AD 2005-13-15 ACTIVE

The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 737-200, -200C, -300, -400, -500, -600, -700, - 700C, -800, and -900 series airplanes. This AD requires a one-time detailed inspection for discrepancies of the secondary fuel vapor barrier of the wing center section, and related investigative/ corrective actions if necessary. This AD is prompted by reports that the secondary fuel vapor barrier was not applied correctly to, or was missing from, certain areas of the wing center section. We are issuing this AD to prevent fuel or fuel vapors from leaking into the cargo or passenger compartments and coming into contact with a possible ignition source, which could result in fire or explosion.

Final rule.

2005-13-15 Boeing: Amendment 39-14152. Docket No. FAA-2004-19567; Directorate Identifier 2004-NM-118-AD. \n\nEffective Date \n\n\t(a) This AD becomes effective July 29, 2005. \n\nAffected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to the airplanes listed in Table 1 of this AD, certificated in any category: \n\n\tTable 1.--Applicability \n\n\nModel \nLine numbers \n737-200, -200C, -300, -400, and -500 series airplanes \n311 through 3132 inclusive. \n737-600, -700, -700C, -800, and -900 series airplanes \n1 through 1088 inclusive and 1090 through 1134 inclusive. \n\nUnsafe Condition \n\n\t(d) This AD is prompted by reports that the secondary fuel vapor barrier was not applied correctly to, or was missing from, certain areas of the wing center section. We are issuing this AD to prevent fuel or fuel vapors from leaking into the cargo or passenger compartments and coming into contact with a possible ignition source, which could result in fire or explosion. \n\nCompliance(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\nService Bulletin References \n\n\t(f) The term "service bulletin," as used in this AD, means the Accomplishment Instructions of the following service bulletins, as applicable: \n\n\t(1) For Model 737-200, -200C, -300, -400, and -500 series airplanes: Boeing Special Attention Service Bulletin 737-57-1261, dated February 27, 2003; and \n\n\t(2) For Model 737-600, -700, -700C, -800, and -900 series airplanes: Boeing Special Attention Service Bulletin 737-57-1250, Revision 1, dated September 4, 2003. \n\nInspection \n\n\t(g) Within 48 months after the effective date of this AD, do a one-time detailed inspection for discrepancies of the secondary fuel vapor barrier of the wing center section; and if discrepancies exist, before further flight, do any applicable related investigative/corrective actions in accordance with the Accomplishment Instructions of the applicable service bulletin. \n\n\tNote 1: For the purposes of this AD, a detailed inspection is: "An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required." \n\nActions Accomplished per Previous Issue of Service Bulletin \n\n\t(h) Actions accomplished before the effective date of this AD in accordance with Boeing Special Attention Service Bulletin 737-57- 1250, dated February 7, 2002, are considered acceptable for compliance with the corresponding actions specified in paragraph (g) of this AD. \n\nAlternative Methods of Compliance (AMOCs) \n\n\t(i) The Manager, Seattle Aircraft Certification Office (ACO), 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(j) You must use Boeing Special Attention Service Bulletin 737- 57-1261, dated February 27, 2003; or Boeing Special Attention Service Bulletin 737-57-1250, Revision 1, dated September 4, 2003; as applicable; 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 these documents in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. For copies of the service information, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. To view the AD docket, go to the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW., room PL-401, Nassif Building, Washington, DC. \n\n\tFor 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 .

The FAA proposed to amend 14 CFR Part 39 with an AD for certain Boeing Model 737-200, -200C, -300, -400, -500, - 600, -700, -700C, -800, and -900 series airplanes. That action, published in the Federal Register on November 10, 2004 (69 FR 65099), proposed to require a one-time detailed inspection for discrepancies of the secondary fuel vapor barrier of the wing center section, and related investigative/corrective actions if necessary. \n\nComments \n\n\tWe provided the public the opportunity to participate in the development of this AD. We have considered the comments that have been submitted on the proposed AD. \n\nAgreement With Proposed AD \n\n\tOne commenter, an operator, agrees with the proposed AD. \n\nRequest for Alternative Procedure \n\n\tOne commenter, an operator, requests that a note be added to paragraph (g) of the AD to allow the use of Boeing 737 Nondestructive Testing (NDT) Manual, Part 6, Section 53-30-27, paragraph 3, for determining vapor barrier thickness. The commenter contends that using this method for determining vapor barrier thickness provides an inspection procedure equivalent to that called out in Boeing Special Attention Service Bulletin 737-57-1261, dated February 27, 2003, and will allow operators to avoid any need for special tooling. \n\n\tWe do not agree. We have reviewed the specified section of the NDT manual and found that it does not adequately describe an inspection procedure that is equivalent to that described in the service bulletin. However, we infer from the comment that the operator is proposing the use of an alternate tool for measuring coating thickness. Boeing Special Attention Service Bulletin 737-57- 1261, dated February 27, 2003, page 40, paragraph F., note (a), states that the isoscope with the probe listed in paragraph F. is only one example of a nonconductive coating thickness gage (NCCTG) that may be used and that any NCCTG is acceptable as long as it has a thickness range from 0.001 to 0.045 inch. We have confirmed with the manufacturer that the service bulletin clearly states the requirements for the tooling required to measure the thickness of the vapor barrier and no additional guidance is required. We have not changed the final rule in this regard. \n\nRequest for Extended Compliance Time \n\n\tOne commenter, an operator, requests that the compliance time be extended from 48 to 72 months. The commenter states that, assuming an effective date for the AD of January 2005, it has 15 aircraft that will not be scheduled for C check maintenance within the proposed 48-month compliance time. The commenter believes that this out-of-phase maintenance would result in financial hardship; therefore, the commenter would like to see the compliance time extended as requested. \n\n\tWe do not agree. In developing an appropriate compliance time for this action, we considered the urgency associated with the subject unsafe condition and the practical aspect of accomplishing the requiredmodification within a period of time that corresponds to the normal scheduled maintenance for most affected operators. However, under the provisions of paragraph (i) of the final rule, we may approve requests for adjustments to the compliance time if data are submitted with the requests to substantiate that such adjustments would provide acceptable levels of safety. We have not changed the final rule in this regard. \n\nConclusion \n\n\tWe have carefully reviewed the available data, including the comments that have been submitted, and determined that air safety and the public interest require adopting the AD as proposed. \n\nCosts of Compliance \n\n\tThis AD will affect about 1,521 airplanes of U.S. registry. There are about 3,861 airplanes of the affected design in the worldwide fleet. We estimate the average labor rate to be $65 per work hour. We estimate that it will take the number of work hours shown in the following table to accomplish the actions for each airplane. Parts and materials are standard and are to be supplied by the operator. Based on these figures, the cost impact of the AD is estimated to range between $325 and $910 per airplane. \n\n\tEstimated Work Hours\n\n\nAffected airplanes as listed in \nAirplane group \nWork hours \n\n\n\n\n\n\nBoeing Special Attention Service Bulletin 737-57-1250, Revision 1, dated September 4, 2003 \n1 \n2 \n3 \n14 \n12 \n5 \n\n\n\nBoeing Special Attention Service Bulletin 737-57-1261, dated February 27, 2003 \n1 \n2 \n14 \n7 \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 asignificant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. \n\n\tWe 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):

For service information identified in this AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124 2207. \n\n\tDocket: The AD docket contains the proposed AD, comments, and any final disposition. You can examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647- 5227) is located on the plaza level of the Nassif Building at the U.S. Department of Transportation, 400 Seventh Street SW, room PL-401, Washington, DC. This docket number is Docket No. FAA-2004-19567; the directorate identifier for this docket is 2004-NM-118-AD.

Doug Pegors, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 917-6504; fax (425) 917-6590.