AD 2015-16-03

This AD becomes effective September 15, 2015.

Katheryn Malatek, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; phone: 781-238-7747; fax: 781-238-7199; email: katheryn.malatek@faa.gov.

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to the specified products. The NPRM was published in the Federal Register on April 29, 2015 (80 FR 23741). The NPRM proposed to correct an unsafe condition for the specified products. The MCAI states:

There were a number of pre-MOD/SB 72-7730 High Pressure Turbine (HPT) blade failures, with some occurring within a relatively short time. Engineering analysis carried out by RR on those occurrences indicates that certain pre-MOD/SB 72-7730 blades, Part Number (P/N) UL32958 and P/N UL21691 (hereafter referred to as `affected HPT blade'), with an accumulated life of 6500 flight hours (FH) since new or more, have an increased risk of in-service failure.

This condition, if not corrected, could lead to HPT blade failure, release of debris and consequent (partial or complete) loss of engine power, possibly resulting in reduced control of the aeroplane.

We gave the public the opportunity to participate in developing this AD. We received no comments on the NPRM (80 FR 23741, April 29, 2015).

We reviewed the available data and determined that air safety and the public interest require adopting this AD as proposed.

We estimate that this AD affects 6 engines installed on airplanes of U.S. registry. We also estimate that it will take about 4 hours per engine to comply with this AD. The average labor rate is $85 per hour. Pro-rated cost of required parts is about $250,000 per engine. Based on these figures, we estimate the cost of this AD on U.S. operators to be $1,502,040.

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.

We determined that 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 this AD:

(1) Is not a “significant regulatory action” under Executive Order 12866,

(2) Is not a “significant rule” under the 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):