Discussion
The EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2019-0042, dated February 27, 2019 (``EASA AD 2019-0042'') (also referred to as the Mandatory Continuing Airworthiness Information, or ``the MCAI''), to correct an unsafe condition for all Airbus SAS Model A330-243, -243F, -341, -342, and - 343 airplanes, certificated in any category.
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2012-22-18, Amendment 39-17256 (77 FR 70366, November 26, 2012) (``AD 2012-22-18''). AD 2012-22-18 applied to all Airbus SAS Model A330-243, -243F, -341, -342, and -343 airplanes. The NPRM published in the Federal Register on June 19, 2019 (84 FR 28431). The NPRM was prompted by additional reports of engine air inlet cowl collapse since AD 2012-22-18 was issued. The NPRM proposed to continue to require repetitive inspections of the three inner acoustic panels of both engine air inlet cowls to detect disbonding, and corrective actions if necessary, with a reduced initial compliance time and reduced repetitive inspection intervals. The NPRM also proposed an optional modification that would be terminating action for the repetitive inspections. The FAA is issuing this AD to address disbonding, which could result in detachment of the engine air inlet cowl from the engine, leading to ingestion of parts, which could cause failure of the engine, and possible injury to persons on the ground. See the MCAI for additional background information.
Comments
The FAA gave the public the opportunity to participate in developing
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this final rule. The following presents the comments received on the NPRM and the FAA's response to each comment.
Support for the NPRM
Patrick Imperatrice indicated his support for the NPRM.
Request To Allow Alternative Tooling
American Airlines (AAL) requested that operators be allowed to use aerospace industry standard tap check tools for the inspection of the engine air inlet cowl acoustic panels instead of the tap check tools specified in Bombardier Service Bulletin RB211-NAC-71-018, Revision 3, dated December 5, 2018 (``Bombardier Service Bulletin RB211-NAC-71-018, Revision 3''). The commenter stated that the tooling paragraph in Bombardier Service Bulletin RB211-NAC-71-018, Revision 3, unnecessarily restricts operators' choices of tap tools with respect to industry standard practices, and places an undue burden on operators with regards to maintaining compliance procedures. The commenter noted that the previous revision level of Bombardier Service Bulletin RB211-NAC- 71-018 provided a more general description of the tap tool and did not prohibit the use of an aluminum tap tool. The commenter noted that it has successfully detected disbonding using a variety of standard industry tap tools made of corrosion resistant steel (CRES), mild steel, brass, and aluminum on similar nacelle component thin-skinned carbon fiber/honeycomb sandwich panels, with and without wire mesh on them, without any negative effects, such as galvanic corrosion. The commenter stated that it considers tools similar to or as described in aviation industry manuals, made from any of the typical listed materials, to have an equivalent level of safety and performance as the tool specified in Bombardier Service Bulletin RB211-NAC-71-018, Revision 3. The commenter also advised that, although not a concern from its experience, any aluminum tool would be contacting the stainless steel wire mesh on the carbon fiber panel surface except for localized areas of missing wire mesh.
The FAA acknowledges the commenter's observation that Bombardier Service Bulletin RB211-NAC-71-018, Revision 3, specifies that the tap tool can be purchased or manufactured, should be made of mild steel or brass rod, and that the use of an aluminum tap tool is prohibited.
However, the FAA does notagree with the commenter's request to revise this AD to allow operators to use any aviation industry standard tap check tool, including those made of aluminum, for the inspection of the engine air inlet cowl acoustic panels. The FAA received additional information from Bombardier stating that Bombardier performed numerous tests on acoustic panels using tap tools manufactured from various materials. Bombardier concluded that a better tonal response was received for both disbond and non-disbond areas when a heavier tap tool made from steel or brass material was used, which resulted in more reliable detection of panel disbond.
This AD refers to EASA AD 2019-0042 for a description of the procedures for repetitive inspections of the engine air inlet cowls having a certain part number, repair or replacement of any engine air inlet cowl that has disbond, and an optional modification that terminated the need for the repetitive inspections. In turn, EASA AD 2019-0042 refers to Airbus Service Bulletin A330-71-3024, Revision 04, dated December 17, 2018 (``Airbus Service Bulletin A330-71-3024, Revision 04''), for information regarding the inspection procedures for the engine air inlet cowl. Paragraphs 3.C. and 3.D. of the Accomplishment Instructions of Airbus Service Bulletin A330-71-3024, Revision 04, are considered ``required for compliance'' (RC) and must be done to comply with the requirements of this AD.
Paragraph 3.C. of Airbus Service Bulletin A330-71-3024, Revision 04, states that the tap test must be done using the procedures in Rolls-Royce Service Bulletin No. RB.211-71-AG419, Revision 3, dated December 7, 2018 (``Rolls-Royce Service Bulletin No. RB.211-71-AG419, Revision 3''). Rolls-Royce Service Bulletin No. RB.211-71-AG419, Revision 3, refers to Bombardier Service Bulletin RB211-NAC-71-018, Revision 3, for the inspection procedures.
Operators may request to use tap tools other than those identified in Bombardier Service Bulletin RB211-NAC-71-018, Revision3, by utilizing the alternative methods of compliance (AMOCs) provision provided in paragraph (j)(1) of this AD and submitting sufficient data to substantiate that the alternative tools would provide an acceptable level of safety. The FAA has not revised this AD in regard to this issue.
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.
Related IBR Material Under 1 CFR Part 51
EASA AD 2019-0042 describes procedures for repetitive inspections of engine air inlet cowls having certain part numbers, repair or replacement of any engine air inlet cowl that has disbonding, andan optional modification that terminates the need for the repetitive inspections. 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 47 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs for Required Actions ----------------------------------------------------------------------------------------------------------------
Cost per
Action Labor cost Parts cost product Cost on U.S. operators ---------------------------------------------------------------------------------------------------------------- Retained actions from AD 2012-22- Up to 20 work-hours $0 $1,700 Up to $79,900.
18. x $85 per hour =
Up to $1,700. ----------------------------------------------------------------------------------------------------------------
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Estimated Costs for Optional Actions ------------------------------------------------------------------------
Labor cost Parts cost Cost per product ------------------------------------------------------------------------ Up to 154 work hours x $85 per (*) Up to $13,090.*
hour = Up to $13,090. ------------------------------------------------------------------------
* The FAA has received no definitive data on the parts costs for the
optional actions.
The FAA estimates the following costs to do any necessary on- condition action 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 action:
Estimated Costs of On-Condition Actions ------------------------------------------------------------------------
Labor cost Parts cost Cost per product ------------------------------------------------------------------------ Up to 34 work-hours x $85 per (*) Up to $2,890.*
hour = Up to $2,890. ------------------------------------------------------------------------
* The FAA has received no definitive data on the parts costs for the on-
condition actions.
The new requirements of this AD add no additional economic burden. However, the optional modification, if done, would result in additional costs as specified in the ``Estimate costs for optional actions'' table.
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 inSubtitle 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 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.