Airworthiness Directives; Rolls-Royce plc Turbofan Engines

[Federal Register Volume 77, Number 185 (Monday, September 24, 2012)]
[Rules and Regulations]
[Pages 58762-58765]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-23442]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0821; Directorate Identifier 2010-NE-30-AD; 
Amendment 39-17183; AD 2012-18-07]
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 superseding an existing airworthiness directive (AD) 
for all Rolls-Royce plc (RR) RB211-Trent 875-17, RB211-Trent 877-17, 
RB211-Trent 884-17, RB211-Trent 884B-17, RB211-Trent 892-17, RB211-
Trent 892B-17, and RB211-Trent 895-17 turbofan engines. That AD 
currently requires initial and repetitive ultrasonic inspections (UIs) 
of certain low-pressure (LP) compressor blades identified by serial 
number (S/N). This new AD requires the same actions but expands the 
population of blades. This AD was prompted by the need to add the 
inspections of the LP compressor blades listed by S/N in Appendices 3H 
through 3L of RR plc Alert Service Bulletin (ASB) No. RB.211-72-AG244, 
Revision 4, dated December 22, 2011. We are issuing this AD to prevent 
multiple LP compressor blades from failing due to blade root cracks, 
which could lead to uncontained engine failure and damage to the 
airplane.

DATES: This AD is effective October 29, 2012.
    The Director of the Federal Register approved the incorporation by 
reference

[[Page 58763]]

of a certain publication listed in the AD as of October 29, 2012.

ADDRESSES: 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. 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 Management Facility 
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 address for the 
Docket Office (phone: 800-647-5527) is Document Management Facility, 
U.S. Department of Transportation, Docket Operations, M-30, West 
Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., 
Washington, DC 20590.

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 supersede AD 2012-06-23 (77 FR 20508, April 5, 2012). That 
AD applies to the specified products. The NPRM published in the Federal 
Register on May 3, 2012 (77 FR 26216). That NPRM proposed to continue 
to require initial and repetitive UIs of certain LP compressor blades 
identified by S/N. This AD requires the same actions but expands the 
population of blades.

Comments

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

Request To Modify Initial Inspection Thresholds

    Commenters RR and The Boeing Company (Boeing) requested that the 
initial inspection thresholds listed in Table 1 of the proposed AD be 
the same as those in RR ASB RB.211-72-AG244. Alternatively, RR and 
Boeing asked that we adjust the calendar months after the effective 
date of the AD to make them equivalent to the calendar dates in the 
ASB. RR claims that allowing parts to remain on wing longer than the 
times specified in the ASB will increase the risk of a fan blade 
failure before a crack is detected.
    We do not agree. The number of months for compliance after the 
effective date of this AD is the same as in the EASA AD 2012-0025, 
dated February 8, 2012. Also, shortening the initial inspection 
thresholds now would require renotice and therefore delay 
implementation of the AD. We did not change the AD.

Request To Revise Unsafe Condition Statement

    RR asked that we change the unsafe condition statement in the AD to 
indicate that the AD is being issued to prevent multiple blades from 
the same engine from failing. RR indicated that this change is needed 
because a single blade failure from the root is, by design, a contained 
event.
    We agree because multiple blades in an engine may develop cracks 
and fail if not inspected. We changed the AD by revising the unsafe 
condition statement in paragraph (d) of the AD from: ``We are issuing 
this AD to prevent LP compressor blades from failing due to blade root 
cracks, which could lead to uncontained engine failure and damage to 
the airplane'' to ``We are issuing this AD to prevent multiple LP 
compressor blades from failing due to blade root cracks, which could 
lead to uncontained engine failure and damage to the airplane.''

Request To Revise Compliance Paragraph (e)(3)

    Commenter American Airlines (American) requested that we change 
paragraph (e)(3) from ``* * * and paragraphs 1. through 3.B. of 
Appendix 1 of that ASB, or paragraphs 3.B.(1) through 3.B.(3) of 
Accomplishment Instructions of RR ASB No. RB.211-72-AG244 * * *,'' to 
``* * * and paragraphs 1. through 3.B. of Appendix 1 of that ASB, or 
paragraph 3.B.(3) of Accomplishment Instructions of RR ASB No. RB.211-
72-AG244 * * *.''. American argued that paragraphs 3.B.(1) and 3.B.(2), 
which require removal of the air intake fairing/spinner and spinner 
extension and annulus fillers, are not needed to resolve the unsafe 
condition noted in the AD.
    We agree in part. We agree to remove the references to paragraphs 
3.B.(1) and 3.B.(2) from the AD because it is not necessary to mandate 
the procedures used to remove the air intake fairing/spinner and 
spinner extension and annulus fillers. We disagree that removal of 
these parts does not need to be mentioned in the AD because these parts 
need to be removed before performing the UI. We therefore revised 
paragraph (e)(3) in the AD from: ``Use paragraph 3.A.(2) of 
Accomplishment Instructions of RR ASB No. RB.211-72-AG244, Revision 4, 
dated December 22, 2011, and paragraphs 1. through 3.B. of Appendix 1 
of that ASB, or paragraphs 3.B.(1) through 3.B.(3) of Accomplishment 
Instructions of RR ASB No. RB.211-72-AG244, Revision 4, dated December 
22, 2011, and paragraphs 1. through 3.C. of Appendix 2 of that ASB, to 
perform the UIs.'' to ``Use paragraph 3.A.(2) of Accomplishment 
Instructions of RR ASB No. RB.211-72-AG244, Revision 4, dated December 
22, 2011, and paragraphs 1. through 3.B. of Appendix 1 of that ASB, or 
paragraphs 3.B.(3) of Accomplishment Instructions of RR ASB No. RB.211-
72-AG244, Revision 4, dated December 22, 2011, and paragraphs 1. 
through 3.C. of Appendix 2 of that ASB, to perform the UIs. Prior to 
inspecting the blades per paragraph 3.B.(3) of the Accomplishment 
Instructions remove the air intake fairing/spinner and spinner 
extension and annulus fillers.''

Request To Revise Compliance Paragraph (e)(6)

    American requested that paragraph (e)(6) of the AD be revised to 
read: ``After the effective date of this AD, do not install any 
affected LP compressor blade that has reached the initial inspection 
threshold in Table 1, unless it has passed the UI required by this 
AD.'' American indicated that the wording of the proposed AD implied 
that if a blade fails a visual inspection, it may not be reinstalled 
even if it passes a subsequent UI.
    We agree. We revised the paragraph to read: ``After the effective 
date of this AD, do not install any affected LP compressor blade that 
has reached the initial inspection threshold in Table 1 to paragraph 
(e), unless it has passed the UI required by this AD.'' We also moved 
this paragraph to a separate Installation Prohibition paragraph (f).

Request To Revise Previous Credit Paragraph

    American asked that the AD allow compressor blades inspected 
ultrasonically before the effective date

[[Page 58764]]

of this AD using RR SB RB.211-72-E175, Revision 7, dated April 11, 
2011, to be installed without further inspection. American indicated 
that the UI instructions in SB RB.211-E175, Revision 7, are identical 
to the UI instructions in ASB RB.211-72-AG244.
    We agree. We changed the Credit for Previous Actions paragraph in 
the AD from, ``You may take credit for the initial inspection that is 
required by paragraph (e)(1) of this AD if you performed the initial 
inspection before the effective date of this AD using RR ASB No. 
RB.211-72-AG244, dated August 7, 2009; ASB No. RB.211-72-AG244, 
Revision 1, dated January 26, 2010; ASB No. RB.211-72-AG244, Revision 
2, dated August 18, 2011; or ASB No. RB.211-72-AG244, Revision 3, dated 
December 13, 2011,'' to ``You may take credit for the initial 
inspection that is required by paragraph (e)(1) of this AD if you 
performed the initial inspection before the effective date of this AD 
using RR ASB No. RB.211-72-AG244, dated August 7, 2009; ASB No. RB.211-
72-AG244, Revision 1, dated January 26, 2010; ASB No. RB.211-72-AG244, 
Revision 2, dated August 18, 2011, ASB No. RB.211-72-AG244, Revision 3, 
dated December 13, 2011 or RB.211-72-E175, Revision 7, dated April 11, 
2011.''

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
the AD with the changes described previously. We also determined that 
these changes will not increase the economic burden on any operator nor 
increase the scope of the AD.

Costs of Compliance

    Based on the service information, we estimate that this AD affects 
about 158 engines installed on airplanes of U.S. registry. We also 
estimate that it will take about 3 hours per engine inspection and six 
inspections will be needed per year. The average labor rate is $85 per 
work-hour. We estimate that one LP compressor blade per year will need 
replacement at a cost of about $82,000. Based on these figures, we 
estimate the annual cost of the AD on U.S. operators to be $323,740. 
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 have 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 that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) 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.

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 removing airworthiness directive (AD) 
2012-06-23, Amendment 39-17004 (77 FR 20508, April 5, 2012), and adding 
the following new AD:

2012-18-07 Rolls-Royce plc: Amendment 39-17183; Docket No. FAA-2010-
0821; Directorate Identifier 2010-NE-30-AD.

(a) Effective Date

    This airworthiness directive (AD) is effective October 29, 2012.

(b) Affected ADs

    This AD supersedes AD 2012-06-23 (77 FR 20508, April 5, 2012).

(c) Applicability

    This AD applies to Rolls-Royce plc (RR) RB211-Trent 875-17, 
RB211-Trent 877-17, RB211-Trent 884-17, RB211-Trent 884B-17, RB211-
Trent 892-17, RB211-Trent 892B-17, and RB211-Trent 895-17 turbofan 
engines.

(d) Unsafe Condition

    This AD was prompted by the need to add the inspections of the 
low-pressure (LP) compressor blades listed by serial number (S/N) in 
Appendices 3H through 3L of Rolls-Royce plc Alert Service Bulletin 
(ASB) No. RB.211-72-AG244, Revision 4, dated December 22, 2011. We 
are issuing this AD to prevent multiple LP compressor blades from 
failing due to blade root cracks, which could lead to uncontained 
engine failure and damage to the airplane.

(e) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.
    (1) Perform an initial ultrasonic inspection (UI) of the 
affected LP compressor blades identified by S/N in Appendices 3A 
through 3L of RR ASB No. RB.211-72-AG244, Revision 4, dated December 
22, 2011. Use Table 1 to paragraph (e) of this AD to determine your 
initial inspection threshold.

         Table 1 to Paragraph (e)--Initial Inspection Thresholds
------------------------------------------------------------------------
Appendix number of RR ASB Number RB.211-
 72-AG244, Revision 4, that identifies
  affected LP compressor blades by S/N     Initial inspection threshold
 
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3A and 3B..............................  Within 70 flight cycles after
                                          the effective date of this AD.
3C.....................................  Within 10 months after the
                                          effective date of this AD.
3D.....................................  Within 22 months after the
                                          effective date of this AD.
3E.....................................  Within 34 months after the
                                          effective date of this AD.
3F.....................................  Within 46 months after the
                                          effective date of this AD.

[[Page 58765]]

 
3G.....................................  Within 58 months after the
                                          effective date of this AD.
3H.....................................  Within 70 months after the
                                          effective date of this AD.
3I.....................................  Within 82 months after the
                                          effective date of this AD.
3J.....................................  Within 94 months after the
                                          effective date of this AD.
3K.....................................  Within 106 months after the
                                          effective date of this AD.
3L.....................................  Within 118 months after the
                                          effective date of this AD.
------------------------------------------------------------------------

    (2) Thereafter, perform repetitive UIs of the affected LP 
compressor blades within every 100 flight cycles.
    (3) Use paragraph 3.A.(2) of Accomplishment Instructions of RR 
ASB No. RB.211-72-AG244, Revision 4, dated December 22, 2011, and 
paragraphs 1. through 3.B. of Appendix 1 of that ASB, or paragraphs 
3.B.(3) of Accomplishment Instructions of RR ASB No. RB.211-72-
AG244, Revision 4, dated December 22, 2011, and paragraphs 1. 
through 3.C. of Appendix 2 of that ASB, to perform the UIs. Prior to 
inspecting the blades per paragraph 3.B.(3) of the Accomplishment 
Instructions remove the air intake fairing/spinner and spinner 
extension and annulus fillers.
    (4) Do not return to service any engine with blades that failed 
the inspection required by this AD.
    (5) For blades that are removed from the engine and pass 
inspection, re-apply dry film lubricant before re-installing the 
blades.

(f) Installation Prohibition

    After the effective date of this AD, do not install any affected 
LP compressor blade that has reached the initial inspection 
threshold in Table 1 to paragraph (e) of this AD, unless it has 
passed the UI required by this AD.

(g) Credit for Previous Actions

    You may take credit for the initial inspection that is required 
by paragraph (e)(1) of this AD if you performed the initial 
inspection before the effective date of this AD using RR ASB No. 
RB.211-72-AG244, dated August 7, 2009; RR ASB No. RB.211-72-AG244, 
Revision 1, dated January 26, 2010; RR ASB No. RB.211-72-AG244, 
Revision 2, dated August 18, 2011; RR ASB No. RB.211-72-AG244, 
Revision 3, dated December 13, 2011; or RR RB.211-72-E175, Revision 
7, dated April 11, 2011.

(h) Alternative Methods of Compliance (AMOCs)

    The Manager, Engine Certification Office, FAA, 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 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) Refer to European Aviation Safety Agency AD 2012-0025, dated 
February 8, 2012, for related information.

(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 Alert Service Bulletin No. RB.211-72-AG244, 
Revision 4, including appendices 1, 2, and 3A through 3L, dated 
December 22, 2011.
    (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; email: http://www.rolls-royce.com/contact/civil_team.jsp.
    (4) You may view this service information at the 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 August 29, 2012.
Colleen M. D'Alessandro,
Assistant Manager, Engine & Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2012-23442 Filed 9-21-12; 8:45 am]
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