PREFACE
There always is a first time. There need not be a second.
Many articles have been written to shake persons from a lethargy, or as might be better stated, to keep them from getting into a state of lethargy. The latter is the author's intent for this article.
We apparently have not as yet learned the art of extending our total knowledge. We can accomplish complex and brilliant basic designs but then we miss some detail point, and the principle of that point missed may have been known for years. We can, and have, learned to profit by others experience. But not consistently. We have avoided repeating the difficulties of others. But there are times we miss.
If this prior information or these experiences are not continually passed along to each and every one, then all cannot benefit and some must of necessity repeat the experiences of others. Some new person or group will then run the gamut, experience the same pitfall.
Many experiences and detail design difficulties encountered each day are not at all peculiar to air transport equipment, nor to aircraft manufacturers, nor to equipment or accessory manufacturers, or any special breed of engineer or breed of shop mechanic or foreman. They are applicable to all industry and to all persons in the technical phases. As an example, the effect of sharp notches in structural members, resulting in stress concentrations and thus reduced fatigue life has been known to all technical industries for years and years. And thousands more could be enumerated. But still on occasion we miss. Apparently they are not always passed on to others so that everyone may profit by them. Sometimes the seasoned, “experienced” man knows, but the neophyte may not be up to date. Perhaps with the urgency and complexity of business today the “experienced” man may miss it too.
May this article encourage those who have had early experiences to pass them on; may it serve as a stimulus to each of us to constantly review and have checked what we already know; may it provide a consciousness of the existence of the problem with a resulting effort to avoid repetitions of mistakes.
On the theory that a brief review would be refreshing to the memory and stimulating to the retentive qualities of the brain, some of the more obvious detail design and manufacturing experiences, picked at random, are presented here.
It should be remembered that these do not apply only to a given unit or type of design; but the problems pointed out herein are of a general nature and can be encountered by any designer, or any shop man whether he is a propeller manufacturer, airplane manufacturer, engine manufacturer, airline operator kitchen utility manufacturer, bathroom designer, or what.
The people and the actual companies involved are not important, therefore no such references are contained herein. It is only the re-emphasis of principles brought out by this review of these problems that are important.
“Learn from the mistakes of others; you won't live long enough to make them all yourself.”