3-7. OPTICS EXPOSED DURING MAINTENANCE
Exposed optics shall be cleaned in accordance with instructions in paragraph 3-8 when directed. If optics
are exposed for more than 5 minutes they must be protected. The following table indicates the optics
assemblies that are exposed during the performance of certain maintenance tasks. Use it as a guide and
proceed with the current task in accordance with the above information.
Optics exposed during maintenance are
identified in the following table by black dots.
Key number locates the optics in the figures.
Some optics are always exposed and should
be checked when performing maintenance.
Do not expose internal optics in windy
conditions when dust and sand could
Optics used for FLIR operation are specially
coated. The coating allows optimum FLIR
operation. Defective or worn coatings could
cause poor FLIR operation.
Cleaning wears away the coating, so optics
must not be cleaned routinely. Optics are to
be checked for contamination when they are
exposed. They are cleaned only when
directed. Refer to paragraph 3-8 for cleaning