Aircraft-engine-accessory vibration

THE vibration of aircraft power-plant accessories is one of those orphan problems which has been given “a thorough tossing around” for a good many years. For example, when an accessory manufacturer finds himself in the midst of an epidemic of accessory failures on a particular power-plant installation, he usually points to successful operation of the same accessory on other power-plant installations as proof of the fact that the failures are not due to a weakness in the accessory; the engine manufacturer points to other installations of the engine where the accessories are not in trouble; the airplane manufacturer easily proves that the airplane does not cause the failures.