Discussion \n\n\n\tThe EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2019-0173, dated July 18, 2019 (''EASA AD 2019-0173'') (also referred to as the Mandatory Continuing Airworthiness Information, or ''the MCAI''), to correct an unsafe condition for certain Airbus SAS Model A318 series airplanes; Model A319-111, -112, -113, -114, -115, -131, -132, and -133 airplanes; Model A320-211, -212, -214, -215, -216, -231, -232, and -233 airplanes; and Model A321-111, -112, -131, -211, -212, -213, -231, and -232 airplanes. Model A320-215 airplanes are not on the U.S. Register; this AD therefore does not include those airplanes in the applicability. \n\tThe FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to certain Airbus SAS Model A318 series airplanes; Model A319-111, -112, -113, -114, -115, - 131, -132, and -133 airplanes; Model A320-211, -212, -214, -215,-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 October 28, 2019 (84 FR 57660). The NPRM was prompted by a report of cracking found on the frame of the right-hand side sliding window in the flight deck. The NPRM proposed to require repetitive inspections for cracking of the vertical stiffeners of the left- and right-hand sides of the window frames and corrective actions if necessary. \n\tThe FAA is issuing this AD to address cracking of the vertical stiffeners of the left- and right-hand sides of the window frames, which could affect the structural integrity of the airplane. See the MCAI for additional background information. \n\nComments \n\n\n\tThe FAA gave the public the opportunity to participate in developing this final rule. The following presents the comments received on the NPRM and the FAA's response to each comment. \n\nSupport for the NPRM \n\n\n\tDelta Airlines (DAL) stated its concurrence with the intent of the NPRM. \n\nRequest To Allow the Use of Additional Service Information \n\n\n\tAirbus asked to allow the use of the following Airbus technical adaptations (TAs) during accomplishment of the related Airbus service bulletins (as identified only in section 13 of each TA), noting that they pertain to an RC (required for compliance) section of the applicable service information. Airbus stated that the TAs will ensure that the \n\n((Page 17491)) \n\neccentric is properly reinstalled in the sliding window frame after removal. \n\n\n\tAirbus TA 80662272/007/2019, Issue 1, dated August 29, 2019 (Airbus Service Bulletin A320-53-1402, dated May 17, 2018) \n\tAirbus TA 80662272/008/2019, Issue 1, dated August 29, 2019 (Airbus Service Bulletin A320-53-1403, dated May 17, 2018) \n\tAirbus TA 80662272/009/2019, Issue 1, dated August 29, 2019 (Airbus Service Bulletin A320-53-1406, dated May 17, 2018) \n\tAirbus TA 80662272/010/2019, Issue 1, dated August 29, 2019 (Airbus Service Bulletin A320-53-1407, dated May 17, 2018) \n\tAirbus TA 80696258/006/2019, Issue 1, dated October 29, 2019 (Airbus Service Bulletin A320-53-1404, dated May 17, 2018) \n\tAirbus TA 80696258/007/2019, Issue 1, dated October 29, 2019 (Airbus Service Bulletin A320-53-1405, dated May 17, 2018) \n\n\n\tThe FAA agrees with the commenter's request for the reason provided. The FAA has added paragraph (h)(4) to this AD to reference these TAs. \n\tAirbus also asked that the requirements in the proposed AD related to these TAs be defined more robustly than merely referring to EASA AD 2019-0173. \n\tThe FAA partially agrees. Paragraph (h)(4) of this AD is an exception to EASA AD 2019-0173 and references the service information specified in EASA AD 2019-0173. Paragraph (h)(4) of this AD has been revised to clarify the use of the TAs when complying with the requirements of this AD. \n\nRequest To Add an Airworthiness Limitations Item (ALI) Task \n\n\n\tUnited Airlines (UAL) asked to add ALI Task 531136 to the proposed AD, to accomplish with the inspection specified in Airbus Service Bulletins A320-53-1402 and A320-53-1403, both dated May 17, 2018. UAL stated that ALI Task 531136 is a new inspection task introduced in Revision 46 of the maintenance planning document (MPD), and that Airbus has cancelled ALI Task 531133 in airworthiness limitations section (ALS) Part 2, Revision 8. UAL noted that Airbus TFU/ISI 53.11.00.018 can be referenced for additional information. UAL added that if ALI Task 531133 remains active, there will be duplicate inspection requirements for the same location (the vertical stiffeners). \n\tThe FAA does not agree with the commenter's request. ALS Part 2, Revision 8, might be mandatory for certain airplanes, but not for all U.S-registered airplanes. The compliance time for certain airplane configurations provided in Appendix 1 of EASA AD 2019-0173 is for inspections performed using ALI Task 531133. The FAA has not received any information fromEASA or Airbus that ALI Task 531133 should be replaced with ALI Task 531136. Paragraph (6) of EASA AD 2019-0173, specifies that accomplishment of the inspection per ALI Task 531133-02- 1 on an airplane within the threshold and intervals as defined in paragraph (1) of EASA AD 2019-0173, constitutes an acceptable method to comply with the requirements of paragraph (1) of EASA AD 2019-0173 for that airplane. Therefore, no duplication of the inspection requirements will occur. The AD has not been changed in this regard. \n\nRequest for Confirmation That Inspections Are Required Using Both EASA AD 2019-0173 and Applicable Repair Design Approval Sheet (RDAS) \n\n\n\tDAL requested confirmation that when an RDAS exists for a repair of the referenced inspection area, the inspection must be accomplished per both the requirements in EASA AD 2019-0173, and each applicable RDAS. DAL stated that paragraph (5) of EASA AD 2019-0173 states that aircraft inspected and repaired before the effective date of the proposed AD per the instructions documented in an RDAS should ''accomplish the next due inspection for each repaired area in accordance with, and within the time period after repair, as specified in Airbus RDAS, as applicable.'' DAL stated that it recognizes that this does not terminate the inspection criteria. DAL further noted that, if this interpretation is correct, a duplicate inspection requirements is created, which could ultimately result in inspection in the same area twice at the same maintenance check. \n\tThe FAA acknowledges DAL's request and has determined that clarification is necessary. The FAA agrees that the requirements of paragraph (5) of EASA AD 2019-0173 do not terminate the repetitive inspection requirements of paragraph (1) of EASA AD 2019-0173. The FAA also agrees that there may be duplicate requirements for inspections in accordance with paragraphs (1) and (5) of the EASA AD; however, if the description and compliance time for the special detailed inspection required by the RDAS and paragraph (1) of the EASA AD are identical, operators need not perform duplicate inspections. If there are differences between the inspection requirements in the RDAS and EASA AD paragraph (1), operators can contact the manufacturer for an alternative method of compliance approved by the FAA, EASA, or EASA's Design Organization Approval (DOA). The AD has not been changed in this regard. \n\nRequest To Revise Reporting Requirement \n\n\n\tDAL asked that the reporting requirement in paragraph (h)(3) of the proposed AD be revised to require reporting of only positive findings, in lieu of both positive and negative findings. DAL stated that, based on substantial cyclical data collected through accomplishment of ALI Task 531133 and multiple reports of positive cracking indications, Airbus has been able to develop and publish standardized repair instructions for cracking, which have been incorporated into modification service information. DAL added that, since a sufficient amount of data has been collected over time to develop these standard repairs and modifications, only positive findings should be reported. DAL concluded that, as long as accomplishment of ALI Task 531133 yielded positive findings, paragraph (h)(3)(ii) of the proposed AD should include a statement that only positive findings should be reported for inspections done before the effective date of the AD. \n\tDAL also requested that, if revising paragraph (h)(3) of the proposed AD to specify reporting of positive inspection findings only, the FAA revise paragraph (h)(3)(ii) to include a statement that only positive findings for inspections accomplished prior to the effective date of the AD require reporting. \n\tThe FAA does not agree with the commenter's requests. The FAA has received no information suggesting that sufficient data has been collected to exclude reports of negative findings. EASA AD 2019-0173 requires repetitive inspections after accomplishing the modification, and there is no terminating action for those inspections. Further, DAL provided no substantiating data to support its assertion that, so long as cracking found during ALI Task 531133 inspections was the driver for inspections using the specified inspection service information, 100 percent of crack findings were found during inspections performed using inspection service information implemented before the effective date of this AD. Therefore, the AD has not been changed in this regard. \n\n((Page 17492)) \n\nConclusion \n\n\n\tThe FAA reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting this final rule with the changes described previously and minor editorial changes. The FAA has determined that these minor changes: \n\tAre consistent with the intent that was proposed in the NPRM for addressing the unsafe condition; and \n\tDo not add any additional burden upon the public than was already proposed in the NPRM. \n\tThe FAA also determined that these changes will not increase the economic burden on any operator or increase the scope of this final rule. \n\nRelated IBR Material Under 1 CFR Part 51 \n\n\n\tEASA AD 2019-0173 describes procedures for repetitive inspections for cracking of the vertical stiffeners of the left- and right-hand sides of the window frame, and corrective actions if necessary. Corrective actions include modification, rework, and repair. \n\tAirbus issued the following TAs, which provide missing torque values used during reinstallation of the eccentric in the sliding window frame. These TAs are distinct since they provide torque values used in reinstallation of the eccentric using service information specified in EASA AD 2019-0173 (service information that applies to different actions and locations). \n\tAirbus TA 80662272/007/2019, Issue 1, dated August 29, 2019. \n\tAirbus TA 80662272/008/2019, Issue 1, dated August 29, 2019. \n\tAirbus TA 80662272/009/2019, Issue 1, dated August 29, 2019. \n\tAirbus TA 80662272/010/2019, Issue 1, dated August 29, 2019. \n\tAirbus TA 80696258/006/2019, Issue 1, dated October 29, 2019. \n\tAirbus TA 80696258/007/2019, Issue 1, dated October 29, 2019. \n\tThis material 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. \n\nCosts of Compliance \n\n\n\tThe FAA estimates that this AD affects 988 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD: \n\n\n\tEstimated Costs for Required Actions * ---------------------------------------------------------------------------------------------------------------- \n\tCost per Cost on U.S. \n\tLabor cost Parts cost product operators ---------------------------------------------------------------------------------------------------------------- 11 work-hours x $85 per hour = $935.......................... $0 $935 $923,780 ---------------------------------------------------------------------------------------------------------------- \n* Table does not include estimated costs for reporting.\n\n\n\n\tThe FAA estimates that it takes about 1 work-hour per product to comply with the reporting requirement in this AD. The average labor rate is $85 per hour. Based on these figures, the FAA estimates the cost of reporting the inspection results on U.S. operators to be $83,980, or $85 per product. \n\tThe FAA estimates the following costs to do any necessary on- condition modifications that would be required based on the results of any required actions. The FAA has no way of determining the number of aircraft that might need this on-condition modification: \n\n\n\tEstimated Costs of On-Condition Modification ---------------------------------------------------------------------------------------------------------------- \n\tCost per \n\tLabor costParts cost product ---------------------------------------------------------------------------------------------------------------- 5 work-hours x $85 per hour = $425............................................ (*) $425 * ---------------------------------------------------------------------------------------------------------------- \n* The FAA has received no definitive data that would enable the agency to provide parts cost estimates for the\n\n\ton-condition modification specified in this AD. \n\n\n\tThe FAA has received no definitive data that would enable the agency to provide cost estimates for the other on-condition actions specified in this AD. \n\nPaperwork Reduction Act \n\n\n\tA federal agency may not conduct or sponsor, and a person is not required to respond to, nor shall a person be subject to penalty for failure to comply with a collection of information subject to the requirements of the Paperwork Reduction Act unless that collection of information displays a current valid OMB control number. The control number for the collection of information required by this AD is 2120- 0056. The paperwork cost associated with this AD has been detailed in the Costs of Compliance section of this document and includes time for reviewing instructions, as well as completing and reviewing the collection of information. Therefore, all reporting associated with this AD is mandatory. Comments concerning the accuracy of this burden and suggestions for reducing the burden should be directed to Information Collection Clearance Officer, Federal Aviation Administration, 10101 Hillwood Parkway, Fort Worth, TX 76177-1524. \n\nAuthority for This Rulemaking \n\n\n\tTitle 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. \n\tThe FAA is 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. \n\nRegulatory Findings \n\n\n\tThis AD will not have federalism implications under Executive Order \n\n((Page 17493)) \n\n13132. 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. \n\tFor the reasons discussed above, I certify that this AD: \n\t(1) Is not a ''significant regulatory action'' under Executive Order 12866, \n\t(2) Will not affect intrastate aviation in Alaska, and \n\t(3) 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. \n\nList of Subjects in 14 CFR Part 39 \n\n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.