Department of Transportation January 4, 2006 – Federal Register Recent Federal Regulation Documents

Pursuant to FAA's rulemaking provisions governing the application, processing, and disposition of petitions for exemption, part 11 of Title 14, Code of Federal Regulations (14 CFR), this notice contains the disposition of certain petitions previously received. The purpose of this notice is to improve the public's awareness of, and participation in, this aspect of FAA's regulatory activities. Neither publication of this notice nor the inclusion or omission of information in the summary is intended to affect the legal status of any petition or its final disposition.

This document revises an earlier proposed airworthiness directive (AD), applicable to Boeing Model 747-400, 777-200, and 777- 300 series airplanes, that would have required an inspection of the flight deck humidifier to determine certain part numbers. That proposed AD also would have required, for certain airplanes, replacing the cell stack of the flight deck humidifier with a supplier-tested cell stack, or replacing the cell stack with a blanking plate and subsequently deactivating the flight deck humidifier, if necessary. For other airplanes, that proposed AD would have required replacing the cell stack with a supplier-tested cell stack, or replacing the cell stack with a blanking plate and subsequently deactivating the humidifier system, if necessary. The proposed AD also would have allowed blanking plates to be replaced with cell stacks. This new action revises the proposed rule by adding airplanes to the applicability, requiring an inspection of the flight deck humidifier to determine certain part numbers on certain airplanes, and requiring replacement of the cell stack on certain other airplanes. The actions specified by this new proposed AD are intended to prevent an increased pressure drop across the humidifier and consequent reduced airflow to the flight deck, which could result in the inability to clear any smoke that might appear in the flight deck. This action is intended to address the identified unsafe condition.

The FAA proposes to adopt a new airworthiness directive (AD) for all EMBRAER Model ERJ 170 airplanes. This proposed AD would require revising the Airworthiness Limitations section (ALS) of the airplane maintenance manual (AMM) to include new, specific maintenance tasks related to the incorporation of a new horizontal stabilizer actuator. This proposed AD also would require revising the ALS of the AMM to include revised repetitive inspection intervals for certain tasks in the maintenance plan related to the aileron and flap/slat flight controls system. This proposed AD results from safety assessments of the aileron and flap/slat flight controls system, conducted after the type certification of the airplane, which showed that some dormant faults did not comply with the safety assessment criteria. We are proposing this AD to prevent failure of the aileron and flap/slat controls system, which could result in reduced controllability of the airplane.

The FAA proposes to adopt a new airworthiness directive (AD) for certain Fokker Model F.28 Mark 0070 and 0100 airplanes. This proposed AD would require an inspection of the main landing gear (MLG) main fitting for cracks, and repair if necessary. This proposed AD would also require installing a placard and revising the airplane flight manual to include procedures to prohibit the application of brakes during backward movement of the airplane. This proposed AD results from a report that an MLG main fitting failed on an airplane that was braking while moving backward. We are proposing this AD to detect and correct cracks in the MLG main fitting, which could result in reduced structural integrity of the MLG main fitting.

The FAA is adopting a new noise standard for single-engine propeller driven small airplanes. This noise standard ensures that the latest available noise reduction technology is incorporated into new aircraft designs. This noise standard is also intended to harmonize the noise certification standard for propeller driven small airplanes newly certificated in the United States with those airplanes that meet the International Civil Aviation Organization (ICAO) Annex 16 noise standard.

The FAA is correcting a typographical error in an existing airworthiness directive (AD) that was published in the Federal Register on December 5, 2005 (70 FR 72366). The error resulted in an incorrect telephone number for the FAA's point of contact. This AD applies to all EMBRAER Model EMB-120, -120ER, -120FC, -120QC, and -120RT airplanes. This AD requires modifying electrical harnesses located at the left- and right-hand wing roots, and re-routing and modifying the harness of the right-hand outboard flap actuator.