Special Conditions: Boeing Model 747SP Series; 747-100 Series; and 747-200B, -200C, and -200F Series Airplanes; High-Intensity Fields (HIRF)

These special conditions are issued for Boeing Model 747SP series; 747-100 series; and 747-200B, -200C, and -200F series airplanes. These airplanes will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. The airplane modification includes the installation of an Electronic Flight Instrument System (EFIS), which performs critical functions. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for the protection of this system from the effects of high-intensity-radiated fields (HIRF). These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.