Airworthiness directives: Rolls-Royce, plc,
[Federal Register: October 24, 2007 (Volume 72, Number 205)]
[Proposed Rules]
[Page 60293-60295]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr24oc07-26]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
[Docket No. FAA-2007-0036; Directorate Identifier 2007-NE-22-AD]
RIN 2120-AA64
Airworthiness Directives; Rolls-Royce plc RB211-524 Series Turbofan Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) provided by the aviation authority of the United Kingdom to identify and correct an unsafe condition on an aviation product. The MCAI states the following:
Recently an RB211 HP turbine disc has been found with a crack which had propagated further than expected from the risk model that was used to establish the original inspection.
We are proposing this AD to detect cracks that could cause the high pressure (HP) turbine disc to fail and result in uncontained failure of the engine.
DATES: We must receive comments on this proposed AD by November 23, 2007.
ADDRESSES: You may send comments by any of the following methods:
Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your
comments electronically.
Mail: Docket Management Facility, U.S. Department of Transportation, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., 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: (202) 493-2251.
You can get the service information identified in this proposed AD from Rolls-Royce plc, P.O. Box 31, DERBY, DE24 8BJ, UK, telephone: 44 (0) 1332 242424; fax: 44 (0) 1332 249936.
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 (800) 647-5527) is the same as the Mail address provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.
FOR FURTHER INFORMATION CONTACT: Jason Yang, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: jason.yang@faa.gov; telephone (781) 238-7747; fax (781) 238-7199.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include ``Docket No. FAA-2007-0036; Directorate Identifier 2007-NE-22-AD'' at the beginning of your comments. We specifically invite comments on the overall regulatory,
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economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD based on 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).
Discussion
The Civil Aviation Authority (CAA), which is the aviation authority for the United Kingdom, has issued United Kingdom Airworthiness Directive G-2006-0002, dated February 13, 2006, to correct an unsafe condition for the specified products. The CAA AD states:
A population of HP turbine discs that were manufactured between 1989-1999 and which were subject to possible machining anomalies, were believed to have an increased chance of suffering from cooling air hole cracking, compared to the general fleet population of HP turbine discs. As a result of this risk, Rolls-Royce issued Non- Modification Service Bulletin (NMSB) 72-C816, recommending in- service inspections of the subject discs.
Recently an RB211 HP turbine disc has been found with a crack which had propagated further than expected from the risk model that was used to establish the original inspection defined in the above NMSB; This has led to the need for a revision of the original inspection requirements.
An HP turbine disc fracture would be uncontained and create a potential unsafe condition. Accordingly, this AD introduces revised inspection requirements to reflect the increased risk of HP turbine disc cracking and potential disc fracture.
You may obtain further information by examining the CAA AD in the AD docket.
Relevant Service Information
RR has issued Service Bulletin RB.211-72-AE718, dated January 24, 2006. The actions described in this service information are intended to correct the unsafe condition identified in the CAA AD.
FAA's Determination and Requirements of This Proposed 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 above. We are issuing this AD because we evaluated all the information provided by the CAA and determined the unsafe condition exists and is likely to exist or develop on other products of the same type design.
Costs of Compliance
Based on the service information, we estimate that this proposed AD would affect about 72 engines installed on airplanes of U.S. registry. We also estimate that it would take about 10.0 work-hours per product to comply with this proposed AD, and that the average labor rate is $80 per work-hour. Required parts would cost about $15,000 per product. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $1,137,600. Our cost estimate is exclusive of possible warranty coverage.
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 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.
For the reasons discussed above, I certify this proposed regulation:
-
Is not a ``significant regulatory action'' under Executive Order 12866;
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Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and
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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 proposed AD and placed it in the AD docket.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
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The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
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The FAA amends Sec. 39.13 by adding the following new AD:
Rolls-Royce plc: Docket No. FAA-2007-0036; Directorate Identifier 2007-NE-22-AD.
Comments Due Date
(a) We must receive comments by November 23, 2007.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Rolls-Royce (RR) RB211-524 series turbofan engines with certain high pressure (HP) turbine disks, specified by part number (P/N) and serial number (SN) listed in Table 1 of this AD, installed. These engines are installed on, but not limited to, Boeing 747 series and 767 series airplanes and Lockheed L1011 series airplanes.
Reason
(d) Recently an RB211 HP turbine disc has been found with a crack which had propagated further than expected from the risk model that was used to establish the original inspection defined in the above NMSB; This has led to the need for a revision of the original inspection requirements.
An HP turbine disc fracture would be uncontained and create a potential unsafe condition. Accordingly, this AD introduces revised inspection requirements to reflect the increased risk of HP turbine disc cracking and potential disc fracture.
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Actions and Compliance
(e) Unless already done, do the following actions.
(f) Carry out the eddy current inspection as detailed in Section 3--Accomplishment Instructions of Rolls-Royce NMSB 72-AE718, dated January 24, 2006, in accordance with the following schedule:
(1) The HP disc serial numbers listed in table 1 are to be inspected as follows:
Table 1.--HP Disk Serial Numbers by Part Number
Part No.
Serial No.
Part No.
Serial No.
UL29473............................. LAQDY6043
UL29472................ LQDY9125 UL29473............................. LAQDY6048
UL29472................ LQDY9554 UL29473............................. LAQDY6079
UL29472................ LQDY9582 UL29473............................. LDRCZ10057
UL29472................ LQDY9895 UL29473............................. LDRCZ10264
UL29472................ LQDY9910 UL29473............................. LDRCZ10415
UL29472................ LQDY9947 UL29473............................. LDRCZ11402
UL29472................ LQDY9960 UL29473............................. LDRCZ11425
UL24994................ LQDY6777 UL29473............................. LDRCZ11497
UL24994................ LQDY6792 UL29473............................. LDRCZ11663
UL24994................ LQDY6859 UL29473............................. LDRCZ11679
UL24994................ LQDY6860 UL29473............................. LDRCZ12301
UL24994................ LQDY6866 UL29473............................. LDRCZ12308
UL24994................ LQDY6869 UL29473............................. LDRCZ12316
UL24994................ LQDY6934 UL29473............................. LDRCZ12319
UL24994................ LQDY6946 UL29473............................. LQDY6957
UL24994................ LQDY6963 UL29473............................. LQDY9075
UL23166................ LQDY6745 UL29473............................. LQDY9084
UL23166................ LQDY6846 UL29473............................. LQDY9557
UL23166................ LQDY6848 UL29473............................. LQDY9906
UL23166................ LQDY6954 UL29473............................. LQDY9956
FK24790................ LDRCZ12492 UL29473............................. LQDY9970
FK24790................ LDRCZ12694 UL29473............................. LQDY9985
(2) For all RB211-524 engine marks except RB211-524D4 variants:
(i) If the HP turbine disc cycles are greater than 6150 cycles since new on the effective date of this AD, inspect the HP turbine disc within 500 cycles after the effective date of this AD.
(ii) If the HP turbine disc cycles are less than 6150 cycles since new on the effective date of this AD, inspect the disc by whichever is the soonest of the conditions below:
(A) Prior to reaching 6650 cycles since new. The HP turbine disc life at inspection must be greater than 700 cycles since new.
(B) At next shop visit where the HP turbine rotor is removed from the Combustor Outer Case and the HP turbine disc life is greater than 700 cycles since new. If a HP turbine disc that meets these cyclic life criteria is currently at shop visit, and if, at the effective date of this Airworthiness Directive, it has not yet been reinstalled into the Combustion Outer Case, then the HP turbine disc must be inspected in accordance with the requirements of this Airworthiness Directive at the current shop visit.
(3) For all RB211-524D4 engine mark variants:
(i) If the HP turbine disc cycles are greater than 5000 cycles since new on the effective date of this AD, inspect the HP turbine disc within 500 cycles after the effective date of this AD.
(ii) If the HP turbine disc cycles were less than 5000 cycles since new on the effective date of this AD, inspect the HP turbine disc by whichever is the soonest of the conditions below:
(A) Prior to reaching 5500 cycles since new. The HP turbine disc life at inspection must be greater than 700 cycles since new.
(B) At the next shop visit where the HP turbine rotor is removed from the Combustor Outer Case and the HP turbine disc life is greater than 700 cycles since new. If a HP turbine disc that meets these cyclic life criteria is currently at shop visit, and if, at the effective date of this Airworthiness Directive, it has not yet been reinstalled into the Combustion Outer Case, then the HP turbine disc must be inspected in accordance with the requirements of this Airworthiness Directive at the current shop visit.
(4) For all other HP turbine discs specified in the Applicability of this Directive but not listed in Table 1 on page 2:
(i) Inspect the HP turbine disc at next shop visit where the HP turbine rotor is removed from the Combustor Outer Case and the HP turbine disc life is greater than 700 cycles since new. If a HP turbine disc that meets these cyclic life criteria is currently at shop visit, and if, at the effective date of this Airworthiness Directive, it has not yet been reinstalled into the Combustion Outer Case, then the HP turbine disc must be inspected in accordance with the requirements of this Airworthiness Directive at the current shop visit.
(ii) If a HP turbine disc has previously passed the inspection to Rolls-Royce NMSB 72-C816 or the focused inspection carried out in accordance with Rolls-Royce TS594-J Overhaul Process Manual Task 70- 00-00-200-223 at greater than 700 cycles since new, then either of these inspections meets the requirements of this Airworthiness Directive.
FAA AD Differences
(g) Wherever the MCAI AD specifies 24 November 2005, this AD specifies the effective date of this AD.
Other FAA AD Provisions
(h) Alternative Methods of Compliance (AMOCs): 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
(i) Refer to the Civil Aviation Authority Airworthiness Directive G-2006-0002, dated February 13, 2006, and RR Nonmandatory Service Bulletin RB.211-72-AE718, dated January 24, 2006, for related information.
(j) Contact Jason Yang, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: jason.yang@faa.gov; telephone (781) 238-7747; fax (781) 238-7199, for more information about this AD.
Issued in Burlington, Massachusetts, on October 17, 2007. Peter A. White, Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service.
[FR Doc. E7-20923 Filed 10-23-07; 8:45 am]
BILLING CODE 4910-13-P
