
[Federal Register: August 11, 2008 (Volume 73, Number 155)]
[Rules and Regulations]               
[Page 46550-46552]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr11au08-9]                         


[[Page 46550]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-0036; Directorate Identifier 2007-NE-22-AD; 
Amendment 39-15636; AD 2008-16-18]
RIN 2120-AA64

 
Airworthiness Directives; Rolls-Royce plc RB211-524 Series 
Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

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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:

    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 issuing 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: This AD becomes effective September 15, 2008. The Director of 
the Federal Register approved the incorporation by reference of certain 
publications listed in this AD as of September 15, 2008.

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: 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: 

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 24, 2007 (72 
FR 60293). That NPRM proposed to correct an unsafe condition for the 
specified products. 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.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We considered the comment received. The commenter supports the 
NPRM.

Editorial Change for Clarity

    We changed the paragraph layering in paragraph (e) of the 
regulatory text to clarify the requirements for disks that have a 
serial number in Table 1 of this AD and disks that don't have a serial 
number in Table 1 of this AD.

Conclusion

    We reviewed the available data, including the comment received, and 
determined that air safety and the public interest require adopting the 
AD with the change described previously. We determined that this change 
will not increase the economic burden on any operator or increase the 
scope of the AD.

Costs of Compliance

    We estimate that this AD will affect 72 engines of U.S. registry. 
We also estimate that it will take about 10 work-hours per product to 
comply with this AD. The average labor rate is $80 per work-hour. 
Required parts will 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 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, 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 (telephone (800) 647-5527) is provided in 
the ADDRESSES section. Comments will be

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available in the AD docket shortly after receipt.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new AD:

2008-16-18 Rolls-Royce plc: Amendment 39-15636. Docket No. FAA-2007-
0036; Directorate Identifier 2007-NE-22-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective 
September 15, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Rolls-Royce (RR) RB211-524 series 
turbofan engines with certain high pressure (HP) turbine discs 
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.

    We are issuing this AD to detect cracks that could cause the HP 
turbine disc to fail and result in uncontained failure of the 
engine.

Actions and Compliance

    (e) Unless already done, do the following actions.
    (1) Carry out the eddy current inspection as detailed in Section 
3--Accomplishment Instructions of Rolls-Royce NMSB RB.211-72-AE718, 
dated January 24, 2006.
    (2) Carry out the eddy current inspection in accordance with the 
following schedule:
    (i) The HP disc serial numbers listed in Table 1 are to be 
inspected as follows:

             Table 1--HP Disc Serial Numbers by Part Number
------------------------------------------------------------------------
               Part No.                            Serial No.
------------------------------------------------------------------------
UL29473...............................  LAQDY6043
UL29473...............................  LAQDY6048
UL29473...............................  LAQDY6079
UL29473...............................  LDRCZ10057
UL29473...............................  LDRCZ10264
UL29473...............................  LDRCZ10415
UL29473...............................  LDRCZ11402
UL29473...............................  LDRCZ11425
UL29473...............................  LDRCZ11497
UL29473...............................  LDRCZ11663
UL29473...............................  LDRCZ11679
UL29473...............................  LDRCZ12301
UL29473...............................  LDRCZ12308
UL29473...............................  LDRCZ12316
UL29473...............................  LDRCZ12319
UL29473...............................  LQDY6957
UL29473...............................  LQDY9075
UL29473...............................  LQDY9084
UL29473...............................  LQDY9557
UL29473...............................  LQDY9906
UL29473...............................  LQDY9956
UL29473...............................  LQDY9970
UL29473...............................  LQDY9985
UL29472...............................  LQDY9125
UL29472...............................  LQDY9554
UL29472...............................  LQDY9582
UL29472...............................  LQDY9895
UL29472...............................  LQDY9910
UL29472...............................  LQDY9947
UL29472...............................  LQDY9960
UL24994...............................  LQDY6777
UL24994...............................  LQDY6792
UL24994...............................  LQDY6859
UL24994...............................  LQDY6860
UL24994...............................  LQDY6866
UL24994...............................  LQDY6869
UL24994...............................  LQDY6934
UL24994...............................  LQDY6946
UL24994...............................  LQDY6963
UL23166...............................  LQDY6745
UL23166...............................  LQDY6846
UL23166...............................  LQDY6848
UL23166...............................  LQDY6954
FK24790...............................  LDRCZ12492
FK24790...............................  LDRCZ12694
------------------------------------------------------------------------

    (A) For all RB211-524 engine marks except RB211-524D4 variants:
    (1) 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.
    (2) 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:
    (i) Prior to reaching 6650 cycles since new. The HP turbine disc 
life at inspection must be greater than 700 cycles since new.
    (ii) 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.
    (B) For all RB211-524D4 engine mark variants:
    (1) 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.
    (2) 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:
    (i) Prior to reaching 5500 cycles since new. The HP turbine disc 
life at inspection must be greater than 700 cycles since new.
    (ii) 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.
    (ii) For all other HP turbine discs specified in the 
Applicability of this Directive but not listed in Table 1 of this 
AD.
    (A) 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.
    (B) 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

    (f) Wherever the MCAI AD specifies 24 November 2005, this AD 
specifies the effective date of this AD.

Other FAA AD Provisions

    (g) 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

    (h) Refer to the Civil Aviation Authority Airworthiness 
Directive G-2006-0002, dated February 13, 2006, for related 
information.
    (i) 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.

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Material Incorporated by Reference

    (j) You must use Rolls-Royce Service Bulletin RB.211-72-AE718, 
dated January 24, 2006, to do the actions required by this AD, 
unless the AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) For service information identified in this AD, contact 
Rolls-Royce plc, PO Box 31, Derby, England; telephone: 011 44 1332-
242424; fax: 011 44 1332-249936.
    (3) You may review copies at the FAA, New England Region, 12 New 
England Executive Park, Burlington, MA; or at 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/cfr/ibr-locations.html.

    Issued in Burlington, Massachusetts, on July 31, 2008.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
 [FR Doc. E8-18102 Filed 8-8-08; 8:45 am]

BILLING CODE 4910-13-P
