AD 2008-25-01

Active

Low-pressure turbine (LPT) discs

Key Information
2008-25-01
Active
December 17, 2008
November 24, 2008
FAA-2008-1122
39-15759
Applicability
["Engine"]
Not specified
Rolls-Royce plc
RB211 Trent 553-61 RB211 Trent 553A2-61 RB211 Trent 556-61 RB211 Trent 556A2-61 RB211 Trent 556B-61 RB211 Trent 556B2-61 RB211 Trent 560-61 RB211 Trent 560A2-61
Summary

We are adopting a new airworthiness directive (AD) for the products listed above. This AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:

Recent analysis of the low-pressure turbine (LPT) discs 1-5 carried out by Rolls-Royce plc concluded that it is necessary to reduce the declared safe cyclic life of all Trent 500 LPT stage 3 discs, part number (P/N) FK29581.

Rolls-Royce plc has reduced the declared safe cyclic life of these LPT stage 3 discs to 7,990 cycles-since-new (CSN). This AD requires actions that are intended to address the unsafe condition described in the MCAI, which could result in uncontained failure of LPT stage 3 discs, resulting in damage to the airplane.

Action Required

Final rule; request for comments.

Regulatory Text

2008-25-01 Rolls-Royce plc: Amendment 39-15759; Docket No. FAA-2008- 1122; Directorate Identifier 2008-NE-35-AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective December 17, 2008.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Rolls-Royce plc RB211 Trent 553-61, 553A2-61, 556-61, 556A2-61, 556B-61, 556B2-61, 560-61, and 560A2-61 turbofan engines with a low-pressure turbine (LPT) stage 3 disc, part number (P/N) FK29581, installed. These engines are installed on, but not limited to, Airbus A340-500 and A340-600 series airplanes.

Reason

(d) European Aviation Safety Agency (EASA) AD No. 2008-0098, dated May 21, 2008, states the unsafe condition as follows:
Recent analysis of the LPT discs 1-5 carried out by Rolls-Royce plc concluded that it is necessary to reduce the declared safe cyclic life of all Trent 500 LPT stage 3 discs, P/N FK29581.
Rolls-Royce plc has reduced the declared safe cyclic life of these LPTstage 3 discs to 7,990 cycles-since-new (CSN). We are issuing this AD to prevent an uncontained failure of the LPT stage 3 disc, resulting in damage to the airplane.

Actions and Compliance

(e) After the effective date of this AD, remove LPT stage 3 discs, P/N FK29581, from service before reaching the new reduced declared safe cyclic life of 7,990 CSN.
(f) Do not install an LPT stage 3 disc, P/N FK29581, onto any engine, unless it has been verified that the disc has not yet accumulated 7,990 CSN.

Alternative Methods of Compliance (AMOCs)

(g) The Manager, Engine Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.

Related Information

(h) Refer to EASA Airworthiness Directive 2008-0098, dated May 21, 2008, and Rolls-Royce plc Alert Service Bulletin No. RB.211-72- AF781, dated April 2, 2008, for related information. Contact Rolls- Royce plc, P.O. Box 31, Derby, England, DE248BJ; telephone: 011-44- 1332-242424; fax: 011-44-1332-245418, for the alert service bulletin.
(i) Contact James Lawrence, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: james.lawrence@faa.gov; telephone (781) 238-7176; fax (781) 238- 7199, for more information about this AD.

Supplementary Information

Discussion

The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, has issued EASA AD 2008-0098, dated May 21, 2008, to correct an unsafe condition for the specified products. The EASA AD states:

Recent analysis of the LPT discs 1-5 carried out by Rolls-Royce plc concluded that it is necessary to reduce the declared safe cyclic life of all Trent 500 LPT stage 3 discs, P/N FK29581.

You may obtain further information by examining the MCAI in the AD docket.

FAA's Determination and Requirements of This AD

This product has been approved by the aviation authority of the United Kingdom, and is approved for operation in the United States. Pursuant to our bilateral agreement with the United Kingdom, they have notified us of the unsafe condition described in the MCAI and service information referenced above. We are issuing this AD because we evaluated all information provided by EASA, and determined the unsafe condition exists and is likely to exist or develop on other products of the same type design. This AD requires removing LPT stage 3 discs, P/N FK29581, from service before reaching the new reduced declared safe cyclic life of 7,990 CSN.

FAA's Determination of the Effective Date

Since there are currently no domestic operators of these engine models, notice and opportunity for public comment before issuing this AD are unnecessary. Therefore, a situation exists that allows the immediate adoption of this regulation.

Comments Invited

This AD is a final rule that involves requirements affecting flight safety, and we did not precede it by notice and opportunity for public comment. We invite you to send any written relevant data, views, or arguments about this AD. Send your comments to an address listed under the ADDRESSES section. Include "Docket No. FAA-2008-1122; Directorate Identifier 2008-NE-35-AD'' at the beginning of your comments. Wespecifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD 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 AD.

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 inair 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.

Regulatory Findings

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); and
3. Will not have a significant economic impact, positive or negative, ona 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 AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Safety.

Adoption of the Amendment

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

PART 39--AIRWORTHINESS DIRECTIVES

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

Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

2. The FAA amends Sec. 39.13 by adding the following new AD:

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Contact Information

James Lawrence, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: james.lawrence@faa.gov; telephone (781) 238-7176; fax (781) 238-7199.

References
Federal Register: December 2, 2008
--- - Part 39
Page 73169-73171
FAA Documents