Special Conditions: Gulfstream Aerospace Corporation Model G-1159, G-1159A, and G-1159B Series Airplanes as Modified by Duncan Aviation; High Intensity Radiated Fields (HIRF)

These special conditions are issued for the Gulfstream Model G-1159, G-1159A, and G-1159B series airplanes modified by Duncan Aviation. These modified airplanes will have a novel or unusual design feature(s) associated with new avionics/electronics and electrical systems that will perform critical functions. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for the protection of these systems from the effects of high- intensity radiated fields (HIRF). These special conditions contain the additional safety standards the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.