Special Conditions: Lockheed Martin Corporation Model 1329-23A, -23D, -23E, and 1329-25 Airplanes; High-Intensity Radiated Fields (HIRF)

These special conditions are issued for Lockheed Martin Corporation Model 1329-23A, -23D, -23E and 1329-25 airplanes modified by Garrett Aviation Services. These modified airplanes will have novel or unusual design features when compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. The modification incorporates the installation of four Honeywell N1 Digital Electronic Engine Controls (DEEC) that 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 that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards.