Summary
This document reopens the comment period for an earlier proposed airworthiness directive (AD) that proposed to supersede AD 90- 13-12, which currently requires modifying the airplane electrical system and revising the emergency procedures section of the Airplane Flight Manual (AFM) on certain Jetstream Aircraft Limited (JAL) Jetstream Models 3101 and 3201 airplanes. The proposal would have retained the requirements of that AD for those airplanes that have not installed modified inverters and restored the inverted transfer function. Since publication of that proposal, the Federal Aviation Administration (FAA) has re-examined various service difficulty reports on the affected airplanes, and determined that the proposed modification is still a valid safety issue (but not an urgent safety of flight issue). Since sufficient time has passed (more than 12 months) since the issuance of the original proposal, the FAA is allowing additional time for the public to comment. The proposed actions are intended to prevent alternating current system failures, which, if not detected and corrected, could result in damage to the airplane navigational systems.