AD 2017-06-01

We are superseding Airworthiness Directive (AD) 2017-03-04, which applied to all The Boeing Company Model 737-500 series airplanes. AD 2017-03-04 required inspections to detect cracks in the fuselage skin panels, permanent repairs of time-limited repairs, skin panel replacement, and related investigative and corrective actions if necessary. This AD reduces the applicability of AD 2017-03-04. This AD was prompted by a determination that airplanes were inadvertently included in the applicability of AD 2017-03-04. We are \n\n((Page 14430)) \n\nissuing this AD to address the unsafe condition on these products.

Final rule; request for comments.

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((Page 14432)) \n\nSec. 39.13 (Amended) \n\n0 2. The FAA amends Sec. 39.13 by removing Airworthiness Directive (AD) 2017-03-04, Amendment 39-18795 (82 FR 11140, February 21, 2017), and adding the following new AD: \n\n2017-06-01 The Boeing Company: Amendment 39-18825; Docket No. FAA- 2017-0129; Directorate Identifier 2017-NM-020-AD. \n\n(a) Effective Date \n\n\n\tThis AD is effective April 5, 2017. \n\n(b) Affected ADs \n\n\n\tThis AD replaces AD 2017-03-04, Amendment 39-18795 (82 FR 11140, February 21, 2017) (''AD 2017-03-04''). \n\n(c) Applicability \n\n\n\t(1) This AD applies to The Boeing Company Model 737-500 series airplanes, certificated in any category; as identified in Boeing Special Attention Service Bulletin 737-53-1315, Revision 1, dated June 30, 2015 (''SASB 737-53-1315 R1''). \n\t(2) Installation of Supplemental Type Certificate (STC) ST01219SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/ rgstc.nsf/0/ebd1cec7b301293e86257cb30045557a/$FILE/ST01219SE.pdf) does not affect the ability to accomplish the actions required by this AD. Therefore, for airplanes on which STC ST01219SE is installed, a ''change in product'' alternative method of compliance (AMOC) approval request is not necessary to comply with the requirements of 14 CFR 39.17. \n\n(d) Subject \n\n\n\tAir Transport Association (ATA) of America Code 53, Fuselage. \n\n(e) Unsafe Condition \n\n\n\tThis AD was prompted by an evaluation by the design approval holder (DAH) that indicates the fuselage skin is subject to widespread fatigue damage (WFD), and reports of cracks at the chem- milled steps in the fuselage skin. We are issuing this AD to detect and correct cracking on the aft lower lobe fuselage skins, which could result in rapid decompression of the airplane. \n\n(f) Compliance \n\n\n\tComply with this AD within the compliance times specified, unless already done. \n\n(g) Retained Inspections, Related Investigative and Corrective Actions, With No Changes \n\n\n\tThis paragraph restates the requirements of paragraph (g) of AD 2017-03-04, with no changes. At the applicable times specified in table 1 of paragraph 1.E., ''Compliance,'' of SASB 737-53-1315 R1, except as required by paragraphs (h)(1) and (h)(2) of this AD: Do the applicable inspections to detect cracks in the fuselage skin panels; and do all applicable related investigative and corrective actions; in accordance with the Accomplishment Instructions of SASB 737-53-1315 R1, except as required by paragraphs (h)(3) and (h)(4) of this AD. Do all applicable related investigative and corrective actions before further flight. Repeat the applicable inspections thereafter at the applicable intervals specified in SASB737-53-1315 R1. Accomplishment of a repair in accordance with ''Part 3: Repair'' of the Accomplishment Instructions of SASB 737-53-1315 R1, except as required by paragraph (h)(3) of this AD, is terminating action for the repetitive inspections required by this paragraph at the repaired locations only. \n\n(h) Retained Exceptions to SASB 737-53-1315 R1, With No Changes \n\n\n\tThis paragraph restates the service information exceptions specified in paragraph (h) of AD 2017-03-04, with no changes. \n\t(1) Where SASB 737-53-1315 R1, specifies compliance times ''after the Revision 1 date of this service bulletin,'' this AD requires compliance within the specified compliance times ''after March 28, 2017 (the effective date of AD 2017-03-04).'' \n\t(2) The Condition column of table 1 of Paragraph 1.E., ''Compliance,'' of SASB 737-53-1315 R1, refers to airplanes in certain configurations ''as of the issue date of Revision 1 of this service bulletin.'' However, this AD applies to airplanes in thespecified configurations ''as of March 28, 2017 (the effective date of AD 2017-03-04).'' \n\t(3) Where SASB 737-53-1315 R1, specifies contacting Boeing for repair instructions or work instructions, before further flight, repair or perform the work instructions using a method approved in accordance with the procedures specified in paragraph (m) of this AD, except as required by paragraph (h)(4) of this AD. \n\t(4) For airplanes on which an operator has a record that a skin panel was replaced with a production skin panel before 53,000 total flight cycles: At the applicable time for the next inspection, as specified in table 1 of paragraph 1.E., ''Compliance,'' of SASB 737- 53-1315 R1, except as provided by paragraphs (h)(1) and (h)(2) of this AD: Perform inspections and applicable corrective actions using a method approved in accordance with the procedures specified in paragraph (m) of this AD. \n\t(5) The Condition column of table 2 of Paragraph 1.E., ''Compliance,'' of SASB 737-53-1315 R1 refers to airplanes in certain configurations as of the ''issue date of Revision 1 of this service bulletin.'' However, this AD applies to airplanes in the specified configurations regardless of when the time-limited repair is installed. \n\n(i) Retained Actions for Airplanes With a Time-Limited Repair Installed, With No Changes \n\n\n\tThis paragraph restates the requirements of paragraph (i) of AD 2017-03-04, with no changes. For airplanes with a time-limited repair installed as specified in Boeing Special Attention Service Bulletin 737-53-1315, dated July 29, 2011; or SASB 737-53-1315 R1: At the applicable times specified in table 2 of paragraph 1.E., ''Compliance,'' of SASB 737-53-1315 R1, except as provided by paragraphs (h)(1) and (h)(5) of this AD, do the actions specified in paragraphs (i)(1) and (i)(2) of this AD. \n\t(1) Do the applicable inspections to detect missing or loose fasteners and any disbonding or cracking of bonded doublers; and do all applicable related investigative and corrective actions; in accordance with the Accomplishment Instructions of SASB 737-53-1315 R1, except as required by paragraph (h)(3) of this AD. Do all applicable related investigative and corrective actions before further flight. Repeat the applicable inspections thereafter at the applicable intervals specified in SASB 737-53-1315 R1. \n\t(2) Make the time-limited repair permanent and do all applicable related investigative and corrective actions in accordance with the Accomplishment Instructions of SASB 737-53-1315 R1, except as required by paragraph (h)(3) of this AD. Do all applicable related investigative and corrective actions before further flight. Accomplishing the permanent repair required by this paragraph terminates the inspections required by paragraph (i)(1) of this AD for the permanently repaired area only. \n\n(j) Retained AD Provisions for Part 26 Supplemental Inspections, With No Changes \n\n\n\tThis paragraph restates the provisions specified in paragraph (j)of AD 2017-03-04, with no changes. Table 3 of paragraph 1.E., ''Compliance,'' of SASB 737-53-1315 R1, specifies post-modification airworthiness limitation inspections in compliance with 14 CFR 25.571(a)(3) at the modified locations, which support compliance with 14 CFR 121.1109(c)(2) or 129.109(b)(2). As airworthiness limitations, these inspections are required by maintenance and operational rules. It is therefore unnecessary to mandate them in this AD. Deviations from these inspections require FAA approval, but do not require an alternative method of compliance. \n\n(k) Retained Skin Panel Replacement, With No Changes \n\n\n\tThis paragraph restates the requirements of paragraph (k) of AD 2017-03-04, with no changes. At the later of the times specified in paragraphs (k)(1) and (k)(2) of this AD: Replace the applicable skin panels, and do all applicable related investigative and corrective actions, in accordance with the Accomplishment Instructions of SASB 737-53-1315 R1. Do all applicable related investigative and corrective actions before further flight. Doing the skin panel replacement required by this paragraph terminates the inspection requirements of paragraph (g) of this AD for that skin panel only, provided the skin panel replacement was done with a production skin panel at or after 53,000 total flight cycles. \n\t(1) Before 60,000 total flight cycles, but not before 53,000 total flight cycles. \n\t(2) Within 6,000 flight cycles after March 28, 2017 (the effective date of AD 2017-03-04), but not before 53,000 total flight cycles. \n\n(l) Retained Credit for Previous Actions, With No Changes \n\n\n\tThis paragraph restates the credit specified in paragraph (l) of AD 2017-03-04, with no changes. This paragraph provides credit for the zone 1 actions required by paragraph (g) of this AD, as described in SASB 737-53-1315 R1, if the zone 1, 2, and 3 actions, as described in Boeing Special Attention \n\n((Page 14433)) \n\nService Bulletin 737-53-1315, dated July 29, 2011, were performed before March 28, 2017 (the effective date of AD 2017-03-04) using Boeing Special Attention Service Bulletin 737-53-1315, dated July 29, 2011, except as required by paragraph (h)(4) of this AD. Boeing Special Attention Bulletin 737-53-1315, dated July 29, 2011, was incorporated by reference in AD 2012-16-07. \n\n(m) Alternative Methods of Compliance (AMOCs) \n\n\n\t(1) The Manager, Los Angeles Aircraft Certification Office (ACO), FAA, has the 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 paragraph (n) of this AD. Information may be emailed to: 9-ANM-LAACO-AMOC-Requests@faa.gov. \n\t(2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking aprincipal 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, modification, or alteration required by this AD if it is approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) that has been authorized by the Manager, Los Angeles ACO, to make those findings. To be approved, the repair method, modification deviation, or alteration deviation must meet the certification basis of the airplane, and the approval must specifically refer to this AD. \n\t(4) AMOCs approved previously for AD 2012-16-07 are approved as AMOCs for the corresponding provisions of paragraph (g) of this AD. \n\n(n) Related Information \n\n\n\tFor more information about this AD, contact Jennifer Tsakoumakis, Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification Office (ACO), 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-5264; fax: 562- 627-5210; email: jennifer.tsakoumakis@faa.gov. \n\n(o) 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(3) The following service information was approved for IBR on March 28, 2017 (82 FR 11140, February 21, 2017). \n\t(i) Boeing Special Attention Service Bulletin 737-53-1315, Revision 1, dated June 30, 2015. \n\t(ii) Reserved. \n\t(4) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740- 5600; telephone 562-797-1717; Internet https://www.myboeingfleet.com. \n\t(5) You may view this service information at the 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(6) 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\tOn January 31, 2017, we issued AD 2017-03-04, Amendment 39-18795 (82 FR 11140, February 21, 2017) (''AD 2017-03-04''), for all The Boeing Company Model 737-500 series airplanes. AD 2017-03-04 required inspections to detect cracks in the fuselage skin panels, permanent repairs of time-limited repairs, skin panel replacement, and related investigative and corrective actions if necessary. AD 2017-03-04 resulted from an evaluation by the design approval holder (DAH) that indicates the fuselage skin is subject to widespread fatigue damage (WFD), and reports of cracks at the chem-milled steps in the fuselage skin. We issued AD 2017-03-04 to detect and correct cracking on the aft lower lobe fuselage skins, which could result in rapid decompression of the airplane. \n\nActions Since AD 2017-03-04 Was Issued \n\n\n\tSince we issued AD 2017-03-04, we determined that airplanes were inadvertently included in the applicability of AD 2017-03-04. AD 2017- 03-04 superseded AD 2012-16-07, Amendment 39-17154 (77 FR 48423, August 14, 2012) (''AD 2012-16-07''), which applied to certain The Boeing Company Model 737-500 series airplanes. The identified unsafe condition only applies to the airplanes identified in AD 2012-16-07 and, therefore, the applicability of AD 2017-03-04 should not have included additional airplanes. \n\tThe affected airplanes are identified in Boeing Special Attention Service Bulletin 737-53-1315, Revision 1, dated June 30, 2015 (which is referred to as the appropriate source of service information for accomplishing the actions required by AD 2017-03-04). In order to correct the applicability, we have referred to Boeing Special Attention Service Bulletin 737-53-1315, Revision 1, dated June 30, 2015, in paragraph (c)(1) of this AD. We are issuing this AD to address the unsafe condition on these products. \n\nRelated Service Information Under 1 CFR Part 51 \n\n\n\tWe reviewed Boeing Special Attention Service Bulletin 737-53-1315, Revision 1, dated June 30, 2015. The service information describes procedures for inspections to detect cracks in the fuselage skin panels, permanent repairs of time-limited repairs, skin panel replacement, and related investigative and corrective actions. This service information is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the ADDRESSES section. \n\nFAA's Determination \n\n\n\tWe are issuing this AD because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design. \n\nAD Requirements \n\n\n\tThis AD requires accomplishing the actions specified in the service information described previously, except as discussed under ''Differences Between this AD and the Service Information.'' This AD also reduces the applicability of AD 2017-03-04. For information on the procedures and compliance times, see this service information at http://www.regulations.gov by searching for and locating Docket No. FAA-2017- 0129. \n\tThe phrase ''related investigative actions'' is used in this AD. Related investigative actions are follow-on actions that (1) are related to the primary action, and (2) further investigate the nature of any condition found. Related investigative actions in an AD could include, for example, inspections. \n\tThe phrase ''corrective actions'' is used in this AD. Corrective actions correct or address any condition found. Corrective actions in an AD could include, for example, repairs. \n\nDifferences Between This AD and the Service Information \n\n\n\tBoeing Special Attention Service Bulletin 737-53-1315, Revision 1, dated June 30, 2015, specifies to contact the manufacturer for instructions on how to repair certain conditions and also to obtain certain work instructions, but this AD requires repairing those conditions and also to obtain those work instructions in one of the following ways: \n\tIn accordance with a method that we approve; or \n\tUsing data that meet the certification basis of the airplane, and that have been approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) whom we have authorized to make those findings. \n\n((Page 14431)) \n\nFAA's Justification and Determination of the Effective Date \n\n\n\tWe determined that airplanes were inadvertently included in the applicability of AD 2017-03-04, which applies to all Model 737-500 series airplanes. However, only airplanes identified in Boeing Special Attention Service Bulletin 737-53-1315, Revision 1, dated June 30, 2015, are affected by the identified unsafe condition. The actions required by this AD are not required to be done on airplanes that are not identified in Boeing Special Attention Service Bulletin 737-53- 1315, Revision 1, dated June 30, 2015. Therefore, we are superseding AD 2017-03-04 to correct the applicability. We find that notice and opportunity for prior public comment are unnecessary and that good cause exists for making this amendment effective in less than 30 days. \n\nComments Invited \n\n\n\tThis AD is a final rule that involves requirements affecting flight safety and was not preceded by notice and an opportunity for public comment. However, we invite you to send any written data, views, or arguments about this AD. Send your comments to an address listed under the ADDRESSES section. Include the docket number FAA-2017-0129 and Directorate Identifier 2017-NM-020-AD at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD because of those comments. \n\tWe will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this AD. \n\nCosts of Compliance \n\n\n\tWe estimate that this AD affects 33 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 ---------------------------------------------------------------------------------------------------------------- Inspections (actions retained Up to 1,538 work- $0 Up to $130,730 per Up to $4,314,090 \n\tfrom AD 2017-03-04). hours x $85 per inspection cycle. per inspection \n\thour = $130,730 cycle. \n\tper inspection \n\tcycle. Skin panel replacement (action 688 work-hours x 96,000 $154,480........... $5,097,840. \n\tretained from AD 2017-03-04). $85 per hour = \n\t$58,480. ---------------------------------------------------------------------------------------------------------------- \n\n\n\tWe estimate the following costs to do any necessary repairs that would be required based on the results of the inspection. We have no way of determining the number of aircraft that might need these repairs: \n\n\n\tOn-Condition Costs ---------------------------------------------------------------------------------------------------------------- \n\tAction Labor cost Parts cost Cost per product ---------------------------------------------------------------------------------------------------------------- Time-limited repair............... 24 work-hours x $85 \(1)\ $2,040. \n\tper hour = $2,040. Permanent repair.................. 31 work-hours x $85 \(1)\ $2,635. \n\tper hour = $2,635. Permanent repair inspection....... 4 work-hours x $85 \(1)\ $340 per inspection cycle. \n\tper hour = $340 per \n\tinspection cycle. ---------------------------------------------------------------------------------------------------------------- \1\ We have received no definitive data that would enable us to provide parts cost estimates for the on- \n\tcondition actions specified in this AD. \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 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\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.