Federal Aviation Administration September 25, 2009 – Federal Register Recent Federal Regulation Documents

We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: Friction or contact between a propeller de-ice bus bar and the backplate assembly can cause failure of the bus bar and a consequent intermittent short circuit. Such a short circuit can cause a dual AC generator shutdown that, particularly in conjunction with an engine failure in icing conditions, could result in reduced controllability of the airplane.

We are revising an earlier proposed airworthiness directive (AD) for certain Boeing Model 747-100, 747-200B, 747-300, and 747SR series airplanes. The original NPRM proposed to require installation of a closeout panel and moisture curtains for the main equipment center. The original NPRM also proposed to require changing the drain tubes for the power drive units (PDU) and the pitot static tubes and installing larger moisture shrouds. The original NPRM resulted from a report of water contamination in the electrical and electronic units in the main equipment center. This action revises the original NPRM by adding airplanes to the applicability and removing certain others, and removing certain requirements. We are proposing this supplemental NPRM to prevent the malfunction of one or more electrical and electronic units in the main equipment center, which could adversely affect the airplane's continued safe flight.

This action corrects a final rule published in the Federal Register on August 26, 2009. In that rule, errors were made in the legal description and the airport name for North Bend, OR. This action corrects those errors.

This action confirms the effective date of an airspace action, which was previously published as a direct final rule in the Federal Register, for the Flagler County Airport in Bunnell, FL.