Downloaded from https://www.everyspec.com MIL-STD-81W IABLE S14.2-111 Test procedure andtimeschedulechartforequipmentinstaled in hcl icopters~ equipmentcategory(c) (peraxis) Fig.514.2-3 Procedure Procedure Sinusoidal SweepTime Curie number part .(Note3) (4:Z!Hf (note1) number Testtimeschedule Equipment mounting configu;at ion Without vibration isolators 1 ‘3 hrs 36 min M With vibration isolators 1 1 3 hrs 36 min M. 2 30 min 30 min B (note2) Normallywith vibration 1 2 30 in 30 nin B isolatorsbut testedwithout isolators Note 1:
Forsinusoidalvibrationcyclinctestsof itemszountedin heli- coptersandweighingmorethan80 pounds,thevibratoryaccelera - tionsshal1 be reducedhy 1 g foreach20-poundincrementof weightover80 pounds. Acceleration deratingshallapplyonly to thehighesttestlevelof the seiectedtestcurve. However, the ~,ibratory acceleration shal1 inno casebe lessthan50 percent of thespecifiedcurveletwl. Not@2: Testitemsof equipmentnormallyprovidedwithvibrationisolators firstshallbc testedwiththeisolatorsin place. Note3: SweepforcurveN is 5-2000-5Nz,curveB is 5-S00-5Nz. B. Curve selectionchartforcategory(c)equipment Selectioncriteria Curve Equipmentdesignedforinstallation without,:ihration isolxtors .
N Equipment instilled on vibration isolatedpanelsor racks when the paml or rack is not availablefortestor whentheequipmentis i testedwiththeisolatursrwm’cd as sveciiiedbY thea?plicablc I I “1’.cd,,rc, . I B 514.2-25 MSTHOD 514.2