Special Conditions: Bombardier Inc. Model CL-600-1A11 Airplane; High-Intensity Radiated Fields (HIRF)

These special conditions are issued for Bombardier Inc. Model CL-600-1A11 airplanes modified by Duncan Aviation, Inc. These modified 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 dual Attitude Heading Reference Systems (AHRS) as well as a new Electronic Flight Information System (EFIS) that displays critical flight parameters to the flightcrew. The applicable airworthiness standards do not contain adequate or appropriate safety standards for the protection of these systems from the effects of high- intensity radiated fields. The 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.