AD 2017-11-15

This AD is effective July 13, 2017.

See the For Further Information Contact section.

Herman Mak, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 1200 District Avenue, Burlington, MA 01803; phone: 781-238-7147; fax: 781-238-7199; email: herman.mak@faa.gov.

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to certain GE CF6-80C2L1F turbofan engines. The NPRM published in the Federal Register on January 23, 2017 (82 FR 7734) (“the NPRM”). The NPRM was prompted by a reduction in the life limit of the affected engines which is the result of a revised operating profile. The NPRM proposed to require replacement of the HPT spacer/impeller, P/N 1539M12P02, at a newer, lower life limit. We are issuing this AD to prevent failure of the HPT spacer/impeller, uncontained release of the HPT spacer/impeller, damage to the engine, and damage to the airplane.

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

GE Aviation requested that we indicate in the compliance section of this AD that the affected HPT spacer/impeller is installed on GE CF6-80C2L1F engines only. GE Aviation commented that this P/N impeller is also installed on other models of the CF6-80C2 engine.

We disagree. We believe that the applicability section is clear that this AD applies to GE CF6-80C2L1F turbofan engines with a HPT spacer/impeller, P/N 1539M12P02, installed. We did not change this AD.

An individual commenter indicated that the proposal showed the FAA's commitment to “staying on top of changes in the industry.” The commenter noted, however, that although GE has updated the life expectancy of this part, it may still be a long time before it needs to be replaced. The commenter indicated, therefore, that the FAA's action may be “over zealous” and lead to “large scale waste.”

We disagree. We are issuing this AD to prevent failure of an engine rotating part, which could lead to failure of the part, uncontained release of the part, damage to the engine, and damage to the airplane. We did not change this AD.

An individual commenter supported the NPRM.

We reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting this AD as proposed.

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:

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 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 to the extent that it justifies making a regulatory distinction, 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):