Discussion
The EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2018-0200, dated September 6, 2018 (``EASA AD 2018-0200'') (also referred to as the Mandatory Continuing Airworthiness Information, or ``the MCAI''), to correct an unsafe condition for certain Airbus SAS Model A320-211, -212, and -231 airplanes. EASA AD 2018-0200 supersedes Direction G[eacute]n[eacute]rale de l'Aviation Civile (DGAC) AD 91-182-020(B) R2, dated December 7, 1994 (which corresponds to FAA AD 96-25-04, Amendment 39-9846 (61 FR 66881, December 19, 1996) (``AD 96-25-04'')).
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 96-25-04. AD 96-25-04 applied to certain Airbus SAS Model A320 series airplanes. The NPRM published in the Federal Register on May 7, 2019 (84 FR 19885). The NPRM was prompted by a determination that there were issues with protective sleeves previously installed as specified in AD 96-25-04. The NPRM proposed to partially retain the requirements of AD 96-25-04 and require modification of the wing electrical installation. The FAA is issuing this AD to address electrical short circuiting due to chafing of the wire bundles in the wing, horizontal stabilizer, or MLG bay, which could result in a fire.
Comments
The 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. Air Line Pilots Association, International (ALPA) indicated its support for the NPRM.
Request To Clarify and Provide Procedures for Previously Installed Sleeves
Delta Air Lines (Delta) requested clarification and further provisioning to address previously installed protective sleeves that are identified as having issues in the NPRM and EASA AD 2018-0200. Delta requested that the FAA explain the issue with the previously installed protectivesleeves and specify corrective action referring to the previous requirements of AD 96-25-04. Delta stated that the instructions in Airbus Service Bulletin A320-92-1115, Revision 01, dated August 14, 2018, and EASA AD 2018-0200 do not identify procedures for removal of previously installed protective sleeves and do not explain the deficiency with those sleeves.
The FAA agrees to clarify. Airbus Service Bulletin A320-92-1115, Revision 01, dated August 14, 2018, does include instructions for removing the previously installed heat shrink tubing (wire loom protection) prior to installation of new wire loom protection. Airbus Service Bulletin A320-92-1115, Revision 01, dated August 14, 2018, also states the unsafe condition associated with previously installed wire loom protection, which allowed the wire loom to be held in contact with the edge of harness breakout from conduits on wing trailing edge harnesses. Subsequent vibration initiated chafing and the eventual short circuit.
Thenew modification requirement in this AD introduces a full- length protective sleeve to protect the wire looms at harness breakout from conduits on wing trailing edge harnesses in Zone 574 and Zone 674. As specified in paragraph (13) of EASA AD 2018-0200, doing the new modification terminates inspections required by paragraph (1) of EASA AD 2018-0200 (which retains the requirements that correspond to paragraph (c) of AD 96-25-04). The AD has not been changed in this regard.
Request To Revise the Applicability
Delta requested the applicability of the proposed AD be changed to only include airplanes produced with the unsafe condition. Delta noted that the applicability exception statement (i.e., except those on which Airbus modification (mod) 22626 has been embodied in production) means the proposed AD would be applicable to any future production airplanes if mod 22626 is not embodied. Delta stated that it assumed the certification basis of new aircraft would address this unsafe condition either through mod 22626 or other mods or design features that would address the unsafe condition.
The FAA agrees to clarify. As specified in EASA AD 2018-0200, the AD is applicable to Airbus SAS Model A320-211, A320-212 and A320-231 airplanes, all manufacturer serial numbers except those on which Airbus modification 22626 has been installed in production. The intent for airplanes modified in production via modification 22626 is that they will not be de-modified and therefore the unsafe condition will not apply. The AD is not applicable if production modification 22626 is installed; however, it is the responsibility of operators to maintain that modification in accordance with the type design requirements of the airplane. The AD has not been changed in this regard.
Request To Clarify if Another AD Is Affected
Delta requested clarification on whether the proposed AD might affect
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AD 2016-19-02, Amendment 39-18651 (81 FR 64051, September 19, 2016) (``AD 2016-19-02''). Delta raised concerns over the risk to inadvertently de-modify the impacted airplanes identified in EASA AD 2018-0200 and therefore no longer be in compliance with AD 2016-19-02. Delta stated that due to the proximity of the modifications specified in Airbus Service Bulletin A320-92-1049, Revision 01, dated November 28, 2011 (referred to in AD 2016-19-02) and Airbus Service Bulletin A320-92-1115, Revision 01, dated August 14, 2018 (referred to in EASA AD 2018-0200) there is potential for de-modification of an AD requirement.
The FAA agrees to clarify. The modifications specified in Airbus Service Bulletin A320-92-1049, Revision 01, dated November 28, 2011 (required by paragraph (h)(1) of AD 2016-19-02); and Airbus Service Bulletin A320-92-1115, Revision 01, dated August 14, 2018 (required by paragraphs (7) through (9) of EASA AD 2018-0200), are in close proximity, but the risk to inadvertently de-modify the airplane is small. There is clearance between the protective sleeve installed using Airbus Service Bulletin A320-92-1049, Revision 01, dated November 28, 2011, and the insert (protective sleeve) installed using Airbus Service Bulletin A320-92-1115, Revision 01, dated August 14, 2018. In addition, Airbus Service Bulletin A320-92-1115, Revision 01, dated August 14, 2018, does not include procedures to remove the protective sleeve installed using Airbus Service Bulletin A320-92-1049, Revision 01, dated November 28, 2011. The AD has not been changed in this regard.
Conclusion
The FAA reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting this final rule as proposed, except for minor editorial changes. The FAA has determined that these minor changes:
Are consistent with the intent that was proposed in the NPRM for addressing the unsafe condition; and
Do not add any additional burden upon the public than was already proposed in the NPRM.
Related IBR Material Under 1 CFR Part 51
EASA AD 2018-0200 describes procedures for repetitive inspections to detect chafing, signs of overheating, and misalignment of the wire looms (bundles) in the wing and the horizontal stabilizer and in certain areas of the MLG bays; repair or replacement, protection, and realignment, if necessary; realignment of bundles that are not guided centrally into the conduit end fittings; and modification of the wing electrical installation.
This 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.
Costs of Compliance
The FAA estimates that this AD affects 27 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs for Required Actions ----------------------------------------------------------------------------------------------------------------
Cost perCost on U.S.
Action Labor cost Parts cost product operators ---------------------------------------------------------------------------------------------------------------- Retained actions from AD 96-25-04 62 work-hours x $85 Negligible............. $5,270 $142,290
per hour = $5,270. New actions...................... 25 work-hours x $85 (*).................... * 2,125 * 57,375
per hour = $2,125. ----------------------------------------------------------------------------------------------------------------
* The FAA has received no definitive data on the parts costs for the new actions.
The FAA has received no definitive data that would enable us to provide cost estimates for the on-condition actions specified in this AD.
Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII: Aviation Programs, describes in more detail the scope of the Agency's authority.
The 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.
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 thistransition period, the Executive Director has delegated the authority to issue ADs applicable to transport category airplanes and associated appliances to the Director of the System Oversight Division.
Regulatory Findings
This AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.
For the reasons discussed above, I certify that this AD:
(1) Is not a ``significant regulatory action'' under Executive Order 12866,
(2) Will not affect intrastate aviation in Alaska, and
(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.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.