MIL-M-48559A, MILITARY SPECIFICATION: MOUNT, TELESCOPE AND QUADRANT - M172A1 (30-MAR-1990) [S/S BY MIL-DTL-48559B]

MIL-M-48559A, MILITARY SPECIFICATION: MOUNT, TELESCOPE AND QUADRANT - M172A1 (30-MAR-1990) [S/S BY MIL-DTL-48559B]., his specification covers one type of telescope and quadrant mount which supports the Fire Control Quadrant: M18 and gives elevation compensation to correct for cant when the mount is leveled by a cross level movement. The mount also supports and aligns the mounting bracket for the Elbow Telescope: M138.