Document ID: FAA-2008-1165-0007
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Rolls-Royce plc RB211-Trent 800 Series Turbofan Engines
Posted Date: 2010-10-04T04:00Z

[Federal Register: October 4, 2010 (Volume 75, Number 191)]
[Proposed Rules]               
[Page 61114-61116]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr04oc10-10]                         

========================================================================
Proposed Rules
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains notices to the public of 
the proposed issuance of rules and regulations. The purpose of these 
notices is to give interested persons an opportunity to participate in 
the rule making prior to the adoption of the final rules.

========================================================================

[[Page 61114]]

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: Supplemental notice of proposed rulemaking (NPRM); reopening of 
comment period.

-----------------------------------------------------------------------

SUMMARY: This supplemental NPRM revises an earlier proposed 
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 was therefore necessary to reduce the life limit.

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 
failure of the HP compressor stage 1 disc, uncontained engine failure, 
and damage to the airplane.

DATES: We must receive comments on this proposed AD by November 18, 
2010.

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.
    Contact Rolls-Royce plc, P.O. Box 31, Derby, England, DE248BJ; 
telephone: 011-44-1332-242424; fax: 011-44-1332-245418 for the service 
information identified in this proposed AD.

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 (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: 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: 

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

    This supplemental NPRM revises an earlier proposed AD, for Rolls-
Royce plc RB211-Trent 800 series turbofan engines. That proposed AD 
would have required 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. That proposed AD resulted from MCAI issued by 
an aviation authority of another country. This supplemental NPRM 
revises the proposed AD to correct certain life limits for the Heavy 
Flight Profile Parts. We are proposing this supplemental NPRM to 
prevent failure of the HP compressor stage 1 disc, uncontained engine 
failure, and damage to the airplane. The European Aviation Safety 
Agency (EASA), which is the Technical Agent for the Member States of 
the European Community, has issued MCAI AD 2010-0087, date May 5, 2010 
(corrected, May 6, 2010), to correct an unsafe condition for the 
specified products. The MCAI states:

    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.

Since we issued the original proposed AD on February 10, 2009 (74 FR 
7563, February 18, 2009):

     EASA issued AD 2010-0087, dated May 5, 2010, and AD 2010-
0087 (corrected May 6, 2010) to correct certain life limits for the 
Heavy Flight Profile Parts.

[[Page 61115]]

     EASA issued AD 2010-0087, dated May 5, 2010 (corrected May 
6, 2010), which retains certain requirements of superseded EASA AD 
2008-0099, and imposes more restrictive life limits in the Heavy Flight 
Profile Parts.

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

Comments

    We provided the public the opportunity to participate in the 
development of the original proposed AD. We considered the comments 
received.

NPRM Would Allow a Part To Go Beyond the Current Time Limits Manual 
(TLM) Limit

    One commenter, Delta Airlines through the Airline Transport 
Association (ATA), states that the NPRM would require a 5,280 cycle 
life limit established in the long term for shafts that are used in the 
``Heavy Flight Profile''. In the draw down period from the initial 
effective date, the NPRM would allow a shaft in the ``Heavy Flight 
Profile'' category to remain in service for up to 7,480 flight cycles 
in the worst case scenario. However, the existing TLM Section 05-10-01-
800-802, Subtask 05-10-01-860-169 (dated March 15, 2008) states that 
the current declared life limit for HP compressor stage 1-4 shaft, P/N 
FK32580, is only 6,850 flight cycles. The NPRM would allow a part to go 
beyond the current TLM limit in the interim draw down period which 
seems to contradict the intent of the NPRM.
    We agree. We changed the supplemental NPRM to use the correct life 
limit reduction.

Allow Later Approved Revisions of the Alert Service Bulletin (ASB) as 
Acceptable for Compliance

    One commenter, American Airlines through the ATA, states that 
subsequent to the writing of the NPRM, Rolls-Royce plc published 
Revision 2 of ASB No. RB.211-72-AF825. The commenter requests that the 
AD should include language that allows later approved revisions of the 
ASB as acceptable for compliance.
    We partially agree. We agree that our ADs should be as current and 
accurate as possible. We changed the AD to include the reference to ASB 
Revision 3 in the related information paragraph.
    We disagree that the NPRM, or this supplemental NPRM, require the 
use of the ASB for compliance, or that we should permit an unknown 
future revision be used for compliance. Since we do not know the 
content of later documents like ASBs, we do not issue a regulation that 
mandates compliance with the unknown. We did not change the proposed AD 
to permit compliance to unknown future revisions.

Request To Change the Base-Lined Compliance Time in the AD

    One commenter, Rolls-Royce plc, states that their SB compliance 
time is base-lined from May 1, 2008. The FAA NPRM is understood to 
permit the same cyclic draw down as the SB. However, the baseline date 
for the applicable draw down would be the issue date of the FAA AD. 
Rolls-Royce plc requests that we change the base-lined compliance time 
in the proposed AD to the compliance base line in the RR SB.
    We do not agree. We cannot pre-date the compliance times in the 
proposed AD. We did not change the AD.

Differences Between This Proposed AD and the MCAI

    We have reviewed the MCAI and, in general, agree with its 
substance. But we have found it necessary to not incorporate the June 
4, 2008 compliance date which is in EASA AD 2010-0087, dated May 5, 
2010 (corrected May 6, 2010). We updated the compliance times in the 
proposed AD based on a more recent assessment of the unsafe condition.

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, as 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.

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:

[[Page 61116]]

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 November 18, 2010.

Affected Airworthiness Directives (ADs)

    (b) None.

Applicability

    (c) This AD applies to Rolls-Royce plc (RR) models 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 2010-0087, dated 
May 5, 2010 (corrected May 6, 2010) 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 was therefore necessary to reduce the life limit.

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 failure of 
the HP compressor stage 1 disc, uncontained engine failure, and 
damage to the airplane.

Actions and Compliance

    (e) Unless already done, do the following actions.

Multiple Flight Profile Monitoring Parts

    (1) For RB211-Trent 800 engines being monitored by ``Multiple 
Flight Profile Monitoring,'' remove the HP compressor stage 1-4 
shaft, P/N FK32580, before accumulating 5,580 standard duty cycles 
(SDC) since-new or within 960 SDC from the effective date of this 
AD, whichever occurs later.

Heavy Flight Profile Parts

    (2) For RB211-Trent 800 engines being monitored by ``Heavy 
Flight Profile,'' remove the HP compressor stage 1-4 shaft, P/N 
FK32580, before accumulating 5,280 flight cycles since new or within 
860 flight cycles from the effective data of this AD, whichever 
occurs later.

FAA Differences

    (f) We have found it necessary to not incorporate the June 4, 
2008 compliance date which is in EASA AD 2010-0087, dated May 5, 
2010 (corrected May 6, 2010). We also updated the compliance times 
in the AD based on a more recent assessment of the unsafe condition.

Alternative Methods of Compliance (AMOCs)

    (g) 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 EASA Airworthiness Directive 2010-0087, dated May 
5, 2010 (corrected May 6, 2010), and Rolls-Royce plc Alert Service 
Bulletin No. RB.211-72-AF825, Revision 3, dated August 25, 2009 for 
related information. Contact Rolls-Royce plc, P.O. Box 31, Derby, 
England, DE248BJ; telephone: 011-44-1332-242424; fax: 011-44-1332-
245418, for a copy of this service 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.

    Issued in Burlington, Massachusetts on September 27, 2010.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2010-24745 Filed 10-1-10; 8:45 am]
BILLING CODE 4910-13-P