d. Check the operation of the focusing mechanism to determine
that it functions smoothly and that parts are not too tight.
e. Check the covers and the eyepiece cover caps for ease of
application and removal. Examine for damaged threads and de-
termine whether they seat properly.
f. Look into the telescope and examine the optical elements for
signs of breakage, dirt, grease, moisture, and deterioration of adhesive
balsam in the compound lenses. Defects of this nature can be seen by
looking through the objective end of the telescope.
g. The image should appear sharp and clear, and should be up-
right when the telescope is in normal operating position.
h. Examine the carrying cases for open seams, broken stitches,
deteriorated elastic, torn or frayed straps and strap loops, defective
fasteners, broken snap rings, etc.
a. Instruments found defective must be repaired or adjusted to
make them serviceable. Defects noted and action to be taken must
be entered on the inspection form (O.O.F. 7229). The action to be
taken will be governed by the facilities available.
a. Tools for the accomplishment of maintenance described in this
manual may be found in the instrument repair kit furnished to ord-
18. CLEANING AND PRESERVING MATERIALS.
GREASE, lubricating, special (for all lubrication where grease is
OIL, lubricating, for aircraft instruments and machine guns (for all
lubrication where oil is required)
b. Cleaning Materials.
ALCOHOL, ethyl, grade 1 (for cleaning optical parts)
BRUSH, artist, camel's hair (for removing dust and lint from optics)
PAPER, lens tissue (for cleaning polished glass surfaces)
SOAP, liquid, lens cleaning
SOLVENT, dry cleaning (for cleaning metal components)