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October 1, 1917

Fog Conditions

News of the Fortnight

Digest of the Foreign Aeronautical Press

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Fog Conditions

Fogs may be divided into two kinds—those which consist of small drops of water which have been precipitated from vapor or in the air, and those which consist of smoke or dust particles and occur only in large towns or in manufacturing districts. Two conditions are necessary for the formation of a smokefog; firstly, the wind velocity near the ground must be very small, so that the air may collect enough smoke to form a fog while passing over the town; and secondly, the air near the ground must be relatively cold compared with the air higher up for a period sufficiently long to collect enough smoke to from a fog.

318319

News of the Fortnight

The bill authorizing the creation of an Aircraft Board was passed by the Senate on Sept. 12, as reported with amendments by Senator Sheppard, Chairman of the Committee on Military Affairs, and on Sept. 27, the Senate agreed to the House amendments officially creating an Aircraft Board, without sending the measure to conference.
316317

Digest of the Foreign Aeronautical Press

The De Havilland Single Seater Fighter.—According to the German aeronautical magazine Flugsport the De Havilland fighter, which the Royal Flying Corps extensively used during 1916, has the following characteristics: The machine is a pusher biplane of equal span and carries the steering gear on outriggers of the Maurice Farman type.
314315

Simplified Method of Propeller Calculation

In a paper called “The Screw Propeller in the Air,” read by M. A. S. Riach on March 21 before the Aeronautical Society of Great Britain, the author developed an analytical theory of the air screw, which was based on empirical results obtained from aerofoil data such as were first enunciated by by S. Drzewiecki, and later amplified by F. W. Lanchester in his work, “Aerial Flight.”
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Strut Charts

Calculations of struts form an important part of airplane design. There are the interwing struts, the interior wing stays for drift, the body longerons and the body struts. There are also the struts of the landing gear. Usually the lengths of these members are known, and also the load to which they will be subjected, the latter being obtained from the stress diagrams.

308309

The Paul Schmitt Airplane

The Paul Schmitt airplane, one of the largest French tractor biplanes, is distinguished by a very ingenious means for varying the angle of incidence of the wings in flight. Before proceeding to describe the means employed to obtain this result, the disadvantages of the fixed angle of incidence may be briefly dwelt upon.

308309

The Shaping of Airplane Propellers

After the propeller has been glued up it will usually be found that the glue has set in about twelve hours. The propeller may then be removed from the clamps. When the propeller is glued up the boards will nearly always be distorted somewhat so that strains in the wood will be introduced from this source.

312313

Book Review

"AIR NAVIGATION FOR FLIGHT OFFICERS." by A. E. Dixie, R. N. (D. Appleton & Co., New York, $4.00. 223 pp.) This book contains condensed information on the subject of aerial navigation. The subject matter is presented in a clear manner, and can be easily followed.
314315

The Design of Airplane Fittings

314315

The Kyle Smith Sporting Airplane

September 151917 October 151917