Document ID: FAA-2010-0364-0005
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Rolls-Royce plc RB211 Trent 700 and Trent 800 Series Turbofan Engines
Posted Date: 2010-09-24T04:00Z

[Federal Register: September 24, 2010 (Volume 75, Number 185)]
[Rules and Regulations]               
[Page 58290-58292]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr24se10-2]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0364; Directorate Identifier 2009-NE-27-AD; 
Amendment 39-16446; AD 2010-20-11]
RIN 2120-AA64

 
Airworthiness Directives; Rolls-Royce plc RB211 Trent 700 and 
Trent 800 Series 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 the 
products listed above. This 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:

    In completing a review of Engine Manual repair/acceptance limits 
for titanium compressor shafts, Rolls-Royce has found the specified 
limits to be incorrect such that the shot peened surface layer at 
life critical features (the axial dovetail slots) may have been 
inadvertently removed in-service. Removal of the shot peened layer 
results in increased vulnerability of the part to tensile stresses, 
which could reduce the life of the shaft to below the published life 
limits.

We are issuing this AD to prevent failure of the intermediate-pressure 
(IP) and high-pressure (HP) shaft, which could result in an overspeed 
condition, possible uncontained disc failure and damage to the 
airplane.

DATES: This AD becomes effective October 29, 2010.

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.

FOR FURTHER INFORMATION CONTACT: James Lawrence, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and 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:

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 April 7, 2010 (75 FR 
17630). That NPRM proposed to correct an unsafe condition for the 
specified products. The MCAI states:

    In completing a review of Engine Manual repair/acceptance limits 
for titanium compressor shafts, Rolls-Royce has found the specified 
limits to be incorrect such that the shot peened surface layer at 
life critical features (the axial dovetail slots) may have been 
inadvertently removed in-service. Removal of the shot peened layer 
results in increased vulnerability of the part to tensile stresses, 
which could reduce the life of the shaft to below the published life 
limits. The acceptable limits for material loss on these surfaces 
have now been corrected in the Engine Manual.
    This AD identifies shafts for which such dressing operations 
have been known to have been carried out and requires that an 
inspection for compliance with the corrected Engine Manual limits be 
accomplished and that the shafts be dispositioned accordingly.

[[Page 58291]]

Comments

    We reviewed the available data, including the comments received, 
and determined that air safety and the public interest require adopting 
the AD as proposed.
    We gave the public the opportunity to participate in developing 
this AD. We considered the comments received.

Requests To Change Paragraphs (e)(1) and (e)(2) of the Proposed AD

    Two commenters, The Boeing Company and American Airlines, ask us to 
change paragraphs (e)(1) and (e)(2) of the proposed AD to clarify the 
focused inspections and to include a reference to Rolls-Royce (RR) 
Alert Non-Modification Service Bulletin (NMSB) RB.211-72-AG086.
    The Boeing Company asks us to change paragraph (e)(2) to include a 
reference to RR Alert NMSB RB.211-72-AG086. They state that guidance on 
full-focused inspections and acceptance limits can be found in either 
the current applicable RR engine manual or RR Alert NMSB RB.211-72-
AG086. The Boeing Company feels that the information contained in the 
engine manual is not as clear or as accessible as in the RR Alert NMSB 
and that including the RR Alert NMSB, as an additional source of 
guidance, will assist the operators in conducting the associated 
inspections properly.
    We agree. We changed paragraph (e)(2) to include a reference to RR 
Alert NMSB RB.211-72-AG086.
    American Airlines, asks us to change paragraph (e)(1) to include a 
requirement for ``all applicable focus inspection subtasks of the IP 
and HP compressor shafts * * *'' American Airlines states that the 
Rolls-Royce Time Limits Manual and the applicable Engine Inspection 
Tasks do not use ``full-focused inspection'' terminology (as used in 
the NPRM). American Airlines believes that the AD terminology should be 
consistent with the manuals.
    We agree. We changed paragraph (e)(1) to state ``Perform a one-
time, piece-part, full inspection, including all applicable focus 
inspection Subtasks, of the IP and HP compressor shafts, listed by part 
number and serial number in Table 1 of this AD, before exceeding the 
compliance period specified in Table 1 of this AD.''

Conclusion

    We reviewed the available data, including the comment[s] 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

    Based on the service information, we estimate that this AD would 
affect about 12 products of U.S. registry. We also estimate that it 
would take about 8 work-hours per product to comply with this AD. The 
average labor rate is $85 per work-hour. Required parts would cost 
about $15,000 per product. Based on these figures, we estimate the cost 
of the AD on U.S. operators to be $188,160. 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 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); 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 AD and placed it in the AD docket.

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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

Adoption of the Amendment

0
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:

    2010-20-11 Rolls-Royce plc: Amendment 39-16446. Docket No. FAA-
2010-0364; Directorate Identifier 2009-NE-27-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective October 
29, 2010.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Rolls-Royce plc model (RR) RB211 Trent 
768-60, 772-60, 772B-60, 875-17, 877-17, 884-17, 884B-17, 892-17, 
892B-17, and 895-17 turbofan engines that have a compressor shaft 
listed by part number and serial number in Table 1 of this AD. These 
engines are installed on, but not limited to, Airbus A330 series and 
Boeing 777 series airplanes.

Reason

    (d) This AD results from a review of engine manual repair/
acceptance limits for titanium compressor shafts by RR. We are 
issuing this AD to prevent failure of the intermediate-pressure (IP) 
and high-pressure (HP) shaft, which could result in an overspeed 
condition, possible uncontained disc failure and damage to the 
airplane.

Actions and Compliance

    (e) Unless already done, do the following actions.
    (1) Perform a one-time, piece-part, full inspection, including 
all applicable focus

[[Page 58292]]

inspection Subtasks, of the IP and HP compressor shafts listed by 
part number and serial number in Table 1 of this AD before exceeding 
the compliance period specified in Table 1 of this AD.
    (2) Guidance on full and focused inspections and acceptance 
limits can be found in the current, applicable RR engine manual and 
RR Alert Non-Modification Service Bulletin (NMSB) RB.211-72-AG086.

                                                            Table 1--List of Affected Shafts
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                                                                                                                                       Compliance period
                                                                                                                                       (flight cycles in
             Engine series                    Affected component                   Part no.                   Shaft serial no.           service after
                                                                                                                                       December 4, 2008)
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Trent 800.............................  1-8 IP Compressor Shaft.......  FK24100                        MW0115238                                     750
Trent 800.............................  1-4 HP Compressor Shaft.......  FK32580                        MW0115512                                     750
Trent 800.............................  1-4 HP Compressor Shaft.......  FK32580                        MW0004708                                    2000
Trent 800.............................  1-4 HP Compressor Shaft.......  FK32580                        MW00063868                                   2500
Trent 800.............................  1-8 IP Compressor Shaft.......  FK24100                        DN65507                                      2500
Trent 800.............................  1-8 IP Compressor Shaft.......  FK24100                        DN65158                                      2500
Trent 800.............................  1-4 HP Compressor Shaft.......  FK32580                        MW0125467                                    3500
Trent 800.............................  1-4 HP Compressor Shaft.......  FW11590                        DN65189                                      3500
Trent 800.............................  1-8 IP Compressor Shaft.......  FK24100                        MW0091518                                    3500
Trent 800.............................  1-8 IP Compressor Shaft.......  FK24100                        MW0126365                                    3500
Trent 800.............................  1-8 IP Compressor Shaft.......  FK24100                        DN66422                                      4750
Trent 800.............................  1-8 IP Compressor Shaft.......  FK24100                        MW0203314                                    4750
Trent 700.............................  1-8 IP Compressor Shaft.......  FK22279                        DN63228                                      3250
Trent 700.............................  1-8 IP Compressor Shaft.......  FK26048                        MW0026046                                    4500
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Other FAA AD Provisions

    (f) Alternative Methods of Compliance (AMOCs): 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 MCAI EASA Airworthiness Directive 2009-0021 
(Corrected February 9, 2009), dated February 6, 2009, and RR Alert 
NMSB RB.211-72-AG086, for related information.
    (h) Contact James Lawrence, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and 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.

Material Incorporated by Reference

    (i) None.

    Issued in Burlington, Massachusetts, on September 17, 2010.
Robert J. Ganley,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2010-23831 Filed 9-23-10; 8:45 am]
BILLING CODE 4910-13-P