Downloaded from https://www.everyspec.com MIL-STD-81OD 19 July 1983 d. Test item configuration: to be tested in both the assembled external1y-carried aircraft stores may have and free-flight configurations. e. Whether one test obviates another: if one test is more stressful in all variables than another; the easier test need not be performed (e.g., func- tional test vs endurance test, captive flight vs. free flight). I-3.1.1 Procedure I . -. ronmenta1 worthiness teSt. The’environmental worthiness test is a relatively short test used during engineering development to identify defects in a prototype‘or flight test item before attempting service’or flight testing““withthe same unit.
It helps to eliminate simple, rapidly occufiingproblems that c“andelay or prevent SerViCe Or flight teSting. The test simulates the most severe environmental conditions expected during service or flight testing. ., . I-3.1..2 Procedure II - Oua-tion t-. The qualification test is ‘usedto demonstrate the fest itemts compliance with contract requirements. Only the most severe anticipated service environments are used as the basia for testing. , It is divided “into functional and endurance tests. The functional test must be tailored to show whether ‘theitem can’perform to specificationin the most severe environment of its service life.
The endurance test is an accelerated test and must”be tailored to simulate the item!s lifetime damage accumulation. Test sequence is one-half hour functional test, endurance test, and another one-half hour functional tegt,. 1-3.1.3 ~. A mission profile teat can be used when a close correlation is desired between test time and acoustic stress exposure time in service. This is not an accelerated test since testing is performed at “realisticstress “levels. ., I-3.1.4 J’rocedureIV - Cavitv resonance test. Aircraft compartments or stores that open during flight can expose cavities to the airstream. Standing waves often become established in such cavities at the resonant frequencies of the cavity.
The resulting acouatic noise is very intense. I-3.2 Choice of test c~. . The choice of test conditions dependa on (1) The procedure chosen. (2) The availability of measured -dataon the test item’s operational acoustic environment. (3) The location of the test item with respect to the noise source. (4) Whether the noise source or distributed. + ,. ,, in the operational environment ie”localized (5) The mission profile(s). (6) The predicted life-cycle O ,, history of the item. METHOD 515.3 19 July 1903 515.3-3