Special Conditions: Raytheon HS.125 Series 700A/B Airplanes; High Intensity Radiated Fields (HIRF)

These special conditions are issued for Raytheon HS.125A Series 700A/B airplanes, modified by Midcoast Aviation, Inc. These modified 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 modification incorporates the installation of dual Rockwell Collins Air Data Computers (ADC-87A) and ALI-80A altimeters. 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 provided by the existing airworthiness standards.