Discussion
We issued AD 2018-13-07, Amendment 39-19319 (83 FR 34758, July 23, 2018), (``AD 2018-13-07''), for all RR Trent 1000-A, Trent 1000-C, Trent 1000-D, Trent 1000-E, Trent 1000-G, and Trent 1000-H turbofan engine models. AD 2018-13-07 required inspecting the IPC stage 1 rotor blades, IPC stage 2 rotor blades, and IPC shaft stage 2 dovetail posts, and removing any cracked parts from service. AD 2018-13-07 resulted from crack findings on the IPC rotor blades and IPC shaft stage 2 dovetail posts, which could lead to rotor blade separations resulting in engine failures. We issued AD 2018-13-07 to prevent failure of the IPC, which could result in failure of one or more engines, loss of thrust control, and loss of the airplane.
Actions Since AD 2018-13-07 Was Issued
Since we issued AD 2018-13-07, the manufacturer determined the need for repetitive inspections of the IPC stage 1 rotor blades, IPC stage 2 rotor blades, and IPC shaft stage2 dovetail posts. Also, since we issued AD 2018-13-07, the European Aviation Safety Agency (EASA) issued AD 2018-0167R2, dated October 16, 2018, which requires initial and repetitive inspections of the IPC stage 1 rotor blades, IPC stage 2 rotor blades, and IPC shaft stage 2 dovetail posts. We are issuing this AD to address the unsafe condition on these products.
Related Service Information Under 1 CFR Part 51
We reviewed RR Alert Non-Modification Service Bulletin (NMSB) Trent 1000 72-AK130, Revision 2, dated July 26, 2018, and RR Alert NMSB Trent 1000 72-K132, dated June 29, 2018. RR Alert NMSB Trent 1000 72-AK130 describes procedures for performing initial and repetitive inspections of the IPC stage 1 rotor blades, IPC stage 2 rotor blades, and IPC shaft stage 2 dovetail posts, and lists engine serial numbers. RR Alert NMSB Trent 1000 72-K132, describes procedures for replacement of the IPC stage 1 rotor blades, IPC stage 2 rotor blades, and the IP compressor drum duringrefurbishment. 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.
Other Related Service Information
We reviewed RR NMSB Trent 1000 72-K099, Initial Issue, dated June 11, 2018; RR NMSB Trent 1000 72-K099, Revision 1, dated July 3, 2018; RR NMSB Trent 1000 72-K100, Initial Issue, dated June 11, 2018; RR NMSB Trent 1000 72-K129, Initial Issue, dated June 11, 2018; and RR NMSB Trent 1000 72-K129, Revision 1, dated July 2, 2018. RR NMSB Trent 1000 72-K099, Initial Issue, and RR NMSB Trent 1000 72-K099, Revision 1, describe procedure for an ultrasonic inspection of the IPC stage 1 rotor blades. RR NMSB Trent 1000 72-K100 Initial Issue describes procedures for a visual borescope inspection of the IPC stage 2 rotor blades and IPC shaft stage 2 dovetail posts. RR NMSB Trent 1000 72- K129, Initial Issue, and RR NMSB Trent 1000 72-K129, Revision 1,describe procedures for an ultrasonic inspection of the IPC stage 2 rotor blades.
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FAA's Determination
This product has been approved by EASA and is approved for operation in the United States. Pursuant to our bilateral agreement with the European Community, EASA has notified us of the unsafe condition described in the MCAI and service information referenced above. We are issuing this AD because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design.
AD Requirements
This AD requires initial and repetitive inspections of the IPC stage 1 rotor blades, IPC stage 2 rotor blades, and IPC shaft stage 2 dovetail posts, and removing any cracked parts from service.
Differences Between This AD and the MCAI or Service Information
This AD allows inspections of any affected IPC part to be completed within 15 days of the effective date of this AD. EASA AD 2018-0167R2, dated October 16, 2018, and RR Alert NMSB Trent 1000 72-AK130, Revision 2, dated July 26, 2018, allow certain affected IPC parts to be completed within 45 days of the effective date of EASA AD 2018-0167R1. We expect most operators to have already complied with EASA AD and find that completing the inspections within 15 days of the effective date of this AD provides an appropriate level of safety.
Interim Action
We consider this AD interim action. The manufacturer is still reviewing this unsafe condition and may develop follow-on actions.
FAA's Justification and Determination of the Effective Date
No domestic operators use this product. Therefore, we find that notice and opportunity for prior public comment are unnecessary and that good cause exists for making this amendment effective in less than 30 days.
Comments Invited
This AD is a final rule that involves requirements affecting flight safety, and we did not provideyou with notice and an opportunity to provide your comments before it becomes effective. However, we invite you to send any written data, views, or arguments about this final rule. Send your comments to an address listed under the ADDRESSES section. Include the docket number FAA-2018-0871 and product identifier 2018-NE-24-AD at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this final rule. We will consider all comments received by the closing date and may amend this final rule because of those comments.
We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this final rule.
Costs of Compliance
We estimate that this AD affects 0 engines installed on airplanes of U.S. registry.
We estimate the following costs to comply with this AD:
Estimated Costs ----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Action Labor cost Parts cost product operators ---------------------------------------------------------------------------------------------------------------- Inspect IPC blades and dovetail post.. 20 work-hours x $85 per $0 $1,700 $0
hour = $1,700. ----------------------------------------------------------------------------------------------------------------
We estimate the following costs to do any necessary replacements that would be required based on the results of the inspection. We have no way of determining the number of aircraft that might need these replacements:
On-Condition Costs ----------------------------------------------------------------------------------------------------------------Cost per
Action Labor cost Parts cost product ---------------------------------------------------------------------------------------------------------------- Replace IPC Stage 1 Rotor blade............... 0 work-hours x $85 per hour = $0 $1,528 $1,528 Replace IPC Stage 2 Rotor blade............... 0 work-hours x $85 per hour = $0 993 993 Replace IPC 1-8 drum.......................... 0 work-hours x $85 per hour = $0 1,365,219 1,365,219 ----------------------------------------------------------------------------------------------------------------
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 engines, propellers, and associated appliances to the Manager, Engine and Propeller Standards Branch, Policy and Innovation 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.
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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 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.