[Federal Register Volume 75, Number 185 (Friday, September 24, 2010)]
[Rules and Regulations]
[Pages 58290-58292]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-23831]
=======================================================================
-----------------------------------------------------------------------
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.
-----------------------------------------------------------------------
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:
[email protected]; 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
--------------------------------------------------------------------------------------------------------------------------------------------------------
Compliance period
(flight cycles in
Engine series Affected component Part no. Shaft serial no. service after
December 4, 2008)
--------------------------------------------------------------------------------------------------------------------------------------------------------
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
--------------------------------------------------------------------------------------------------------------------------------------------------------
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:
[email protected]; 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