2010-26115. Airworthiness Directives; Rolls-Royce plc (RR) RB211-524 Series Turbofan Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Supplemental notice of proposed rulemaking (NPRM); reopening of comment period.

SUMMARY:

This action revises an earlier proposed airworthiness directive (AD), applicable to certain RR RB211-524 series turbofan engines. That proposal would have required initial and repetitive borescope inspections of the head section and meterpanel assembly of the combustion liner, and replacement if necessary with serviceable parts. That proposal was prompted by an inquiry submitted by an operator, which resulted in RR performing a complete review of the affected front combustion liner part numbers (P/Ns). This action revises the proposed rule by clarifying the applicability paragraph (c) of the proposed AD. We are proposing this AD to prevent deterioration of the engine combustion liner, which can result in combustion liner breakup, case burn-through, engine fire, and damage to the airplane.

DATES:

We must receive comments on this proposed AD by December 17, 2010.

ADDRESSES:

You may send comments by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.
• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.
• Fax: [phone].

Contact Rolls-Royce plc, P.O. Box 31, Derby, DE24 8BJ, United Kingdom; telephone: [phone]; fax: [phone] for the service information identified in this proposed AD.

The Docket Operations office is located at Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.

FOR FURTHER INFORMATION CONTACT:

Ian Dargin, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: [e-mail]; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send us any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2009-0162; Directorate Identifier 2004-NE-19-AD” in the subject line of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light 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 with FAA personnel concerning this proposed AD. Using the search function of the Web site, anyone can find and read the comments in any of our dockets, including, if provided, the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78).

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov;​; or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone [phone]) is the same as the Mail address provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

Discussion

The FAA proposed to amend 14 CFR part 39 with a proposed AD. The proposed AD applies to certain RB211-524 series turbofan engines. We published the proposed AD in the Federal Register on March 2, 2009 (74 FR 9050). That action proposed to require:

• Initial and repetitive borescope inspections of the combustion liner head section and meterpanel assembly of the combustion liner and, if necessary, replacement.
• Reduction of the inspection intervals of certain RB211-524 engine models that have not been repaired to RR Field Repair Scheme FRS5367/B, and
• A mandatory terminating action to the repetitive inspections.

Since we issued that NPRM, we determined that we need to remove the P/Ns of the combustion chamber cases from paragraph (c) of the proposed AD. Because this proposed AD expands the population of engines affected by the proposed AD, this supplemental NPRM reopens the comment period.

Costs of Compliance

We estimate that this AD would affect 18 engines installed on airplanes of U.S. registry. We also estimate that it would take about 2 work-hours per engine to perform the proposed actions, and that the average labor rate is $85 per work-hour. No parts are required, so parts would cost $0. Based on these figures, we estimate the total cost of the AD to U.S. operators would be $3,060.

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 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); 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 at the address listed under ADDRESSES.

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 proposes to amend 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.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by removing Amendment 39-13917 (70 FR 680, January 5, 2005), and by adding a new airworthiness directive to read as follows:

Rolls-Royce plc: Docket No. FAA-2009-0162; Directorate Identifier 2004-NE-19-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by December 17, 2010.

Affected ADs

(b) This AD supersedes AD 2004-26-05, Amendment 39-13917.

Applicability

(c) This AD applies to Rolls-Royce plc (RR) engine models RB211-524B-02, -524B3-02 engines and RB211-524B2, -524B4, -524C2, and -524D4 series engines with a front combustion liner assembly that incorporates RR Service Bulletin (SB) No. RB.211-72-7221 or RR SB No. RB.211-72-7998, but doesn't incorporate RR SB No. RB.211-72-9670 or RR SB No. RB.211-72-9764, and engine models RB211-524G and -524H series engines with a front combustion liner assembly that doesn't incorporate RR SB No. RB.211-72-9764. These engines are installed on, but not limited to, Boeing 747 and Lockheed L1011 series airplanes.

Unsafe Condition

(d) This AD results from an inquiry submitted by an operator which resulted in RR performing a complete review of the affected front combustion liner part numbers. We are issuing this AD to prevent deterioration of the engine combustion liner, which can result in combustion liner breakup, case burn-through, engine fire, 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.

Credit for Previous Inspections

(f) Engine inspections previously made to RR Service Bulletin No. RB.211-72-B482, Revision 8, dated November 15, 2001, meet the requirements of this AD for the initial or repetitive inspections specified in paragraphs (g) through (g)(2) and (h) through (h)(4) of this AD.

Inspections of Combustion Liner Head Sections—Not Previously Repaired

(g) Borescope-inspect combustion liner head sections that have not been previously repaired. Use paragraphs 3.A.(1) through 3.A.(5) of the Accomplishment Instructions of RR Alert Service Bulletin (ASB) No. RB.211-72-AB482, Revision 9, dated July 28, 2003, and the cycles-since-new (CSN), cycles-since-last inspection (CSLI), and cycles-in-service (CIS) compliance thresholds in Table 1 of this AD.

Table 1—Combustion Liner Head Section—Not Previously Repaired

Engine series	Initial inspection	Repetitive inspection	Parts exceeding initial inspection cycles
(1) RB211-524C2, -524D4, -524G, and -524H	Within 1,400 to 1,600 CSN	Within 200 CSLI	Within 100 CIS after the effective date of this AD.
(2) RB211-524B-02, -524B2, -524B3-02, and -524B4	Within 3,000 to 3,200 CSN	Within 200 CSLI	Within 200 CIS after the effective date of this AD.

Inspections of Combustion Liner Head Sections—Previously Repaired Using RR Field Repair Scheme FRS5367/B

(h) If the combustion liner head section was previously repaired using RR Field Repair Scheme FRS5367/B, do the following:

(1) Borescope-inspect combustion liner head sections. Use paragraphs 3.A.(1) through 3.A.(5) of the Accomplishment Instructions of RR ASB No. RB.211-72-AB482, Revision 9, dated July 28, 2003, and the cycles-since-last repair (CSLR), CSLI, and CIS compliance thresholds in Table 2 of this AD.

(2) If all 18 struts on a combustion liner that is subject to RR ASB No. RB.211-72-AB482, Revision 9, dated July 28, 2003, were repaired using the nicrobraze repair specified in RR Field Repair Scheme FRS5367, that repair is equivalent to compliance with RR Field Repair Scheme FRS5367/B. Borescope-inspect the combustion liner as specified in paragraph (h)(1) of this AD.

Table 2—Combustion Liner Head Section—Previously Repaired Using RR Field Repair Scheme FRS5367/B

Engine series	Initial inspection	Repetitive inspection	Parts exceeding initial inspection cycles
(3) RB211-524C2, -524D4, -524G, and -524H	Within 1,800 to 2,200 CSLR	Within 400 CSLI	Within 200 CIS after the effective date of this AD.
(4) RB211-524B-02, -524B2, -524B3-02, and -524B4	Within 3,000 to 3,200 CSLR	Within 400 CSLI	Within 200 CIS after the effective date of this AD.

Inspections of Combustion Liner Head Sections That Have Been Repaired But Did Not Use RR Field Repair Scheme FRS5367/B

(i) For engines that have a combustion liner head section repaired using a method other than RR Field Repair Scheme FRS5367/B, do the following:

(1) Borescope-inspect combustion liner head section. Use paragraphs 3.A.(1) through 3.A.(5) of the Accomplishment Instructions of RR ASB No. RB.211-72-AB482, Revision 9, dated July 28, 2003, and the CSLR, CSLI, and CIS compliance thresholds in Table 3 of this AD.

Table 3—Combustion Liner Head Section—Repaired, But Did Not Use RR Field Repair Scheme FRS5367/B

Engine series	Initial inspection	Repetitive inspection	Parts exceeding initial inspection cycles
(2) RB211-524C2, -524D4, -524G, and -524H	Within 500 to 700 CSLR	Within 200 CSLI	Within 100 CIS after the effective date of this AD.
(3) RB211-524B-02, -524B2, -524B3-02, and -524B4	Within 2,000 to 2,200 CSLR	Within 200 CSLI	Within 200 CIS after the effective date of this AD.

(4) Head sections repaired by replacement of all 18 struts using RR Field Repair Scheme FRS6548 are considered as equivalent to fitting a new head section for inspection purposes. Borescope-inspect the combustion liner as specified in paragraph (h)(1) of this AD.

Inspections of Meterpanel Assemblies—Not Repaired

(j) Borescope-inspect meterpanel assemblies that incorporate SB No. RB.211-72-7998, that have not been previously repaired. Use paragraphs 3.B.(1) through 3.B.(7) of the Accomplishment Instructions of RR ASB No. RB.211-72-AB482, Revision 9, dated July 28, 2003, and the CSN, CSLI, and CIS compliance thresholds in Table 4 of this AD.

Table 4—Meterpanel Assembly—Not Repaired

Engine series	Initial inspection	Repetitive inspection	Parts exceeding initial inspection cycles
(1) RB211-524D4, -524G, and -524H	Within 1,000 to 1,200 CSN	Within 400 CSLI	Within 50 CIS after the effective date of this AD.
(2) RB211-524D4, -524G, and -524H that have not used RB211-524H ratings at any time	Within 1,800 to 2,000 CSN	Within 400 CSLI	Within 50 CIS after the effective date of this AD.

Inspections of Meterpanel Assemblies—Repaired

(k) For meterpanel assemblies that incorporate SB No. RB.211-72-7998, and have been repaired previously, do the following:

(1) Borescope-inspect meterpanel assemblies that have been previously repaired. Use paragraphs 3.B.(1) through 3.B.(7) of the Accomplishment Instructions of RR ASB No. RB.211-72-AB482, Revision 9, dated July 28, 2003, and the CSLR, CSLI, and CIS compliance thresholds in Table 5 of this AD.

Table 5—Meterpanel Assembly—Repaired

Engine series	Initial inspection	Repetitive inspection	Parts exceeding initial inspection cycles
(2) RB211-524D4, -524G, and -524H	Within 500 to 700 CSLR	Within 400 CSLI	Within 50 CIS after the effective date of this AD.

Reject Parts

(l) Replace parts that exceed the acceptance criteria. Information about the acceptance criteria can be found in the Aircraft Maintenance Manual, 72-00-00, Inspection/Check.

Mandatory Terminating Action

(m) Replace the front combustion liner assembly with a front combustion liner not affected by this AD at the next shop visit.

(n) For RB211-524B02, -524B2, -524B3-02, -524B4-02, -524C2 and -524D4 engines, replacing the front combustion liner assembly with a front combustion liner assembly that incorporates the modifications in RR SB No. RB.211-72-9670, Original Issue, dated August 27, 1993; or RR SB No. RB.211-72-9764, Revision 3, dated January 16, 1998, constitutes terminating action to the repetitive inspections in paragraphs (g), (h), (i), (j), and (k), of this AD.

(o) For RB211-524G and -524H engines, replacing the front combustion liner assembly with a front combustion liner assembly that incorporates the modifications in RR SB No. RB.211-72-9764, Revision 3, dated January 16, 1998, constitutes terminating action to the repetitive inspections in paragraphs (g), (h), (i), (j), and (k) of this AD.

Definition of Shop Visit

(p) For the purpose of this AD, a shop visit is any time that the 04 module is removed for repair or overhaul.

Related Information

(q) Contact Ian Dargin, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: [e-mail]; telephone [phone]; fax [phone], for more information about this AD.

(r) Rolls-Royce ASB No. RB.211-72-AB482, Revision 9, dated July 28, 2003; SB No. RB.211-72-9764, Revision 3, dated January 16, 1998; and SB No. RB.211-72-9670, Original Issue, dated August 27, 1993, pertain to the subject of this AD. Contact Rolls-Royce plc, P.O. Box 31, Derby, DE24 8BJ, United Kingdom; telephone: [phone]; fax: [phone], for a copy of this service information.

Issued in Burlington, Massachusetts, on October 6, 2010.

Diane S. Romanosky,

Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service.