February 15, 1919

Topographic Surveying by Aerial Photography

The 80 Hp. Le Rhone Airplane Engine

Design of Airplane Struts


Topographic Surveying by Aerial Photography

Maps made from aerial photographs may be grouped into two principal divisions, namely, plain surface maps and contour maps. The present article deals mainly with contour maps, since they embody features which render them especially valuable for civil and commercial purposes, and thereby tend to make topographic surveying by means of aerial photography one of the leading uses for airplanes in peace times.


The 80 Hp. Le Rhone Airplane Engine

The 80 hp. Le Rhone revolving cylinder engine is one of the few pre-war types existent today. It has been used extensively at the front for scout and combat duty, but of late principally in observation and bombing, notably in the twin engined Caudron biplane.

Design of Airplane Struts

The failure of struts under end load is due to two causes, crushing, due to direct compression, and excessive bending, due to elastic instability. In a general way, we may say that the end portions of the strut tend to fail by crushing and the middle portion tends to fail by bending, but we cannot make a rule to decide where the middle portion ends and the end portions begin, because both causes are really operating simultaneously all along the strut, and we can only form a vague impression of their relative importance at various sections of the strut.


Navy Issues Seaplane Specifications

The Bureau of Supplies and Accounts of the Navy Department has issued a schedule for furnishing plans, supervisory assistance and construction of seaplanes, bids on which will be opened on 10 a. m., March 25, 1919. This schedule asks for (1) proposals for furnishing plans and such detailed data as will enable a producing aircraft concern to construct two experimental machines, including a proposal for rights of the Navy Department to manufacture other seaplanes of the type, and to incorporate any features in other seaplanes; (2) proposals for furnishing expert supervisory assistance in the construction and demonstration of the aforenamed two experimental machines in accordance with plans submitted by the bidders under item (1); and (3) proposals for the construction of three machines in accordance with items (1) and (2) and demonstration of one of them as herein provided, making the guarantees called for in this proposal.

Winds and the Trans-Atlantic Flight


News of the Fortnight

The annual meeting of the Society of Automotive Engineers, held on Feb. 4-6, 1919, at the headquarters of the society, in New York, was a representative gathering of the aeronautical world, both owing to the several important papers dealing with aeronautics that were presented and the large number of aircraft engineers and officers of the Army and Navy Air Services who attended the meeting.

Formula for Approximating Propeller Diameter

Before we can proceed to the design of a propeller by the usual methods, it is necessary to estimate the diameter that will be required, so that we may be able to choose proper proportions for the various sections. Unless we can find some formula which will obviate the element of guesswork, the first estimate is likely to be far astray, the diameter being either underestimated or overestimated, resulting in an absurdly wide or an absurdly narrow blade to absorb the required power.


The Curtiss Model K-6 Aircraft Engine

The Curtiss Model K-6 aircraft engine is of the vertical type, with six cylinders arranged in line; it is rated 150 hp. at 1700 r.p.m. The bore is 4.5 in., the stroke, 6 in. The cooling is effected by a centrifugal water pump, and lubrication by pressure feed; two high tension magnetos are used for ignition.

The Radial Fixed Cylinder Engine


The Curtiss Type 18-2 Triplane

The Curtiss type 18-2 triplane is a high-speed two-seater fighter of distinctly original design which promised to constitute a remarkable American contribution to the Allies’ fighting air forces, had not the war come to an end through the armistice.
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