[Federal Register Volume 78, Number 121 (Monday, June 24, 2013)]
[Rules and Regulations]
[Pages 37703-37706]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-14922]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-1327; Directorate Identifier 2012-NE-47-AD; 
Amendment 39-17478; AD 2013-12-01]
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 adopting a new airworthiness directive (AD) for all 
Rolls-Royce plc (RR) model RB211 Trent 768-60, 772-60, and 772B-60 
turbofan engines. This AD was prompted by low-pressure (LP) compressor 
blade partial airfoil release events. This AD requires a one-time 
ultrasonic inspection of LP compressor blades that had accumulated more 
than 2,500 flight cycles (FC) since new. We are issuing this AD to 
prevent LP compressor blade airfoil separations, engine damage, and 
damage to the airplane.

DATES: This AD becomes effective July 29, 2013. The Director of the 
Federal Register approved the incorporation by reference of certain 
publications listed in this AD as of July 29, 2013.

ADDRESSES: The Docket Operations office is located at Docket Management 
Facility, U.S. Department of Transportation, 1200 New Jersey Avenue 
SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-
0001.

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 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

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an AD that would apply to the specified products. 
That NPRM was published in the Federal Register on January 31, 2013 (78 
FR 6749). That NPRM proposed to require a one-time ultrasonic C-scan 
inspection of LP compressor blades that have accumulated more than 
2,500 FC since new. The European Aviation Safety Agency (EASA) 
subsequently superseded EASA AD 2012-0247, dated November 20, 2012, by 
issuing EASA AD 2013-0060, dated March 11, 2013, to include a re-
inspection requirement for certain LP compressor blades that were not 
inspected correctly.
    The new mandatory continuing airworthiness information (MCAI) 
states:

    Low-Pressure (LP) compressor partial aerofoil blade release 
events have occurred in service on RR Trent 700 engines. While 
primary containment of the released sections has been achieved in 
each case, some of the

[[Page 37704]]

releases did exhibit secondary effects that are considered to 
present a potential hazard. Previously, expeditious actions by RR 
have mitigated the risks presented by these effects, by removal from 
service of batches of LP compressor blades. However, some causal 
factors still exist that are not fully understood.
    This condition, if not detected and corrected, could lead to LP 
compressor blade release with possible consequent loss of the engine 
nose cowl, under cowl fires and forward projection of secondary 
debris, possibly resulting in damage to the aeroplane and/or injury 
to persons on the ground.
    To mitigate the risk of further partial fan blade release 
events, RR issued Non-Modification Service Bulletin (NMSB) RB.211-
72-G872, providing instructions for an ultrasonic inspection of the 
affected LP compressor blades to detect subsurface anomalies in the 
aerofoil and, depending on findings, replacement of LP compressor 
blades.
    To address this potential unsafe condition, EASA issued AD 2012-
0247 to require a one-time inspection of the affected LP compressor 
blades.
    Since that AD was issued, a population of LP compressor blades 
have been identified as incorrectly inspected and therefore require 
re-inspection. Consequently, RR issued NMSB RB.211-72-H311 to 
provide the instructions for this re-inspection.
    For the reason described above, this AD retains the requirements 
of EASA AD 2012-0247, which is superseded, and adds, for the 
affected group of LP compressor blades, a one-time re-inspection.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We considered the comments received.

Request To Change Summary

    RR requested that we change the Summary to state that the AD would 
require a one-time ultrasonic inspection of LP compressor blades 
(without being specific to C-scan). The reason for this request is that 
RR issued Revision 2 to NMSB RB.211-72-G872, dated March 8, 2013, which 
added phased array as an alternative ultrasonic technique to C-scan.
    We agree. We changed the AD Summary to state: ``This AD requires a 
one-time ultrasonic inspection of LP compressor blades that had . . .''

Request To Change Discussion

    RR requested that we change the Discussion to note that EASA AD 
2012-0247, dated November 20, 2012, was superseded by EASA AD 2013-
0060, dated March 11, 2013, which includes a re-inspection requirement 
for certain LP compressor blades that were not inspected correctly.
    We agree. We referenced EASA AD 2013-0060, dated March 11, 2013 in 
the Discussion and Related Information paragraphs of this AD.

Request To Change Relevant Service Information

    RR requested that the Relevant Service Information paragraph be 
changed because they issued NMSB RB.211-72-G872, Revision 2, dated 
March 8, 2013. This NMSB adds phased array ultrasonic inspection as an 
on-wing or in-shop alternative to the C-scan inspection technique. 
Also, because certain LP compressor blades were not inspected correctly 
in accordance with RR NMSB RB.211-72-G872, Revision 1, dated July 2, 
2012, RR issued NMSB RB.211-72-H311, dated March 8, 2013, to require 
re-inspection of blades identified by serial number (S/N). The 
accomplishment instructions and compliance period for NMSB RB.211-72-
H311, dated March 8, 2013, are identical to those of NMSB RB.211-72-
G872, Revision 2, dated March 8, 2013. Blades inspected to NMSB RB.211-
72-H311, dated March 8, 2013, do not then need inspection to NMSB 
RB.211-72-G872, Revision 2, dated March 8, 2013.
    We partially agree. We agree that RR updated its service 
information. We do not agree that the Relevant Service Information 
paragraph be changed, because that paragraph only exists in the 
proposed AD (78 FR 6749, January 31, 2013). We did not change the AD.

Request To Change AD Requirements Statement

    RR requested that we replace the requirements statement, of 
inspections specific to C-scan, with a statement requiring a one-time 
ultrasonic inspection of LP compressor blades (without being specific 
to C-scan).
    We agree. We changed the AD Summary to state that the AD requires a 
one-time ultrasonic inspection of LP compressor blades that had 
accumulated more than 2,500 FC since new.

Request To Change Compliance Time

    RR requested that the compliance time be changed from within 500 
FC, to within 500 FC or 10 months, whichever is earlier. RR stated that 
this change is necessary to ensure compliance within a reasonable 
period of time.
    We agree that a calendar end date is appropriate for AD management, 
and for that purpose, we agree 10 months is appropriate. We changed the 
AD to include the 10-month compliance end date.

Request To Change Actions and Compliance

    RR requested that paragraph (e) of the AD be changed to reflect the 
revised inspection methods issued in RR NMSB RB.211-72-G872, Revision 
2, dated March 8, 2013, to include a re-inspection requirement for 
certain blades provided by NMSB RB.211-72-H311, dated March 8, 2013, 
and to eliminate the requirement to remove the LP compressor blades. RR 
stated that these changes were needed because the revised inspections 
in their service information adds phased array ultrasonic inspection 
and on-wing inspection instructions. RR NMSB RB.211-72-H311 introduces 
a re-inspection requirement for blades that were previously inspected 
incorrectly. The on-wing phased array ultrasonic inspection added by 
NMSB RB.211-72-G872, Revision 2, dated March 8, 2013, and included in 
NMSB RB.211-72-H311, does not require removal of the blades from the 
engine for inspection.
    We agree. We changed paragraph (e) of this AD to state the 
following:
    For engines with LP compressor blades that have 2,500 FC or more 
since new or since last inspection using RR NMSB RB.211-72-G702, dated 
May 23, 2011, perform an ultrasonic inspection of each compressor blade 
within 500 FC or within 10 months after the effective date of this AD, 
whichever is sooner. Use paragraphs 3.C through 3.H of RR NMSB RB.211-
72-G872, Revision 2, dated March 8, 2013, to do the inspection. You may 
do the on-wing phased array ultrasonic inspection added by NMSB RB.211-
72-G872, and included in NMSB RB.211-72-H311, without removing the 
blades from the engine for the inspection.
    We added a Credit for Previous Actions paragraph (g) of this AD, 
which states that you may take credit for the ultrasonic C-scan 
inspection of each LP compressor blade if you performed the inspection 
before the effective date of this AD using RR NMSB RB.211-72-G872, 
dated April 3, 2012, or Revision 1, dated July 2, 2012.

Request To Change Actions and Compliance

    RR requested that the Actions and Compliance paragraph be changed 
from ``. . . do not install on an engine any LP compressor blade . . 
.'' to `` . . . do not install on an engine any replacement blade . . 
.''. RR stated that the purpose of this change was to avoid confusion 
in the case that the blades are removed for routine maintenance such as 
re-lubrication of the blade root.
    We partially agree. We agree that blades removed for routine on-
wing

[[Page 37705]]

maintenance such as the re-lubrication of the blade roots should not be 
subject to the installation prohibition if they are within the 
compliance period interval. We do not agree with the use of the word 
``replacement'' as it is ambiguous. We changed the Installation 
Prohibition paragraph (f) of this AD to read: ``After the effective 
date of this AD, do not install, on any engine, any LP compressor blade 
that has 2,500 FC or more since new or since last inspection using RR 
NMSB RB.211-72-G702, dated May 23, 2011, unless the LP compressor blade 
has passed the ultrasonic inspection required in paragraphs (e)(1) or 
(e)(2) of this AD. LP compressor blades that are removed for routine 
on-wing maintenance such as blade root re-lubrication that will 
subsequently be reassembled into the engine are not subject to this 
Installation Prohibition.''

Conclusion

    We reviewed the available data, including the comments received, 
and determined that air safety and the public interest require adopting 
the AD with the changes described previously. We determined that these 
changes will not increase the economic burden on any operator or 
increase the scope of the AD.

Costs of Compliance

    We estimate that this AD will affect 56 engines installed on 
airplanes of U.S. registry. We also estimate that it will take about 38 
hours per engine to comply with this AD. The average labor rate is $85 
per hour. Based on these figures, we estimate the cost of the AD on 
U.S. operators to be $180,880.

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),
    (3) Will not affect intrastate aviation in Alaska to the extent 
that it justifies making a regulatory distinction, 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.
    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, 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:

2013-12-01 Rolls-Royce plc: Amendment 39-17478; Docket No. FAA-2012-
1327; Directorate Identifier 2012-NE-47-AD.

(a) Effective Date

    This airworthiness directive (AD) becomes effective July 29, 
2013.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all Rolls-Royce plc (RR) model RB211 Trent 
768-60, 772-60, and 772B-60 turbofan engines.

(d) Reason

    This AD was prompted by low-pressure (LP) compressor blade 
partial airfoil release events. We are issuing this AD to prevent LP 
compressor blade airfoil separations, engine damage, and damage to 
the airplane.

(e) Actions and Compliance

    Unless already done, do the following actions.

(1) Inspection of LP Compressor Blade On-Wing or In-Shop

    (i) For engines with LP compressor blades that have 2,500 flight 
cycles (FC) or more since new or since last inspection using RR Non-
Mandatory Service Bulletin (NMSB) RB.211-72-G702, dated May 23, 
2011, perform an ultrasonic inspection of each LP compressor blade 
within 500 FC or within 10 months after the effective date of this 
AD, whichever is sooner.
    (ii) Use paragraphs 3.C through 3.H of the Accomplishment 
Instructions of RR NMSB RB.211-72-G872, Revision 2, dated March 8, 
2013, to do the inspection.
    (iii) You may do the on-wing phased array ultrasonic inspection 
added by NMSB RB.211-72-G872, Revision 2, dated March 8, 2013, and 
included in NMSB RB.211-72-H311, without removing the blades from 
the engine for the inspection.

(2) Re-Inspection of LP Compressor Blade Identified by Serial Number 
(S/N)

    (i) For engines with LP compressor blades installed and 
identified by S/N in Appendix 1 of RR NMSB RB.211-72-H311, dated 
March 8, 2013, and that have, on the effective date of this AD, 
accumulated 2,500 FC since new or since last inspection using RR 
NMSB RB.211-72-G702, dated May 23, 2011, perform an ultrasonic 
inspection of each LP compressor blade.
    (ii) The inspection, either on-wing or in-shop, must be 
performed within 500 FC or 10 months, whichever is sooner, after the 
effective date of this AD.
    (iii) Use paragraphs 3.C through 3.H of the Accomplishment 
Instructions of RR NMSB RB.211-72-H311, dated March 8, 2013, to do 
the inspection.

(f) Installation Prohibition

    (1) After the effective date of this AD, do not install, on any 
engine, any LP compressor blade that has 2,500 FC or more since new 
or since last inspection using RR NMSB RB.211-72-G702, dated May 23, 
2011, unless the LP compressor blade has passed the ultrasonic 
inspection required in paragraphs (e)(1) or (e)(2) of this AD.
    (2) LP compressor blades that are removed for routine on-wing 
maintenance such as blade root re-lubrication that will subsequently 
be reassembled into the engine are not subject to this Installation 
Prohibition.

(g) Credit for Previous Actions

    You may take credit for the ultrasonic C-scan inspection of each 
compressor blade if you performed the inspection before the 
effective date of this AD using RR NMSB RB.211-72-G872, dated April 
3, 2012, or Revision 1, dated July 2, 2012.

[[Page 37706]]

(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 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) European Aviation Safety Agency AD 2013-0060, dated March 
11, 2013, pertains to the subject of this AD. You may examine this 
AD on the Internet at http://ad.easa.europa.eu/ad/2013-0060.
    (3) RR Non-Mandatory Service Bulletin (NMSB) RB.211-72-G702, 
dated May 23, 2011, which is not incorporated by reference in this 
AD, can be obtained from Rolls-Royce plc using the contact 
information in paragraph (j)(3) of this AD.

(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 Non-Modification Service Bulletin RB.211-72-
H311, dated March 8, 2013.
    (ii) Rolls-Royce plc Non-Modification Service Bulletin RB.211-
72-G872, Revision 2, dated March 8, 2013.
    (3) For Rolls-Royce plc service information identified in this 
AD, contact Rolls-Royce plc, P.O. Box 31, Derby DE24 8BJ, UK; phone: 
44 (0) 1332 242424; fax: 44 (0) 1332 249936.
    (4) You may view this service information at 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 June 5, 2013.
Colleen M. D'Alessandro,
Assistant Manager, Engine & Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2013-14922 Filed 6-21-13; 8:45 am]
BILLING CODE 4910-13-P