AD 2012-20-01

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737-100, -200, and -200C series airplanes. This AD was prompted by a report of a severed upper butt strap, and cracks in the forward skin and bonded doubler, on one airplane. This AD requires repetitive inspections for cracks and a chemical spot test in the area of station (STA) 908, and related investigative and corrective actions, if necessary. For certain airplanes, this AD requires an inspection and modification. We are issuing this AD to prevent cracks at the adjacent mating skins (forward and aft), which could initiate just above stringers S-4R and S-4L; and could grow and result in a decompression event.

Final rule.

Adoption of the Amendment \n\n\n\tAccordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: \n\nPART 39--AIRWORTHINESS DIRECTIVES \n\n0 1. The authority citation for part 39 continues to read as follows: \n\n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n\n\nSec. 39.13 (Amended) \n\n0 2. The FAA amends Sec. 39.13 by adding the following new airworthiness directive (AD): \n\n2012-20-01 The Boeing Company: Amendment 39-17207; Docket No. FAA- 2012-0491; Directorate Identifier 2011-NM-265-AD. \n\n(a) Effective Date \n\n\n\tThis AD is effective November 9, 2012. \n\n(b) Affected ADs \n\n\n\tNone. \n\n(c) Applicability \n\n\n\tThis AD applies to The Boeing Company Model 737-100, -200, and - 200C series airplanes; certificated in any category; as identified in Boeing Special Attention Service Bulletin 737-53-1313, dated November 3, 2011. \n\n(d) Subject \n\n\n\tJoint Aircraft System Component (JASC)/Air Transport Association (ATA) of America Code 53; Fuselage. \n\n(e) Unsafe Condition \n\n\n\tThis AD was prompted by a report of a severed upper butt strap, and cracks in the forward skin and bonded doubler, on one airplane. We are issuing this AD to prevent cracks at the adjacent mating skins (forward and aft), which could initiate just above stringers S-4R and S-4L; and could grow and result in a decompression event. \n\n(f) Compliance \n\n\n\tComply with this AD within the compliance times specified, unless already done. \n\n(g) Actions for Group 1 Airplanes \n\n\n\tFor Group 1 airplanes, as identified in Boeing Special Attention Service Bulletin 737-53-1313, dated November 3, 2011: Within 120 days after the effective date of this AD, inspect and modify, as required, using a method approved in accordance with the procedures specified in paragraph (k) of this AD. \n\n(h) Actions for Groups 2 and 3 Airplanes \n\n\n\tFor Groups 2 and 3 airplanes, as identified in Boeing Special Attention Service Bulletin 737-53-1313, datedNovember 3, 2011: Except as provided by paragraph (i)(1) of this AD, at the applicable times identified in paragraph 1.E., ''Compliance,'' of Boeing Special Attention Service Bulletin 737-53-1313, dated November 3, 2011, do the actions specified in paragraphs (h)(1) and (h)(2) of this AD, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-53-1313, dated November 3, 2011, except as provided by paragraph (i)(2) of this AD. \n\t(1) Do one of the inspection options identified in paragraphs (h)(1)(i), (h)(1)(ii), and (h)(1)(iii) of this AD; and do all applicable related investigative and corrective actions. Do all applicable related investigative and corrective actions before further flight. \n\t(i) Inspection Option 1: Do a detailed inspection for cracks of the station (STA) 908 forward and aft skin. Thereafter, repeat the inspection at intervals not to exceed 500 flight cycles until the chemical spot test required by paragraph (h)(2) of thisAD is done. \n\t(ii) Inspection Option 2: Do a one-time external low-frequency eddy current (LFEC) inspection for cracks of the STA 908 upper butt strap. \n\t(iii) Inspection Option 3: Do a one-time internal LFEC inspection for cracks of the STA 908 upper butt strap. \n\t(2) Do a chemical spot test of the STA 908 upper butt strap to determine the part material, and do all applicable related investigative and corrective actions. Do all applicable related investigative and corrective actions at the times specified in paragraph 1.E., ''Compliance,'' of Boeing Special Attention Service Bulletin 737-53-1313, dated November 3, 2011, except as provided by paragraph (i)(1) of this AD. Confirming the upper butt strap is made from 2000 series aluminum terminates the inspections required by paragraph (h)(1) of this AD. \n\n(i) Exceptions to the Service Information \n\n\n\t(1) Where Boeing Special Attention Service Bulletin 737-53-1313, dated November 3, 2011, specifies a compliance time ''after the original issue date of the service bulletin,'' this AD requires compliance within the specified compliance time after the effective date of this AD. \n\t(2) Where Boeing Special Attention Service Bulletin 737-53-1313, dated November 3, 2011, specifies to contact Boeing for repair \n\n((Page 60891)) \n\ninstructions: Before further flight, repair using a method approved in accordance with the procedures specified in paragraph (k) of this AD. \n\n(j) Terminating Action \n\n\n\tReplacing the STA 908 upper butt strap and doing all applicable related investigative and corrective actions, in accordance with Part 4, Part 5, and Part 6, of the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-53-1313, dated November 3, 2011, except as provided by paragraph (i)(2) of this AD, terminates the inspections and chemical spot test required by this AD. \n\n(k) Alternative Methods of Compliance (AMOCs) \n\n\n\t(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, hasthe authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the ACO, send it to the attention of the person identified in the Related Information section of this AD. Information may be emailed to: 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov. \n\t(2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office. \n\t(3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD if it is approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) that has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane, and the approval must specifically refer to this AD. \n\n(l) Related Information \n\n\n\tFor more information about this AD, contact Wayne Lockett, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: (425) 917-6447; fax: (425) 917-6590; email: wayne.lockett@faa.gov. \n\n(m) Material Incorporated by Reference \n\n\n\t(1) The Director of the Federal Register approved the incorporation by reference (IBR) of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51. \n\t(2) You must use this service information as applicable to do the actions required by this AD, unless the AD specifies otherwise. \n\t(i) Boeing Special Attention Service Bulletin 737-53-1313, dated November 3, 2011. \n\t(ii) Reserved. \n\t(3) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544- 5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. \n\t(4) You may view this service information at FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, WA. For information on the availability of this material at the FAA, call (425) 227-1221. \n\t(5) You may view this service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

Discussion \n\n\n\tWe issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to the specified products. That NPRM published in the Federal Register on June 4, 2012 (77 FR 32918). That NPRM proposed to require repetitive inspections for cracks and a chemical spot test in the area of STA 908, and related investigative and corrective actions, if necessary. For certain airplanes, that NPRM also proposed to require an inspection and modification. \n\nComments \n\n\n\tWe gave the public the opportunity to participate in developing this AD. The following presents the comment received on the proposal (77 FR 32918, June 4, 2012) and the FAA's response to the comment. \n\nRequest To Relocate Terminating Action Statement \n\n\n\tBoeing requested that we relocate the terminating action statement related to confirmed 2000 series aluminum from paragraph (h)(2) of the NPRM (77 FR 32918, June 4, 2012) to paragraph (j) of theNPRM. \n\tWe disagree with the request to relocate the sentence. The terminating action specified in paragraph (h)(2) of this AD only terminates the actions specified in paragraph (h)(1) of this AD. Paragraph (j) of the AD allows operators to forego all requirements of this AD, including the initial inspection, repetitive inspections, and chemical spot test requirements, by replacing the butt strap with a new part made of the correct material, and doing related investigative and corrective actions, as applicable. No change has been made to the AD in this regard. \n\nConclusion \n\n\n\tWe reviewed the relevant data, considered the comment received, and determined that air safety and the public interest require adopting the AD as proposed. \n\nCosts of Compliance \n\n\n\tWe estimate that this AD affects 61 airplanes of U.S registry. \n\tWe estimate the following costs to comply with this AD: \n\n\n\tEstimated Costs ---------------------------------------------------------------------------------------------------------------- \n\tCost on U.S. \n\tAction Labor cost Parts cost Cost per product operators ---------------------------------------------------------------------------------------------------------------- Inspection and test............ 166 work-hours x $85 $0 $14,110 per $860,710 per \n\tper hour = $14,110 per inspection cycle. inspection cycle. \n\tinspection cycle. ---------------------------------------------------------------------------------------------------------------- \n\n\n\tIn addition, we have received no definitive data that would enable us to provide cost estimates for the actions that would be required for Group 1 airplanes. \n\tWe estimate the following costs to do any necessary related investigative actions, repairs, and installations that would be required based on the results of the inspection and test. We have no way of determining the number of aircraft that mightneed these actions: \n\n((Page 60890)) \n\n\n\n\n\n\n\tOn-Condition Costs ---------------------------------------------------------------------------------------------------------------- \n\tCost per \n\tAction Labor cost Parts cost product ---------------------------------------------------------------------------------------------------------------- Related investigative actions, repair, 173 work-hours x $85 per hour = $0 $14,705 \n\tinstallation. $14,705. ---------------------------------------------------------------------------------------------------------------- \n\n\n\tAccording to the manufacturer, some of the costs of this AD may be covered under warranty, thereby reducing the cost impact on affected individuals. We do not control warranty coverage for affected individuals. As a result, we have included all costs in our cost estimate. \n\nAuthority for This Rulemaking \n\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\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\n\tThis AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect on theStates, 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\tFor the reasons discussed above, I certify that this AD: \n\t(1) Is not a ''significant regulatory action'' under Executive Order 12866, \n\t(2) Is not a ''significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), \n\t(3) Will not affect intrastate aviation in Alaska, and \n\t(4) 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. \n\nList of Subjects in 14 CFR Part 39 \n\n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.