AD 2018-14-09

We are adopting a new airworthiness directive (AD) for certain Airbus Model A318 series airplanes; Model A319 series airplanes; Model A320-211, -212, -214, -216, -231, -232, and -233 airplanes; and Model A321-111, -112, -131, -211, -212, -213, -231, and -232 airplanes. This AD was prompted by reports of early cracking on certain holes of the crossbeam splicing at certain fuselage frames. This AD requires repetitive inspections for cracking of the fastener holes in certain fuselage frames, and depending on airplane configuration, provides an optional terminating action to the repetitive inspections. 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 adding the following new airworthiness directive (AD):

2018-14-09 Airbus: Amendment 39-19329; Docket No. FAA-2017-1093; Product Identifier 2017-NM-018-AD.

(a) Effective Date

This AD is effective August 23, 2018.

(b) Affected ADs

None.

(c) Applicability

This AD applies to Airbus Model A318-111, -112, -121, and -122 airplanes; Model A319-111, -112, -113, -114, -115, -131, -132, and - 133 airplanes; Model A320-211, -212, -214, -216, -231, -232, and - 233 airplanes; and Model A321-111, -112, -131, -211, -212, -213, - 231, and -232 airplanes, certificated in any category, all manufacturer serial numbers, except the airplanes specified in paragraphs (c)(1), (c)(2), and (c)(3) of this AD.
(1) Airplanes on which Airbus modification 161255 has been embodied in production.
(2) Model A319 series airplanes on which Airbus modifications 28238, 28162, and 28342 have been concurrently embodied in production.
(3) Model A318 series airplanes on which Airbus modification 39195 has been embodied in production.

(d) Subject

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

(e) Reason

This AD was prompted by reports of early cracking on the four holes of the crossbeam splicing at certain fuselage frames (FR). We are issuing this AD to detect and correct cracking at two upper rows of fasteners of the crossbeam splicing at FR16 and FR20, on both the left-hand (LH) and right-hand (RH) sides, which can result in reduced structural integrity of the airplane due to the failure of structural components.

(f) Compliance

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

(g) Repetitive Rototest Inspections

Before exceeding the threshold specified in table 1 to paragraphs (g) and (n) of this AD, or table 2 to paragraphs (g) and (n) of this AD, as applicable to airplane configuration (pre- or post-modification 20416 or pre- or post-modification 21999): Do a special detailed (rototest) inspection of the two upper rows of fasteners of the crossbeam splicing at FR16 and FR20 on both LH and RH sides, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-53-1286, Revision 01, dated December 22, 2015. Thereafter, repeat the inspection at the intervals specified in table 1 to paragraphs (g) and (n) of this AD, or table 2 to paragraphs (g) and (n) of this AD, as applicable to airplane configuration (pre- or post-modification 20416 or pre- or post- modification 21999).

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(h) Post-Inspection Actions

Depending on the results from any inspection required by paragraph (g) of this AD, do the actions in paragraphs (h)(1) or (h)(2) of this AD, as applicable.
(1) If, during any inspection required by paragraph (g) of this AD, any crack is detected: Before further flight, do all applicable related investigative and corrective actions in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-53-1286, Revision 01, dated December 22, 2015; except where Airbus Service Bulletin A320-53-1286, Revision 01, dated December 22, 2015, specifies to contact Airbus for appropriate repair, and specifies that action as ``RC'' (Required for Compliance), accomplish corrective actions before further flight in accordance with the procedures specified in paragraph (s)(2) of this AD. Repair of an airplane as required by this paragraph does not constitute terminating action for therepetitive inspections required by paragraph (g) of this AD for that airplane, unless specified otherwise in the repair instructions.
(2) If, during any inspection required by paragraph (g) of this AD, no cracks are detected: Before further flight, do all applicable fastener installations, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-53-1286, Revision 01, dated December 22, 2015.

(i) Airplanes on Which Airbus Repair Instruction R53112926 With Installation of EN6114 Countersunk Fasteners Was Applied on the Frame and/or Crossbeam

For airplanes on which Airbus Repair Instruction R53112926 at issue A or B with installation of EN6114 countersunk fasteners was applied on the frame and/or crossbeam at FR16 LH or RH, or at FR20 LH or RH: Within 24 months after the effective date of this AD, modify the repair 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.

(j) Airplanes on Which a Repair With Installation of EN6114 Countersunk Fasteners Was Applied on the Frame and/or Crossbeam

For airplanes on which a repair with installation of EN6114 countersunk fasteners, approved by the FAA, EASA, Airbus's EASA DOA, or an EASA DOA (other than Airbus's EASA DOA), was applied on the frame and/or crossbeam at FR16 LH or RH, or at FR20 LH or RH, in the area covered by paragraph (g) of this AD: Within 24 months after the effective date of this AD, modify the repair using a method 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.

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(k) Optional Terminating Action for Airplanes Post-Modification 20416 or Post-Modification 21999

Modificationof an airplane post-modification 20416 or post- modification 21999 in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-53-1295, including Appendixes 01 and 02, dated June 29, 2015, except as required by paragraph (r) of this AD, constitutes terminating action for the repetitive inspections required by paragraph (g) of this AD for that airplane.

(l) Information on Post-Repair Actions for Certain Airplanes

For an airplane that has been inspected per ALI task 531110 and repaired before the effective date of this AD using the instructions in an Airbus Repair Design Approval Sheet (RDAS): each applicable RDAS contains next inspection and compliance time for the inspection for each repaired hole.

(m) Partial Terminating Action for Airplanes Post-Modification 20416 or Post-Modification 21999

For an airplane post-modification 20416 or post-modification 21999, modification in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-53-1295, including Appendixes 01 and 02, dated June 29, 2015, except as required by paragraph (r) of this AD, for the applicable fastener holes, where no damage or cracks were detected (i.e., those not repaired) during the latest inspection as required by paragraph (g) of this AD, constitutes terminating action for the repetitive inspections of those fastener holes as required by paragraph (g) of this AD for that airplane.

(n) Actions for Airplanes With Certain Repairs

For an airplane that has been repaired before the effective date of this AD in the areas described in this AD using the instructions in an Airbus RDAS unrelated to ALI task 531110: Before exceeding the compliance times specified in table 1 to paragraphs (g) and (n) of this AD or table 2 to paragraphs (g) and (n) of this AD, as applicable, contact the Manager, International Section, Transport Standards Branch, FAA; or EASA; or Airbus's EASA DOA for corrective action instructions and accomplish those instructions accordingly. If approved by the DOA, the approval must include the DOA-authorized signature. Accomplishment of corrective action(s) on an airplane, as required by this paragraph, does not constitute terminating action for the repetitive inspections required by paragraph (g) of this AD for that airplane, as applicable, unless specified otherwise in the instructions.

(o) Terminating Action for ALI Tasks

(1) Accomplishment of an inspection as required by paragraph (g) of this AD or instructions as required by paragraph (l) of this AD, as applicable, constitutes terminating action for the inspection requirements of ALI task 531110, for that airplane.
(2) Modification of the two upper rows of fasteners of the crossbeam splicing at FR16 and FR20 on both LH and RH sides of an airplane, in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-53-1295, including Appendixes 01 and 02, dated June 29, 2015, except as required by paragraph (r)of this AD, as specified in paragraphs (k) and (m) of this AD, constitutes terminating action for the inspection requirements of ALI task 531110, for those holes for that airplane.

(p) No Reporting Requirement

Although Airbus Service Bulletin A320-53-1286, Revision 01, dated December 22, 2015, specifies to submit certain information to the manufacturer, and specifies that action as ``RC'' (Required for Compliance), this AD does not include that requirement.

(q) Credit for Previous Actions

This paragraph provides credit for actions required by paragraph (g) and (h) of this AD, if those actions were performed before the effective date of this AD using Airbus Service Bulletin A320-53- 1286, dated June 29, 2015.

(r) Service Information Exceptions

Where Subtasks 531295-960-001-001 and 532195-960-002-001 of Airbus Service Bulletin A320-53-1295, including Appendixes 01 and 02, dated June 29, 2015, refer to actions when an existing hole diameter is ``more thanor equal to the minimum starting hole diameter,'' this AD requires applicable actions in cases where the hole diameter is ``more than or equal to the maximum starting hole diameter.''

(s) 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 Section, send it to the attention of the person identified in paragraph (t)(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: 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 EASA; or Airbus's EASA DOA. If approved by the DOA, the approval must include the DOA- authorized signature.
(3) Required for Compliance (RC): Except as required by paragraphs (h)(1) and (p) 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 can be 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.

(t) Related Information

(1) Refer to Mandatory Continuing Airworthiness Information (MCAI) EASA AD 2016-0139, dated July 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-2017-1093.
(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 and fax 206-231-3223.
(3) Service information identified in this AD that is not incorporated by reference is available at the addresses specified in paragraphs (u)(3) and (u)(4) of this AD.

(u) 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.
(i) Airbus Service Bulletin A320-53-1286, Revision 01, dated December 22, 2015.
(ii) Airbus Service Bulletin A320-53-1295, including Appendixes 01 and 02, dated June 29, 2015.
(3) For service information identified in this AD, contact Airbus, Airworthiness Office--EIAS, Rond-Point Emile Dewoitine No: 2, 31700 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.
(4) 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.
(5) You may view this service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to certain Airbus Model A318 series airplanes; Model A319 series airplanes; Model A320-211, -212, - 214, -216, -231, -232, and -233 airplanes; and Model A321-111, -112, - 131, -211, -212, -213, -231, and -232 airplanes. The NPRM published in the Federal Register on November 27, 2017 (82 FR 55955) (``the NPRM''). The NPRM was prompted by reports of early cracking on certain holes of the crossbeam splicing at certain fuselage frames. The NPRM proposed to require repetitive inspections for cracking of the fastener holes in certain fuselage frames, and depending on airplane configuration, would provide an optional terminating action to the repetitive inspections. We are issuing this AD to address cracking at two upper rows of fasteners of the crossbeam splicing at frame (FR)16 and FR20, on both the left-hand (LH) and right-hand (RH) sides, which can result in reduced structural integrity of the airplane due to the failure of structural components.
The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2016-0139, dated July 14, 2016 (referred to after this as the Mandatory Continuing Airworthiness Information, or ``the MCAI''), to correct an unsafe condition

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for certain Model A318 series airplanes; Model A319 series airplanes; Model A320-211, -212, -214, -216, -231, -232, and -233 airplanes; and Model A321-111, -112, -131, -211, -212, -213, -231, and -232 airplanes. The MCAI states:

Following addition of a new airworthiness limitation item (ALI) task 531110 in the Airworthiness Limitation Section (ALS) Part 2 in the revision dated April 2012, numerous findings have been reported of early cracks on the four holes of the crossbeam splicing at frame (FR)16 and FR20 on both left-hand (LH) and right-hand (RH) sides.
This condition, if not detected and corrected, could affect the structural integrity of the airframe.
To allow an earlier crack detection, Airbus decided to transfer the repetitive inspections from ALI task 531110 to Airbus Service Bulletin (SB) A320-53-1286, later revised, including new recommended inspection thresholds.
For the reasons described above, this [EASA] AD requires repetitive special detailed [rototest] inspections (SDI) of the two upper rows of fasteners of the crossbeam splicing at FR16 and FR20, on both LH and RH sides, [installation of new fasteners on crack- free frames, related investigative and corrective actions,] and, depending on aeroplane configuration, provides an optional terminating action to the repetitive inspections required by this [EASA] AD.

Related investigative actions include checking the edge margins of the holes. Corrective actions include reaming affected crossbeams and frames and cold working the frames. 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-2017-1093.

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.

Requests To Revise Repair Instructions for Repairs Done Using an Airbus Repair Design Approval Sheet (RDAS)

American Airlines (AAL) and United Airlines (UAL) requested that the repair instructions in paragraph (l) of the proposed AD be revised to remove requirements to obtain new repair instructions for any airplanes on which repairs were done using the instructions in an Airbus RDAS. AAL noted that the original RDAS approval was given by an EASA Design Organization Approval (DOA), so new approval should not be needed. Instead, AAL suggested that the issuer of the RDASs should be required to revise the RDASs as necessary. UAL noted that an RDAS already defines repairlife and inspection instructions or limits. UAL also noted that the MCAI does not require obtaining new repair instructions, but instead says to accomplish the repair instructions given in the RDAS for repaired fastener holes.
We disagree to require the issuer of the RDAS to revise the RDAS. An RDAS is an Airbus document that is not approved by the FAA, and the FAA has no authority to require Airbus to revise the RDAS.
We agree with the requests to remove the requirement to obtain repair instructions in paragraph (l) of this AD. We have confirmed that EASA intended the corresponding paragraph in the MCAI to be informational, rather than a new requirement. We have revised paragraph (l) of this AD to note that the information on the next inspection and compliance time for the inspection of repaired holes is specified in the applicable RDAS; therefore, there is no requirement to obtain and follow new instructions.

Request To Supersede Certain Inspections

UAL requested that we revise paragraph (l) of the proposed AD to state that previous repair instructions that superseded ALI 531110 also terminate the inspections required by paragraph (g) of the proposed AD for the repaired holes. UAL noted that they had several RDASs that state that the inspection requirements of the RDAS supersede ALI 531110 for the repaired fasteners. UAL stated that these repairs involved enlarging the holes and fasteners, thereby making it impossible for them to accomplish the inspections in accordance with Airbus Service Bulletin A320-53-1286, Revision 01, dated December 22, 2015.
We disagree with revising paragraph (l) of this AD to specify terminating action to paragraph (g) of this AD. An operator who is unable to complete certain requirements in this AD due to existing repairs may request an alternative method of compliance (AMOC) under the provisions of paragraph (s)(1) of this AD.

Request To Remove or Revise Paragraph (n) of the Proposed AD

AAL requested thatparagraph (n) of the proposed AD be revised to remove requirements to obtain new repair instructions for any airplanes on which repairs were done using the instructions in an Airbus RDAS unrelated to ALI task 531110. AAL noted that the original RDAS approval was given by an EASA DOA, so new approval should not be needed. Instead, AAL suggested that the issuer of the RDASs should be required to revise the RDASs as necessary.
UAL requested that paragraph (n) of the proposed AD be removed. UAL stated that determining if a repair is unrelated to ALI task 531110 may be inconclusive, since the ALI task is an inspection that may or may not be referenced in a documented repair. UAL added that each repair approval will have damage tolerance considerations regardless of how the damage was found. UAL further noted that if a repair unrelated to ALI task 531110 prevents inspection or repair as specified in the proposed AD, operators would need to request an AMOC.
We disagree with the commenters' requests. EASA has determined that repairs unrelated to ALI task 531110, which could include minor repairs unrelated to the unsafe condition, may not adequately address the unsafe condition. For this reason, operators must request new corrective actions for such repairs, as specified in paragraph (n) of this AD.

Requests To Revise Repair Instructions for Airplanes on Which Certain Repairs Were Previously Applied

UAL and AAL requested that paragraphs (i) and (j) of the proposed AD be revised to list specific affected manufacturer serial numbers (MSNs). In addition, UAL and AAL requested that the original equipment manufacturer (OEM) revise the Airbus RDASs to correct any problems. AAL pointed out that the original RDAS was approved by an EASA DOA and stated that operators should therefore not be required to obtain a new approval. UAL requested that if we do not provide revised RDASs or a list of affected MSNs, we instead provide a pre-defined solution for the repair. UALsuggested that we should provide instructions for replacing EN6114 fasteners with EN6115 fasteners. UAL further requested that if the repairs require case-by-case evaluations, the repair instructions should define the repair compliance time, rather than having a set 24 month compliance time, which may not work for every configuration.
UAL also noted that the issue with Airbus Repair Instruction R53112926 issue A or B is that it called out the wrong fastener; EN6115 should have been used instead of EN6114.
UAL requested that we add a statement to paragraph (j) of this AD stating that no additional repair instructions are needed if a repair was accomplished using Airbus Repair Instruction R53112926 issue A or B and EN6115 fasteners.

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We disagree with the commenters' requests to revise paragraphs (i) and (j) of this AD to list specific affected MSNs. EASA, as the state of design authority, and Airbus have both stated that they do not have knowledge of priorapproved repairs; therefore we do not have a list of affected MSNs. In addition, an RDAS is an Airbus document that is not approved by the FAA, and the FAA has no authority to require Airbus to revise the RDAS. Therefore, each existing repair must be individually analyzed before a new corrective action can be provided. For this reason, we are not able to provide a single pre-defined solution for the repair that would address every affected configuration. We have determined that 24 months is an appropriate time frame to address the unsafe condition related to the EN6114 fasteners. An AMOC in accordance with paragraph (s)(1) of this AD may be requested if additional time is needed to address the unsafe condition.
We do not agree to add a statement to paragraphs (i) or (j) of this AD regarding no additional repair instructions are necessary if those repairs were applied with the installation of EN6115 fasteners, but we do agree to clarify that paragraphs (i) and (j) of this AD only apply to airplanes on which Airbus Repair Instruction R53112926 issue A or B or any other repair involving the installation of EN6114 fasteners was applied. If EN6115 fasteners were installed in the accomplishment of Airbus Repair Instruction R53112926 issue A or B or any other repair, the actions specified in paragraphs (i) or (j) of this AD are not required on the repaired airplane.

Request To Include Corrections to Service Information

UAL requested that we update paragraph (k) of the proposed AD to reflect corrections to Airbus Service Bulletin A320-53-1295, including Appendixes 01 and 02, dated June 29, 2015. UAL noted that Airbus has released Operators Information Transmission (OIT) 15-0097, Revision 01, dated January 7, 2016, to correct discrepancies in the effectivity section and existing hole diameters for certain subtasks in Airbus Service Bulletin A320-53-1295, including Appendixes 01 and 02, dated June 29, 2015.
We agree with the commenter's request for the reasons provided. We have added paragraph (r) to this AD to clarify the hole-diameter correction provided in Airbus OIT 15-0097, Revision 01, dated January 7, 2016. We have also updated other paragraphs of this AD that refer to Airbus Service Bulletin A320-53-1295, including Appendixes 01 and 02, dated June 29, 2015, to include this exception. We also acknowledge the discrepancy in the effectivity section of Airbus Service Bulletin A320- 53-1295, including Appendixes 01 and 02, dated June 29, 2015, and the correction provided in Airbus OIT 15-0097, Revision 01, dated January 7, 2016. However, the applicability of this AD does not refer to Airbus Service Bulletin A320-53-1295, including Appendixes 01 and 02, dated June 29, 2015. Therefore, we have not changed this AD in this regard.

Request To Verify Title of Table 1 to Paragraphs (g) and (n) of This AD

Virgin America requested that we review the title of table 1 to paragraphs (g) and (n) of this AD. Virgin America noted that therelated MCAI table refers to airplanes having not embodied any of ``mod 20416 and mod 21999,'' while the proposed AD refers to ``pre- modification 20416 or pre-modification 21999'' airplanes. Virgin America suggested this might be a typographical error, and asked that it be corrected if it is in error.
We acknowledge that the wording in the MCAI and this AD is not the same and agree to clarify. Table 1 of the MCAI is intended to apply to airplanes that have not embodied any part of modification 20416 or any part of modification 21999. Therefore, it is accurate to state ``pre- modification 20416 or pre-modification 21999 airplanes.'' We have not changed this AD in this regard.

Request To Verify Referenced Service Information is at the Latest Revision

UAL requested that we verify the service bulletins referenced in the proposed AD are at the latest revision level. UAL noted this would eliminate the need to request an AMOC immediately following publication of this AD.
Weagree with the commenter's request. We have verified that no revisions of the referenced service information have been published since we issued our proposed AD.

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 AD.

Related Service Information Under 1 CFR Part 51

Airbus has issued the following service information.
Service Bulletin A320-53-1286, Revision 01, dated December 22, 2015, which describes procedures for rototest inspections for cracking of the holes in certain fuselage frames and crossbeams.
Service Bulletin A320-53-1295, including Appendixes 01 and 02, dated June 29, 2015, which describes procedures for modifying the airplane, including cold working instructions in certain fuselage frames and crossbeams.
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 928 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 ----------------------------------------------------------------------------------------------------------------Inspections..................... 116 work-hours x $85 $960 $10,820 per $10,040,960 per
per hour = $9,860 inspection cycle. inspection cycle.
per inspection cycle. Optional Modification........... 28 work-hours x 3,020 $5,400.............. Up to $5,011,200.
times; $85 per hour
= $2,380. ----------------------------------------------------------------------------------------------------------------

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

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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 authoritydescribed 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 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 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.