It is extremely important in building aircraft engines to determine the requisite cylinder dimensions as accurately as possible, in order that the weight required for a given power shall not be excessive. This report presents a calculation method that depends on the air requirement of the fuel.

Memorandum presenting a glossary of terms used to describe flying boat hulls and the elements used in construction.

Report describing a competition for safety fuel tanks, including the prizes, requirements that must be fulfilled, some other characteristics, tests, and regulations.

Essential principles for building small diesel engines and also structural details so far as feasibility are presented.

The mechanism here described belongs to the class of dynamometer brake in which the motive power is transformed into heat in the brake itself. This mechanism was invented by the writer for the purpose of measuring forces in which the two factors, torque and speed, vary within broad limits, the mechanism itself being of simple construction and of still simpler operation.

Report details the characteristics and advantages of the swift traffic airplane constructed by Zeppelin Works at Staaken. The maximum speed, weight, construction, layout, and landing capabilities of the plane are included.

This report presents a listing of the many experiments in aerodynamics taking place at Cuatro Vientos. Some of the studies include: testing spheres, in order to determine coefficients; mechanical and chemical tests of materials; and various tests of propeller strength and flexibility.

Where, in the following report, mention is made of fatigue, it always refers to the weakening of the material produced by rapidly changing stresses below the point of elasticity. The alternating stress was obtained by a test bar which was held at one end and subjected to rotation. Most of the tests were conducted on connecting rods.

Any one endeavoring to solve the problem of soaring flight is confronted not only by structural difficulties, but also by the often far more difficult aerodynamic problem of flight properties and efficiency, which can only be determined by experimenting with the finished glider. The report primarily considers open-air experiments with glider models and some specific elements of gliders that have been studied using these experiments.

A design for a wind vane is presented and various applications are discussed. The equations that can be used to calculate effects on the aircraft using the vane and control assistance that can be provided using the wind vane are provided.

It is hardly possible for the most imaginative aeronautical enthusiast to look forward to a time when the airplane will have reached the dimensions commensurate with those already attained by the airship.

This article discusses two areas of international air travel, namely, passports and customs, as well as smuggling.

From Introduction: "In the following discussion, a knowledge of the theoretical principles of airplane construction is assumed, as presented in detail by Vogt and Lippisch in Nos. 7 and 10-19 of the 1919 volume of this publication. A few quantities will however be otherwise designated, in accordance with the Gottingen symbols."

The present report will treat only the smallest airplanes equipped with engines. The two types discussed are those airplanes with the smallest dimensions, and those that have the smallest power requirements.

"The end of the war saw every belligerent with vast stocks of aircraft and aircraft supplies in all stages of usefulness, much of the material being absolutely new. The question of the best method of getting rid of this accumulation is one which has been agitating those responsible for its disposal for more than three years now, but no wholly satisfactory solution has yet been reached" (p. 1).

The decrease in air traffic on the London-Paris route is examined and possible solutions are presented.

On an airplane, the safeguards adopted may be divided into three classes, those intended to prevent a fire from getting started, those intended to put it out if it does get under way, and, finally, those designed to limit the damage which a fire can do. Some of the fire-related elements discussed include protecting the gasoline, fire extinguishers, a flame-tight bulkhead, and airship hazards.

These new regulations are intended to replace those of November 1, 1922, and give the directions to be followed in the supervision of aircraft by the agents of the Aeronautical Section of the Bureau Veritas. The rules consist of four sections: rules regarding an aircraft leaving a repair shop, the objects of quarterly and weekly inspections, and rules regarding the upkeep and repair of airplanes.

Report presenting an exploration of the concept that the ratio between the volume and the surface area also exerts an influence on other secondary characteristics of airships.

The author describes experiments in designing nonrigid airships. A nonrigid airship of 32,000 cubic meters, the PL 27 withstood all stresses with 20 kg/m(exp 2) hull pressure during its life of two years. The moment of resistance is known, as also the stresses in the envelope for the given hull pressure. The mean internal pressure necessary to give the airship the requisite rigidity and to prevent buckling was also investigated.

"The Commissariat of Aviation deems it expedient to issue a few rules of a general character which should be followed by constructors in designing aircraft, into the manufacture of which metal enters to a considerable extent. The materials covered include: aluminum, duralumin, soft steel, high-resistance steel, in sheets, tubing, and shaped elements" (p. 1).

Turbulence was generated by using screens, and the turbulence percentage was measured by a hot-wire anemometer both in the boundary layer and the free stream. The local heat-transfer coefficient was measured at 12 locations along the plate for the cases of various turbulence levels. The transition Reynolds number from laminar to turbulent flow decreases as the main-stream turbulence level increases. In the range of laminar heat transfer the effect of turbulence in the main flow was not great, but in the range of turbulent heat transfer the heat-transfer coefficient increases according to the increase of turbulence.

"The climb of turbojet aircraft is analyzed and discussed including the accelerations. Three particular flight performances are examined: minimum time of climb, climb with minimum fuel consumption, and steepest climb. The theoretical results obtained from a previous study are put in a form that is suitable for application on the following simplifying assumptions: the Mach number is considered an independent variable instead of the velocity; the variations of the airplane mass due to fuel consumption are disregarded; the airplane polar is assumed to be parabolic; the path curvatures and the squares of the path angles are disregarded in the projection of the equation of motion on the normal to the path; lastly, an ideal turbojet with performance independent of the velocity is involved" (p. 1).

Equations are developed using the source distribution method for the velocity potential function and pressure on thin wings in steady and unsteady motion. Closed form solutions are given for harmonically oscillating wings of general plan form including the effect of the wing wake. Some useful examples are presented in an appendix for arrow, semielliptical, and hexagonal plan form wings.