as the latching mechanism, handle assembly, headrest assembly and lever
assembly, etc. Any of the possible defects defined above shall be cause
to consider a mount defective. Mounts which have passed the above
examination shall be subjected to all other tests of this specification.
220.127.116.11.1 Tetention. - Immediately following vibration, the shield
and the temporary reference marks shall be subjected to a visual examination.
The shield shall not have closed and the temporary reference marks shall
indicate no movement or change in position of the headrest due to vibration.
18.104.22.168 Extreme operating temperatures.- The testing equipment
utilized in this test shall be in accordance with the "Test Facilities"
requirements of MIL-F-13926 and the conditions of 3.4.2. The mount shall
be placed in the chamber and the temperature lowered gradually until the
chamber temperature is -40F. The mount shall be kept at this temperature
for a period of two hours. While still at the specified lower temperature
the mount shall then be subjected to the tests specified in 4.6.3. Upon
completion of these tests the mount shall be returned to standard ambient
temperature and it shall be visually examined for any failures in workman-
ship or materials. The mount shall again be placed in the test chamber
and the temperature gradually increased until the chamber temperature is
150F. The mount shall be kept at this temperature for a period of 2 hours.
At the end of this period and while still at the specified higher temperature
the mount shall be subjected to the tests specified in 4.6.3. When the
above tests have been completed the mount shall be returned to standard
ambient temperature and once again visually examined for any failures in
workmanship or material.
4.6.2 Orientation.- Special test equipment conforming to the require-
ments of Drawing F1055466O (Holding Fixture) shall be utilized to accept
the mount, completely assembled, and secure it in the position required
by 3.5. Set-up of the test equipment and installation of the mount under
test shall be performed in accordance with the applicable set-up instructions
contained on Drawing F11728872 (Set-Up Final Test Fixture for Mount Peri-
4.6.3 Performance. - To determine compliance with 3.6, the following
tests shall be performed with the complete mount positioned on the special
test equipment specified in 4.6.2.
22.214.171.124 Shield assembly.- To determine compliance with 3.6.1, the
locking plunger shall be released from its detent and the handle raised
to open the protective shield. The plunger shall then be positioned in
the upper detent where it shall lock the shield in the opened position.
The plunger shall be depressed once again and the handle lowered to close
the shield." When the plunger is engaged in the lower detent the shield
shall be locked in the closed position. The clearance between the shield
and the mount shall be 1/16 1/32 inch as shown in Drawing F8620000,
Mount, Periscope: M115.