# AD 2011-22-07: Cracks in the front combustion liner - Type: Airworthiness directive - Status: Current - Products: Rolls-Royce RB211-524G2-T-19, RB211-524G3-T-19, RB211-524H-T-36, RB211-524H2-T-19, RB211-Trent 875-17, RB211-Trent 877-17, RB211-Trent 884-17, RB211-Trent 884B-17, RB211-Trent 892-17, RB211-Trent 892B-17, RB211-Trent 895-17, RB211 Trent 768-60 and 2 more - Effective: November 29, 2011 - Published: October 25, 2011, 76 FR 65941–65944 - Issued: October 18, 2011 - Issued as: Final rule - Superseded by: Nothing supersedes this AD - Product type: Engine - Amendment: 39-16849 - Docket: FAA-2010-0993 (https://www.regulations.gov/docket/FAA-2010-0993) - Project: 2010-NE-08-AD - Registered aircraft: 184 may be affected, by airframe or engine model (OpenAirDocs) - Official PDF: https://openairdocs.org/files/sha256/26/a7/26a7e2081f832715bf0daeb65fdf0666eb837ba1017b86eec651b3f3024e3810 (from https://www.govinfo.gov/content/pkg/FR-2011-10-25/pdf/2011-27513.pdf) - Federal Register: https://www.federalregister.gov/documents/2011/10/25/2011-27513/airworthiness-directives-rolls-royce-plc-rb211-524-series-rb211-trent-700-series-and-rb211-trent-800 - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/F98CD67FDC3D531D86257935005C87EA.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/2011-22-07 ## 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: Cracking has been found on the inner wall between intermediate dilution chutes on a total of five front combustion liners of the standard corresponding to Rolls-Royce RB211 Service Bulletin No. 72-D133. The lives of two of these liners were confirmed to be below the currently valid borescope inspection interval. Ultimately, crack propagation could result in hot gas breakout with potential of downstream component distress and multiple turbine blade release beyond containment capabilities of the engine casings. Thus, cracking of this nature constitutes a potentially unsafe condition. Since Rolls-Royce Service Bulletin No. 72-E902 introduces further developments of Rolls-Royce RB211 Service Bulletin No. 72-D133, engines incorporating Rolls-Royce RB211 Service Bulletin No. 72-E902 are also considered to be potentially affected and are therefore included in the applicability of this AD. ## The airworthiness directive 1. The authority citation for part 39 continues to read as follows: ## Rule preamble ### Dates This AD becomes effective November 29, 2011. The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of November 29, 2011. ### Addresses 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 Alan Strom, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: alan.strom@faa.gov; phone: 781-238-7143; fax: 781-238-7199. ### Discussion We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to the specified products. That NPRM was published in the Federal Register on October 5, 2010 (75 FR 61363). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI states that: Cracking has been found on the inner wall between intermediate dilution chutes on a total of five front combustion liners of the standard corresponding to Rolls-Royce RB211 Service Bulletin No. 72-D133. The lives of two of these liners were confirmed to be below the currently valid borescope inspection interval. Ultimately, crack propagation could result in hot gas breakout with potential of downstream component distress and multiple turbine blade release beyond containment capabilities of the engine casings. Thus, cracking of this nature constitutes a potentially unsafe condition. Since Rolls-Royce Service Bulletin No. 72-E902 introduces further developments of Rolls-Royce RB211 Service Bulletin No. 72-D133, engines incorporating Rolls-Royce RB211 Service Bulletin No. 72-E902 are also considered to be potentially affected and are therefore included in the applicability of this AD. This AD requires a change to the initial and repeat borescope inspection intervals for the front combustion liner. ### Comments We gave the public the opportunity to participate in developing this AD. We considered the comments received. ### Request To Expand Address for Service Information One commenter, Rolls-Royce plc (RR), asked us to consider changing the information for getting the service information to “For any questions concerning the technical content of the requirements in this AD (NPRM), please contact your designated Rolls-Royce representative for a copy of the service information, please download the publication from your Aeromanager account at http://www.aeromanager.com. If you do not have a designated representative or an Aeromanager account, please contact Corporate Communications at Rolls-Royce plc, PO Box 31, Derby, DE24 8BJ, United Kingdom, phone: 011-44-1331-242424, fax: 011-44-1332-249936, or e-mail: http://www.rolls-royce.com/contact/civil_team.jsp identifying the correspondence as being related to Airworthiness Directives.” RR states that this should make sure that any questions from operators of their engines and those from other parties are directed to the area best equipped to answer. We partially agree. We agree that operators and maintenance providers need to get timely and accurate service information, and that additional information is worth including. We changed paragraph (k) of the AD to state “* * * contact Corporate Communications at Rolls-Royce plc PO Box 31, Derby, DE24 8BJ, United Kingdom, Phone: 011-44-1331-242424, fax 011-44-1332-249936 or e-mail from http://www.rolls-royce.com/contact/civil_team.jsp identifying the correspondence as being related to Airworthiness Directives.” We do not agree that operators or maintenance providers should contact RR for questions about this AD. We did not include that information in the AD. ### Requests To Change References to the Service Bulletin That Is Incorporated by Reference Two commenters, American Airlines (AA) and The Boeing Company (Boeing), asked us to add “or later revision” after “Service Bulletin No. RB.211-72-AF458, Revision 2, dated December 21, 2007.” Boeing stated the latest revision of Service Bulletin (SB) No. RB.211-72-AF458 is Revision 4. Boeing stated that airlines have been inspecting their combustion liners to Revision 4 of the SB and the compliance intervals specified in the NPRM are consistent with RR SB RB.211-72-AF458, Revision 4 and EASA AD 2009-0243R1. AA stated the borescope inspection is the same on later revisions, so the life should be counted from the latest SB revision. We do not agree. On review of the SB, we determined that the inspection requirements and limits called out in the SB are already in the engine and aircraft maintenance manuals. We changed the AD to remove the incorporation by reference of the SB. One commenter, AA, asked us to revise paragraph (f) of the AD to specifically call out which paragraphs of SB RB.211-72-AF458 are incorporated by reference. AA stated the NPRM called out all of section 3 of the SB, which is too prescriptive given the nature of the inspections. We do not agree. On review of the SB, we found incorporation by reference unnecessary. We changed the AD to remove the incorporation by reference of the SB. ### Request To Remove an Engine Model From the Applicability One commenter, AA, asked us to remove the RR RB211-535 engine model from the applicability of the proposed AD. AA stated they have recorded no crack findings against the RB211-535 model. We agree. The thermal, acoustical, and vibratory stress environment of the RB211-535 combustion liner is different from that of the other engines to which this AD applies. We removed the RB211-535E4-37, RB211-535E4-B-37, RB211-535E4-C-37, and RB211-535E4-B-75 from the Applicability paragraph (c) of this AD, and updated our cost estimate to reflect the fewer affected engines. ### Request To Change the Number of Cracking Events One commenter, Boeing, asked us to change paragraph (d) of the proposed AD to specify that six cracking events have been found instead of five. Boeing states that changing paragraph (d) of the proposed AD will more accurately reflect the need for the inspections. We agree. Although an additional cracking event has occurred, the AD was prompted by the investigation of five events. We changed paragraph (d) of this AD to reflect six known cracking events. ### Request To Add a Grace Period for Compliance One commenter, Boeing asked us to change paragraphs (f)(1)(i) and (f)(1)(iii) of the proposed AD to add “within 15 cycles of the date of issue of the AD” before the word “or.” Boeing states that adding the 15 cycle grace period will give operators time to get back to base for the inspection. We partially agree. No additional grace period is required. This AD does not require inspecting any engine earlier than 250 cycles after the effective date of the AD. We clarified the wording of paragraph (f) to make this clearer. ### Statement of the Possibility of Cost and Operational Impact Increasing One commenter, Federal Express, stated that cost and operational impact could increase if certain RB211-535 models are added to the applicability of the proposed AD. The commenter provided no reason for its statement. We agree. However, additional engine models are not being added, and we are specifically excluding the RB211-535 engine in response to another comment. We did not change the AD in response to this comment. ### Conclusion We reviewed the available data, including the comments received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We determined that these changes will not increase the economic burden on any operator or increase the scope of the AD. ### Costs of Compliance Based on the service information, we estimate that this AD will affect about 46 products of U.S. registry. We also estimate that it will take about 1.5 work-hours per product to comply with this AD. The average labor rate is $85 per work-hour. No parts are required so parts will cost $0 per product. Based on these figures, we estimate the cost of the AD on U.S. operators to be $5,865. ### 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 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, 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. We prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket. ### 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 AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (phone: (800) 647-5527) is provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt. ### Adoption of the Amendment Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: ## Affected data sheets (3) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS E00050EN](https://openairdocs.org/tcds/E00050EN): Rolls-Royce Deutschland Ltd & Co KG; names 7 of 7 models: RB211-Trent 875-17, RB211-Trent 884B-17, RB211-Trent 877-17, RB211-Trent 892B-17, RB211-Trent 892-17, RB211-Trent 895-17, RB211-Trent 884-17 - [TCDS E30NE](https://openairdocs.org/tcds/E30NE): Rolls-Royce Deutschland Ltd & Co KG; names 4 of 8 models: RB211-524H-T-36, RB211-524G2-T-19, RB211-524H2-T-19, RB211-524G3-T-19 - [TCDS E39NE](https://openairdocs.org/tcds/E39NE): Rolls-Royce Deutschland Ltd & Co KG; names 3 of 3 models: RB211 Trent 768-60, RB211 Trent 772-60, RB211 Trent 772B-60 ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 184 (0 by airframe model, 184 by engine model) - Makers: Boeing 183, Airbus 1 Models with the most aircraft: - [Rolls-Royce RB-211 series](https://openairdocs.org/engine/rolls-royce-rb-211-series): 182 aircraft (engine model) - [Rolls-Royce RB211-524HT36](https://openairdocs.org/engine/rolls-royce-rb211-524ht36): 2 aircraft (engine model) All 2 models: https://openairdocs.org/ad/2011-22-07/models.md Every aircraft: https://openairdocs.org/ad/2011-22-07/aircraft.md ## Related documents - [Proposed rule FAA-2010-0993](https://openairdocs.org/proposed/FAA-2010-0993): Notice of proposed rulemaking (NPRM), published Oct 5, 2010 Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.