America's Munitions 1917-1918

by Benedict Crowell; United States. War Department

Broadly stated, and without reference to types of planes produced, these figures mean that the United States in her second year of the war produced for the American Army alone almost as many airplanes as Great Britain in her third year of the war built for both her army and navy. In October, 1918, factories in this country turned out 1,651 planes, which, without allowing for the monthly expansion in the production, was at the rate of 20,000 planes per year. Assuming no increase in the October rate of production, we would have attained the 22,000 airplanes in 23 months after July 1, 1917, the date on which the production effort may be said to have started. Our production of fighting planes in the war period was 3,328.

On the day the armistice was signed we had received from all sources 16,952 planes. Of these 5,198 had been produced for us by the allies. We had 48 flying fields, 20,568 Air Service officers, and 174,456 enlisted men and civilian personnel. These figures do not mean that we had more than 17,000 planes on hand at that time, because the mortality in airplanes is high from accidents and ordinary wear and tear.

THE PROBLEM OF MATERIAL.

Once we had started out on this enterprise we soon discovered that the production of airplanes was something more than a mere manufacturing job. With almost any other article we might have made our designs, given orders to the factories, and rested in the security that in due time the articles would be forthcoming. But with airplanes we had to create the industry; and this meant not only the equipping of factories, but the procurement and sometimes the actual production of the raw materials.

For instance, the ideal lubricant for the airplane motor is castor oil. When we discovered that the supply of castor oil was not nearly sufficient for our future needs, the Government itself secured from Asia a large quantity of castor beans, enough to seed more than 100,000 acres in this country and thus to provide for the future lubrication for our motors. This actual creation of raw materials was conducted on a much larger scale in the cases of certain other commodities used in airplane construction, particularly in the production of lumber and cotton and in the manufacture of the chemicals for the "dope" with which the airplane wings are covered and made air-tight.

An airplane must have wings and an engine with a propeller to make it go; and, like a bird, it must have a tail to make it fly straight and a body (fuselage) to hold all together. Part of the tail (the rudder) moves sideways and steers the airplane from left to right; part moves up and down (the elevators) and makes the airplane go up or down, and parts of the wings (the ailerons) move up and down and make the airplane tip from side to side. All of these things must be connected to the controls in the hands of the pilot. The front edges of the wings are raised above the line of flight; and when the propeller driven by the engine forces the wings through the air, the airplane is lifted and flies.

All of the airplanes built for the United States during the war were tractor biplanes. In a plane of the tractor type the propeller is in front and pulls the machine. The biplane is so called because it has two planes or wings, one above the other. The biplane has been the most largely used of all types in war for two reasons: first, the struts and wires between the planes form a truss structure, and this gives the needed strength; and second, there is less danger of enemy bullets wrecking a biplane in the air because its wing support is greater than that of the monoplane or single-winged machine.

Since the airplane can lift only a limited weight, every part of the mechanism must be as light as possible. An airplane engine weighs from 2 to 3 pounds per horsepower, whereas an automobile motor weighs from 8 to 10 pounds per horsepower. The skeleton of the airplane is made of wood, mostly spruce, with sheet-steel fittings to join the wood parts together, and steel wires and rods to make every part a truss. This skeleton is covered with cloth, and the cloth is stretched and made smooth by dope.

Wood, sheet steel, wire, cloth, varnish—these are the principal components of an airplane. As raw materials they all seem easy to obtain in America. And so they are in peace times and for ordinary purposes. But never before had quality been so essential in an American industry, from the raw material up to the finished product—quality in the materials used, and quality in the workmanship which fashions the parts. But combined with this quality we were forced to produce in quantities, bounded only by our own physical limitations, and these quantities must include not only the materials for our own air program but also some of the principal raw materials used by the airplane builders in France and England, specifically, all of the spruce which the allies would require and, later, much of the wing fabric and dope for their machines.