Airworthiness Directives; Rolls-Royce plc RB211 Series Turbofan Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

The FAA is superseding an existing airworthiness directive (AD) for Rolls-Royce plc (RR) models RB211-535E4-37, RB211-535E4-B-37, RB211-535C-37, RB211-535E4-B-75, and RB211-22B-02 turbofan engines. That AD currently requires inspecting certain high pressure (HP) turbine discs, manufactured between 1989 and 1999, for cracks in the rim cooling air holes, and, if necessary, replacing the disc's serviceable parts. This AD requires the same actions but at reduced compliance schedules and adds the RR model RB211-535E4-C turbofan engine to the applicability. This AD results from a report of cracks in a model RB211-524 HP turbine disc that had propagated further than expected. We are issuing this AD to prevent possible disc failure, which could result in an uncontained engine failure and damage to the airplane.

DATES:

Effective January 13, 2005. The incorporation by reference of certain publications listed in the AD is approved by the Director of the Federal Register as of January 13, 2005.

We must receive any comments on this AD by February 28, 2005. On December 24, 2001 (66 FR 57859, November 19, 2001), the Director of the Federal Register approved the incorporation by reference of certain other publications, as listed in the regulations.

ADDRESSES:

Use one of the following addresses to comment on this AD:

• By mail: Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 2000-NE-62-AD, 12 New England Executive Park, Burlington, MA 01803-5299.
• By fax: (781) 238-7055.
• By e-mail: 9-ane-adcomment@faa.gov.

You can get the service information referenced in this AD from Rolls-Royce plc, PO Box 31, Derby, England; telephone: 011 44 1332-249428, fax: 011 44 1332-249223.

You may examine the AD docket, by appointment, at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT:

Ian Dargin, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-7178, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

On November 5, 2001, the FAA issued AD 2001-23-02, Amendment 39-12499 (66 FR 57859, November 19, 2001), for RR models RB211-535E4-37, RB211-535E4-B-37, RB211-535C-37, RB211-535E4-B-75, and RB211-22B-02 turbofan engines. That AD requires inspecting certain HP turbine discs, manufactured between 1989 and 1999, for cracks in the rim cooling air holes, and, if necessary, replacing the discs with serviceable parts. That AD resulted from reports of cracks in rim cooling air holes in two high-life RR Trent 800 discs. That condition, if not corrected, could result in possible disc failure, which could result in an uncontained engine failure and damage to the airplane.

Actions Since AD 2001-23-02 Was Issued

Since that AD was issued, the Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, recently notified the FAA that an unsafe condition may exist on Rolls-Royce plc models RB211-535E4-37, RB211-535E4-B-37, RB211-535C-37, RB211-535E4-B-75, and RB211-535E4-C series turbofan engines. The CAA advises that cracks in a model RB211-524 HP turbine disc had propagated further than expected based on recent inspection findings and a re-assessment of the disc lifing model used to define the inspection thresholds in AD 2001-23-02. This AD requires inspection of certain HP turbine discs, manufactured between 1989 and 1999, for cracks in the rim cooling air holes, and, if necessary, replacement with serviceable parts. We are reducing the inspection schedules required by AD 2001-23-02, for the high risk discs which includes all models except for model RB211-22B-02 engines and adds the RB211-535E4-C due to manufacture at the same facility as the Trent 800 discs using the same tooling. Discs used in the model RB211-535 engines have a significantly higher HP turbine life than those used in the RB211-524 and operate in a harsher environment. Therefore, although the cracking of the rim cooling air holes will not affect the safe operation of the RB211-524 discs, the 535 discs are at higher risk of failure and the inspection intervals must be reduced. This AD retains the same inspection schedules, currently required for the model RB211-22B-02 engine, that were in AD 2001-23-02. The actions specified in this AD are intended to prevent possible disc failure, which could result in an uncontained engine failure and damage to the airplane.

Bilateral Airworthiness Agreement

This engine model is manufactured in the United Kingdom and is type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Under this bilateral airworthiness agreement, the CAA has kept the FAA informed of the situation described above. We have examined the findings of the CAA, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

FAA's Determination and Requirements of This AD

The unsafe condition described previously is likely to exist or develop on other RR models RB211-535E4-37, RB211-535E4-B-37, RB211-535C-37, RB211-535E4-B-75, RB211-535E4-C, and RB211-22B-02 turbofan engines of the same type design. We are issuing this AD to prevent possible disc failure, which could result in an uncontained engine failure and damage to the airplane. This AD requires inspection of certain HP turbine discs, manufactured between 1989 and 1999, for cracks in the rim cooling air holes, and, if necessary, replacement with serviceable parts.

FAA's Determination of the Effective Date

Since an unsafe condition exists that requires the immediate adoption of this AD, we have found that notice and opportunity for public comment before issuing this AD are impracticable, and that good cause exists for making this amendment effective in less than 30 days.

Comments Invited

This AD is a final rule that involves requirements affecting flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to make any written relevant data, views, or arguments regarding this AD. Send your comments to an address listed under ADDRESSES. Include “AD Docket No. 2000-NE-62-AD” in the subject line of your comments. If you want us to acknowledge receipt of your mailed comments, send us a self-addressed, stamped postcard with the docket number written on it; we will date-stamp your postcard and mail it back to you. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify it. If a person contacts us verbally, and that contact relates to a substantive part of this AD, we will summarize the contact and place the summary in the docket. We will consider all comments received by the closing date and may amend the AD in light of those comments.

Examining the AD Docket

You may examine the AD Docket (including any comments and service information), by appointment, between 8 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays. See ADDRESSES for the location.

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 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.

Regulatory Findings

We have 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 that the regulation:

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, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

We prepared a summary of the costs to comply with this AD and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under ADDRESSES. Include “AD Docket No. 2000-NE-62-AD” in your request.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (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.

2. The FAA amends § 39.13 by removing Amendment 39-12499 ( 66 FR 57859, November 19, 2001), and by adding a new airworthiness directive, Amendment 39-13915, to read as follows:

2004-26-03 Rolls-Royce plc: Amendment 39-13915. Docket No. 2000-NE-62-AD. Supersedes AD 2001-23-02, Amendment 39-12499.

Effective Date

(a) This airworthiness directive (AD) becomes effective January 13, 2005.

Affected ADs

(b) This AD supersedes AD 2001-23-02, Amendment 39-12499.

Applicability

(c) This AD applies to Rolls-Royce plc (RR) models RB211-535E4-37, RB211-535E4-B-37, RB211-535C-37, RB211-535E4-B-75, RB211-535E4-C, and RB211-22B-02 turbofan engines with turbine discs having part numbers and serial numbers listed in the following Tables 1, 3, and 5 of this AD. These turbofan engines are installed on, but not limited to, Boeing 757, Tupolev Tu204, and Lockheed L-1011 series airplanes.

Unsafe Condition

(d) This AD results from a report of cracks, in an RB211 HP turbine disc, that had propagated further than expected. We are issuing this AD to prevent possible disc failure, which could result in an uncontained engine failure and damage to the airplane.

Compliance

(e) You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.

Eddy Current Inspection for All Except Model RB211-22B-02

(f) For all except model RB211-22B-02 engines, do the following:

(1) Perform an eddy current inspection of the high pressure (HP) turbine discs listed in Table 1 of this AD, for cracks in the rim cooling air holes. Use paragraph 3. of the Accomplishment Instructions of RR Alert SB No. RB.211-72-AE651, dated November 22, 2004, to perform the eddy current inspection.

(2) Use the compliance schedule in Table 2 of this AD.

(3) On discs that pass inspection, use paragraph 3. of the Accomplishment Instructions of RR Alert SB No. RB.211-72-AE651, dated November 22, 2004, to permanently etch NMSB 72-AE651 onto the disc, adjacent to the part number.

(4) Perform an eddy current inspection of the HP turbine discs listed in Table 3 of this AD, for cracks in the rim cooling air holes. Use paragraph 3. of the Accomplishment Instructions of RR Alert SB No. RB.211-72-AE651, dated November 22, 2004, to perform the eddy current inspection.

(5) Use the compliance schedule in Table 4 of this AD.

(6) For discs that pass inspection, use paragraph 3. of the Accomplishment Instructions of RR Alert SB No. RB.211-72-AE651, dated November 22, 2004, to permanently etch NMSB 72-AE651 onto the disc, adjacent to the part number.

Eddy Current Inspection for Model RB211-22B-02

(g) For model RB211-22B-02 engines, do the following:

(1) Perform an eddy current inspection of the HP turbine discs listed in Table 5 of this AD, for cracks in the rim cooling air holes. Use paragraph 3. of the Accomplishment Instructions of RR SB No. RB.211-72-C877, Revision 1, dated March 7, 2001, to perform the eddy current inspection.

(2) Use the compliance schedule in Table 6 of this AD.

(3) For discs that pass inspection, use paragraph 3. of the Accomplishment Instructions of RR SB No. RB.211-72-C877, Revision 1, dated March 7, 2001, to permanently etch NMSB 72-C877 onto the disc, adjacent to the part number.

Other Conditions for All Engines

(h) Do not perform the actions of this AD to a disc until that disc has reached at least 1,500 CSN.

(i) Engines with an affected HP turbine disc at shop visit on the effective date of this AD and with the HPT rotor still removed from the combustor outer case, must have the disc eddy current inspected before assembling the engine.

(j) Engines with an affected HP turbine disc at shop visit on the effective date of this AD with the HPT rotor reinstalled in the combustor case need not have the disc eddy current inspected at this time.

(k) HP turbine discs previously eddy current inspected at fewer than 1,500 CSN must be inspected again using this AD.

(l) Replace cracked HP turbine discs with a serviceable disc.

Definition

(m) For the purpose of this AD, next shop visit is defined as the first shop visit opportunity when the HPT rotor is removed from the combustion case.

(n) For the purpose of this AD, a serviceable part is one with cyclic life remaining and either not listed in any of the preceding tables or one listed in a preceding table, but previously eddy current inspected and permanently etch marked with the Service Bulletin (SB) number NMSB 72-AE651 or NMSB 72-C877 on the disc.

Previous Credit

(o) Previous credit is allowed for the actions in this AD for HP turbine discs with 1,500 CSN or more that were eddy current inspected using applicable RR SB No. RB.211-72-C817, Revision 2, dated March 7, 2001, RR TSD 594-J, Overhaul Processes Manual, Task 70-00-00-200-223, or RR SB No. RB.211-72-C877, Revision 1, dated March 7, 2001.

Reporting Requirements

(p) For all except model RB211-22B-02 engines, report findings of the inspection using paragraph 3.E. of the Accomplishment Instructions of RR ASB RB.211-72-AE651, dated November 22, 2004. The Office of Management and Budget (OMB) has approved the reporting requirements specified in paragraph 3.E. of the Accomplishment Instructions of RR ASB RB.211-72-AE651, dated November 22, 2004, and assigned OMB control number 2120-0056.

(q) For model RB211-22B-02 engines, report findings of the inspection using paragraph 3.E. of the Accomplishment Instructions of RR SB RB.211-72-C877, Revision 1, dated March 7, 2001. The Office of Management and Budget (OMB) has approved the reporting requirements specified in paragraph 3.E. of the Accomplishment Instructions of RR SB RB.211-72-C877, Revision 1, dated March 7, 2001, and assigned OMB control number 2120-0056.

Alternative Methods of Compliance

(r) 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.

Material Incorporated by Reference

(s) You must use the service information specified in Table 7 of this AD to perform the inspections required by this AD. The Director of the Federal Register approved the incorporation by reference of RR Alert SB No. RB.211-72-AE651, dated November 22, 2004, listed in Table 7 of this AD in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. The incorporation by reference of RR MSB No. RB.211-72-C877, Revision 1, dated March 7, 2001, was approved previously by the Director of the Federal Register as of December 24, 2001 (66 FR 57859, November 19, 2001). You can get a copy from Rolls-Royce plc, PO Box 31, Derby, England; telephone: 011 44 1332-249428, fax: 011 44 1332-249223, for a copy of this service information. You may review copies at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA; or the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. Table 7 follows:

Related Information

(t) CAA airworthiness directive G-2004-0027, dated November 19, 2004, also addresses the subject of this AD.