TEST AND INSPECTION - Continued
Elevation Travel and Travel Deviation Inspection - Continued
If testing M171A1 mount, four quick release pins (item 5A, WP 0133 00) must be
installed on M137 panoramic telescope used for testing.
To ensure accuracy of travel deviation inspection, two maintenance personnel may be
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Rotate elevation handwheel (3) from 270 mils depression through 800 mils elevation (line of sight must
not deviate more than 0.25 mil); rotate from 801 mils elevation through 1333 mils elevation (line of
sight must not deviate more than 0.50 mil).
Use fire control quadrant on adapter plate to ensure that optical instrument support
is parallel and perpendicular to mounting surface of M171/M171A1 mount within 0.5
If deviation exceeds 0.25 mil from -270 to 800 mils or 0.50 mil from 801 to 1333 mils,
the M137/M137A2/M137A3 telescope reticle line must be brought in coincidence with
center line of wall target. To accomplish this, perform the following steps.