MAINTAINABILITY DESIGN TECHNIQUES METRIC - AcqNotes.com

Downloaded from http://www.everyspec.com on 2011-10-29T14:56:01.DOD-HDBK-791(AM)Figure 10-6. 90% Motion Sickness Protection Limits for Human Exposure to Very LowFrequency Vibrationcontrol vibration by isolation, proper balancing of rotatingmachinery, and provision of damping materials orcushioned seats for personnel.10-3.1.4 Terrain FactorsThe terrain factors listed in Table 10-2 do not affect theperformance of maintenance personnel directly. Thesefactors may make it more difficult to arrive at the scenewhere maintenance is required or to recover materiel thatrequires maintenance. The terrain factors may also makeit more difficult to locate a suitable shop area.10-3.2 EFFECTS ON EQUIPMENTEquipment must be designed for ease of maintenance inthe environments identified in Table 10-2 and discussed inpar. 10-2. The risk of failure due to natural and inducedenvironmental factors and their combined effects must beminimized to limit the maintenance demand. Accord-ingly, environmental design criteria should be included inmaintainability considerations. The maintainability factorsof simplicity, ease of access, location of drains, permanentidentification of parts, etc., have been discussedin previous chapters; it is important that they be appliedwith consideration to the expected environment. Themaintainability engineer must be aware of the specificenvironment in which materiel will be operated and maintainedin order to develop a comprehensive maintainabilityplan.The current philosophy that equipment must bedesigned to operate anywhere in the world has addedclimatic and terrain factors to the performance efficiencyevaluation criteria. The destructive effects of inducedenvironmental factors—e.g., shock, vibration, and chemicalagents -and natural environmental factors e.g.,wind, sand, dust, humidity, and solar radiation—are notto be ignored. However, they play a minor role whencompared to the relentless attack of induced moisture-10-12