Special Conditions: Raytheon Aircraft MU-300 Airplanes; High Intensity Radiated Fields (HIRF)

These special conditions are issued for Raytheon Aircraft Company Model MU-300 airplanes modified by ARINC, Inc. These airplanes will have novel and 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 a Thommen AD32 Air Data Display Unit (ADDU) which incorporates a Digital Air Data Computer and Altimeter. 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.