Department of Transportation December 6, 2006 – Federal Register Recent Federal Regulation Documents

The FAA is revising an earlier NPRM for an airworthiness directive (AD) that applies to certain EMBRAER Model EMB-145, -145ER, - 145MR, -145LR, -145XR, -145MP, and -145EP airplanes. The original NPRM would have required replacing the electrical bonding clamps inside the fuel tanks and adjacent areas. The original NPRM resulted from a report of the failure of a fitting clamp of an electrical bonding cable for the fuel tubing. This action revises the original NPRM by adding airplanes to the applicability. We are proposing this supplemental NPRM to prevent loss of bonding protection in the interior of the fuel tanks or adjacent areas, and a consequent potential source of ignition in a fuel tank and possible fire or explosion.

The FAA issues these special conditions for Learjet 25, 25A, 25B, 25C, 25D, and 25F airplanes modified by Envoy Aerospace, LLC. These modified airplanes will have novel or unusual design features when compared with the state of technology envisioned in the airworthiness standards for transport category airplanes. The modification consists of installing Universal Avionics EFI-890 Electronic Flight Displays and Rockwell Collins AHS-1000A Attitude Heading Reference Systems. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for protecting these systems from 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.