Special Conditions: Sabreliner Model NA-265-60 Airplanes; High-Intensity Radiated Fields (HIRF).

These special conditions are issued for Sabreliner Model NA- 265-60 airplanes modified by Flight Research, 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 altimeter/air data display units manufactured by Innovative Solutions and Support, Inc. These display units 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.