Special Conditions: Aerospace Design & Compliance, LLC (ADC), Textron Aviation Inc. Model 550, 560, and 560XL Airplane; Electronic System Security Protection From Unauthorized External Access

These special conditions are issued for the Textron Aviation, Inc. (Textron) 550 (Bravo), 560 (Ultra Encore), and 560XL (Excel) series airplanes as modified by Aerospace Design & Compliance, LLC (ADC). This airplane will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport-category airplanes. This design feature is the installation of an electronic networks system architecture that will allow increased connectivity to and access from external network sources to the airplane's previously isolated electronic assets (networks, systems, and databases). The applicable airworthiness regulations do not contain adequate or appropriate safety standards for this design feature. 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.