Digital avionics susceptibility to high energy radio frequency fields

Generally, noncritical avionic systems for transport category aircraft have been designed to meet radio frequency (RF) susceptibility requirements set forth in RTCA DO 160B, environmental conditions and test procedures for airborne equipment. Section 20 of this document controls the electromagnetic interference (EMI) hardening for avionics equipment to levels of 1 and 2 V/m. Currently, US equipment manufacturers are designing flight-critical fly-by-wire avionics to a much higher level. The US Federal Aviation Administration (FAA) has requested that the RTCA SC-135 high-energy radio frequency (HERF) working group develop appropriate testing procedures for section 20 of RTCA DO 160B for radiated and conducted susceptibility at the box and systems level. The FAA has also requested the SAE AE4R committee to address installed systems testing, airframe shielding effects and RF environment monitoring. Emitters of interest include radar (ground, ship, and aircraft) commercial broadcast and TV station, mobile communication, and other transmitters that could possibly affect commercial aircraft