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, -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 July 25, 2017 (82 FR 34449) (``the NPRM''). The NPRM was prompted by reports of fatigue damage in the structure for the door stop fittings on certain fuselage frames. The NPRM proposed to require repetitive rototest inspections for cracking of the fastener holes in certain door stop fittings, and repair if necessary. We are issuing this AD to detect and correct cracking at the door stop fitting holes of fuselage FR66 and FR68. Such cracking could 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 2016-0238, dated December 2, 2016; corrected January 4, 2017 (referred to after this as the Mandatory Continuing Airworthiness Information, or ``the MCAI''), to correct an unsafe condition for certain Airbus Model A318 series airplanes; Model A319 series airplanes; Model A320-211, - 212, -214, -231, -232, and -233 airplanes; and Model A321-111, -112, - 131, -211, -212, -213, -231, and -232 airplanes. The MCAI states:
During an A320 fatigue test campaign, it was determined that fatigue damage could appear at the door stop fitting holes of fuselage frame (FR) 66 and FR 68 on left hand (LH) and right hand (RH) sides.
This condition, if not detected and corrected, could affect the structural integrity of the airframe.
Two inspections, Airworthiness Limitations Item (ALI) tasks 534129 and 534130, were introduced in the Airworthiness Limitations Section (ALS) Part 2 with theApril 2012 revision and with some compliance time changes with Revision 3 of ALS Part 2 of October 2014.
Since these ALI tasks were implemented, a significant number of reports [were] received concerning non-critical damage and early crack findings. Prompted by these reports, Airbus published SB A320- 53-1288 and SB A320-53-1290, providing inspection instructions to improve damage management and modification instructions.
Consequently, EASA issued AD 2016-0015, requiring repetitive rototest inspections of the affected door stop fitting holes and, depending on findings, repair of any cracked area(s).
Since that [EASA] AD was issued, ALS Part 2 Revision 04 and later on Revision 05 were published, introducing updated thresholds and/or intervals for some tasks as specified in Airbus SB A320-53- 1288, introducing new configuration of aeroplane with RETRO WING having accomplished SB A320-57-1193 (mod 160080), and keeping the threshold or interval only in flight cycles (FC).
Forthe reasons described above, this [EASA] AD retains the requirements of EASA AD 2016-0015, which is superseded, but requires those actions within the updated thresholds and intervals. In addition, a corrected threshold for pre-mod 160021 A321 aeroplanes is introduced and the Applicability is reduced to exclude configurations that are not affected.
This [EASA] AD is republished to clarify some requirements in Appendix 1 [in this EASA 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- 0707.
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 Add a Grace Period for Certain Repetitive Inspections
United Airlines (UAL) requested that we revise paragraph (h) of the proposed AD to allow a 60-day grace period after
[[Page 5907]]the effective date of this AD to give operators time to update their maintenance programs. UAL noted that for airplanes on which inspections were previously accomplished as specified in airworthiness limitation item (ALI) task 534129 or 534130, paragraph (h) of the proposed AD requires future inspections be done in accordance with Airbus Service Bulletin A320-53-1288, Revision 01, including Appendixes 01, 02, and 03, dated October 3, 2016. UAL noted that operators who are not yet incorporating Airbus Service Bulletin A320-53-1288, Revision 01, including Appendixes 01, 02, and 03, dated October 3, 2016, may have to schedule special inspection visits instead of doing the inspections during scheduled maintenance.
We agree with the commenter's request to add a grace period to paragraph (h) of this AD to allow operators to plan for the new inspection interval. However, since the commenter did not provide adequate justification to support a 60-day grace period, we have determined that a30-day grace period is appropriate. Additionally, under the provisions of paragraph (q)(1) of this AD, we will consider requests for approval of an extension of the compliance time if sufficient data are submitted to substantiate that the new compliance time would provide an acceptable level of safety. We have revised paragraph (h) of this AD to include a 30-day grace period.
Request To Allow Deviations From the Service Information for Certain Modified Airplanes
UAL requested that either the service information or the proposed AD be revised to provide alternate instructions for airplanes with modified hardware. UAL noted that ``paragraph (i)'' of the proposed AD requires repetitive inspections on airplanes modified by cold working fastener holes, which includes installing oversize hardware. UAL pointed out that the inspections must be done in accordance with Airbus Service Bulletin A320-53-1288, Revision 01, including Appendixes 01, 02, and 03, dated October 3, 2016, whichrequires using nominal size hardware that no longer exists on modified airplanes.
We infer that the commenter meant to refer to paragraph (j) of the proposed AD, which discusses post-modification inspections, rather than paragraph (i) of the proposed AD, which discusses an optional modification. We agree with the commenter's request. We acknowledge that Airbus Service Bulletin A320-53-1288, Revision 01, including Appendixes 01, 02, and 03, dated October 3, 2016, does not specifically address oversize hardware; however, EASA has stated that ``the same inspection principle applies for post SB [Service Bulletin] 53-1290 configuration.'' Therefore, we have retained Airbus Service Bulletin A320-53-1288, Revision 01, including Appendixes 01, 02, and 03, dated October 3, 2016, in paragraph (j) of this AD. We have also revised paragraph (j) of this AD to include an option for operators to obtain inspection instructions using a method approved by the Manager, International Section, TransportStandards Branch, FAA; or EASA; or Airbus's EASA Design Organization Approval (DOA).
Request To Remove a Reference to a Non-Terminating Action
UAL requested that we remove the statement ``repair of an airplane as required by this paragraph does not constitute terminating action for the repetitive inspections required by paragraph (g) or (j) of this AD for that repair, unless specified otherwise'' from paragraph (k) of the proposed AD. UAL suggested that statement be replaced with one instructing operators to accomplish inspections as specified in the repair instructions.
UAL noted that paragraph (k) of the proposed AD states that a crack repair must be done using a method approved by the Manager, International Section, Transport Standards Branch, FAA; or EASA; or Airbus's EASA DOA and says that such a repair does not constitute terminating action for the repetitive inspections done in accordance with Airbus Service Bulletin A320-53-1288, Revision 01, including Appendixes01, 02, and 03, dated October 3, 2016, unless specified otherwise.
UAL pointed out that Airbus Service Bulletin A320-53-1288, Revision 01, including Appendixes 01, 02, and 03, dated October 3, 2016, contains language to allow operators to accomplish crack repairs in accordance with structural repair manual (SRM) 53-41-12, and then perform inspections of the repaired area in accordance with SRM 53-41- 12. UAL noted that the SRM repair instructions do not state that they terminate the inspections in Airbus Service Bulletin A320-53-1288, Revision 01, including Appendixes 01, 02, and 03, dated October 3, 2016. UAL further noted that Airbus Service Bulletin A320-53-1288, Revision 01, including Appendixes 01, 02, and 03, dated October 3, 2016, only applies to unrepaired areas with nominal size holes (the repaired areas would have oversized holes).
We disagree with the commenter's request. We acknowledge that Airbus Service Bulletin A320-53-1288, Revision 01, including Appendixes 01, 02, and 03, dated October 3, 2016, allows repairs to be done using an SRM. However, this AD does not include that allowance since SRMs published before the effective date of this AD might not address the unsafe condition identified in this AD. Therefore, paragraph (k) of this AD requires repairs to be done using a method approved by the Manager, International Section, Transport Standards Branch, FAA; or EASA; or Airbus's EASA DOA.
Additionally, the statement that the commenter requested us to remove from paragraph (k) of this proposed AD aligns with the MCAI. The statement is meant to clarify that doing a repair does not necessarily terminate the repetitive inspections; the repetitive inspections would only be terminated if the repair approved by the Manager, International Section, Transport Standards Branch, FAA; or EASA; or Airbus's EASA DOA specifically states that the inspections are terminated. If the approved repair does not state that the inspections are terminated, operatorsmust continue to inspect using Airbus Service Bulletin A320- 53-1288, Revision 01, including Appendixes 01, 02, and 03, dated October 3, 2016, or using a method approved by the Manager, International Section, Transport Standards Branch, FAA; or EASA; or Airbus's EASA DOA. Therefore, we have not changed the requirements in paragraph (k) of this AD nor have we removed the statement identified by the commenter. However, we have revised paragraph (g) of this AD to include an option for operators to obtain inspection instructions using a method approved by the Manager, International Section, Transport Standards Branch, FAA; or EASA; or Airbus's EASA DOA.
Request To Remove Requirement To Obtain Certain Inspection Instructions
UAL requested that we remove paragraph (l)(2) of the proposed AD because it has no real purpose. UAL noted that paragraph (l)(2) of the proposed AD requires operators to obtain inspection instructions and corrective actions for all repaired fastener holes bycontacting the Manager, International Section, Transport Standards Branch, FAA; or EASA; or Airbus's EASA DOA. UAL claimed that if a repair was accomplished using the instructions in an SRM or repair design approval sheet (RDAS), the repair approval contains, at a minimum, the initial compliance threshold. UAL added that it is standard
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practice for operators to contact Airbus prior to the inspection threshold if the compliance method and intervals are not yet defined.
We disagree with the commenter's request. Airbus intends to provide specific instructions for airplanes inspected in accordance with ALI task 534129 or task 534130 and repaired in accordance with an SRM or RDAS published before the effective date of this AD. Since repair instructions published before the effective date of this AD might not address the unsafe condition identified in this AD, the SRM or RDAS instructions might need to be re-evaluated or revised to address the unsafe condition. In addition, we do not rely on an operator's standard practices, and instead require operators to obtain inspections and corrective actions to address the unsafe condition. We have not revised this AD regarding this issue.
Request To Clarify Actions for Airplanes With Certain Repairs
UAL requested that we delete paragraph (n) of the proposed AD. UAL noted that paragraph (n) of the proposed AD requires operators to determine if a repair was done using an RDAS that is unrelated to ALI task 534129 or task 534130. UAL suggested that the repair instructions would have to state that the damage was found as a result of the applicable ALI, but noted that the ALI task is an inspection that may not be referenced in a documented repair. UAL questioned the relevance of whether or not a repair was related to ALI task 534129 or task 534130, noting that the same considerations are given to repair instructions, regardless of how damage was found. UAL stated that operators would know to seek an alternative method of compliance (AMOC) if they cannot inspect a previously repaired area in accordance with Airbus Service Bulletin A320-53-1288, Revision 01, including Appendixes 01, 02, and 03, dated October 3, 2016.
We disagree with the commenter's request. The intent of paragraph (n) of the proposed AD is to require operators to re-evaluate existing repairs performed using an Airbus RDAS unrelated to ALI task 534129 or task 534130 because those repairs may not address the findings from the specific inspection types required by the ALI tasks. Therefore, the corresponding repairs might not address the unsafe condition and operators might need new instructions. We have not changed this AD in this regard.
Request To Verify the Latest Service Information is Referenced
UAL requested that, prior to the release of this final rule, we verify that we are referencing the latest revisions of Airbus Service Bulletin A320-53-1288, Revision 01, including Appendixes 01, 02, and 03, dated October 3, 2016; and Airbus Service Bulletin A320-53-1290, Revision 01, dated October 3, 2016.
We agree with the commenter's request. We have verified that no later revisions of the service information have been issued, and no change is needed to this AD.
Explanation of Change to the Final Rule
In the proposed AD, Table 1 to paragraphs (g) and (j) of this AD and Table 2 to paragraphs (g) and (j) of this AD included a compliance time that stated ``. . . or before November 30, 2017. . . .'' Since this final rule will become effective after November 30, 2017, we have changed this statement to read ``. . . or within 30 days after the effective date of this AD. . . .'' We have determined that this revised compliance time addresses the unsafe condition.
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.
Airbus Service Bulletin A320-53-1288, Revision 01, including Appendixes 01, 02, and 03, dated October 3, 2016. This service information describes procedures for rototest inspections for cracking of the fastener holes in the airframe structure for the door stop fittings installation in FR66 and FR68.
Airbus Service Bulletin A320-53-1290, Revision 01, dated October 3, 2016. This service information describes procedures for cold working the fastener holes in the airframe structure for the door stopfittings installation in FR66 and FR68.
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 1,084 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................ 23 work-hours x $85 $0 $1,955 per inspection $2,119,220 per
per hour = $1,955 cycle. inspection cycle.
per inspection cycle. ----------------------------------------------------------------------------------------------------------------
We estimate the following costs to do any necessary repairs that would be required based on the results of the required inspection. We have no way of determining the number of aircraft that might need this repair.
On-Condition Costs ----------------------------------------------------------------------------------------------------------------
Cost per
Action Labor cost Parts cost product ---------------------------------------------------------------------------------------------------------------- Repair..................................... 27 work-hours x $85 per hour = $610 $2,905
$2,295. ----------------------------------------------------------------------------------------------------------------
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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 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.