Special Conditions; Avidyne Corporation, Inc.; Various Airplane Models; Protection of Systems for High Intensity Radiated Fields (HIRF)

These amended special conditions are issued to Avidyne Corporation, 55 Old Bedford Road, Lincoln, MA 01773, for a Supplemental Type Certificate for the models listed under the heading "Type Certification Basis." This special condition amends special condition 23-143, which was published on February 25, 2004 (69 FR 8551), to add two more airplane models and to change the Avidyne part number from Model 700-00006-1XX to 700-00006-XXX. This amendment also removes three aircraft models that do not require these special conditions. AC 23-143 includes various airplane models to streamline the certification process needed to improve the safety of the airplane fleet by fostering the incorporation of new technologies that can be certificated affordably under 14 CFR part 23. The airplanes will have novel and unusual design features when compared to the state of technology envisaged in the applicable airworthiness standards. These novel and unusual design features include the installation of an electronic flight instrument system (EFIS) display, Model 700-00006-XXX( ), manufactured by Avidyne Corporation, Inc., for which the applicable regulations do not contain adequate or appropriate airworthiness 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 the airworthiness standards applicable to these airplanes.