"Preliminary information on the complex subject of the fatigue strength of fabricated structural members for aircraft is presented in the test results obtained on several different types of airship girders subjected to axial tension and compression in a resonance fatigue machine. A description of this machine as well as numerous photographs of the fatigue failures are given. There is also presented an extended bibliography on the subject of fatigue strength" (p. 1).

"This work proposes to sketch, in broad outline, the status of airship construction in the various countries, at a time when commerce over great distances might be finally opened up to the airship through the performances of the "Graf Zeppelin." After a short historical review, a survey of the most important rigid and semirigid airships built since 1925, their differences and special problems, is made. In more detailed treatment, the framing construction of the more recent rigid airships and some especially interesting structural questions are investigated" (p. 1).

Memorandum presenting the history and development of airships. Tables containing information and statistics regarding some of the current airships are provided.

Many treatises in regard to construction of airship sheds are lacking in data on air currents, for which reason this phase of the problem will be here thoroughly discussed in connection with the accompanying photographs of currents.

Memorandum presenting a description of the development of the mooring mast and how it contributes to the technique of landing large airships. Some of its fundamental requirements and how it can factor into safe landings are provided.

Report includes the National Advisory Committee for Aeronautics letter of submittal to the President, Congressional report, summaries of the committee's activities and research accomplished, bibliographies, and financial report.

The causes of the destruction of the Dixmude are discussed and some conclusions are drawn. The author believes a gasoline fire instead of a lightning strike was probably responsible, but the public believes otherwise.

It became evident during World War I that ever-increasing demands were being placed on the mean power of aircraft engines as a result of the increased on board equipment and the demands of aerial combat. The need was for increased climbing efficiency and climbing speed. The response to these demands has been in terms of lightweight construction and the adaptation of the aircraft engine to the requirements of its use.

Report includes the National Advisory Committee for Aeronautics letter of submittal to the President, Congressional report, summaries of the committee's activities and research accomplished, bibliographies, and financial report.

Report includes the National Advisory Committee for Aeronautics letter of submittal to the president, congressional report, summaries of the committee's activities and research accomplished, bibliographies, and financial report.

Note presenting a graphic method for calculating the speed and climbing ability of airplanes. This method starts from the actual power developed by the engine and makes it possible to determine all factors which together constitute what are known as flight performances for any combination of engine and airplane from the single graphic diagram given.

Goldbeater's skin, which is the prepared outside membrane of the large intestine of an ox, is examined as a balloon fabric and details of how goldbeater's skin is prepared for use are provided. The construction techniques employed by Germany, France, and England are all discussed.

Report includes the National Advisory Committee for Aeronautics letter of submittal to the president, congressional report, summaries of the committee's activities and research accomplished, bibliographies, and financial report.

A historical sketch of duralumin is presented, especially in regards to its manufacture by various countries. The properties of duralumin are discussed and strength characteristics listed. Increasing the hardness of duralumin by tempering is discussed as well as the uses of the metal.

"Many experimental arrangements of varying kind involve the problems of assuring a large, steady air stream both as to volume and to time. For this reason a separate discussion of the methods by which this is achieved should prove of particular interest. Motors and blades receive special attention and a review of existent wind tunnels is also provided" (p. 1).

Report includes the National Advisory Committee for Aeronautics letter of submittal to the President, Congressional report, summaries of the committee's activities and research accomplished, bibliographies, and financial report.

The economic costs and benefits of speed on airship traffic are calculated and different factors are considered.

The purpose of this paper is to summarize the present status of the problem of mooring airships. Mooring with one, two and even three cables are all discussed.

Report includes the National Advisory Committee for Aeronautics letter of submittal to the President, Congressional report, summaries of the committee's activities and research accomplished, and expenditures.

Attempts by other countries to develop patents for alloys similar to duralumin are presented. Duralumin is aluminum alloyed with 3.5-4.5% copper, 0.5% magnesium, and 0.25-1% of manganese. A description of various materials that some have attempted to patent are provided.

Report includes the National Advisory Committee for Aeronautics letter of submittal to the president, congressional report, summaries of the committee's activities and research accomplished, bibliographies, and financial report.

Report includes the National Advisory Committee for Aeronautics letter of submittal to the President, Congressional report, summaries of the committee's activities and research accomplished, bibliographies, and financial report.

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.

This report gives a brief description of the present state of development and of the performance characteristics of instruments included in the following group: speed instruments, altitude instruments, navigation instruments, power-plant instruments, oxygen instruments, instruments for aerial photography, fog-flying instruments, general problems, summary of instrument and research problems. The items considered under performance include sensitivity, scale errors, effects of temperature and pressure, effects of acceleration and vibration, time lag, damping, leaks, elastic defects, and friction.