5.20.1 RS105 applicability.
This requirement is
applicable to equipment and subsystem enclosures when the equipment or
subsystem is to be located external to a hardened (shielded) platform or
facility. The requirement is applicable for equipment intended solely for use
on non-metallic platforms when specified by the procuring activity. The
requirement is applicable to Army aircraft for safety critical equipment and
subsystems located in an external installation.