AD 2018-06-04

We are superseding Airworthiness Directive (AD) 2004-03-07, which applied to certain Airbus Model A320-111, -211, -212, and -231 series airplanes. AD 2004-03-07 required repetitive inspections for fatigue cracking around the fasteners attaching the pressure panel to the flexible bracket at a certain frame (FR), adjacent to the longitudinal beams on the left and right sides of the airplane; and repair as necessary. This new AD retains certain requirements of AD 2004-03-07, expands the applicability, and requires an inspection of the fastener holes on the pressure panel and modification or repair as applicable. This AD was prompted by fatigue tests which revealed cracking around the fasteners attaching the pressure panel to the flexible bracket, and by the discovery of additional cracks under the longitudinal beams at locations that are not included in the inspection area required by AD 2004-03-07. We are issuing this AD to address the unsafe condition on these products.

Final rule.

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

0 1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

0 2. The FAA amends Sec. 39.13 by removing Airworthiness Directive (Airworthiness Directive (AD) 2004-03-07, Amendment 39-13451 (69 FR 5907, February 9, 2004), and adding the following new AD:

2018-06-04 Airbus: Amendment 39-19224; Docket No. FAA-2017-0902; Product Identifier 2016-NM-188-AD.

(a) Effective Date

This AD is effective May 3, 2018.

(b) Affected ADs

This AD replaces AD 2004-03-07, Amendment 39-13451 (69 FR 5907, February 9, 2004) (``AD 2004-03-07'').

(c) Applicability

This AD applies to the Airbus airplanes identified in paragraphs (c)(1) through (c)(4) of this AD, certificated in any category, except for airplanes on which Airbus Modification 151574 was embodied in production.
(1) Model A318-111, -112, -121, and -122 airplanes.
(2) Model A319-111, -112, -113, -114, -115, -131, -132, and -133 airplanes.
(3) Model A320-211, -212, -214, -231, -232, and -233 airplanes.
(4) Model A321-111, -112, -131, -211, -212, -213, -231, and -232 airplanes.

(d) Subject

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

(e) Reason

This AD was prompted by fatigue tests which revealed cracking around the fasteners attaching the pressure panel to the flexible bracket at frame (FR) 36, adjacent to the longitudinal beams on the left and right sides of the airplane, and by the discovery of additional cracks under the longitudinal beams at locations that are not included in the inspection area required by AD 2004-03-07. We are issuing this AD to detect and correct fatigue cracking around the fasteners attaching the pressure panel to the flexible bracket at theFR 36 adjacent to the longitudinal beams, which could result in reduced structural integrity of the airplane and possible rapid decompression of the airplane.

(f) Compliance

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

(g) Retained Inspection and Follow-on Actions, With No Changes

This paragraph restates the requirements of paragraphs (a) and (b) of AD 2004-03-07, with no changes.
(1) For Model A320-211, -212, and -231 series airplanes having serial numbers 0002 through 0107 inclusive, except those airplanes on which Airbus Modification 21202/K1432 has been incorporated in production, or on which Airbus Service Bulletin A320-53-1029, Revision 01, including Appendix 01, dated April 29, 2002, has been incorporated in service: Prior to the accumulation of 30,000 total flight cycles, do a rotating probe inspection on airplanes with a center fuel tank, or a detailed inspection on airplanes without a center fuel tank, to detect cracking around the fasteners that attach the pressure panel to the flexible bracket at FR 36, adjacent to the longitudinal beams on the left and right sides of the airplane, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-53-1030, Revision 01, excluding Appendix 01, dated May 21, 2002.
(2) If no crack is detected by the inspection required by paragraph (g)(1) of this AD, repeat the applicable inspection thereafter at intervals not to exceed 6,000 flight cycles for airplanes without a center fuel tank, and at intervals not to exceed 18,000 flight cycles for airplanes with a center fuel tank.

(h) Retained Corrective Actions, With Specific Delegation Approval Language

This paragraph restates the requirements of paragraphs (c) and (d) of AD 2004-03-07, with specific delegation approval language.
(1) If any crack is detected during any inspection required by paragraph (g)(1) of this AD, before further flight, repair the affected structure byaccomplishing all applicable actions in accordance with paragraphs 3.B. through 3.E. of the Accomplishment Instructions of Airbus Service Bulletin A320-53-1030, Revision 01, excluding Appendix 01, dated May 21, 2002. Repeat the applicable inspection thereafter at intervals not to exceed 6,000 flight cycles for airplanes without a center fuel tank, and at intervals not to exceed 18,000 flight cycles for airplanes with a center fuel tank. For any area where cracking is repaired, the repair constitutes terminating action for the repetitive inspection of that area.
Note 1 to paragraph (h)(1) of this AD: Airbus Service Bulletin A320-53-1030 references Airbus Service Bulletin A320-53-1029, Revision 01, including Appendix 01, dated April 29, 2002, as an additional source of service information for certain repairs.
(2) If Airbus Service Bulletin A320-53-1030, Revision 01, excluding Appendix 01, dated May 21, 2002, specifies to contact the manufacturer for appropriate action: Before further flight, repair using a method approved in accordance with the procedures specified in paragraph (p)(2) of this AD.

(i) Retained Optional Terminating Action, With Revised Compliance Language

This paragraph restates the requirements of paragraph (e) of AD 2004-03-07, with revised compliance language, to provide optional terminating action for paragraphs (g) and (h) of this AD. For Model A320-211, -212, and -231 series airplanes having serial numbers 0002 through 0107 inclusive, except those airplanes on which Airbus Modification 21202/K1432 has been incorporated in production, or Airbus Service Bulletin A320-53-1029, Revision 01, including Appendix 01, dated April 29, 2002, has been incorporated in service: Modification, before the effective date of this AD, of the structure around the fasteners that attach the pressure panel to the flexible bracket at FR 36, adjacent to the longitudinal beams on the left and right sides of the airplane, by accomplishing all applicable actions in accordance with paragraphs 3.A. through 3.E. of the Accomplishment Instructions of Airbus Service Bulletin A320-53-1029, Revision 01, including Appendix 01, dated April 29, 2002, constitutes terminating action for the actions required by paragraphs (g) and (h) of this AD.

(j) New Requirement of This AD: Inspection

For all airplanes, except for airplanes identified in paragraph (l) of this AD: At the applicable time specified in table 1 to paragraph (j) of this AD, do a special detailed inspection for cracking of the fastener holes

[[Page 13392]]

on the pressure panel between FR 35 and FR 36 under the longitudinal beam, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-53-1264, Revision 01, excluding Appendix 01, dated July 4, 2016. [GRAPHIC] [TIFF OMITTED] TR29MR18.007

[GRAPHIC] [TIFF OMITTED] TR29MR18.008

[[Page 13393]]

[GRAPHIC] [TIFF OMITTED] TR29MR18.009

[GRAPHIC] [TIFF OMITTED] TR29MR18.010

(k)On-Condition Actions

(1) If, during any inspection required by paragraph (j) of this AD, no cracking is found, or cracking is found that is within the limits specified in Airbus Service Bulletin A320-53-1264, Revision 01, excluding Appendix 01, dated July 4, 2016: Before further flight, modify the pressure panel above the left and right longitudinal beams, including doing all applicable related investigative and corrective actions, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-53-1240, Revision 02, dated March 14, 2017; or Service Bulletin A320-53-1263, Revision 02, excluding

[[Page 13394]]

Appendix 01 and including Appendix 02, dated December 6, 2017, as applicable. Do all related investigative and corrective actions before further flight. Where Airbus Service Bulletin A320-53-1240, Revision 02, dated March 14, 2017; or Service Bulletin A320-53-1263, Revision 02, excluding Appendix 01 and including Appendix 02, dated December 6, 2017; specify to contact Airbus for appropriate action: Before further flight, accomplish the repair using a method approved in accordance with the procedures specified in paragraph (p)(2) of this AD.
(2) If, during any inspection required by paragraph (j) of this AD, any cracking is found that exceeds the limits specified in Airbus Service Bulletin A320-53-1264, Revision 01, excluding Appendix 01, dated July 4, 2016: Before further flight, repair any cracking in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-53-1264, Revision 01, excluding Appendix 01, dated July 4, 2016. Where Airbus Service Bulletin A320- 53-1264, Revision 01, excluding Appendix 01, dated July 4, 2016, specifies to contact Airbus for appropriate action, and specifies that action as ``RC'' (Required for Compliance), before further flight, request approval of repair instructions using a method approved in accordance with the procedures specified in paragraph (p)(2) of this AD, and accomplish the repair accordingly within the compliance time specified in those instructions. If no compliance time is defined in the repair instructions, accomplish the repair before further flight.

(l) Actions for Certain Airplanes

For Model A319 and Model A320 series airplanes on which the actions specified in Airbus Service Bulletin A320-57-1193 have been embodied and the airplane has accumulated 33,000 flight cycles or 66,000 flight hours or more since the airplane's first flight on the effective date of this AD: Within 30 days after the effective date of this AD, contact the Manager, International Section, Transport Standards Branch FAA; or the European Aviation Safety Agency (EASA); or Airbus's EASA Design Organization Approval (DOA) for approved repair instructions and within the compliance time specified in those instructions, accomplish the repair accordingly. If approved by the DOA, the approval must include the DOA-authorized signature. If no compliance time is defined in the repair instructions, accomplish the repair before the next flight.

(m) Terminating Action for Repetitive Inspections

(1) Modification of an airplane as specified in paragraph (m)(1)(i), (m)(1)(ii), or (m)(1)(iii) of this AD constitutes terminating action for the repetitive inspection required by paragraph (g)(2) of this AD for that airplane only.
(i) Modification of an airplane as required by paragraph (k)(1) of this AD.
(ii) Modification of an airplane prior to the effective date of this AD, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-53-1240, Revision 01, dated April 4, 2016; or Airbus Service Bulletin A320-53-1263, Revision 01, dated February 29, 2016; as applicable.
(iii) Modification of an airplane using instructions obtained in accordance with the procedures specified in paragraph (p)(2) of this AD.
(2) Repair of an airplane as required by paragraph (k)(2) of this AD constitutes terminating action for the repetitive inspections required by paragraph (g)(2) of this AD for that airplane, unless specified otherwise in the repair instructions approved by the Manager, International Section, Transport Standards Branch, FAA; or EASA; or Airbus's EASA DOA. If approved by the DOA, the approval must include the DOA-authorized signature.

(n) No Reporting Requirement

Although Airbus Service Bulletin A320-53-1264, Revision 01, excluding Appendix 01, dated July 4, 2016, specifies to submit certain information to the manufacturer, and specifies that action as ``RC'' (Required for Compliance), this AD does not include that requirement.

(o) Credit for Previous Actions

(1) This paragraph provides credit for actions required by paragraphs (g) and (h)(1) of this AD, if those actions were performed before March 15, 2004 (the effective date of AD 2004-03- 07) using Airbus Service Bulletin A320-53-1030, dated January 5, 2000; or Airbus Service Bulletin A320-53-1029, dated January 5, 2000.(2) This paragraph provides credit for actions required by paragraph (j) of this AD, if those actions were performed before the effective date of this AD using Airbus Service Bulletin A320-53- 1264, dated March 19, 2015.
(3) This paragraph provides credit for actions required by paragraph (k)(1) of this AD, if those actions were performed before the effective date of this AD using the applicable service information specified in paragraphs (o)(3)(i) through (o)(3)(iv) of this AD, for that airplane only.
(i) Airbus Service Bulletin A320-53-1240, dated March 19, 2015.
(ii) Airbus Service Bulletin A320-53-1240, Revision 01, dated April 4, 2016.
(iii) Airbus Service Bulletin A320-53-1263, dated March 19, 2015.
(iv) Airbus Service Bulletin A320-53-1263, Revision 01, dated February 29, 2016.
(4) This paragraph provides credit for actions required by paragraph (m)(1)(ii) of this AD if those actions were performed before the effective date of this AD using Airbus Service Bulletin A320-53-1240, dated March 19, 2015; or Service Bulletin A320-53- 1263, dated March 19, 2015.

(p) Other FAA AD Provisions

The following provisions also apply to this AD:
(1) Alternative Methods of Compliance (AMOCs): The Manager, International Section, Transport Standards 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 International Branch, send it to the attention of the person identified in paragraph (q)(2) of this AD. Information may be emailed to: 9-ANM-116-AMOC-REQUESTS@faa.gov. 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.
(2) Contacting the Manufacturer: Asof the effective date of this AD, for any requirement in this AD to obtain corrective actions from a manufacturer, the action must be accomplished using a method approved by the Manager, International Section, Transport Standards Branch, FAA; or the European Aviation Safety Agency (EASA); or Airbus's EASA Design Organization Approval (DOA). If approved by the DOA, the approval must include the DOA-authorized signature.
(3) Required for Compliance (RC): Except as required by paragraphs (k)(2) and (n) of this AD: If any service information contains procedures or tests that are identified as RC, those procedures and tests must be done to comply with this AD; any procedures or tests that are not identified as RC are recommended. Those procedures and tests that are not identified 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 procedures and tests identified as RC canbe done and the airplane can be put back in an airworthy condition. Any substitutions or changes to procedures or tests identified as RC require approval of an AMOC.

(q) Related Information

(1) Refer to Mandatory Continuing Airworthiness Information (MCAI) EASA AD 2016-0206, dated October 13, 2016; corrected October 14, 2016; for related information. This MCAI may be found in the AD docket on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2017-0902.
(2) For more information about this AD, contact Sanjay Ralhan, Aerospace Engineer, International Section, Transport Standards Branch, FAA, 2200 South 216th St., Des Moines, WA 98198; telephone 206-231-3223; fax 206-231-3398.
(3) Service information identified in this AD that is not incorporated by reference is available at the addresses specified in paragraphs (r)(5) and (r)(6) of this AD.

(r) 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 this AD specifies otherwise.
(3) The following service information was approved for IBR on May 3, 2018.
(i) Airbus Service Bulletin A320-53-1029, Revision 01, including Appendix 01, dated April 29, 2002.
(ii) Airbus Service Bulletin A320-53-1240, Revision 01, dated April 4, 2016.
(iii) Airbus Service Bulletin A320-53-1240, Revision 02, dated March 14, 2017.

[[Page 13395]]

(iv) Airbus Service Bulletin A320-53-1263, Revision 01, dated February 29, 2016.
(v) Airbus Service Bulletin A320-53-1263, Revision 02, excluding Appendix 01 and including Appendix 02, dated December 6, 2017.
(vi) Airbus Service Bulletin A320-53-1264, Revision 01, excluding Appendix 01, dated July 4, 2016.
(4) The following service information was approved for IBR on March 15, 2004 (69 FR 5907, February 9, 2004).
(i) Airbus Service Bulletin A320-53-1030, Revision 01, excluding Appendix 01, dated May 21, 2002.
(ii) Reserved.
(5) For service information identified in this AD, contact Airbus, Airworthiness Office--EIAS, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone +33 5 61 93 36 96; fax +33 5 61 93 44 51; email account.airworth-eas@airbus.com; internet http://www.airbus.com.
(6) You may view this 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.
(7) 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

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2004-03-07, Amendment 39-13451 (69 FR 5907, February 9, 2004) (``AD 2004-03-07''). AD 2004-03-07 applied to certain Airbus Model A320-111, -211, -212, and -231 series airplanes. The NPRM published in the Federal Register on October 6, 2017 (82 FR 46729). The NPRM was prompted by fatigue tests which revealed cracking around the fasteners attaching the pressure panel to the flexible bracket at FR 36, adjacent to the longitudinal beams on the left and right sides of the airplane, and by the discovery of additional cracks under the longitudinal beams at locations that are not included in the inspection area required by AD 2004-03-07. The NPRM proposed to continue to require certain requirements of AD 2004-03-07. The NPRM also proposed to expand the applicability and require an inspection of the fastener holes on the pressure panel between FR 35 and FR 36under the longitudinal beam and modification or repair as applicable. We are issuing this AD to detect and correct fatigue cracking around the fasteners attaching the pressure panel to the flexible bracket at the FR 36 adjacent to the longitudinal beams, which could result in reduced structural integrity of the airplane and possible rapid decompression of the airplane.
The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union, has issued EASA Airworthiness Directive 2016-0206, dated October 13, 2016; corrected October 14, 2016 (referred to after this as the Mandatory Continuing Airworthiness Information, or ``the MCAI''), to correct an unsafe condition for certain Airbus Model A318 and Model A319 series airplanes, Model A320-211, -212, -214, -231, -232, and -233 airplanes, and Model A321-111, -112, -131,-211, -21-, 213, -231, and -232 airplanes. The MCAI states:

During fatigue tests, cracks were found around the fasteners connecting the pressure panel with the flexible bracket at fuselage frame (FR) 36, adjacent to the longitudinal beams on left-hand (LH) and right-hand (RH) sides.
This condition, if not detected and corrected, could impair the structural integrity of the aeroplane.
To address this unsafe condition, DGAC [Direction G[eacute]n[eacute]rale de l'Aviation Civile] France issued [French] AD 2000-531-155(B) [which corresponds with FAA AD 2004-03-07] to require repetitive inspections of the longitudinal beams of the FR 36 pressure panel and, depending on findings, the accomplishment of a repair.
Since that [French] AD was issued, additional cracks have been found under the beams, but in locations not covered by the required inspections. Fatigue and damage tolerance analyses were performed, the results of which indicated that all the holes in the pressure panel above all the longitudinal beams have to be cold worked.
For the reasons described above, this [EASA] AD retains the requirements of DGAC France AD 2000-531-155(B), which is superseded, extends the applicability to all A320 family aeroplanes and requires [a special detailed inspection of the fastener holes on the pressure panel between FR35 and FR36 under the longitudinal beam and] modification [or repair] of all the affected holes.
This [EASA] AD is republished to correct the number of the superseded DGAC AD.

You may examine the MCAI in the AD docket on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2017- 0902.

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.

Request To Remove Reporting Requirement

United Airlines (UAL) requested that we omit paragraph (k)(2)(ii) of the proposed AD, which would require operators to report any findings of cracking that exceeded the limits specified in Airbus Service Bulletin A320-53-1264, Revision 01, excluding Appendix 01, dated July 4, 2016, from the proposed AD. UAL stated that paragraph (k)(2)(ii) of the proposed AD is confusing and unjustified because there is no explanation for why it is required when it was not included in EASA AD 2016-0206. UAL stated the requirement to report findings in paragraph (k)(2)(ii) is redundant with the actions of paragraph (k)(2)(i) of the proposed AD. UAL noted that for the

[[Page 13389]]

crack repair specified in paragraph (k)(2)(i) of the proposed AD, the findings would be reported. UAL suggested the paragraph (k)(2)(ii) of the proposed AD required using an unconventional means to report findings that might require additional procedures and training specific to the proposed AD. UAL also stated that restricting reporting to a website may cause issues if the sender does not have access and that Airbus Service Bulletin A320-53-1264, Revision 01, excluding Appendix 01, dated July 4, 2016, lists alternativeoptions for reporting, like email, fax, or mail.
We agree to remove the reporting requirement specified in paragraph (k)(2)(ii) of the proposed AD from this AD. Neither Airbus Service Bulletin A320-53-1264, Revision 01, excluding Appendix 01, dated July 4, 2016, nor the MCAI specifically includes reporting to a website as specified in paragraph (k)(2)(ii) of the proposed AD. We note that Airbus Service Bulletin A320-53-1264, Revision 01, excluding Appendix 01, dated July 4, 2016, does include reporting within the required for compliance (RC) procedure for the repair, which indicates that reporting would be required regardless of whether reporting was called out in the MCAI. We also verified with EASA that reporting should be done as defined in the service information. However, we have determined that a specific reporting requirement is not necessary. As stated by the commenter, operators will report findings to obtain the repair, which is specified in paragraph (k)(2)(i) of the proposed AD. We have removed paragraphs (k)(2)(i) and (k)(2)(ii) from this AD and revised paragraph (k)(2) of this AD to include the information that was in paragraph (k)(2)(i) of the proposed AD. We have also added paragraph (n) to this AD to specify that reporting is not required for this AD and redesignated the subsequent paragraphs accordingly.

Request To Refer to Latest Service Information

Two commenters requested that we refer to the latest service information. UAL requested that we update paragraph (k) of the proposed AD to use Airbus Service Bulletin A320-53-1264, Revision 02, dated March 14, 2017, which corrects an error with the fastener lengths for part number (P/N) EN6115K3. We infer that UAL intended to refer to Airbus Service Bulletin A320-53-1240, Revision 02, dated March 14, 2017, because there is no Revision 02 for Airbus Service Bulletin A320- 53-1264, and because P/N EN6115K3 is referenced in Airbus Service Bulletin A320-53-1240, Revision 02, dated March 14,2017. Airbus requested that we refer to Airbus Service Bulletin A320-53-1240, Revision 02, dated March 14, 2017, in the proposed AD.
We agree to refer to the latest service information in this AD. In addition to Airbus Service Bulletin A320-53-1240, Revision 02, dated March 14, 2017, we have also reviewed Airbus Service Bulletin A320-53- 1263, Revision 02, excluding Appendix 01 and including Appendix 02, dated December 6, 2017, which updates kit information and figures among other minor changes. We have revised paragraph (k)(1) of this AD accordingly. We have also provided credit for Airbus Service Bulletin A320-53-1240, Revision 01, dated April 4, 2016; and Airbus Service Bulletin A320-53-1263, Revision 01, dated February 29, 2016; in paragraphs (o)(3)(ii) and (o)(3)(iv) of this AD, respectively.

Request To Include Additional Airplane Models in the Applicability

Airbus requested that Model A320-215 and Model A320-216 airplanes be in included in the applicability of the proposed AD. The commenter noted that these airplane models are included in the MCAI.
We do not agree with the commenter's request. We have not certified Model A320-215 airplanes for operation in the U.S., and therefore, we did not include that model in the applicability of this AD. We did not include Model A320-216 airplanes in the applicability of this AD because the MCAI was already added to the required airworthiness action list (RAAL) for Model A320-216 airplanes. We have not changed this AD in this regard.

Request To Revise Service Bulletin Descriptions in the Related Service Information Under 1 CFR Part 51 Paragraph in the Preamble of the NPRM

Airbus stated that the proposed AD identifies the means of inspection, i.e., rototest inspection, using three different wordings in the descriptions of the service bulletins specified in the Related Service Information under 1 CFR part 51 paragraph in the preamble of the NPRM. Airbus also stated that Service Bulletin A320-53-1240, Revision 02, dated March 14, 2017, no longer contains a rototest inspection requirement. In addition, Airbus noted that Service Bulletin A320-53-1240, Revision 02, dated March 14, 2017, does not contain repair instructions. We infer the commenter is requesting that we revise the service bulletin descriptions in the Related Service Information under 1 CFR part 51 paragraph in the preamble of the NPRM.
We acknowledge the description of the rototest inspection is different for each service bulletin specified in the Related Service Information under 1 CFR part 51 paragraph in the preamble of the NPRM. In the NPRM, we matched the description of the inspection as given in each service bulletin specified in the Related Service Information under 1 CFR part 51 paragraph. We have revised the description of Airbus Service Bulletin A320-53-1240, Revision 02, dated March 14, 2017, to remove the reference to an inspection and repair.

Request To Clarify What Prompted the Proposed ADAirbus requested that we revise paragraph (e) of the proposed AD to clarify that the proposed AD was prompted by a report of cracking in an additional area. Airbus stated that paragraph (e) of the proposed AD describes only the fatigue test results that prompted AD 2004-03-07.
We agree to revise paragraph (e) of this AD for clarity. This AD was prompted by the original report of cracking and the additional report. We have revised paragraph (e) of this AD to include the additional cracking that prompted the issuance of this AD.

Request To Revise Repair Language in Paragraph (k)(2)(i) of the Proposed AD

Airbus requested that we revise the language in paragraph (k)(2)(i) of the proposed AD, which specifies to repair any cracking in accordance with Airbus Service Bulletin A320-53-1264, Revision 01, excluding Appendix 01, dated July 4, 2016. Airbus stated that this service information does not provide direct repair instructions and instead specifies to contact Airbus.
Weagree to clarify the language in paragraph (k)(2) of this AD (which corresponds with paragraph (k)(2)(i) of the proposed AD). Paragraph (k)(2) of this AD also specifies that where Airbus Service Bulletin A320-53-1264, Revision 01, excluding Appendix 01, dated July 4, 2016, specifies to contact Airbus for appropriate action, and specifies that action as ``RC'' (Required for Compliance), operators must request approval of repair instructions using a method approved in accordance with the procedures specified in paragraph (p)(2) of this AD, and accomplish the repair accordingly within the compliance time specified in those instructions. We have not changed this AD in this regard.

[[Page 13390]]

Request To Include Wording From the MCAI in Paragraph (m)(1)(iii) of the Proposed AD

Airbus requested that we revise paragraph (m)(1)(iii) of the proposed AD. Airbus stated the wording is similar to paragraph (9) of the MCAI except that the important wording ``in accordance with Airbus approved instructions that identify the repair as technically equivalent to the accomplishment of Airbus SB A320-53-1240 or SB A320- 53-1263'' is omitted.
We disagree with the commenter's request. The intent of paragraph (m)(1)(iii) of this AD is to obtain corrective actions from the manufacturer that are approved by the FAA, EASA, or Airbus's EASA Design Organization Approval (DOA). These approved instructions will provide an equivalent level of safety. We have not changed this AD in this regard.

Conclusion

We reviewed the available data, including 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 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 determinedthat these changes will not increase the economic burden on any operator or increase the scope of this AD.

Related Service Information Under 1 CFR Part 51

Airbus has issued Service Bulletin A320-53-1029, Revision 01, including Appendix 01, dated April 29, 2002. The service information describes procedures for repairing cracking.
Airbus has also issued Service Bulletin A320-53-1240, Revision 01, dated April 4, 2016; and A320-53-1240, Revision 02, dated March 14, 2017, which describe procedures for modifying the pressure panel above the left and right longitudinal beams, by cold working the attachment holes under the longitudinal beam at FR 36 for airplanes on which no cracking was found. Service Bulletin A320-53-1240, Revision 01, dated April 4, 2016 also includes related investigative action (e.g., high frequency eddy current (rototest) inspection of all the removed fastener holes) and corrective actions (e.g., repair). These documents are distinct since they are different revision levels.
Airbus has also issued Service Bulletin A320-53-1263, Revision 01, dated February 29, 2016; and A320-53-1263, Revision 02, excluding Appendix 01 and including Appendix 02, dated December 6, 2017, which describe procedures for modifying the pressure panel above the left and right longitudinal beams, including related investigative actions (e.g., eddy current rotating probe inspection of the fastener holes) and corrective actions (e.g., repair), by adding a doubler and a filler, and cold expansion of the holes under the longitudinal beam at FR 36 for airplanes on which cracking was found. These documents are distinct because they are different revision levels.
Airbus has also issued Service Bulletin A320-53-1264, Revision 01, excluding Appendix 01, dated July 4, 2016. The service information describes procedures for a special detailed inspection (rotating probe) for cracking of the fastener holes on the pressure panel between FR 35 and FR 36 under the longitudinal beam and repair of any crack.
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 737 airplanes of U.S. registry.
We estimate the following costs to comply with this AD:

Estimated Costs ----------------------------------------------------------------------------------------------------------------
Cost on U.S.
Action Labor cost Parts cost Cost per product operators ---------------------------------------------------------------------------------------------------------------- Inspection [Retained from AD Up to 2 work-hours x $0 Up to $170 per Up to $125,290 per
2004-03-07]. $85 per hour = $170 inspection cycle. inspection cycle.
per inspection cycle. Inspection [new proposed 13 work-hours x $85 per $0 $1,105............ $814,385.
requirement]. hour = $1,105. ----------------------------------------------------------------------------------------------------------------

We estimate the following costs to do any necessary modifications that will be required based on the results of the inspection. We have no way of determining the number of aircraft that might need these modifications:

On-Condition Costs ----------------------------------------------------------------------------------------------------------------
Action Labor cost Parts cost Cost per product ---------------------------------------------------------------------------------------------------------------- Modification....................... Up to 213 work-hours x $85 Up to $8,510.......... Up to $26,615.
per hour = $18,105. ----------------------------------------------------------------------------------------------------------------

We have received no definitive data that will enable us to provide a cost estimate for the on-condition repairs 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 unsafecondition that is likely to exist or develop on products identified in this rulemaking action.
This AD is issued in accordance with authority delegated by the Executive Director, Aircraft Certification Service, as authorized by FAA Order 8000.51C.

[[Page 13391]]

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 to the Director of the System Oversight Division.

Regulatory Findings

We 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.
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 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.