Airworthiness Directives; Rolls-Royce plc Turbofan Engines

[Federal Register Volume 78, Number 20 (Wednesday, January 30, 2013)]
[Rules and Regulations]
[Pages 6206-6208]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-01361]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2013-0030; Directorate Identifier 2012-NE-42-AD; 
Amendment 39-17325; AD 2013-02-04]
RIN 2120-AA64


Airworthiness Directives; Rolls-Royce plc Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: We are adopting a new airworthiness directive (AD) for all 
Rolls-Royce plc RB211-Trent 970-84, RB211-Trent 970B-84, RB211-Trent 
972-84, RB211-Trent 972B-84, RB211-Trent 977-84, RB211-Trent 977B-84 
and RB211-Trent 980-84 turbofan engines. This AD requires on-wing 
inspections of low-pressure turbine (LPT) disk seal fins and interstage 
seals when post-flight review indicates Engine Health Monitoring (EHM) 
vibratory maintenance-alert limits were exceeded in flight. The AD also 
requires in-shop inspections of the LPT disk seal fins and interstage 
seals to detect cracks or damage and, depending on the findings, 
accomplishment of corrective action. This AD is prompted by a Trent 900 
engine experiencing LPT stage 2 disk interstage seal material loss and 
increased low-pressure rotor vibration while in flight. We are issuing 
this AD to prevent cracks in the LPT disk, which could result in 
uncontained engine failure and damage to the airplane.

DATES: This AD becomes effective February 14, 2013.
    We must receive comments on this AD by March 18, 2013.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of February 14, 
2013.

ADDRESSES: You may send comments by any of the following methods:
    <bullet> Federal eRulemaking Portal: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
    <bullet> Mail: U.S. Department of Transportation, 1200 New Jersey 
Avenue SE., West Building Ground Floor, Room W12-140, Washington, DC 
20590-0001.
    <bullet> Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    <bullet> Fax: (202) 493-2251.
    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: http://www.rolls-royce.com/contact/civil_team.jsp. You may view this service 
information at the FAA, Engine & Propeller Directorate, 12 New England 
Executive Park, Burlington, MA 01803. For information on the 
availability of this material at the FAA, call 781-238-7125.

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 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: Robert Green, Aerospace Engineer, 
Engine Certification Office, FAA, Engine & Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803; phone: 781-238-7754; 
fax: 781-238-7199; email: [email protected].

SUPPLEMENTARY INFORMATION:

Discussion

    The European Aviation Safety Agency (EASA), which is the Technical 
Agent for the Member States of the European Community, has issued EASA 
Airworthiness Directive 2012-0220, dated October 22, 2012, a Mandatory

[[Page 6207]]

Continuing Airworthiness Information (referred to after this as ``the 
MCAI''), to correct an unsafe condition for the specified products. The 
MCAI states:

    Following a revenue service flight, a Trent 900 engine 
experienced increased low-pressure vibration. The vibration did not 
exceed any engine limits, and the engine was not shut down during 
flight. Upon post-flight inspection of the engine, debris was found 
in the exhaust tail pipe and the engine was removed. The results of 
a subsequent strip inspection revealed that the stage 2 Low-Pressure 
Turbine (LPT) disc had suffered material loss from a portion of the 
Interstage Seal (ISS) area of the disc, with impact damage to 
downstream LPT stages. All debris was contained within the engine 
casings.
    Preliminary findings show that the ISS fin had rubbed into the 
stage 2 vane honeycomb seal, which overheated and cracked, finally 
resulting in releasing a portion of the ISS area of the disc.
    This condition, if not detected and corrected, could lead to LPT 
stage 2 disc cracks, possibly resulting in an uncontained engine 
failure and subsequent damage to the aeroplane.

We are issuing this AD to prevent cracks in the LPT disks, which could 
result in uncontained engine failure and damage to the airplane. You 
may obtain further information by examining the MCAI in the AD docket.

Relevant Service Information

    RR has issued Repeater Technical Variance 125060, Issue 1, dated 
July 27, 2012; Repeater Technical Variance 125658, Issue 2, dated 
August 14, 2012; Alert Non-Modification Service Bulletin (NMSB) RB.211-
72-AH054, Initial issue, dated September 14, 2012; and Alert NMSB 
RB.211-72-AH054, Revision 1, dated November 5, 2012. 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

    This product has been approved by the United Kingdom and is 
approved for operation in the United States. Pursuant to our bilateral 
agreement with the European Community, they have notified us of the 
unsafe condition described in the MCAI and service information 
referenced above. We are issuing this AD because we evaluated all 
information provided by EASA and determined the unsafe condition exists 
and is likely to exist or develop on other products of the same type 
design. This AD requires on-wing inspections of LPT disk seal fins and 
interstage seals when post-flight review of the EHM low-pressure rotor 
(N1) vibration data indicates maintenance-alert limits were exceeded in 
flight. The AD also requires in-shop inspections of the LPT disk seal 
fins and interstage seals to detect cracks or damage and, depending on 
the findings, the accomplishment of corrective action.

FAA's Determination of the Effective Date

    No domestic operators use this product. Therefore, we find that 
notice and opportunity for prior public comment are unnecessary and 
that good cause exists for making this amendment effective in less than 
30 days.

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-2013-0030; Directorate 
Identifier 2012-NE-42-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 
with FAA personnel concerning this 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).

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

    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:

2013-02-04 Rolls-Royce plc: Amendment 39-17325; Docket No. FAA-2013-
0030; Directorate Identifier 2012-NE-42-AD.

(a) Effective Date

    This airworthiness directive (AD) becomes effective February 14, 
2013.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Rolls-Royce plc (RR) RB211-Trent 970-84, 
RB211-Trent 970B-84,

[[Page 6208]]

RB211-Trent 972-84, RB211-Trent 972B-84, RB211-Trent 977-84, RB211-
Trent 977B-84, and RB211-Trent 980-84 engines, all serial numbers.

(d) Reason

    This AD was prompted by a Trent 900 engine experiencing low-
pressure turbine (LPT) stage 2 disk interstage seal material loss 
and increased low-pressure rotor vibration while in flight. We are 
issuing this AD to prevent cracks in the LPT disk, which could 
result in uncontained engine failure and damage to the airplane.

(e) Actions and Compliance

    Unless already done, do the following.
    (1) After every flight after the effective date of this AD, 
review the Engine Health Monitoring (EHM) low-pressure rotor (N1) 
vibration data. If you find that the maximum and average vibrations 
exceed 0.7 inches/sec (ips) and 0.5 ips, respectively, then within 
10 engine flight cycles, confirm that the vibration data was not the 
result of indicator error.
    (2) If you cannot show that the vibration increase was caused by 
indicator error, inspect the LPT disk seal fins and interstage 
seals. Use RR Repeater Technical Variance 125060, Issue 1, dated 
July 27, 2012, to do the inspections.
    (3) After the effective date of this AD, at each engine shop 
visit inspect the LPT disk seal fins and interstage seals. Use RR 
Alert Non-Modification Service Bulletin RB.211-72-AH054, Revision 1, 
dated November 5, 2012, or Initial Issue, dated September 14, 2012, 
to do the inspections.
    (4) If, during the inspection required by paragraphs (e)(2) or 
(e)(3) of this AD, you find any cracks in the disk seal fins or that 
the interstage seals are missing seal material, replace the parts 
with hardware eligible for installation before returning the engine 
to service.

(f) Definitions

    For the purposes of this AD, a shop visit is defined as whenever 
engine maintenance performed prior to reinstallation requires one of 
the following:
    (1) Separation of a pair of major mating engine module flanges. 
However, separation of flanges solely for the purpose of shipment 
without subsequent internal maintenance is not a shop visit. 
Separation of the external gearbox engine mating flanges or removal 
of the external gearbox is also not classified as a shop visit.
    (2) Removal of a disk, hub, or spool.

(g) Credit for Previous Actions

    If you took corrective action before the effective date of this 
AD in accordance with RR Repeater Technical Variance 125658, Issue 
2, dated August 14, 2012, for detected excessive vibration, you met 
the inspection requirements of this AD.

(h) 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.

(i) Related Information

    (1) For more information about this AD, contact Robert Green, 
Aerospace Engineer, Engine Certification Office, FAA, Engine & 
Propeller Directorate, 12 New England Executive Park, Burlington, MA 
01803; phone: 781-238-7754; fax: 781-238-7199; email: 
[email protected].
    (2) Refer to MCAI European Aviation Safety Agency AD 2012-0220, 
dated October 22, 2012.

(j) 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 plc (RR) Non-Modification Service Bulletin 
(NMSB) RB.211-72-AH054, Initial Issue, dated September 14, 2012.
    (ii) RR NMSB RB.211-72-AH054, Revision 1, dated November 5, 
2012.
    (iii) RR Repeater Technical Variance 125060, Issue 1, dated July 
27, 2012.
    (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: http://www.rolls-royce.com/contact/civil_team.jsp.
    (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 January 15, 2013.
Thomas A. Boudreau,
Acting Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2013-01361 Filed 1-29-13; 8:45 am]
BILLING CODE 4910-13-P

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