MIL-DTL-48557B
vibration, the mount shall exhibit no evidence of damage or physical failure and shall meet
the requirements of 3.5 through 3.11 inclusive.
3.4.5 Vibration "B". The mount shall be vibrated in the vertical plane shown in
Figure 1 for a total of 15 ± 1 minutes of sweep cycle vibration. A complete sweep-cycle
shall consist of vibration from origin (5 Hz at 1 inch double amplitude) to mid-point (5 ±
0.5 g s at 500 Hz) to origin, and shall have a duration of 15 ± 1 minutes. Double amplitude
shall be constant at 1 inch between 5 Hz and 10 Hz and varied with frequency to maintain a
constant 5 ± 0.5 g s acceleration between 10 Hz and 500 Hz. Upon completion of
vibration, the mount shall exhibit no evidence of damage or physical failure and shall meet
the requirements of 3.5 through 3.11 inclusive.
3.5 Locating keys for M137A2 telescope. The locating keys for the M137A2
telescope shall be parallel to the recessed mounting surface of the mount within 1.0 mil.
3.6 Mounting surfaces of M17A1 quadrant. The mounting surfaces for the M17A1
quadrant shall be parallel to the recessed mounting surface of the mount within 1.0 mil.
3.7 Performance.
3.7.1 Locating keys for M17A1 quadrant. The locating keys for the M17A1
quadrant shall be parallel to the locating keyway of the recessed mounting surface within
0.5 mils.
3.7.2 Elevation level vial. When the mounting surface for the M137A2 telescope is
level, the elevation level vial bubble shall be centered within the width of a level vial
graduation line.
3.7.3 Elevation adjustment range. From a level starting position, the locating
keyway of the vertical mounting surface shall rotate through an excursion of not less than
1333 mils in elevation and not less than 270 mils in depression.
3.7.4 Elevation plumb travel. The line of sight shall not deviate horizontally from a
plumbed line by more than 0.25 mils when rotated through an excursion of 270 mils
depression to 800 mils elevation. From 801 to 1333 mils elevation, the total lateral spread
from the leftmost line of sight observed to the rightmost line of sight observed during the
excursion shall not be greater than 0.5 mils.
3.7.5 Pitch adjustment range. From a level starting position and using only the
pitch adjustment, the mount shall travel through an excursion of not less than 178 mils in
depression and not less than 178 mils in elevation.
3.7.6 Pitch plumb travel. The line of sight shall not deviate horizontally from a
plumbed line by more than 0.5 mils total lateral spread while it is being subjected to the
pitch travel excursion specified in 3.7.5.
5
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business