
[Federal Register: November 14, 2008 (Volume 73, Number 221)]
[Rules and Regulations]               
[Page 67361-67363]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr14no08-2]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-1063; Directorate Identifier 2008-NE-32-AD; 
Amendment 39-15725; AD 2008-23-04]
RIN 2120-AA64

 
Airworthiness Directives; Rolls-Royce plc RB211 Trent 553-61, 
553A2-61, 556-61, 556A2-61, 556B-61, 556B2-61, 560-61, and 560A2-61 
Turbofan Engines

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

ACTION: Final rule; request for comments.

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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 affecting 
only RB211 Trent 500 series turbofan engines that have not incorporated 
Rolls-Royce plc (RR) Service Bulletin (SB) No. RB.211-72-D733, dated 
August 21, 2002, or Revision 1 of that SB, dated March 6, 2008, as 
follows:

    The intermediate-pressure (IP) turbine blade shrouds of the 
RB211 Trent 500 series engines feature closure welds (dust caps). 
Development engine testing has revealed the potential for dust caps 
to crack, lift and release. The latter may potentially allow hot 
annulus gas to be ingested down the core passages of IP turbine 
blades. Radial inflow of annulus gas into the IP disc rim region 
could cause local heating of the disc firtree, resulting in creep of 
the disc material. Failure of the disc rim in creep could 
simultaneously release two blades and a disc post. Failure to this 
extent could be beyond the containment capabilities of the casing. 
Consequently, release of the dust caps would constitute a 
potentially unsafe condition.

This AD requires actions that are intended to address the unsafe 
condition described in the MCAI, which could result in uncontained 
release of IP turbine blades and disc posts, resulting in damage to the 
airplane.

DATES: This AD becomes effective December 1, 2008.
    We must receive comments on this AD by December 15, 2008.
    The Director of the Federal Register approved the incorporation by 
reference of Rolls-Royce plc Alert Service Bulletin (ASB) No. RB.211-
72-AF994, Revision 1, dated September 1, 2008 and SB No. RB.211-72-
D733, Revision 1, dated March 6, 2008, listed in the AD as of December 
1, 2008.

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: 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: (202) 493-2251.

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 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: James Lawrence, Aerospace Engineer, 
Engine Certification Office, FAA, Engine & Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803; e-mail: 
james.lawrence@faa.gov; telephone (781) 238-7176; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: 

Discussion

    EASA, which is the Technical Agent for the Member States of the 
European Community, has issued EASA AD 2008-0109 R1, dated June 17, 
2008, to correct an unsafe condition for the specified products. The 
EASA AD states that for RB211 Trent 500 series turbofan engines that 
have not incorporated RR SB No. RB.211-72-D733, dated August 21, 2002, 
or Revision 1 of that SB, dated March 6, 2008, the unsafe condition is 
as follows:

    The intermediate-pressure (IP) turbine blade shrouds of the 
RB211 Trent 500 series engines feature closure welds (dust caps). 
Development engine testing has revealed the potential for dust caps 
to crack, lift and release. The latter may potentially allow hot 
annulus gas to be ingested down the core passages of IP turbine 
blades. Radial inflow of annulus gas into the IP disc rim region 
could cause local heating of the disc firtree, resulting in creep of 
the disc material. Failure of the disc rim in creep could 
simultaneously release two blades and a disc post. Failure to this 
extent could be beyond the containment capabilities of the casing. 
Consequently, release of the dust caps would constitute a 
potentially unsafe condition.

You may obtain further information by examining the MCAI in the AD 
docket.

Relevant Service Information

    Rolls-Royce plc has issued ASB No. RB.211-72-AF994, Revision 1, 
dated September 1, 2008 and SB No. RB.211-72-D733, Revision 1, dated 
March 6, 2008. The actions described in this service information are 
intended to correct the unsafe condition identified in the MCAI.

FAA's Determination and Requirements of This AD

    Although no airplanes registered in the United States use these 
engines, the possibility exists that the engines could be used on 
airplanes registered in the United States in the future. The unsafe 
condition described previously is likely to exist or develop on other 
engines of

[[Page 67362]]

the same type design. We are issuing this AD to prevent release of IP 
turbine blades and disc posts, resulting in damage to the airplane. 
This AD requires:
     Initial and repetitive borescope inspections for missing 
or lifting IP turbine blade outer shroud dust caps; and
     Installation of core restrictor plugs in the IP turbine 
blade roots, if 20 or more IP turbine blade outer shroud dust caps are 
found lifting, or if 1 or more dust caps are missing.

FAA's Determination of the Effective Date

    Since there are currently no domestic operators of this engine 
model, notice and opportunity for public comment before issuing this AD 
are unnecessary. Therefore, a situation exists that allows the 
immediate adoption of this regulation.

Differences Between the AD and the MCAI

    We have reviewed the MCAI and related service information and, in 
general, agree with their substance. But we require the initial 
borescope inspection to be done within 5 flight cycles, since the MCAI 
required the initial inspection to be done before July 1, 2008, which 
has already passed.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety, and we did not precede it by notice and opportunity for public 
comment. We invite you to send any written relevant data, views, or 
arguments about this AD. Send your comments to an address listed under 
the ADDRESSES section. Include ``Docket No. FAA-2008-1063; Directorate 
Identifier 2008-NE-32-AD'' at the beginning of your comments. We 
specifically invite comments on the overall regulatory, economic, 
environmental, and energy aspects of this AD. We will consider all 
comments received by the closing date and may amend this AD because 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 we 
receive about this AD.

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.

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:

2008-23-04 Rolls-Royce plc: Amendment 39-15725.; Docket No. FAA-
2008-1063; Directorate Identifier 2008-NE-32-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective December 
1, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Rolls-Royce plc (RR) RB211 Trent 553-61, 
553A2-61, 556-61, 556A2-61, 556B-61, 556B2-61, 560-61, and 560A2-61 
turbofan engines that have not incorporated RR Service Bulletin (SB) 
No. RB.211-72-D733, dated August 21, 2002, or Revision 1 of that SB, 
dated March 6, 2008. These engines are installed on, but not limited 
to, Airbus A340-500 and -600 series airplanes.

Reason

    (d) European Aviation Safety Agency (EASA) AD No. 2008-0109 R1, 
dated June 17, 2008, states that for RB211 Trent 500 series turbofan 
engines that have not incorporated RR SB No. RB.211-72-D733, dated 
August 21, 2002, or Revision 1 of that SB, dated March 6, 2008, the 
unsafe condition is as follows:

    The intermediate-pressure (IP) turbine blade shrouds of the 
RB211 Trent 500 series engines feature closure welds (dust caps). 
Development engine testing has revealed the potential for dust caps 
to crack, lift and release. The latter may potentially allow hot 
annulus gas to be ingested down the core passages of IP turbine 
blades. Radial inflow of annulus gas into the IP disc rim region 
could cause local heating of the disc firtree, resulting in creep of 
the disc material. Failure of the disc rim in creep could 
simultaneously release two blades and a disc post. Failure to this 
extent could be beyond the containment capabilities of the casing. 
Consequently, release of the dust caps would constitute a 
potentially unsafe condition.

We are issuing this AD to prevent uncontained release of IP turbine 
blades and disc posts, resulting in damage to the airplane.

Actions and Compliance

    (e) Unless already done, do the following actions.
    (1) Within 5 flight cycles, on engines installed or not 
installed, carry out the initial borescope inspection of the IP 
turbine blade outer shroud dust caps, using Section 3, 
Accomplishment Instructions of RR Alert Service Bulletin (ASB) No. 
RB.211-72-AF994, Revision 1, dated September 1, 2008.
    (2) Thereafter, depending on the results of the inspection 
specified in paragraph (e)(1) of this AD, follow the appropriate 
action in the following Table 1:

[[Page 67363]]



             Table 1--Required Actions and Compliance Times
------------------------------------------------------------------------
   Results of Borescope inspection      Actions that must be carried out
------------------------------------------------------------------------
(i) Total number of IP turbine blade   At intervals not to exceed 100
 outer shroud dust caps lifting is 0.   cycles, re-inspect the dust caps
                                        using Section 3, Accomplishment
                                        Instructions of Rolls-Royce plc
                                        ASB No. RB.211-72-AF994,
                                        Revision 1, dated September 1,
                                        2008.
(ii) Total number of IP turbine blade  At intervals not to exceed 20
 outer shroud dust caps lifting         cycles, re-inspect the dust caps
 exceeds 0 but is equal to or fewer     using Section 3, Accomplishment
 than 10.                               Instructions of Rolls-Royce plc
                                        ASB No. RB.211-72-AF994,
                                        Revision 1, dated September 1,
                                        2008.
(iii) Total number of IP turbine       At intervals not to exceed 10
 blade outer shroud dust caps lifting   cycles, re-inspect the dust caps
 exceeds 10 but is equal to or fewer    using Section 3, Accomplishment
 than 20.                               Instructions of Rolls-Royce plc
                                        ASB No. RB.211-72-AF994,
                                        Revision 1, dated September 1,
                                        2008.
(iv) Total number of IP turbine blade  Within 10 cycles, remove the
 outer shroud dust caps lifting         engine from service and install
 exceeds 20.                            core restrictor plugs in the IP
                                        turbine blade roots, using
                                        Section 3, Accomplishment
                                        Instructions of RR Service
                                        Bulletin (SB) No. RB.211-72-
                                        D733, Revision 1, dated March 6,
                                        2008.
(v) Total number of IP turbine blade   Before further flight, remove the
 outer shroud dust caps missing         engine from service and install
 exceeds 1.                             core restrictor plugs in the IP
                                        turbine blade roots, using
                                        Section 3, Accomplishment
                                        Instructions of RR SB No. RB.211-
                                        72-D733, Revision 1, dated March
                                        6, 2008.
------------------------------------------------------------------------

FAA AD Differences

    (f) This AD differs from the Mandatory Continuing Airworthiness 
Information (MCAI) EASA AD by requiring the initial borescope 
inspection to be done within 5 flight cycles. The MCAI required the 
initial inspection to be done before July 1, 2008, which has already 
passed.
    (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 MCAI EASA AD 2008-0109 R1, dated June 17, 2008, for 
related information.
    (i) Contact James Lawrence, Aerospace Engineer, Engine 
Certification Office, FAA, Engine & Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; e-mail: 
james.lawrence@faa.gov; telephone (781) 238-7176; fax (781) 238-
7199, for more information about this AD.

Material Incorporated by Reference

    (j) You must use the Rolls-Royce plc service information 
specified in the following Table 2 to do the actions required by 
this AD.

               Table 2--Material Incorporated by Reference
------------------------------------------------------------------------
         Document No.               Page       Revision        Date
------------------------------------------------------------------------
Alert Service Bulletin No.     All...........         1  September 1,
 RB.211-72-AF994.                                         2008.
    Total Pages: 24.
Service Bulletin No. RB.211-   All...........         1  March 6, 2008.
 72-D733, including
 Supplement.
    Total Pages: 9.
------------------------------------------------------------------------

    (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, P.O. Box 31, Derby, DE24 8BJ, UK, telephone 44-0-
1332 242424; fax 44-0-1332 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 October 28, 2008.
Diane S. Romanosky,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
 [FR Doc. E8-26200 Filed 11-13-08; 8:45 am]

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