Airworthiness Directives; Rolls-Royce plc Turbofan Engines

[Federal Register Volume 78, Number 1 (Wednesday, January 2, 2013)]
[Rules and Regulations]
[Pages 5-7]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-30383]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-0482; Directorate Identifier 2012-NE-14-AD; 
Amendment 39-17290; AD 2012-25-09]
RIN 2120-AA64


Airworthiness Directives; Rolls-Royce plc Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for all 
Rolls-Royce plc (RR) RB211-524G2-19; RB211-524G2-T-19; RB211-524G3-19; 
RB211-524G3-T-19; RB211-524H2-19; RB211-524H2-T-19; RB211-524H-36; 
RB211-524H-T-36; RB211-535E4-37; RB211-535E4-B-37; RB211-535E4-B-75; 
and RB211-535E4-C-37 turbofan engines. This AD was prompted by an 
investigation by RR concluding that certain intermediate-pressure (IP) 
turbine discs produced before 1997 by a certain supplier may contain 
steel inclusions. This AD requires removal of the affected IP turbine 
discs to inspect them for steel inclusions, and removal of the affected 
discs from service if they fail the inspection. This AD also requires 
removal from service of some IP turbine discs at reduced life limits. 
We are issuing this AD to prevent uncontained IP turbine disc failure, 
engine failure, and damage to the airplane.

DATES: This AD becomes effective February 6, 2013. The Director of the 
Federal Register approved the incorporation by reference of certain 
publications listed in this AD as of February 6, 2013.

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; phone: 781-238-7143; fax: 
781-238-7199; email: [email protected].

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 July 11, 2012 (77 FR 
40820). That NPRM proposed to correct an unsafe condition for the 
specified products. The MCAI states:

    The inspection of several intermediate pressure (IP) turbine 
discs at past engine overhauls identified the presence of steel 
inclusions in these parts. Further investigation concluded that all 
affected parts were manufactured from billets produced before 1997 
at a certain supplier who also melted steel in the same furnaces. 
Initial engineering evaluation concluded that the lives of the parts 
would not be affected by the presence of the said steel inclusions. 
This evaluation has been recently repeated, utilising improved 
structural analysis, and it is now concluded that the currently 
published lives of the components cannot be supported for some discs 
with a steel inclusion.

    We are issuing this AD to prevent uncontained IP turbine disc 
failure, engine failure, and damage to the airplane.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We considered the comments received. The following presents 
the comments received on the proposal and the FAA's response to each 
comment.

Request To Provide Alternative to Inspection

    One commenter, American Airlines, requested that we allow 
replacement of the removed IP turbine disc with a serviceable part as 
an alternative to the inspection mandated by paragraph (f) in the 
proposed AD. American noted that including this alternative would allow 
operators to avoid the added expense of an inspection of discs that are 
being removed from service.
    We agree. We revised paragraph (f) of the Compliance section of the 
AD to allow replacement of an affected disc with a part eligible for 
installation.

Request To Redefine ``Shop Visit''

    One commenter, FedEx Express, requested that we redefine ``shop 
visit'' as any IP turbine disc exposed at shop visit, engine Level 3 
(Refurbishment), Level 4 (Overhaul), or 05 Module Level 2 (Check and 
Repair). FedEx Express indicated that this change would align the AD 
with the current wording in RR Alert Service Bulletin (ASB) RB.211-72-
AG493, dated October 12, 2012.
    We do not agree. The terms `Level 3' and `Level 4' are not specific 
enough to be enforceable. Our definition of shop visit in the AD is 
consistent with the definition in MCAI AD No. 2012-0060, dated April 
18, 2012. We did not change the AD based on this comment.

Request To Remove Reference to Demagnetization

    Commenter Rolls-Royce requested that we remove the reference to 
demagnetization from Compliance paragraph (f). The disc does not need 
to be demagnetized as it will be magnetized as part of the 
Superconductive Quantitative Inductive Device (SQUID) inspection 
process required by paragraph (f).
    We agree. We changed the references in Compliance paragraphs (f)(1) 
and (f)(2) from ``clean, demagnetize, and perform * * *'' to ``clean 
and perform * * *''. The first sentence in paragraph (f)(1) now reads: 
``If below the inspection threshold, clean and perform a 
Superconductive Quantitative Inductive Device (SQUID) inspection of the 
disc at the next shop visit or before the disc reaches the inspection

[[Page 6]]

threshold, whichever is later.'' The first sentence in paragraph (f)(2) 
now reads: ``If above the inspection threshold, clean and perform a 
SQUID inspection of the disc if in the shop or, at the next shop visit, 
whichever occurs first.''

Request To Allow Full Life Limit for Parts That Pass Inspection

    Commenter Rolls-Royce asked that we clarify in the AD that the new, 
lower life limits in Appendix 2 of ASB RB.211-72-AG493 do not apply to 
a part that has passed the SQUID inspection. Rolls-Royce noted that the 
maximum life as defined in Appendix 2 only limits the disc until it has 
had the SQUID inspection and been confirmed as inclusion-free. If the 
disc has successfully passed the inspection, then it can be returned to 
service for the remainder of its life as defined by the Time Limits 
Manual.
    We agree. We changed the AD by adding the phrase ``unless it has 
passed the inspection required by paragraph (f) of the AD'' to 
paragraph (g)(3). This paragraph now reads: ``Do not return to service 
any disc that exceeds its maximum life (in cycles), as found in 
Appendix 2 of RR ASB No. RB.211-72-AG493, Revision 2, dated October 12, 
2012, unless it has passed the inspection required by paragraph (f) of 
the AD.''

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

    We estimate that this AD will affect about 200 engines installed on 
airplanes of U.S. registry. We also estimate that it will take about 
12.5 work-hours per engine to inspect an IP turbine disc. The average 
labor rate is $85 per work-hour. In addition, 77 discs must be removed 
earlier than the existing Airworthiness Limitation Section requires. A 
prorated replacement IP turbine disc would cost about $9,925 per 
engine. We also estimate the cost of replacing a disc if it fails the 
inspection is $225,000. Based on these figures, we estimate the cost of 
the AD on U.S. operators to be $976,725.

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 (phone: (800) 647-5527) is provided in the 
ADDRESSES section. Comments will be 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

    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:

2012-25-09 Rolls-Royce plc: Amendment 39-17290; Docket No. FAA-2012-
0482; Directorate Identifier 2012-NE-14-AD.

(a) Effective Date

    This airworthiness directive (AD) becomes effective February 6, 
2013.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all Rolls-Royce plc (RR) RB211-524G2-19; RB211-
524G2-T-19; RB211-524G3-19; RB211-524G3-T-19; RB211-524H2-19; RB211-
524H2-T-19; RB211-524H-36; RB211-524H-T-36; RB211-535E4-37; RB211-
535E4-B-37; RB211-535E4-B-75; and RB211-535E4-C-37 turbofan engines 
with intermediate-pressure (IP) discs listed in Appendix 1 and Appendix 
2 of RR Alert Service Bulletin (ASB) No. RB.211-72-AG493, Revision 2, 
dated October 12, 2012.

(d) Reason

    This AD was prompted by an investigation by RR concluding that 
certain IP turbine discs produced before 1997 by a certain supplier may 
contain steel inclusions. We are issuing this AD to prevent uncontained 
IP turbine disc failure, engine failure, and damage to the airplane.

(e) Actions and Compliance

    Unless already done, do the following actions.

(f) Disc Inspection

    After the effective date of this AD, use Appendix 1 and Appendix 2 
of RR ASB No. RB.211-72-AG493, Revision 2, dated October 12, 2012, to 
determine if the IP turbine disc is below or above the inspection 
threshold.
    (1) If below the inspection threshold, clean and perform a 
Superconductive Quantitative Inductive Device (SQUID) inspection of the 
disc at the next shop visit or before the disc reaches the inspection 
threshold, whichever is later.

[[Page 7]]

Use Appendix 4 of RR ASB No. RB.211-72-AG493, Revision 2, dated October 
12, 2012, to perform the SQUID inspection.
    (2) If above the inspection threshold, clean and perform a SQUID 
inspection of the disc if in the shop or, at the next shop visit, 
whichever occurs first. Use Appendix 4 of RR ASB No. RB.211-72-AG493, 
Revision 2, dated October 12, 2012, to perform the SQUID inspection.
    (3) Do not return to service any disc that fails the inspection 
required by this AD.
    (4) Instead of performing the inspection required by paragraph (f), 
you may replace an affected disc with a part eligible for installation. 
See Appendix 1 and Appendix 2 of RR ASB No. RB.211-72-AG493, Revision 
2, dated October 12, 2012, to determine if you have an affected disc.

(g) Disc Life Intervals

    (1) After the effective date of this AD, use Appendix 2 of RR ASB 
No. RB.211-72-AG493, Revision 2, dated October 12, 2012, to determine 
the maximum life (in cycles) of affected IP turbine disc(s).
    (2) Remove from service any disc at the next shop visit or before 
it exceeds its maximum life (in cycles), whichever is later, as found 
in Appendix 2 of RR ASB No. RB.211-72-AG493, Revision 2, dated October 
12, 2012.
    (3) Do not return to service any disc that exceeds its maximum life 
(in cycles) as found in Appendix 2 of RR ASB No. RB.211-72-AG493, 
Revision 2, dated October 12, 2012, unless it has passed the inspection 
required by paragraph (f) of the AD.

(h) Definition of Shop Visit

    For purposes of this AD, a shop visit is defined as induction into 
the shop where the IP and low pressure (LP) turbine module is removed 
from the engine, and any casing is removed from the IP and LP turbine 
module.

(i) Credit for Previous Actions

    If you performed the actions required by paragraph (f) using RR ASB 
No. RB.211-72-AG493, Revision 1, dated November 11, 2011, you met the 
requirements of this AD.

(j) Alternative Methods of Compliance (AMOCs)

    The Manager, Engine Certification Office, may approve AMOCs for 
this AD. Use the procedures found in 14 CFR 39.19 to make your request.

(k) Related Information

    (1) For more information about this AD, contact Alan Strom, 
Aerospace Engineer, Engine Certification Office, FAA, Engine & 
Propeller Directorate, 12 New England Executive Park, Burlington, MA 
01803; phone: 781-238-7143; fax: 781-238-7199; email: 
[email protected].
    (2) European Aviation Safety Agency AD 2012-0060, dated April 18, 
2012 pertains to the subject of this AD.

(l) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the incorporation 
by reference (IBR) of the service information listed in this paragraph 
under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do the 
actions required by this AD, unless the AD specifies otherwise.
    (i) Rolls-Royce (RR) plc Alert Service Bulletin No. RB.211-72-
AG493, Revision 2, dated October 12, 2012.
    (ii) Reserved.
    (3) For service information identified in this AD, contact Rolls-
Royce plc, Corporate Communications, P.O. Box 31, Derby, England, 
DE248BJ; phone: 011-44-1332-242424; fax: 011-44-1332-245418 or email 
from http://www.rolls-royce.com/contact/civil_team.jsp, or download 
the publication from https://www.aeromanager.com.
    (4) You may view this service information at FAA, FAA, Engine & 
Propeller Directorate, 12 New England Executive Park, Burlington, MA. 
For information on the availability of this material at the FAA, call 
781-238-7125.
    (5) You may view this service information 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 December 7, 2012.
Colleen M. D'Alessandro,
Assistant Manager, Engine & Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2012-30383 Filed 12-31-12; 8:45 am]
BILLING CODE 4910-13-P

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