1919-01-01

PROBABLE EFFECT ON AUTOMOBILE DESIGN OF EXPERIENCE WITH WAR AIRPLANES 190007

THE impression that recent aircraft experience should have taught engineers how to revolutionize automobile construction and performance, is not warranted by the facts involved. Aircraft and automobiles both embody powerplants, transmission mechanisms, running gear, bodies and controls, but their functions are entirely different. The controls of an airplane, except in work on the ground, act upon a gas, whereas with an automobile the resistant medium is a relatively solid surface. Similarly, the prime function of the fuselage is strength, weight considerations resulting in paying scant attention to comfort and convenience, which are the first requirements of an automobile body. Aircraft running-gear is designed for landing on special fields, and is not in use the major portion of the time. The running-gear is the backbone of an automobile, in use continuously for support, propulsion and steering; hence its utterly different design. In an airplane the transmission system does not require variable ratios, is rigidly aligned and covers only short distances, so that the automobile can borrow little from it.
While much of the information acquired in aircraft work will undoubtedly be beneficial in automobile work, it must be considerably discounted because automobile flexibility and quietness are much more important than light weight and high mean effective pressure. Probably more aluminum will be used in automobile engines as commercial conditions permit, but wholesale adoptions of all-steel cylinders, sections machined to utmost lightness, etc., are prohibited at present by first-cost considerations. Most of the extreme methods of raising horsepower per pound are barred in automobiles on account of noise or their effect on flexibility.
Summarizing it is believed that the chief advantage derived from aircraft experience, aside from comparatively minor points, will be the tendencies of engineers to seek lighter weights at a cost within reason, better metallurgical results, better workmanship, and the like. In other words, the benefit will be from inspiration rather than from design details.

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