2017-12631. Airworthiness Directives; The Boeing Company Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule.

SUMMARY:

We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 737-300, -400, and -500 series airplanes. This AD was prompted by a report of a crack in a certain body station (BS) frame inboard chord during supplemental structural inspection document (SSID) inspections. This AD requires repetitive detailed and high frequency eddy current (HFEC) inspections for any crack at the frame inboard chords, and repair if necessary. We are issuing this AD to address the unsafe condition on these products.

DATES:

This AD is effective July 27, 2017.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of July 27, 2017.

ADDRESSES:

For service information identified in this final rule, contact Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740; telephone: [phone]; Internet: https://www.myboeingfleet.com. 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. It is also available on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2016-9391.

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-2016-9391; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this final rule, the regulatory evaluation, any comments received, and other information. The address for the Docket Office (phone: [phone]) is Docket Management Facility, U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT:

Galib Abumeri, Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification Office (ACO), 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: [phone]; fax: [phone]; email: [e-mail].

SUPPLEMENTARY INFORMATION:

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to all The Boeing Company Model 737-300, -400, and -500 series airplanes. The NPRM published in the Federal Register on November 18, 2016 (81 FR 81707) (“the NPRM”). The NPRM was prompted by a report of a crack in a certain BS frame inboard chord during SSID inspections. The NPRM proposed to require repetitive detailed and HFEC inspections for any crack at the frame inboard chords, and repair if necessary. We are issuing this AD to detect and correct any crack in the inboard chord of the BS 578 (737-400 series airplanes) and BS 616 (737-300 and -500 series airplanes) frame below stringers S-11L or S-11R, which could result in structural failure of the frame and possible rapid decompression.

Comments

We gave the public the opportunity to participate in developing this AD. The following presents the comments received on the NPRM and the FAA's response to each comment.

Support for the NPRM

United Airlines expressed support for the NPRM.

Effect of Winglets on Accomplishment of the Proposed Actions

Aviation Partners Boeing stated that accomplishing the supplemental type certificate (STC) ST01219SE does not affect the actions specified in the NPRM.

We concur with the commenter. We have redesignated paragraph (c) of the NPRM as paragraph (c)(1) of this AD and added paragraph (c)(2) to this AD to state that installation of STC ST01219SE 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.

Request for Clarification of Location

Boeing requested that we clarify the location of the body station for the inspection of the frame inboard chords. Boeing pointed out that the NPRM stated: “in the inboard chord of the BS 616 frame.” Boeing also pointed out that the service information specifies that for 737-300 and -500 airplanes the corresponding body station is BS 616, but for 737-400 airplanes, with two overwing exit doors, the corresponding body station is BS 578.

We agree that clarification of the body station for the corresponding airplane configuration is necessary. We have revised the Discussion section of this final rule and paragraph (e) of this AD to specify “the inboard chord of the BS 578 (737-400 series airplanes) and BS 616 (737-300 and -500 series airplanes) frame.”

Request for Additional AMOC Delegation Authority

Boeing requested that we include “Authorized Representative” (AR) and “Seattle ACO” in paragraph (j)(3) of the proposed AD. Specifically, the commenter requested that “Boeing Commercial Airplanes Organization Designation Authorization (ODA) that has been authorized by the Manager, Los Angeles ACO” be revised to “Authorized Representative for the Boeing Commercial Airplanes ODA that has been authorized by the Manager, Los Angeles ACO or by the Manager, Seattle ACO.” The commenter mentioned that AMOCs are approved by individual ARs of the Boeing Commercial Airplanes ODA but not all unit members of the ODA have the authority to provide AMOC approvals to the AD. The commenter also pointed out that Los Angeles ACO and Seattle ACO have both authorized specific ARs to make findings.

We disagree with including ARs and the Seattle ACO in paragraph (j)(3) of this final rule. The Los Angeles ACO is now responsible for the Continued Operational Safety of the affected Model 737 airplanes, and delegates AMOC authority to the Boeing Commercial Airplanes ODA based on individual ADs. As a result, AMOC delegation authority is limited to the Manager of the Los Angeles ACO and does not include the Manager of the Seattle ACO. Additionally, including ARs is unnecessary because both the Los Angeles ACO and Seattle ACO authorize only specific ARs to approve AMOCs. We have not changed this AD in this regard.

Conclusion

We reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting this AD with the changes described previously and minor editorial changes. We have determined that these minor changes:

• Are consistent with the intent that was proposed in the NPRM for correcting the unsafe condition; and
• Do not add any additional burden upon the public than was already proposed in the NPRM.

We also determined that these changes will not increase the economic burden on any operator or increase the scope of this final rule.

Related Service Information Under 1 CFR Part 51

We reviewed Boeing Alert Service Bulletin 737-53A1366, dated May 17, 2016. The service information describes procedures for repetitive detailed and HFEC inspections for cracking at certain BS frame inboard chords, and repair. 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.

Costs of Compliance

We estimate that this AD affects 400 airplanes of U.S. registry. We estimate the following costs to comply with this AD:

Estimated Costs

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Detailed and HFEC Inspections	8 work-hours × $85 per hour = $680 per inspection cycle	$0	$680 per inspection cycle	$272,000 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 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.

Regulatory Findings

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.

For the reasons discussed above, I certify that this AD:

(1) Is not a “significant regulatory action” under Executive Order 12866,

(2) Is not a “significant rule” under 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

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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

[Amended]

2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):

2017-13-01 The Boeing Company: Amendment 39-18931; Docket No. FAA-2016-9391; Directorate Identifier 2016-NM-129-AD.

(a) Effective Date

This AD is effective July 27, 2017.

(b) Affected ADs

None.

(c) Applicability

(1) This AD applies to all The Boeing Company Model 737-300, -400, and -500 series airplanes, certificated in any category.

(2) Installation of Supplemental Type Certificate (STC) ST01219SE (http://rgl.faa.gov/​Regulatory_​and_​Guidance_​Library/​rgstc.nsf/​0/​EBD1CEC7B301293E86257CB30045557A?​OpenDocument&​Highlight=​st01219se) 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.

(d) Subject

Air Transport Association (ATA) of America Code 53, Fuselage.

(e) Unsafe Condition

This AD was prompted by a report of a crack in the body station (BS) 616 frame inboard chord during supplemental structural inspection document (SSID) inspections; the crack was located at the lowest fastener hole of the inboard chord inboard strap below stringer S-11R. We are issuing this AD to detect and correct any crack in the inboard chord of the BS 578 (737-400 series airplanes) and BS 616 (737-300 and -500 series airplanes) frame below stringers S-11L or S-11R, which could result in structural failure of the frame and possible rapid decompression.

(f) Compliance

Comply with this AD within the compliance times specified, unless already done.

(g) Repetitive Detailed and High Frequency Eddy Current (HFEC) Inspections

Except as required by paragraph (i) of this AD, at the applicable times specified in table 1 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-53A1366, dated May 17, 2016: Do detailed and HFEC inspections for any crack at the frame inboard chords, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-53A1366, dated May 17, 2016. Repeat the inspections thereafter at the time specified in table 1 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-53A1366, dated May 17, 2016.

(h) Repair

If any crack is found during any inspection required by paragraph (g) of this AD, repair before further flight using a method approved in accordance with the procedures specified in paragraph (j) of this AD. Although Boeing Alert Service Bulletin 737-53A1366, dated May 17, 2016, specifies to contact Boeing for repair instructions, and specifies that action as “RC” (Required for Compliance), this AD requires repair as specified in this paragraph.

(i) Service Information Exceptions

Where Boeing Alert Service Bulletin 737-53A1366, dated May 17, 2016, specifies a compliance time “after the original issue date of this service bulletin,” this AD requires compliance within the specified compliance time after the effective date of this AD.

(j) Alternative Methods of Compliance (AMOCs)

(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 (k) of this AD. Information may be emailed to [e-mail].

(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, 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.

(4) Except as required by paragraph (h) of this AD: For service information that contains steps that are labeled as RC, the provisions of paragraphs (j)(4)(i) and (j)(4)(ii) of this AD apply.

(i) The steps labeled as RC, including substeps under an RC step and any figures identified in an RC step, must be done to comply with the AD. If a step or sub-step is labeled “RC Exempt,” then the RC requirement is removed from that step or sub-step. An AMOC is required for any deviations to RC steps, including substeps and identified figures.

(ii) Steps not labeled as RC may be deviated from using accepted methods in accordance with the operator's maintenance or inspection program without obtaining approval of an AMOC, provided the RC steps, including substeps and identified figures, can still be done as specified, and the airplane can be put back in an airworthy condition.

(k) Related Information

For more information about this AD, contact Galib Abumeri, Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles ACO, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: [phone]; fax: [phone]; email: [e-mail].

(l) Material Incorporated by Reference

(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.

(2) You must use this service information as applicable to do the actions required by this AD, unless the AD specifies otherwise.

(i) Boeing Alert Service Bulletin 737-53A1366, dated May 17, 2016.

(ii) Reserved.

(3) For Boeing 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; telephone: [phone]; Internet: https://www.myboeingfleet.com.

(4) 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.

(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.

Issued in Renton, Washington, on June 9, 2017.

Michael Kaszycki,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.