Mitigation of EMP coupling into sensitive, mission critical equipment is essential for Aircraft required to operate in adverse nuclear environments. As has been demonstrated in several aircraft test-fix-test programs, traditional hardening can eliminate most EMP problems but generally adds weight, volume, and complexity which impacts system reliability, maintainability and hardness surveillance. Fiber optic technology reduces weight, volume, and complexity while reducing overall life cycle costs and can also mitigate or eliminate many EMP related problems. As requirements for data transfer volume increase, aircraft system expansion utilizing present technology within extended design constraints is hampered by mission requirements for extensive EMI, RFI, EMP, lightning and short circuit shielding and protection. The criticality of excessive weight and space needed for shielding protection is well known and so are the problems of bent pins associated with filter pin connec-tors. The use of non-metallic composite structural materials for the aircraft skin further exacerbates the traditional shielding and filtering problems. The complete elimination of shielding and filtering is not possible. However, the use of fiber optics paths, complex penetrations and other intentional or inherent inadvertent conductors and thereby greatly simplifies EMP hardening. The inherent dielectric nature of fiber optics makes it relatively resistant or immune to the upset/damage potential of EMP. Fiber optic technology is also capable of electromagnetic interference and cross talk. The vulnerability of fiber optic technology to other significant factors in the operational environment, i.e., ionizing radiation, should also be examined and assessed.