§25.1317 High-Intensity Radiated

Fields (HIRF) protection (See AMC 20-158) (a) Each electrical and electronic system that performs a function whose failure would prevent the continued safe flight and landing of the aeroplane must be designed and installed so that: (1) The function is not adversely affected during and after the time the aeroplane is exposed to HIRF environment I, as described in Appendix R; (2) The system automatically recovers normal operation of that function, in a timely manner, after the aeroplane is exposed to HIRF environment I, as described in Appendix R, unless the system’s recovery conflicts with other operational or functional requirements of the system that would prevent continued safe flight and landing of the aeroplane; and (3) The system is not adversely affected during and after the time the aeroplane is exposed to HIRF environment II, as described in Appendix R. (b) Each electrical and electronic system that performs a function whose failure would significantly reduce the capability of the aeroplane or the ability of the flight crew to respond to an adverse operating condition must be designed and installed so that the system is not adversely affected when the equipment providing the function is exposed to equipment HIRF test level 1 or 2, as described in Appendix R. (c) Each electrical and electronic system that performs a function whose failure would reduce the capability of the aeroplane or the ability of the flight crew to respond to an adverse operating condition must be designed and installed so that the system is not adversely affected when the equipment providing the function is exposed to equipment HIRF test level 3, as described in Appendix R.