Discrepancies Caused by Common Industry Standard Practices Part 1: Environment Specification

Industry standard practices lead to discrepancies in the severity of flight and test environments. Steps in common processes defined in guidance documents are based upon assumptions and simplifications not always evident. Not acknowledging these assumptions leads to non-flight like environments in test and analysis. Documents such as MIL-STD-1540, NASA-HDBK-7005, and MIL-STD-810 all provided valuable guidance but should not be applied without consideration of underlying assumptions and simplifications. Hypothetical examples, based on real experiences, will be reviewed to illustrate the importance of understanding, modifying, or eliminating the assumptions and simplifications. The examples provided are primarily random vibration environments but the messages also apply to other dynamic environments including shock and acoustics. This paper is separated into two parts. The first addresses environment specification. The second addresses qualification and acceptance test requirements.