the main portion of the aileron.

Brief summary of the geographic distribution, habits, history, and subgenera of Synaptomys.

From Summary: "Tests have been made in the atmospheric wind tunnel of the National Advisory Committee for Aeronautics to determine the effects of pitching oscillations upon the lift of an airfoil. It has been found that the lift of an airfoil, while pitching, is usually less than that which would exist at the same angle of attack in the stationary condition, although exceptions may occur when the lift is small or if the angle of attack is being rapidly reduced. It is also shown that the behavior of a pitching airfoil may be qualitatively explained on the basis of accepted aerodynamic theory."