Document ID: FAA-2016-6744-0006
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Rolls-Royce plc Turbofan Engines
Posted Date: 2016-12-16T05:00Z

[Federal Register Volume 81, Number 242 (Friday, December 16, 2016)]
[Rules and Regulations]
[Pages 90974-90976]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-30065]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2016-6744; Directorate Identifier 2016-NE-12-AD; 
Amendment 39-18736; AD 2016-25-10]
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 certain 
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. This AD requires 
machining and inspecting parts related to the high-pressure compressor 
(HPC) and replacing HPC parts found defective. This AD was prompted by 
inspection of RR Trent 800 engines returned from service that revealed 
flame erosion and axial cracking on the stage 3 disk rim of the HPC 
stage 1-4 rotor disks shaft. We are issuing this AD to correct the 
unsafe condition on these products.

DATES: This AD becomes effective January 20, 2017.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of January 20, 
2017.

ADDRESSES: For service information identified in this final rule, 
contact Rolls-Royce plc, Corporate Communications, P.O. Box 31, Derby, 
England, DE24 8BJ; phone: 011-44-1332-242424; fax: 011-44-1332-249936; 
email: http://www.rolls-royce.com/contact/civil_team.jsp; Internet: 
https://customers.rolls-royce.com/public/rollsroycecare. You may view 
this service information at the FAA, Engine & Propeller Directorate, 
1200 District Avenue, Burlington, MA. For information on the 
availability of this material at the FAA, call 781-238-7125. It is also 
available on the Internet at http://www.regulations.gov by searching 
for and locating Docket No. FAA-2016-6744.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2016-
6744; 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 mandatory continuing airworthiness information 
(MCAI), 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: Robert Green, Aerospace Engineer, 
Engine Certification Office, FAA, Engine & Propeller Directorate, 1200 
District Avenue, Burlington, MA 01803; phone: 781-238-7754; fax: 781-
238-7199; email: robert.green@faa.gov.

SUPPLEMENTARY INFORMATION: 

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 by adding an AD that would apply to the specified products. The 
NPRM was published in the Federal Register on July 26, 2016 (81 FR 
48724). The NPRM proposed to correct an unsafe condition for the 
specified products. The MCAI states:

    Inspection of Trent 800 engines returned from service revealed 
flame eroded areas and axial cracking on the rear Stage 3 disc of 
the High Pressure Compressor (HPC) Stage 1-4 drum. This is 
considered to be the result of a localised fire originating from an 
excessive rub at the stage 3-4 forward seal fin.
    This condition, if not detected and corrected, could lead to an 
uncontained engine failure and release of high energy debris, 
possibly resulting in damage to the aeroplane and injury to 
occupants.

    You may obtain further information by examining the MCAI in the AD 
docket on the Internet at http://www.regulations.gov by searching for 
and locating Docket No. FAA-2016-6744.

Comments

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

Request To Revise Inspection for Wear and Cracks

    American Airlines, Inc., (AAL) requested that the requirement in 
paragraph (e)(1)(i) of this AD be revised

[[Page 90975]]

to allow the standards in the RR Trent 800 Engine Manual (EM) to be 
used in the assessment for wear and cracks. AAL indicated that RR Trent 
800 EM task 72-41-31-200-801 addresses the conditions of wear and 
cracking and provides limits and rejection criteria. AAL commented that 
RR has noted that the types of damage described in RR Standard 
Practices Manual 70-01-02-200-000 including the terms ``burned/
charred'' and ``eroded'' provide an adequate description of flame 
erosion.
    AAL further indicated that if, based on the proposed requirement in 
paragraph (e)(1)(ii) of this AD, any wear is found on the forward stage 
3-4 seal fin, then the HPC 1-4 rotor would have to be replaced. AAL 
noted, however, that EM task 72-41-31-200-801 allows the seal fin to 
exhibit wear within the diametral limits of 23.665 to 23.722 inches.
    RR indicated that the requirement in this AD to reject the part for 
evidence of wear should be eliminated. RR noted that the EM for the 
affected engines already includes inspections for wear and other 
damage.
    We partially agree. We agree with AAL's assessment that the EM task 
would allow wear as defined above while paragraph (e)(1)(i) in this AD, 
as proposed, would not have allowed any wear. We also agree with RR 
that it is not necessary to specify an inspection for wear.
    We disagree that it is necessary to refer to the EM task in the 
requirements of this AD. We have revised the requirements of this AD to 
remove the requirement to inspect for ``wear.'' We are removing this 
requirement because seal tooth wear serviceability limits are already 
defined in the RR Trent 800 EM.

Request To Revise Requirement to Machine HPC Stage 3 Inner Shroud

    RR and AAL requested that the requirement in paragraph (e)(1)(ii) 
of this AD to machine the HPC stage 3 inner shroud be revised. AAL 
noted that the HPC 1-4 disks shaft is a life-limited part; therefore, 
AAL tracks its cycle use, both total part cycles and cycles since last 
piece-part inspection. There is, however, no mandatory tracking 
requirement for the HPC stage 3 inner shroud. AAL, therefore, cannot 
ensure that it can comply with RR Service Bulletin (SB) RB211.72-J195, 
dated February 26, 2016, before exceeding 5,000 duty cycles since new 
or since last piece-part inspection of the HPC stage 1-4 rotor disks 
shaft, as proposed in this AD. AAL and RR suggested that the 
requirement in paragraph (e)(1)(ii) of this AD become an optional 
terminating action.
    We partially agree. We disagree with revising the requirement in 
paragraph (e)(1)(ii) in this AD to machine the HPC stage 1-3 shroud 
because that addresses the unsafe seal clearance condition. We agree, 
however, that the proposed language in paragraph (e)(1) may be 
misinterpreted to refer to tracking the cycles on the HPC stage 3 inner 
shroud. Therefore, we clarified paragraph (e)(1) of this AD to read: 
``(1) Before the HPC stage 1-4 rotor disks shaft cyclic life exceeds 
5,000 duty cycles since new, or 5,000 duty cycles since last HPC stage 
1-4 rotor disks shaft piece-part inspection, whichever occurs later, do 
the following: . . . .'' This change clarifies that the 5,000 duty 
cycles since new criterion in this AD applies only to the HPC stage 1-4 
rotor disks and not the HPC stage 3 inner shroud.

Support for the NPRM

    The Boeing Company, Inc., commented that it supported the proposed 
rule as written.

Conclusion

    We reviewed the available data, including the comments received, 
and determined that air safety and the public interest require adopting 
this 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 this AD.

Related Service Information Under 1 CFR Part 51

    RR has issued SB RB.211-72-J195, dated February 26, 2016. The SB 
describes procedures to machine the HPC stage 3 inner shroud and to 
inspect the HPC stage 1-4 rotor disks shaft. This service information 
is reasonably available because the interested parties have access to 
it through their normal course of business or by the means identified 
in the ADDRESSES section.

Costs of Compliance

    We estimate that this AD affects 125 engines installed on airplanes 
of U.S. registry. We did not estimate any time to machine the HPC stage 
3 inner shroud because this is accomplished during routine overhaul. We 
estimate the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Inspection of the HPC stage 1-4 rotor   8 work-hours x $85 per                $0            $680         $85,000
 disks.                                  hour = $680.
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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

[[Page 90976]]

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 adding the following new airworthiness 
directive (AD):

2016-25-10 Rolls-Royce plc: Amendment 39-18736; Docket No. FAA-2016-
6744; Directorate Identifier 2016-NE-12-AD.

(a) Effective Date

    This AD becomes effective January 20, 2017.

(b) Affected ADs

    None.

(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 that have not incorporated RR modification 72-J195, in 
production, or RR Service Bulletin RB.211-72-J195, dated February 
26, 2016, in service.

(d) Reason

    This AD was prompted by inspection of RR Trent 800 model engines 
returned from service that revealed flame erosion and axial cracking 
on the aft face of the stage 3 disk rim of the high-pressure 
compressor (HPC) stage 1-4 rotor disks shaft. We are issuing this AD 
to correct the unsafe condition on these products.

(e) Actions and Compliance

    Comply with this AD within the compliance times specified, 
unless already done.
    (1) Before the HPC stage 1-4 rotor disks shaft cyclic life 
exceeds 5,000 duty cycles since new, or 5,000 duty cycles since last 
HPC stage 1-4 rotor disks shaft piece-part inspection, whichever 
occurs later, do the following:
    (i) Perform fluorescent penetrant and visual inspections of the 
HPC stage 1-4 rotor disks shaft forward stage 3-4 seal fin and aft 
face of the stage 3 disk rim for cracks and flame erosion. Any 
findings of cracks or flame erosion constitute a failure of the HPC 
stage 1-4 rotor disks shaft.
    (ii) Machine the HPC stage 3 inner shroud to the dimensions 
shown in Figure 1 of RR Service Bulletin (SB) RB.211-72-J195, dated 
February 26, 2016.
    (2) If the HPC stage 1-4 rotor disks shaft fails the inspections 
required by paragraph (e)(1)(i) of this AD, replace with a part 
eligible for installation before further flight.

(f) 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. You may email your request to: ANE-AD-AMOC@faa.gov.

(g) Related Information

    (1) For more information about this AD, contact Robert Green, 
Aerospace Engineer, Engine Certification Office, FAA, Engine & 
Propeller Directorate, 1200 District Avenue, Burlington, MA 01803; 
phone: 781-238-7754; fax: 781-238-7199; email: robert.green@faa.gov.
    (2) Refer to MCAI European Aviation Safety Agency AD 2016-0078, 
dated April 20, 2016 (corrected April 27, 2016), for more 
information. You may examine the MCAI in the AD docket on the 
Internet at http://www.regulations.gov by searching for and locating 
it in Docket No. FAA-2016-6744.

(h) 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) SB RB.211-72-J195, dated February 26, 
2016.
    (ii) Reserved.
    (3) For RR service information identified in this AD, contact 
Rolls-Royce plc, Corporate Communications, P.O. Box 31, Derby, 
England, DE24 8BJ; phone: 011-44-1332-242424; fax: 011-44-1332-
249936; email: http://www.rolls-royce.com/contact/civil_team.jsp; 
Internet: https://customers.rolls-royce.com/public/rollsroycecare.
    (4) You may view this service information at FAA, Engine & 
Propeller Directorate, 1200 District Avenue, 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 November 23, 2016.
Colleen M. D'Alessandro,
Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2016-30065 Filed 12-15-16; 8:45 am]
 BILLING CODE 4910-13-P