Daily Rules, Proposed Rules, and Notices of the Federal Government
We invite you to send us any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under
We will post all comments we receive, without change, to
You may examine the AD docket on the Internet at
In February 2009, we were made aware by CFM International, S.A. of stage 3 LPT disks, part number (P/N) 336-002-006-0, S/Ns DE255844, DE256388, DE256622, DE256623, DE256625, DE256627, DE256628, DE256631, and DE256637, being suspect of material non-conformity. This batch of parts was subject to a quality problem during manufacturing. CFM International, S.A. states that the manufacturing process has since been revised to eliminate the quality problem. The non-conformity requires removal from service of the suspect disks before their certified life limits. Operating engines with these affected disks to the certified life limit could result in uncontained failure of the stage 3 LPT disk and damage to the airplane.
We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other products of this same type design. This proposed AD would require removing from service any affected stage 3 LPT disks from engines before their certified life limit. We are proposing this AD, which would require removing the affected stage 3 LPT disks from service before accumulating 9,500 cycles-since-new.
We estimate that this proposed AD would affect two engines installed on airplanes of U.S. registry. The pro-rated cost of the replacement parts is $40,375 per engine. We estimate that no additional labor costs would be incurred to perform the required disk removals, because the removals would be done at time of engine shop visit. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $80,750.
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
We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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.
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); and
3. Would not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.
We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD. You may get a copy of this summary at the address listed under
Air transportation, Aircraft, Aviation safety, Safety.
Under the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 14 CFR part 39 as follows:
1. The authority citation for part 39 continues to read as follows:
49 U.S.C. 106(g), 40113, 44701.
2. The FAA amends § 39.13 by adding the following new airworthiness directive:
(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by May 17, 2010.
(c) This AD applies to CFM International CFM56-5, -5B, and -7B series turbofan engines with stage 3 low-pressure turbine (LPT) disks installed with the following serial numbers, (S/Ns) DE255844, DE256388, DE256622, DE256623, DE256625, DE256627, DE256628, DE256631, and DE256637. The -5 and -5B series engines are installed on, but not limited to, Airbus A318, A319, A320, A321, and A340 airplanes, and the -7B series engines are installed on, but not limited to, Boeing 737 series airplanes.
(d) This AD results from the discovery of a material nonconformity requiring removal of the disk before the certified disk life of certain stage 3 LPT disks. We are issuing this AD to prevent uncontained failure of the stage 3 LPT disk and damage to the airplane.
(e) You are responsible for having the actions required by this AD performed within the compliance time specified unless the actions have already been done.
(f) Before accumulating 9,500 cycles-since-new, remove stage 3 LPT disks from service.
(g) After the effective date of this AD do not reinstall any stage 3 LPT disk removed from service per paragraph (f) of this AD into any engine.
(h) The Manager, Engine Certification Office, has the authority to approve alternative methods of compliance for this AD if requested using the procedures found in 14 CFR 39.19.
(i) Contact Antonio Cancelliere, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail:
(j) CFM International, S.A. Service Bulletin (SB) No. CFM56-5B S/B 72-0733, dated October 26, 2009, and SB No. CFM56-7B S/B 72-0743, dated October 26, 2009, pertain to the subject of this AD. Contact CFM International, Technical Publications Department, 1 Neumann Way, Cincinnati, OH 45215; telephone (513) 552-2800; fax (513) 552-2816, for a copy of this service information.