AD 2018-15-04

This AD is effective October 2, 2018.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of October 2, 2018.

For service information identified in this final rule, contact General Electric Company, GE Aviation, Room 285, 1 Neumann Way, Cincinnati, OH, 45215; phone: 513-552-3272; email: aviation.fleetsupport@ge.com. You may view this service information at the FAA, Engine and Propeller Standards Branch, 1200 District Avenue, Burlington, MA, 01803. For information on the availability of this material at the FAA, call 781-238-7759. It is also available on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2017-0792.

Matthew Smith, Aerospace Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA, 01803; phone: 781-238-7735; fax: 781-238-7199; email: matthew.c.smith@faa.gov.

We issued a supplemental notice of proposed rulemaking (SNPRM) to amend 14 CFR part 39 by adding an AD that would apply to certain GE CF6-80A, CF6-80A1, CF6-80A2, CF6-80A3, CF6-80C2A1, CF6-80C2A2, CF6-80C2A3, CF6-80C2A5, CF6-80C2A5F, CF6-80C2A8, CF6-80C2B1, CF6-80C2B1F, CF6-80C2B2, CF6-80C2B2F, CF6-80C2B4, CF6-80C2B4F, CF6-80C2B5F, CF6-80C2B6, CF6-80C2B6F, CF6-80C2B6FA, CF6-80C2B7F, CF6-80C2D1F, CF6-80C2L1F, and CF6-80C2K1F turbofan engines with HPT disks with part numbers and serial numbers (S/Ns) listed in Table 1 and 2 of Appendix A in GE Service Bulletin (SB) CF6-80C2 SB 72-1562 R03, dated January 10, 2018 and Table 1 of Appendix A in GE SB CF6-80A SB 72-0869 R01, dated October 19, 2017. The SNPRM published in the Federal Register on March 30, 2018 (83 FR 13703). We preceded the SNPRM with a notice of proposed rulemaking (NPRM) that published in the Federal Register on September 7, 2017 (82 FR 42261). The NPRM proposed to require UI of HPT stage 1 and 2 disks. The NPRM was prompted by an uncontained failure of an HPT stage 2 disk that resulted in a fire. The SNPRM proposed to require the same UI of HPT stage 1 and 2 disks, remove certain engine models, and to add a new part number to the applicability of this AD. The SNPRM also proposed to revise references to the service information in this AD because, since the publication of the NPRM, GE published the list of affected HPT S/Ns in two separate SBs applicable to the CF6-80A and CF6-80C2 engines. We are issuing this AD to address the unsafe condition on these products.

We gave the public the opportunity to participate in developing this final rule. The following presents the comments received on the SNPRM and the FAA's response to each comment.

All Nippon Airways (ANA) and Japan Airlines (JAL) requested that we change the applicability, paragraph (c), to include S/Ns that are listed in revisions of GE CF6-80C2 SB 72-1562 and GE CF6-80A SB 72-0869 that have not yet been published. ANA and JAL reasoned that the SB revisions will include an updated list of affected S/Ns.

We disagree. While future SB revisions may include additional affected S/Ns, we do not require compliance based on service information that has not been published. The applicability of this AD is based on the most recently published service information. Any further change in applicability would require a notice and comment rulemaking for those affected S/Ns. We did not change this AD.

JAL requested that we improve the UI criteria to avoid false-positive indications resulting in rejection of disks. JAL reasoned that GE may publish a GE CF6-80C2 SB 72-1562 revision in which GE will modify the UI criteria.

We disagree. While a future SB revision may include updated UI criteria, we do not require compliance based on service information that has not yet been published. We based the UI criteria on the most recently published service information. We will review any Alternative Methods of Compliance (AMOC) requests submitted if different UI criteria, not specified in this AD, are desired. We did not change this AD.

ANA requested that we change the definition of “piece-part exposure” to the separation of the HPT stage 1 or stage 2 disk from the thermal shield within the HPT rotor module.

We disagree. The current definition is sufficient to describe the piece-part exposure. We did not change this AD.

Boeing Company, FedEx, and United Airlines expressed support for the SNPRM as written.

We 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. We have determined that these minor changes:

• Are consistent with the intent that was proposed in the SNPRM for addressing the unsafe condition; and

• Do not add any additional burden upon the public than was already proposed in the SNPRM.

We also determined that these changes will not increase the economic burden on any operator or increase the scope of this final rule.

We reviewed GE CF6-80C2 SB 72-1562 R03, dated January 10, 2018. The SB describes procedures for UI of CF6-80C2 turbofan engine HPT stage 1 and 2 disks. We also reviewed GE CF6-80A SB 72-0869 R01, dated October 19, 2017. The SB describes procedures for UI of CF6-80A turbofan engine HPT stage 2 disks. 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.

We estimate that this AD affects 640 HPT disks on engines installed on airplanes of U.S. registry.

We estimate the following costs to comply with this AD:

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.

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 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.

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

1. The authority citation for part 39 continues to read as follows:

2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):