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 Department of Transportation Federal Aviation Administration 14 CFR Part 39
[Docket No. FAA-2018-0793; Product Identifier 2018-NM-057-AD]
RIN 2120-AA64
 AGENCY: Federal Aviation Administration (FAA), DOT.
 ACTION: Notice of proposed rulemaking (NPRM).
 SUMMARY: We propose to adopt a new airworthiness directive (AD) for all The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. This proposed AD was prompted by a report of cracks in the body station (STA) 303.9 frame web and doubler at fastener holes common to the stop fitting at stringer 16 left (S-16L). This proposed AD would require repetitive surface high frequency eddy current (HFEC) inspections for cracking of the STA 303.9 frame web and doubler at the stop fitting at S-16L, and applicable on-condition actions. We are proposing this AD to address the unsafe condition on these products.
 DATES: We must receive comments on this proposed AD by November 1, 2018.
 ADDRESSES: You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods: *Federal eRulemaking Portal:*
                         Go to 
                        *http://www.regulations.gov.*
                         Follow the instructions for submitting comments.
                    *Fax:*
                         202-493-2251.
                    *Mail:*
                         U.S. Department of Transportation, Docket Operations,M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.
                    *Hand Delivery:*
                         Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. For service information identified in this NPRM, contact Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-5600; phone: 562-797-1717; internet: 
                        *https://www.myboeingfleet.com.*
                         You may view this referenced service information at the FAA, Transport Standards Branch, 2200 South 216th St., Des Moines, WA. For information on the availability of this material at the FAA, call 206-231-3195. It is also available on the internet at 
                        *http://www.regulations.gov*
                         by searching for and locating Docket No. FAA-2018-0793. Examining the AD Docket You may examine the AD docket on the internet at 
                    *http://www.regulations.gov*
                     by searching for and locating Docket No. FAA-2018-0793; or in person at Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this NPRM, the regulatory evaluation, any comments received, and other information. The street address for Docket Operations (phone: 800-647-5527) is in the 
                    **ADDRESSES**
                     section. Comments will be available in the AD docket shortly after receipt.
 FOR FURTHER INFORMATION CONTACT: Galib Abumeri, Aerospace Engineer, Airframe Section, FAA, Los Angeles ACO Branch, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-5324; fax: 562-627-5210; email: 
                        *galib.abumeri@faa.gov.*


SUPPLEMENTARY INFORMATION:  Comments Invited We invite you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under the 
                    **ADDRESSES**
                     section. Include “Docket No. FAA-2018-0793; Product Identifier 2018-NM-057-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this NPRM. We will consider all comments received by the closing date and may amend this NPRM because of those comments. We 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 proposed AD. Discussion We have received a report indicating cracks in the STA 303.9 frame web and doubler at fastener holes common to the stop fitting at S-16L. The cracks were found during accomplishment of Boeing Service Bulletin 737-53A1188. We have determined that the existing inspection programs are not sufficient to find any crack in the STA 303.9 frame web and doubler at the stop fitting at S-16L. This condition, if not addressed, could result in the inability of a principal structural element to sustain limit loads and possible rapid decompression of the airplane. Related Service Information Under 1 CFR Part 51 We reviewed Boeing Requirements Bulletin 737-53A1375 RB, dated March 12, 2018. The service information describes procedures for repetitive surface HFEC inspections for cracking of the STA 303.9 frame web and doubler at the stop fitting at S-16L, and applicable on-condition 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. FAA's Determination We are proposing 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. Proposed AD Requirements This proposed AD would require accomplishment of the actions identified in Boeing Requirements Bulletin 737-53A1375 RB, dated March 12, 2018, described previously, except for any differences identified as exceptions in the regulatory text of this proposed AD. 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-2018-0793. Explanation of Applicability Model 737 airplanes having line numbers 1 through 291 have a limit of validity (LOV) of 34,000 total flight cycles, and the actions proposed in this NPRM, as specified in Boeing Requirements Bulletin 737-53A1375 RB, dated March 12, 2018, would be required at a compliance time occurring after that LOV. Although operation of an airplane beyond its LOV is prohibited by 14 CFR 121.1115 and 129.115, this NPRM would include those airplanes in the applicability so that these airplanes are tracked in the event the LOV is extended in the future. Explanation of Requirements Bulletin The FAA worked in conjunction with industry, under the Airworthiness Directives Implementation Aviation Rulemaking Committee (AD ARC), to enhance the AD system. One enhancement is a process for annotating which steps in the service information are “required for compliance” (RC) with an AD. Boeing has implemented this RC concept into Boeing service bulletins. In an effort to further improve the quality of ADs and AD-related Boeing service information, a joint process improvement initiative was worked between the FAA and Boeing. The initiative resulted in the development of a new process in which the service information more clearly identifies the actions needed to address the unsafe condition in the “Accomplishment Instructions.” The new process results in a Boeing Requirements Bulletin, which contains only the actions needed to address the unsafe condition (
                    *i.e.,*
                     only the RC actions).
                    ( print page 46904) Costs of Compliance We estimate that this proposed AD affects 67 airplanes of U.S. registry. We estimate the following costs to comply with this proposed AD: Estimated Costs for Required Actions
Action
Labor cost
Parts cost
Cost per product
Cost on U.S. operatorsHFEC Inspections
13 work-hours × $85 per hour = $1,105 per inspection cycle
$0
$1,105 per inspection cycle
$74,035 per inspection cycle.
 We have received no definitive data that would enable us to provide cost estimates for the on-condition actions specified in this proposed AD. Authority for This Rulemaking Title 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. We 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. This proposed AD is issued in accordance with authority delegated by the Executive Director, Aircraft Certification Service, as authorized by FAA Order 8000.51C. In accordance with that order, issuance of ADs is normally a function of the Compliance and Airworthiness Division, but during this transition period, the Executive Director has delegated the authority to issue ADs applicable to transport category airplanes and associated appliances to the Director of the System Oversight Division. Regulatory Findings We determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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. For the reasons discussed above, I certify this proposed regulation: (1) Is not a “significant regulatory action” under Executive Order 12866, (2) Is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will not affect intrastate aviation in Alaska, and (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. List of Subjects in 14 CFR Part 39 Air transportation
Aircraft
Aviation safety
Incorporation by reference
Safety
 The Proposed Amendment Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows: PART 39—AIRWORTHINESS DIRECTIVES
 1.The authority citation for part 39 continues to read as follows: Authority:
                    49 U.S.C. 106(g), 40113, 44701. § 39.13
 2.The FAA amends § 39.13 by adding the following new airworthiness directive (AD): **The Boeing Company:**
                         Docket No. FAA-2018-0793; Product Identifier 2018-NM-057-AD. (a) Comments Due Date We must receive comments by November 1, 2018. (b) Affected ADs None. (c) Applicability This AD applies to all The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes, certificated in any category. (d) Subject Air Transport Association (ATA) of America Code 53, Fuselage. (e) Unsafe Condition This AD was prompted by a report of cracks in the body station (STA) 303.9 frame web and doubler at fastener holes common to the stop fitting at stringer 16 left (S-16L). We are issuing this AD to address cracks in the STA 303.9 frame web and doubler at the stop fitting at S-16L, which, if not addressed, could result in the inability of a principal structural element to sustain limit loads and possible rapid decompression of the airplane. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Required Actions for Group 1 For airplanes identified as Group 1 in Boeing Requirements Bulletin 737-53A1375 RB, dated March 12, 2018: Within 120 days after the effective date of this AD, inspect the airplane and do all applicable on-condition actions using a method approved in accordance with the procedures specified in paragraph (j) of this AD. (h) Required Actions for Groups 2Through 5 Except as specified in paragraph (i) of this AD: For airplanes identified as Groups 2 through 5 in Boeing Requirements Bulletin 737-53A1375 RB, dated March 12, 2018, at the applicable times specified in the “Compliance” paragraph of Boeing Requirements Bulletin 737-53A1375 RB, dated March 12, 2018, do all applicable actions identified in, and in accordance with, the Accomplishment Instructions of Boeing Requirements Bulletin 737-53A1375 RB, dated March 12, 2018. Note 1 to paragraph (h) of this AD: Guidance for accomplishing the actions required by this AD can be found in Boeing Alert Service Bulletin 737-53A1375, dated March 12, 2018, which is referred to in Boeing Requirements Bulletin 737-53A1375 RB, dated March 12, 2018. (i) Exceptions to Service Information Specifications (1) For purposes of determining compliance with the requirements of this AD: Where Boeing Requirements Bulletin 737-53A1375 RB, dated March 12, 2018, uses the phrase “the original issue date of Requirements Bulletin 737-53A1375 RB,” this AD requires using “the effective date of this AD.” (2) Where Boeing Requirements Bulletin 737-53A1375 RB, dated March 12, 2018, specifies contacting Boeing for repair instructions, this AD requires repair using a method approved in accordance with the procedures specified in paragraph (j) of this AD.
                        ( print page 46905) (j) Alternative Methods of Compliance (AMOCs) (1) The Manager, Los Angeles ACO Branch, 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 certification office, send it to the attention of the person identified in paragraph (k)(1) of this AD. Information may be emailed to:
                        *9-ANM-LAACO-AMOC-Requests@faa.gov.* (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. (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 Branch, FAA, 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. (k) Related Information (1) For more information about this AD, contact Galib Abumeri, Aerospace Engineer, Airframe Section, FAA, Los Angeles ACO Branch, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-5324; fax: 562-627-5210; email: 
                        *galib.abumeri@faa.gov.* (2) 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; phone: 562-797-1717; internet: 
                        *https://www.myboeingfleet.com.*
                         You may view this referenced service information at the FAA, Transport Standards Branch, 2200 South 216th St., Des Moines, WA. For information on the availability of this material at the FAA, call 206-231-3195. Issued in Des Moines, Washington, on August 30, 2018. Jeffrey E. Duven, Director, System Oversight Division, Aircraft Certification Service.


[FR Doc. 2018-19840 Filed 9-14-18; 8:45 am] BILLING CODE 4910-13-P