MIL-DTL-48559B
4.3.4 Conformance rejection. If any item of the sample fails to comply with any of
the conformance requirements, the lot shall be rejected.
4.4 Environmental.
4.4.1 Storage temperature. The mount shall be placed in the test chamber and the
temperature of the chamber reduced gradually to -60 ± 5°F and shall remain at this
temperature for a minimum of 4 hours. At the completion of this 4 hour period, the mount
shall be removed from the environmental chamber and inspected for signs of physical
failure or damage. The mount shall be placed back in the environmental chamber and the
temperature shall then be gradually raised to +160 ± 5°F and the mount shall remain at this
temperature for a minimum of 4 hours. At the completion of this 4 hour period, the mount
shall be removed from the environmental chamber and inspected for signs of physical
failure or damage. The mount shall be placed back in the environmental chamber and the
temperature of the test chamber shall be gradually reduced to room ambient temperature
(+60°F to +90°F) at which time the mount shall be removed from the test chamber. The
mount shall then meet the requirements of 3.5 through 3.10 inclusive. (See 6.6, Thermal
shock.)
4.4.2 Operating temperature. The mount shall be placed in the environmental
chamber and the temperature of the chamber reduced gradually to -50 ± 5°F. The mount
shall remain at this temperature for a minimum of 4 hours. At the completion of this 4
hour period, and while at -50 ± 5°F, the mount shall meet the requirements of 3.5, 3.7, 3.8,
and 3.9 inclusive. Upon completion of this portion of the test, the mount shall then be
placed back in the environmental chamber and the temperature shall be raised gradually to
+145 ± 5°F. The mount shall remain at this temperature for a period of 4 hours. At the
completion of this 4 hour period, and while at +145 ± 5°F the mount shall again meet the
requirements of 3.5, 3.7, 3.8, and 3.9 inclusive. Upon completion of this test, the mount
shall be returned to the environmental chamber and the temperature shall be gradually
reduced to room ambient temperature (+60°F to +90°F) at which time the mount shall be
removed from the test chamber and shall meet the requirements of 3.5 through 3.10
inclusive. (See 6.6, Thermal shock.) The same units may be used for both storage
temperature and operating temperature verifications, if desired.
4.4.3 Shock. The M172A1 mount shall be mounted to the test equipment utilizing
the keyway and four mounting bolts torqued to 85-90 foot-pounds, a M18A1 Quadrant and
a M138A1 telescope or equivalent weight and center of gravity simulators shall be
mounted to it in the designated locations, and then it shall be subjected to the shock
requirements in accordance with 3.4.3. Fixture 11747193 may be used to adapt the mount
to the shock test equipment. Upon completion of the shock test, the mount shall be
examined and inspected to meet the requirements of 3.5 through 3.10 inclusive.
4.4.4 Vibration "A". The mount shall be mounted utilizing the keyway and four
mounting bolts torqued to 85-90 foot-pounds and then subjected to the vibration
requirements in accordance with 3.4.4. Fixture 11747193 may be used to adapt the mount
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