Airworthiness Directives; Rolls-Royce plc (RR) RB211-535 Series Turbofan Engines, 30529-30531 [2011-13014]

Download as PDF srobinson on DSK4SPTVN1PROD with RULES Federal Register / Vol. 76, No. 102 / Thursday, May 26, 2011 / Rules and Regulations mode that is shown to be a stable limit cycle oscillation (LCO), with the system operative and inoperative. (An LCO is considered ‘‘stable’’ if it maintains the same frequency and amplitude for a given excitation input and flight condition.) In addition, the type of sustained oscillation covered by these special conditions must not be a hazard to the airplane nor its occupants with the active system failed. These systems must be shown to reduce the amplitude of the sustained oscillation to acceptable levels and effectively control the aeroelastic instability. Specifically, the following criteria address the existence of such a sustained oscillation on the Boeing Model 747–8/–8F airplanes and the Outboard Aileron Modal Suppression (OAMS) system that will be used to control it. 2. In lieu of the requirements contained in § 25.629, the existence of a sustained, or limit cycle, oscillation that is controlled by an active flight control system is acceptable, provided that the following requirements are met: (a) OAMS System Inoperative: The sustained, or limit cycle, oscillation must be shown by test and analysis to be stable throughout the nominal aeroelastic stability envelope specified in § 25.629(b)(1) with the OAMS system inoperative. This should include the consideration of disturbances above the sustained amplitude of oscillation. (b) Nominal Conditions: (1) With the OAMS system operative it must be shown that the airplane remains safe, stable, and controllable throughout the nominal aeroelastic stability envelope specified in § 25.629(b)(1) by providing adequate suppression of the aeroelastic modes being controlled. All applicable airworthiness and environmental requirements should continue to be complied with. Additionally, loads imposed on the airplane due to any amplitude of oscillation must be shown to have a negligible impact on structure and systems, including wear, fatigue and damage tolerance. The OAMS system must function properly in all environments that may be encountered. (2) The applicant must establish by test and analysis that the OAMS system can be relied upon to control and limit the sustained amplitude of the oscillation to acceptable levels (per § 25.251) and control the stability of the aeroelastic mode. This should include the consideration of disturbances above the sustained amplitude of oscillation; maneuvering flight, icing conditions; manufacturing variations; Master Minimum Equipment List (MMEL) items; spare engine carriage; engine removed or inoperative ferry flights; and VerDate Mar<15>2010 16:14 May 25, 2011 Jkt 223001 wear, repairs, and modifications throughout the service life of the airplane by: (i) Analysis to the nominal aeroelastic stability envelope specified in § 25.629(b)(1), and (ii) Flight flutter test to the VDF/MDF boundary. These tests must demonstrate that the airplane has a proper margin of damping for disturbances above the sustained amplitude of oscillation at all speeds up to VDF/MDF, and that there is no large and rapid reduction in damping as VDF/MDF is approached. (iii) The structural modes must have adequate stability margins for any OAMS flight control system feedback loop at speeds up to the fail-safe aeroelastic stability envelope specified in § 25.629(b)(2). (c) Failures, Malfunctions, and Adverse Conditions: (1) For the OAMS system operative and failed, for any failure, or combination of failures not shown to be extremely improbable, and addressed by §§ 25.629(d), 25.571, 25.631, 25.671, 25.672, 25.901(c) or 25.1309 that results in LCO, it must be established by test or analysis up to the aeroelastic stability envelope specified in § 25.629(b)(2) that the LCO: (i) Is stable and decays to an acceptable limited amplitude once an external perturbing force is removed; (ii) Does not result in loads that would cause static, dynamic, or fatigue failure of structure during the expected exposure period; (iii) Does not result in repeated loads that would cause an additional failure due to wear during the expected exposure period that precludes safe flight and landing; (iv) Has, if necessary, sufficient indication of OAMS failure(s) and crew procedures to properly address the failure(s); (v) Does not result in a vibration condition on the flight deck that is severe enough to interfere with control of the airplane, ability of the crew to read the flight instruments, perform vital functions like reading and accomplishing checklist procedures, or to cause excessive fatigue to the crew; (vi) Does not result in adverse effects on the flight control system or on airplane stability, controllability, or handling characteristics (including airplane-pilot coupling (APC) per § 25.143) that would prevent safe flight and landing; and (vii) does not interfere with the flight crew’s ability to correctly distinguish vibration from buffeting associated with the recognition of stalls or high speed buffet. PO 00000 Frm 00021 Fmt 4700 Sfmt 4700 30529 (2) The applicant must show that particular risks such as engine failure, uncontained engine, or APU rotor burst, or other failures not shown to be extremely improbable, will not adversely or significantly change the aeroelastic stability characteristics of the airplane. (3) No MMEL dispatch is allowed with the OAMS system inoperative. Issued in Renton, Washington, on May 20, 2011. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 2011–13022 Filed 5–25–11; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2010–0994; Directorate Identifier 2009–NE–39–AD; Amendment 39– 16707; AD 2011–11–08] RIN 2120–AA64 Airworthiness Directives; Rolls-Royce plc (RR) RB211–535 Series Turbofan Engines Federal Aviation Administration (FAA), DOT. ACTION: Final rule. AGENCY: 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: SUMMARY: There have been several findings of cracking at the firtrees of LP Turbine discs. Fatigue crack initiation and subsequent crack propagation at the firtree may result in multiple LP Turbine blade release. The latter may potentially be beyond the containment capabilities of the engine casings. Thus, cracking at the firtrees of LP Turbine discs constitutes a potentially unsafe condition. We are issuing this AD to detect cracks in the low-pressure (LP) turbine stage 1, 2, and 3 discs, which could result in an uncontained release of LP turbine blades and damage to the airplane. DATES: This AD becomes effective June 30, 2011. ADDRESSES: The Docket Operations office is located at Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, SE., West Building Ground E:\FR\FM\26MYR1.SGM 26MYR1 30530 Federal Register / Vol. 76, No. 102 / Thursday, May 26, 2011 / Rules and Regulations Floor, Room W12–140, Washington, DC 20590–0001. FOR FURTHER INFORMATION CONTACT: Frederick Zink, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: frederick.zink@faa.gov; telephone (781) 238–7779; 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 October 5, 2010 (75 FR 61361). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI states: There have been several findings of cracking at the firtrees of LP Turbine discs. Fatigue crack initiation and subsequent crack propagation at the firtree may result in multiple LP Turbine blade release. The latter may potentially be beyond the containment capabilities of the engine casings. Thus, cracking at the firtrees of LP Turbine discs constitutes a potentially unsafe condition. Therefore this Airworthiness Directive requires a change to the inspection intervals of LP Turbine Discs. Comments We gave the public the opportunity to participate in developing this AD. We considered the comments received. Request To Change Related Information Paragraph One commenter, Rolls-Royce plc asked us to use a different statement for Rolls-Royce contact information in paragraph (i) of the proposed AD. RollsRoyce is concerned that responses to requests for information will be delayed if the statement is not clear on how to request information on service bulletins. We partially agree. Paragraph (i) is now paragraph (j) of this AD, and we have changed paragraph (j) of the AD to supply the relevant contact information. srobinson on DSK4SPTVN1PROD with RULES Support for the Proposed AD as Written Two commenters, Continental Airlines and The Boeing Company support the proposed AD as written. Request To Change the Definition of a Shop Visit Three commenters, FedEx, American Airlines, and Rolls-Royce plc asked us to change the definition of a shop visit to the definition in the Rolls-Royce Alert Service Bulletin (ASB) RB.211– 72–AG272,’’at every engine refurbishment and at every 04 and 05 Module Level 3 (Refurbishment) or VerDate Mar<15>2010 16:14 May 25, 2011 Jkt 223001 Level 4 (Overhaul) shop visit.’’ The commenters believed that the proposed AD definition of a shop visit is too conservative and will result in unnecessarily increased costs without a significant improvement in safety. We partially agree. We agree that the current definition in the proposed AD is too broad because inspecting the LP turbine disks every time an unrelated major flange is separated is not required. We disagree with using the definition in the service bulletin because the service bulletin definition is not sufficient for our needs. We changed paragraph (f) of the proposed AD to ‘‘For the purpose of this AD, an ‘‘engine shop visit’’ is the induction of an engine into the shop for maintenance involving the separation of the intermediate-pressure/low-pressure (IP/LP) turbine module from the engine, separation of the IP turbine case from the combustion outer case, or separation of the LP turbine case from the IP turbine case, except that the separation of engine flanges solely for the purposes of transportation without subsequent engine maintenance does not constitute an engine shop visit.’’ Request To Clarify the Compliance Time One commenter, American Airlines, asked us to clarify the compliance time in paragraph (e)(1) of the proposed AD to state that for engines currently in the shop on the effective date of the AD, the initial inspection is to be carried out if the affected parts are exposed and rebuild has not yet started. The commenter believed that the proposed AD is unclear as to whether engines which have begun their shop visits prior to the effective date of the AD are required to undergo the initial inspection before re-introduction into service. We agree. Engines currently in the shop at piece part exposure or in a condition prior to, must comply with the AD before any approval for return to service. Engines built up beyond this point will not require compliance with the AD until the next piece part exposure. Engines that are in the shop and have been approved for return to service are considered not to be in the shop. We changed paragraph (f) of the proposed AD to clarify a shop visit. Request To Change the Initial Inspection Requirements One commenter, American Airlines, asked us to change the initial inspection requirements in paragraph (e)(1) of the proposed AD to specify ‘‘paragraphs 3.C through 3.E.’’ in ASB RR.211–72– AG272, instead of ‘‘Section 3.’’ The commenter believed that only Section PO 00000 Frm 00022 Fmt 4700 Sfmt 4700 3.C. through 3.E. address the unsafe condition. We partially agree. The ASB we reference in paragraph (e)(1) of the proposed AD is not incorporated by reference, so requiring operators to follow specific paragraphs in the ASB is unnecessary. We agree, however, that including the reference may induce confusion. We deleted the reference from the proposed AD. Request To Change the Costs of Compliance One commenter, American Airlines, asked us to change the Costs of Compliance Section of the proposed AD. American Airlines stated the number of 90 products installed on U.S. registered airplanes and the number of work-hours for performing the inspections are incorrect. American Airlines stated that they operate more RB211–535 engines than the number listed in the proposed AD. American Airlines also stated that ASB RB.211– 72–AG272 lists the total hour for accomplishing the required actions as 70 work-hours. American Airlines requests that the AD reflect the workhours required as 70 work-hours if limited to refurbishment shop visits. If non-refurbishment shop visits are included, American Airlines estimates the average work-hours at 1,300 hours per shop visit. We partially agree. As of July 9, 2010, 588 installed engines were on U.S. registered airplanes. We changed the Costs of Compliance Section from ‘‘90 products of U.S. registry’’ to ‘‘588 products of U.S. registry.’’ We also changed the ‘‘cost of the AD on U.S. operators’’ from $229,500 to $1,499,400. We don’t agree with the request to change the time to comply if performed during non-refurbishment shop visits. We base the number of hours in the cost estimate on performing the inspection during the next shop visit as defined in this AD. We made no change to the AD. 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 scope of the AD. Costs of Compliance Based on the service information, we estimate that this AD would affect about 588 products installed on airplanes of U.S. registry. We also estimate that it would take about 30 work-hours per product to comply with this AD. The average labor rate is $85 per work-hour. E:\FR\FM\26MYR1.SGM 26MYR1 Federal Register / Vol. 76, No. 102 / Thursday, May 26, 2011 / Rules and Regulations Required parts would cost about $0 per product. Based on these figures, we estimate the cost of the AD on U.S. operators to be $1,499,400. available in the AD docket shortly after receipt. 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. Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. srobinson on DSK4SPTVN1PROD with RULES 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 https:// 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 VerDate Mar<15>2010 16:14 May 25, 2011 Jkt 223001 List of Subjects in 14 CFR Part 39 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 1. The authority citation for part 39 continues to read as follows: ■ Authority: 49 U.S.C. 106(g), 40113, 44701. § 39.13 [Amended] 2. The FAA amends § 39.13 by adding the following new AD: ■ 2011–11–08 Rolls-Royce plc: Amendment 39–16707. Docket No. FAA–2010–0994; Directorate Identifier 2009–NE–39–AD. Effective Date (a) This airworthiness directive (AD) becomes effective June 30, 2011. Affected ADs (b) None. Applicability (c) This AD applies to Rolls-Royce plc RB211–535E4–37, –535E4–B–37, –535E4–B– 75, and –535E4–C–37 turbofan engines. These engines are installed on, but not limited to, Boeing 757–200 series, –200PF series, –200CB series, and –300 series airplanes and Tupolev Tu204 series airplanes. Reason (d) This AD results from several findings of cracking at the firtrees of low-pressure (LP) turbine discs. Fatigue crack initiation and subsequent crack propagation at the firtree may result in multiple LP turbine blade release. We are issuing this AD to detect cracks in the LP turbine stage 1, 2, and 3 discs, which could result in an uncontained release of LP turbine blades and damage to the airplane. Actions and Compliance (e) Unless already done, do the following actions. Initial Inspection Requirements (1) At the next engine shop visit after the effective date of this AD, perform a visual and a fluorescent penetrant inspection (FPI) of the LP turbine stage 1, 2, and 3 disc. Repeat Inspection Requirements (2) At each engine shop visit after accumulating 1,500 cycles since the last inspection of the LP turbine stage 1, 2 and 3 discs, repeat the inspections specified in paragraph (e)(1) of this AD. PO 00000 Frm 00023 Fmt 4700 Sfmt 9990 30531 Remove Cracked Discs (3) If you find cracks, remove the disc from service. Definitions (f) For the purpose of this AD, an ‘‘engine shop visit’’ is: (1) Induction of an engine into the shop for maintenance involving the separation of the intermediate-pressure/low-pressure (IP/LP) turbine module from the engine, or (2) Separation of the IP turbine case from the combustion outer case, or (3) Separation of the LP turbine case from the IP turbine case, except that the separation of engine flanges solely for the purposes of transportation without subsequent engine maintenance does not constitute an engine shop visit. (g) Engines that have been approved for return to service but are still physically in the shop are not considered to be in the shop. FAA AD Differences (h) This AD differs from the Mandatory Continuing Airworthiness Information (MCAI) and or service information as follows in that while the MCAI compliance requires action at a current shop visit, this AD requires compliance at the next shop visit after the effective date of this AD. Other FAA AD Provisions (i) 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 (j) Refer to MCAI European Aviation Safety Agency Airworthiness Directive 2009–0244, dated November 9, 2009, and Rolls-Royce plc Alert Service Bulletin No. RB.211–72–AG272 for related information. Contact Rolls-Royce plc., P.O. Box 31, Derby, DE24 8BJ, United Kingdom; phone: 011 44 1332 242424, fax: 011 44 1332 249936; or e-mail from:https:// www.rollsroyce.com/contact/civil_team.jsp, for a copy of this service information or download the publication from https:// www.aeromanager.com. (k) Contact Frederick Zink, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: frederick.zink@faa.gov; telephone (781) 238–7779; fax (781) 238– 7199, for more information about this AD. Material Incorporated by Reference (l) None. Issued in Burlington, Massachusetts, on May 20, 2011. Peter A. White, Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. 2011–13014 Filed 5–25–11; 8:45 am] BILLING CODE 4910–13–P E:\FR\FM\26MYR1.SGM 26MYR1

Agencies

[Federal Register Volume 76, Number 102 (Thursday, May 26, 2011)]
[Rules and Regulations]
[Pages 30529-30531]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-13014]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0994; Directorate Identifier 2009-NE-39-AD; 
Amendment 39-16707; AD 2011-11-08]
RIN 2120-AA64


Airworthiness Directives; Rolls-Royce plc (RR) RB211-535 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:

    There have been several findings of cracking at the firtrees of 
LP Turbine discs. Fatigue crack initiation and subsequent crack 
propagation at the firtree may result in multiple LP Turbine blade 
release. The latter may potentially be beyond the containment 
capabilities of the engine casings. Thus, cracking at the firtrees 
of LP Turbine discs constitutes a potentially unsafe condition.

We are issuing this AD to detect cracks in the low-pressure (LP) 
turbine stage 1, 2, and 3 discs, which could result in an uncontained 
release of LP turbine blades and damage to the airplane.

DATES: This AD becomes effective June 30, 2011.

ADDRESSES: The Docket Operations office is located at Docket Management 
Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, 
SE., West Building Ground

[[Page 30530]]

Floor, Room W12-140, Washington, DC 20590-0001.

FOR FURTHER INFORMATION CONTACT: Frederick Zink, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803; e-mail: 
frederick.zink@faa.gov; telephone (781) 238-7779; 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 October 5, 2010 (75 
FR 61361). That NPRM proposed to correct an unsafe condition for the 
specified products. The MCAI states:

    There have been several findings of cracking at the firtrees of 
LP Turbine discs. Fatigue crack initiation and subsequent crack 
propagation at the firtree may result in multiple LP Turbine blade 
release. The latter may potentially be beyond the containment 
capabilities of the engine casings. Thus, cracking at the firtrees 
of LP Turbine discs constitutes a potentially unsafe condition.
    Therefore this Airworthiness Directive requires a change to the 
inspection intervals of LP Turbine Discs.

Comments

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

Request To Change Related Information Paragraph

    One commenter, Rolls-Royce plc asked us to use a different 
statement for Rolls-Royce contact information in paragraph (i) of the 
proposed AD. Rolls-Royce is concerned that responses to requests for 
information will be delayed if the statement is not clear on how to 
request information on service bulletins.
    We partially agree. Paragraph (i) is now paragraph (j) of this AD, 
and we have changed paragraph (j) of the AD to supply the relevant 
contact information.

Support for the Proposed AD as Written

    Two commenters, Continental Airlines and The Boeing Company support 
the proposed AD as written.

Request To Change the Definition of a Shop Visit

    Three commenters, FedEx, American Airlines, and Rolls-Royce plc 
asked us to change the definition of a shop visit to the definition in 
the Rolls-Royce Alert Service Bulletin (ASB) RB.211-72-AG272,''at every 
engine refurbishment and at every 04 and 05 Module Level 3 
(Refurbishment) or Level 4 (Overhaul) shop visit.'' The commenters 
believed that the proposed AD definition of a shop visit is too 
conservative and will result in unnecessarily increased costs without a 
significant improvement in safety.
    We partially agree. We agree that the current definition in the 
proposed AD is too broad because inspecting the LP turbine disks every 
time an unrelated major flange is separated is not required. We 
disagree with using the definition in the service bulletin because the 
service bulletin definition is not sufficient for our needs. We changed 
paragraph (f) of the proposed AD to ``For the purpose of this AD, an 
``engine shop visit'' is the induction of an engine into the shop for 
maintenance involving the separation of the intermediate-pressure/low-
pressure (IP/LP) turbine module from the engine, separation of the IP 
turbine case from the combustion outer case, or separation of the LP 
turbine case from the IP turbine case, except that the separation of 
engine flanges solely for the purposes of transportation without 
subsequent engine maintenance does not constitute an engine shop 
visit.''

Request To Clarify the Compliance Time

    One commenter, American Airlines, asked us to clarify the 
compliance time in paragraph (e)(1) of the proposed AD to state that 
for engines currently in the shop on the effective date of the AD, the 
initial inspection is to be carried out if the affected parts are 
exposed and rebuild has not yet started. The commenter believed that 
the proposed AD is unclear as to whether engines which have begun their 
shop visits prior to the effective date of the AD are required to 
undergo the initial inspection before re-introduction into service.
    We agree. Engines currently in the shop at piece part exposure or 
in a condition prior to, must comply with the AD before any approval 
for return to service. Engines built up beyond this point will not 
require compliance with the AD until the next piece part exposure. 
Engines that are in the shop and have been approved for return to 
service are considered not to be in the shop. We changed paragraph (f) 
of the proposed AD to clarify a shop visit.

Request To Change the Initial Inspection Requirements

    One commenter, American Airlines, asked us to change the initial 
inspection requirements in paragraph (e)(1) of the proposed AD to 
specify ``paragraphs 3.C through 3.E.'' in ASB RR.211-72-AG272, instead 
of ``Section 3.'' The commenter believed that only Section 3.C. through 
3.E. address the unsafe condition.
    We partially agree. The ASB we reference in paragraph (e)(1) of the 
proposed AD is not incorporated by reference, so requiring operators to 
follow specific paragraphs in the ASB is unnecessary. We agree, 
however, that including the reference may induce confusion. We deleted 
the reference from the proposed AD.

Request To Change the Costs of Compliance

    One commenter, American Airlines, asked us to change the Costs of 
Compliance Section of the proposed AD. American Airlines stated the 
number of 90 products installed on U.S. registered airplanes and the 
number of work-hours for performing the inspections are incorrect. 
American Airlines stated that they operate more RB211-535 engines than 
the number listed in the proposed AD. American Airlines also stated 
that ASB RB.211-72-AG272 lists the total hour for accomplishing the 
required actions as 70 work-hours. American Airlines requests that the 
AD reflect the work-hours required as 70 work-hours if limited to 
refurbishment shop visits. If non-refurbishment shop visits are 
included, American Airlines estimates the average work-hours at 1,300 
hours per shop visit.
    We partially agree. As of July 9, 2010, 588 installed engines were 
on U.S. registered airplanes. We changed the Costs of Compliance 
Section from ``90 products of U.S. registry'' to ``588 products of U.S. 
registry.'' We also changed the ``cost of the AD on U.S. operators'' 
from $229,500 to $1,499,400.
    We don't agree with the request to change the time to comply if 
performed during non-refurbishment shop visits. We base the number of 
hours in the cost estimate on performing the inspection during the next 
shop visit as defined in this AD. We made no change to the AD.

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 scope of the AD.

Costs of Compliance

    Based on the service information, we estimate that this AD would 
affect about 588 products installed on airplanes of U.S. registry. We 
also estimate that it would take about 30 work-hours per product to 
comply with this AD. The average labor rate is $85 per work-hour.

[[Page 30531]]

Required parts would cost about $0 per product. Based on these figures, 
we estimate the cost of the AD on U.S. operators to be $1,499,400.

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 https://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, 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:

2011-11-08 Rolls-Royce plc: Amendment 39-16707. Docket No. FAA-2010-
0994; Directorate Identifier 2009-NE-39-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective June 30, 
2011.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Rolls-Royce plc RB211-535E4-37, -535E4-B-
37, -535E4-B-75, and -535E4-C-37 turbofan engines. These engines are 
installed on, but not limited to, Boeing 757-200 series, -200PF 
series, -200CB series, and -300 series airplanes and Tupolev Tu204 
series airplanes.

Reason

    (d) This AD results from several findings of cracking at the 
firtrees of low-pressure (LP) turbine discs. Fatigue crack 
initiation and subsequent crack propagation at the firtree may 
result in multiple LP turbine blade release. We are issuing this AD 
to detect cracks in the LP turbine stage 1, 2, and 3 discs, which 
could result in an uncontained release of LP turbine blades and 
damage to the airplane.

Actions and Compliance

    (e) Unless already done, do the following actions.

Initial Inspection Requirements

    (1) At the next engine shop visit after the effective date of 
this AD, perform a visual and a fluorescent penetrant inspection 
(FPI) of the LP turbine stage 1, 2, and 3 disc.

Repeat Inspection Requirements

    (2) At each engine shop visit after accumulating 1,500 cycles 
since the last inspection of the LP turbine stage 1, 2 and 3 discs, 
repeat the inspections specified in paragraph (e)(1) of this AD.

Remove Cracked Discs

    (3) If you find cracks, remove the disc from service.

Definitions

    (f) For the purpose of this AD, an ``engine shop visit'' is:
    (1) Induction of an engine into the shop for maintenance 
involving the separation of the intermediate-pressure/low-pressure 
(IP/LP) turbine module from the engine, or
    (2) Separation of the IP turbine case from the combustion outer 
case, or
    (3) Separation of the LP turbine case from the IP turbine case, 
except that the separation of engine flanges solely for the purposes 
of transportation without subsequent engine maintenance does not 
constitute an engine shop visit.
    (g) Engines that have been approved for return to service but 
are still physically in the shop are not considered to be in the 
shop.

FAA AD Differences

    (h) This AD differs from the Mandatory Continuing Airworthiness 
Information (MCAI) and or service information as follows in that 
while the MCAI compliance requires action at a current shop visit, 
this AD requires compliance at the next shop visit after the 
effective date of this AD.

Other FAA AD Provisions

    (i) 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

    (j) Refer to MCAI European Aviation Safety Agency Airworthiness 
Directive 2009-0244, dated November 9, 2009, and Rolls-Royce plc 
Alert Service Bulletin No. RB.211-72-AG272 for related information. 
Contact Rolls-Royce plc., P.O. Box 31, Derby, DE24 8BJ, United 
Kingdom; phone: 011 44 1332 242424, fax: 011 44 1332 249936; or e-
mail from:https://www.rollsroyce.com/contact/civil_team.jsp, for a 
copy of this service information or download the publication from 
https://www.aeromanager.com.
    (k) Contact Frederick Zink, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; e-mail: 
frederick.zink@faa.gov; telephone (781) 238-7779; fax (781) 238-
7199, for more information about this AD.

Material Incorporated by Reference

    (l) None.

    Issued in Burlington, Massachusetts, on May 20, 2011.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2011-13014 Filed 5-25-11; 8:45 am]
BILLING CODE 4910-13-P
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