=-.. Downloaded from https://www.everyspec.com MIL-STD-81OD 19 July 1983 I-3.6 lrocedure ~it drw . Procedure IV is intended for equipment in its transit or o a. combination case as prepared for field use (carried to a combat situation by man, “truck,rail, etc.). It is used to determine if the test item is.capable of withstanding the shocks normally induced by loading and unloading of equipment.~ ~ b. Procedure IV is”not intended for shocks encountered in a normal logistic ahipping environment as experienced by shipping containers. c. ~. Test levels for this test are shown in table 516.3-II. The test item shall be tested in the same configuration that is carried into .acombat situation.
For test items under 45 Kg (100 pounds), the 26-drop requirement may be divided among up to five ‘copiesof the same test item if desired, in any combination. Toppling of the item following impact will occur in the field and, therefore, toppling of the test item following its ;1 the required drop surface. initial impact ehould not be restrained as long as the test item does not leave d. ~. Levels for this test were set by considering how a field equipment item might commonly be dropped.
(For example, a light equipment item might be carried by one man cheat high; thus, it could drop 122 cm.) Field data have shown that a typical piece of man-portable equipment will be dropped from heights up to 122 am (48 inches) an average of four to six times during its life cvcle. The 26-droo requirement exists to insure that each vulnerable position . (facea, edges, and”cor~ers) of a typical teat item receives one impact. I-3.7 procedure V - C ash biiaa&d r . a. Procedure V is for equipment mounted in an air or ground vehicle that could break looee from its mounts and present a hazard to vehicle occupants. It is intended to verify the structural integrity Of equipment.
mounts during simulated crash conditions. b. Procedure V is not intended for equipment transported as cargo. (For cargo; uae method 514.3) c. Use figure 516.3-1 as the test spectrum for the axis of test, provided that the effective shock duration TE falls between 6 and 9 milliseconds for flight equipment and between 3.5 and 5.0 milliseconds for ground equipment. If shock spectrum analysis capabilities are not avsilable,. figure 516.3-4 may be used as an alternative to figure 516.3-1. :, d. E&&n&2. An aircraft crash level of 40 is based on the fact that, during a survivable crash, localized g levels can approach 40’g’s.
Ground transportation vehicles are designed with a higher safety factor and, therefore, can sustain a much higher g level; thus, the higher test level. I-3.8 ErQ.wdure VI - ~ a. Procedure VI should be used for equipment that may experience bench or bench-type maintenance. It is used to determine the ability of the test item to withstand the usual level of shock encountered during typical bench maintenance or repair. MZTHOD 516.3 19 July 1983 516.3-12