Document ID: FAA-2008-1165-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Turbofan Engines; Rolls-Royce plc RB211 Trent 800 Series
Posted Date: 2009-02-18T05:00Z

[Federal Register: February 18, 2009 (Volume 74, Number 31)]
[Proposed Rules]
[Page 7563-7565]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr18fe09-13]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-1165; Directorate Identifier 2008-NE-38-AD]
RIN 2120-AA64

Airworthiness Directives; Rolls-Royce plc RB211 Trent 800 Series
Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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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) 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:

    During manufacture of high-pressure (HP) compressor stage 1
discs, a small number of parts have been rejected due to a machining
defect that was found during inspection. Analysis of the possibility
of less severe examples having been undetected and passed into
service has concluded that action is required to reduce the risk of
failure. It is therefore necessary to reduce the life limit from
that currently published for the applicable parts.

    The HP compressor stage 1 disc is part of the HP compressor stage
1-4 shaft, part number (P/N) FK32580. We are proposing this AD to
prevent uncontained failure of the HP compressor stage 1 disc,
resulting in an in-flight engine shutdown and possible damage to the
airplane.

DATES: We must receive comments on this proposed AD by March 20, 2009.

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: Docket Management Facility, 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 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: James Lawrence, Aerospace Engineer,
Engine Certification Office, FAA, Engine

[[Page 7564]]

& 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:

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-2008-1165;
Directorate Identifier 2008-NE-38-AD'' at the beginning of your
comments. We specifically invite comments on the overall regulatory,
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 European Aviation Safety Agency (EASA), which is the Technical
Agent for the Member States of the European Community, has issued EASA
Airworthiness Directive 2008-0099, dated May 21, 2008 (corrected June
12, 2008) (referred to after this as ``the MCAI''), to correct an
unsafe condition for the specified products. The MCAI states:

    During manufacture of HP compressor stage 1 discs, a small
number of parts have been rejected due to a machining defect that
was found during inspection. Analysis of the possibility of less
severe examples having been undetected and passed into service has
concluded that action is required to reduce the risk of failure. It
is therefore necessary to reduce the life limit from that currently
published for the applicable parts.

    You may obtain further information by examining the MCAI in the AD
docket. This proposed AD would require removing HP compressor stage 1-4
shafts, P/N FK32580, from service at reduced life limits based on part
assessment using either ``Multiple Flight Profile Monitoring'', or
``Heavy Flight Profile'' calculations.

Relevant Service Information

    Rolls-Royce plc has issued Alert Service Bulletin RB.211-72-AF825,
Revision 1, dated September 8, 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 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 in the MCAI and service
information referenced above. We are proposing 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 proposed AD requires removing HP compressor
stage 1-4 shafts, P/N FK32580, from service at reduced life limits
based on part assessment using either ``Multiple Flight Profile
Monitoring'', or ``Heavy Flight Profile'' calculations.

Costs of Compliance

    Based on the service information, we estimate that this proposed AD
would affect about 78 products of U.S. registry. Required parts would
cost about $15,095 per product. We estimate that no additional labor
costs would be incurred to perform the proposed actions. We anticipate
that the removal from service of the HP compressor stage 1-4 shafts
will occur while the engine is inducted into the shop for routine
maintenance. Based on these figures, we estimate the cost of the
proposed AD on U.S. operators to be $1,177,410. 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:
    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 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

    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]

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

Rolls-Royce plc: Docket No. FAA-2008-1165; Directorate Identifier
2008-NE-38-AD.

Comments Due Date

    (a) We must receive comments by March 20, 2009.

Affected Airworthiness Directives (ADs)

    (b) None.

Applicability

    (c) This airworthiness directive (AD) applies to Rolls-Royce plc
(RR) models

[[Page 7565]]

RB211 Trent 875-17, Trent 877-17, Trent 884-17, Trent 884B-17, Trent
892-17, Trent 892B-17, and Trent 895-17 turbofan engines, with high-
pressure (HP) compressor stage 1-4 shafts, part number (P/N)
FK32580, installed. These engines are installed on, but not limited
to, Boeing 777 series airplanes.

Reason

    (d) European Aviation Safety Agency (EASA) AD 2008-0099, dated
May 21, 2008 (corrected June 12, 2008) states the unsafe condition
is as follows:
    During manufacture of high-pressure (HP) compressor stage 1
discs, a small number of parts have been rejected due to a machining
defect that was found during inspection. Analysis of the possibility
of less severe examples having been undetected and passed into
service has concluded that action is required to reduce the risk of
failure. It is therefore necessary to reduce the life limit from
that currently published for the applicable parts.

The HP compressor stage 1 disc is part of the HP compressor stage 1-
4 shaft, P/N FK32580. We are issuing this AD to prevent uncontained
failure of the HP compressor stage 1 disc, resulting in an in-flight
engine shutdown and possible damage to the airplane.

Actions and Compliance

    (e) Unless already done, do the following actions.
    (1) RB211 Trent 800 critical part lives may be monitored by one
of two methods: ``Multiple Flight Profile Monitoring'', or ``Heavy
Flight Profile''. Information on these profiles can be found in the
RR Engine Manual Airworthiness Limitations Section.
    (2) Standard Duty Cycles (SDC) is the product of Flight Cycles
and Beta Factor. Information on Flight Cycles and Beta Factor can be
found in the RR Engine Manual Airworthiness Limitations Section.

Multiple Flight Profile Monitoring Parts

    (3) For RB211 Trent 800 engines being monitored by ``Multiple
Flight Profile Monitoring,'' do the following:
    (i) On the effective date of this AD, if the life of HP
compressor stage 1-4 shaft, P/N FK32580, is equal to or over 5,580
SDC, then the part must be withdrawn from service before exceeding
7,780 SDC.
    (ii) On the effective date of this AD, if the life of HP
compressor stage 1-4 shaft, P/N FK32580, is between 3,380 and 5,580
SDC, then the part must be withdrawn from service before exceeding
an additional 2,200 SDC.
    (iii) On the effective date of this AD, if the life of HP
compressor stage 1-4 shaft, P/N FK32580, is equal to or below 3,380
SDC, then the part must be withdrawn from service before exceeding
5,580 SDC.

Reassessment of the Revised Life Limit

    (4) Operators should be aware that reassessment of the revised
life limit in accordance with this AD (including possible
reassessment per the applicable subparagraph (e)(3)(i), (e)(3)(ii),
or (e)(3)(iii) of this AD, will be necessary if, at some time in the
future, the operator changes the flight profile that was applicable
before the Effective Date of this AD, such that parts which are the
subject of this AD are affected. To recalculate the revised life
limit, the life of the part in SDC at the Effective Date of this AD,
must be recalculated from the part's entry into service (zero life),
and must use the Beta Factor(s) for the new Flight Profile(s).

Heavy Flight Profile Parts

    (5) For RB211 Trent 800 engines being monitored by ``Heavy
Flight Profile,'' do the following:
    (i) On the effective date of this AD, if the life of HP
compressor stage 1-4 shaft, P/N FK32580, is equal to or over 5,280
flight cycles, then the part must be withdrawn from service before
exceeding 7,480 flight cycles.
    (ii) On the effective date of this AD, if the life of HP
compressor stage 1-4 shaft, P/N FK32580, is between 3,080 flight
cycles and 5,280 flight cycles, then the part must be withdrawn from
service before exceeding an additional 2,200 flight cycles.
    (iii) On the effective date of this AD, if the life of HP
compressor stage 1-4 shaft, P/N FK32580, is equal to or below 3,080
flight cycles, then the part must be withdrawn from service before
exceeding 5,280 flight cycles.

Alternative Methods of Compliance (AMOCs)

    (f) 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

    (g) Refer to EASA Airworthiness Directive 2008-0099, dated May
21, 2008 (corrected June 12, 2008), and Rolls-Royce plc Alert
Service Bulletin No. RB.211-72-AF825, Revision 1, dated September 8,
2008, for related information. Contact Rolls-Royce plc, PO Box 31,
Derby, England, DE248BJ; telephone: 011-44-1332-242424; fax: 011-44-
1332-245418, for a copy of this service information.
    (h) 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.

    Issued in Burlington, Massachusetts, on February 10, 2009.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. E9-3358 Filed 2-17-09; 8:45 am]

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