AD 2005-05-17

The FAA is adopting a new airworthiness directive (AD) for Boeing Model 737-300, -400, and -500 series airplanes modified in accordance with STC ST00127BO. This AD requires installation of bonding straps to the safe side harnesses of the digital transient suppression device of the fuel quantity indicating system. This AD is prompted by the results of fuel system reviews conducted by the STC holder. We are issuing this AD to prevent unsafe levels of current or energy from entering the fuel tank, due to hot short faults or threat conditions associated with the safe side harness assembly, which could result in a fire or explosion of the fuel tank.

Final rule.

2005-05-17 Boeing: Amendment 39-14006. Docket No. FAA-2004-19891; Directorate Identifier 2004-NM-136-AD. \n\nEffective Date \n\n\t(a) This AD becomes effective April 18, 2005. \n\nAffected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to Boeing Model 737-300, -400, and -500 series airplanes; certificated in any category; modified in accordance with Supplemental Type Certificate (STC) ST00127BO. \n\nUnsafe Condition \n\n\t(d) This AD was prompted by the results of fuel system reviews conducted by the STC holder. We are issuing this AD to prevent unsafe levels of current or energy from entering the fuel tank, due to hot short faults or threat conditions associated with the safe side harness assembly, which could result in a fire or explosion of the fuel tank. \n\nCompliance \n\n\t(e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. \n\nModification \n\n\t(f) Within 12 months after the effective date of this AD, modify the safe side harness connectors at the tank penetrations and the digital transient suppression devices, in accordance with the Accomplishment Instructions of Goodrich Service Bulletin 737-300766- 28-2, Revision 2, dated July 28, 2004. \n\nParts Installation \n\n\t(g) As of the effective date of this AD, no person may install a safe side harness, Part Number 50367-01XX, on any airplane, unless that safe side harness has been modified in accordance with Goodrich Service Bulletin 737-300766-28-2, Revision 2, dated July 28, 2004.\n\t\n\nAlternative Methods of Compliance (AMOCs) \n\n\t(h) The Manager, Boston Aircraft Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19. \n\nMaterial Incorporated by Reference \n\n\t(i) You must use Goodrich Service Bulletin 737-300766-28-2, Revision 2, dated July 28, 2004, to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approves the incorporation by reference of this document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. For copies of the service information, contact Goodrich Fuel & Utility Systems, Goodrich Corporation, 100 Panton Road, Vergennes, Vermont 05491. For information on the availability of this material at the National Archives and Records Administration (NARA), call (202) 741-6030, or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html . \n\n\tYou may view the AD docket at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., room PL- 401, Nassif Building, Washington, DC.

The FAA proposed to amend 14 CFR Part 39 with an AD for Boeing Model 737-300, -400, and -500 series airplanes modified in accordance with STC ST00127BO. That action, published in the Federal Register on December 16, 2004 (69 FR 75280), proposed to require installation of bonding straps to the safe side harnesses of the digital transient suppression device of the fuel quantity indicating system. \n\nComments \n\n\tWe provided the public the opportunity to participate in the development of this AD. No comments have been submitted on the proposed AD or on the determination of the cost to the public. \n\nConclusion \n\n\tWe have carefully reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed. \n\nCosts of Compliance \n\n\tThere are about 404 airplanes of the affected design in the worldwide fleet. This AD affects about 2 airplanes of U.S. registry. The actions take about 9 work hours per airplane, at an average labor rate of $65 per work hour. For airplanes equipped with a Cinch rectangular connector, required parts will cost about $1,650 per airplane. For all other airplanes, required parts will cost about $1,500 per airplane. Based on these figures, the estimated cost of the AD for U.S. operators is between $2,085 and $2,235 per airplane. \n\nAuthority for This Rulemaking \n\n\tTitle 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority. \n\n\tWe are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, "General requirements." Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. \n\nRegulatory Findings \n\n\tWe have determined that this AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. \n\n\tFor the reasons discussed above, I certify that this AD: \n\n\t(1) Is not a "significant regulatory action" under Executive Order 12866; \n\n\t(2) Is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and \n\n\t(3) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.We prepared a regulatory evaluation of the estimated costs to comply with this AD. See the ADDRESSES section for a location to examine the regulatory evaluation. \n\nList of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \n\nAccordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: \n\nPART 39--AIRWORTHINESS DIRECTIVES \n\n1. The authority citation for part 39 continues to read as follows: \n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\nSec. 39.13 (Amended) \n\n2. The FAA amends Sec. 39.13 by adding the following new airworthiness directive (AD):