Airworthiness Directives; Rolls-Royce Corporation Models 250-C30, 250-C40, and 250-C47 Series Turboshaft Engines, 56864-56866 [06-8230]

Download as PDF 56864 Federal Register / Vol. 71, No. 188 / Thursday, September 28, 2006 / Rules and Regulations TABLE 1.—CREDIT SERVICE BULLETINS Revision level Service bulletin Boeing Boeing Boeing Boeing Service Service Service Service Bulletin Bulletin Bulletin Bulletin 747–53A2409 747–53A2409 747–53A2409 747–53A2409 .................................................................................................................... .................................................................................................................... .................................................................................................................... .................................................................................................................... jlentini on PROD1PC65 with RULES Alternative Methods of Compliance (AMOCs) (k)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19. (2) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards Certificate Holding District Office. (3) AMOCs approved previously in accordance with AD 96–23–02, are approved as AMOCs for the corresponding provisions of paragraph (f) of this AD, except AMOCs for terminating action based upon inspection results using a sliding probe low frequency eddy current (LFEC), sliding probe high frequency eddy current (HFEC), or mid frequency surface eddy current (MFEC) inspection methods; and provided that any alternative method for future inspections did not incorporate a sliding probe LFEC, sliding probe HFEC, or MFEC inspection methods. (4) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD, if it is approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane and the approval must specifically refer to this AD. Material Incorporated by Reference (l) You must use Boeing Alert Service Bulletin 747–53A2409, dated September 26, 1996; or Boeing Alert Service Bulletin 747– 53A2409, Revision 5, dated August 18, 2005, as applicable, to perform the actions that are required by this AD, unless the AD specifies otherwise. (1) The Director of the Federal Register approved the incorporation by reference of Boeing Alert Service Bulletin 747–53A2409, Revision 5, dated August 18, 2005, in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. (2) On November 27, 1996 (61 FR 57994, November 12, 1996), the Director of the Federal Register approved the incorporation by reference of Boeing Alert Service Bulletin 747–53A2409, dated September 26, 1996. (3) Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124– 2207, for a copy of this service information. You may review copies at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Room PL–401, Nassif Building, Washington, DC; on the Internet at https://dms.dot.gov; or VerDate Aug<31>2005 17:21 Sep 27, 2006 Jkt 208001 at the National Archives and Records Administration (NARA). For information on the availability of this material at the NARA, call (202) 741–6030, or go to https:// www.archives.gov/federal_register/code_of_ federal_regulations/ibr_locations.html. Issued in Renton, Washington, on September 14, 2006. Kalene C. Yanamura, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 06–8227 Filed 9–27–06; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2005–23392; Directorate Identifier 2005–NE–47–AD; Amendment 39– 14776; AD 2006–20–07] RIN 2120–AA64 Airworthiness Directives; Rolls-Royce Corporation Models 250–C30, 250–C40, and 250–C47 Series Turboshaft Engines Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Final rule. AGENCY: SUMMARY: The FAA is adopting a new airworthiness directive (AD) for RollsRoyce Corporation (RRC) models 250– C30, 250–40, and 250–C47 series turboshaft engines with a third-stage turbine wheel, part number (P/N) 6898663 or P/N 23065843 installed, or a fourth-stage turbine wheel, P/N 6892764 or P/N 23066744, installed. This AD adds an additional life limit for third- and fourth-stage turbine wheels. This AD results from analysis by RRC of failures of third-stage turbine wheels. We are issuing this AD to prevent loss of power, possible engine shutdown, or uncontained engine failure. DATES: This AD becomes effective November 2, 2006. The Director of the Federal Register approved the incorporation by reference of certain publications listed in the regulations as of November 2, 2006. PO 00000 Frm 00012 Fmt 4700 Sfmt 4700 1 2 3 4 Date May 29, 1997. August 6, 1998. October 22, 1998. February 17, 2000. You can get the service information identified in this AD from Rolls-Royce Corporation, P.O. Box 420, Indianapolis, IN 46206–0420; telephone (317) 230–6400; fax (317) 230–4243. You may examine the AD docket on the Internet at https://dms.dot.gov or in Room PL–401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC. FOR FURTHER INFORMATION CONTACT: John Tallarovic, Aerospace Engineer, Chicago Aircraft Certification Office, FAA, 2300 East Devon Avenue, Des Plaines, IL 60018–4696; telephone (847) 294–8180; fax (847) 294–7834. SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39 with a proposed AD. The proposed AD applies to RRC models 250–C30, 250– 40, and 250–C47 series turboshaft engines. We published the proposed AD in the Federal Register on January 25, 2006 (71 FR 4065). That action proposed to add an additional life limit for thirdand fourth-stage turbine wheels. ADDRESSES: Examining the AD Docket You may examine the docket that contains the AD, any comments received, and any final disposition in person at the Docket Management Facility Docket Office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone (800) 647–5227) is located on the plaza level of the Department of Transportation Nassif Building at the street address stated in ADDRESSES. Comments will be available in the AD docket shortly after the DMS receives them. Comments We provided the public the opportunity to participate in the development of this AD. We have considered the comments received. Request to Correct Factual Errors One commenter, RRC, requests that we correct factual errors in the NPRM and revise the Discussion paragraph, to state that: • Only third-stage turbine wheels actually failed in the past; and • Only the third-stage turbine wheel (not the third-and-fourth-stage turbine E:\FR\FM\28SER1.SGM 28SER1 Federal Register / Vol. 71, No. 188 / Thursday, September 28, 2006 / Rules and Regulations jlentini on PROD1PC65 with RULES wheels) could prematurely fail if operated too many times in the transient overspeed region. We agree with these factual corrections. We changed the AD by removing certain references to the fourth-stage turbine wheel and changing the AD to state that it results from analysis by RRC of failures of third-stage turbine wheels. Final Rule Should Include the LowerSpeed Avoidance Range A private citizen states that the final rule should include the lower-speed avoidance range (68.4% to 87.1%) in addition to the high-speed transient range, when counting speed excursions and retiring turbine wheels. The commenter gave three reasons for the request: First, that operation in the lowerspeed avoidance range probably does more cumulative damage to the turbine wheel than operation in the high-speed excursion range. The commenter bases this on data that he claims shows higher stress levels at the low-speed transient range compared to the high-speed transient range. Second, the fact that the engine control unit does not record operation in the low-speed avoid range, emphasizes the importance to inform operators about the danger of cumulative damage. Third, the current commercial engine bulletin gives no information about cumulative damage in the low-speed avoid range. The commenter states that currently there is no warning to operators of the potential damage to turbine wheels operated for any length of time in the avoid range which may cause more cumulative damage than high-speed excursions. We do not agree. The supporting data the commenter provided includes information from a manufacturer development configuration that does not represent the current production configuration. The data also does not represent the manufacturer’s current, more detailed, knowledge of the stresses on the turbine airfoils. Transients in the low-speed range do not need to be tracked and used to retire turbine wheels. The low-speed range from 22,000 rpm to 28,045 rpm is a speed range that is normally passed through transiently, during the start up and shutdown procedures. The rate of speed change during the start up or shutdown is high enough that no significant time is spent at any resonant speed and no significant dynamic stresses are encountered that would lead to damage. In comparison to the low-speed excursions, if an operational situation VerDate Aug<31>2005 17:21 Sep 27, 2006 Jkt 208001 occurs that results in a speed excursion above the maximum continuous speed, the rate of change of speed goes from positive to negative as it accelerates up to the maximum speed before returning back to the continuous operating range. During this transition, speed may hold close to constant, or only change very slowly, for a number of seconds. In this case, there could be sufficient time for the dynamic stresses to build to their full resonant values and potentially cause some level of damage to a turbine wheel. This difference between a fast acceleration or deceleration through a resonant speed, and a potential slow motion or hold in a resonant speed is why counting of occurrences in the low speed range is unnecessary. Finally, the inclusion of a specific ‘‘steady state operation prohibited’’ speed avoid zone denotes that failure could occur if operation outside of the defined continuous operating range was performed. RRC SB No. CEB A–72– 3272, CEB A–72–5048, and CEB A–72– 6054 (combined in one document), all Revision 2, dated June 27, 2006, clearly instruct operators to avoid the lowspeed region. As stated above, this speed range is not of concern for normal transient operation of the engine. We did not change the AD. Conclusion We have carefully 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 have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD. Costs of Compliance We estimate that this AD will affect 1,300 engines installed on airplanes of U.S. registry. We also estimate that it will take about 42 work-hours per engine to replace the third- and fourthstage turbine wheels, and that the average labor rate is $65 per work-hour. Required parts will cost about $25,000 per engine. We estimate that only 10% of all turbine wheel replacements will result from operators exceeding the new transient overspeed event limits. Based on these figures, we estimate the total potential maximum cost of the AD to U.S. operators to be $3,604,900. 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 PO 00000 Frm 00013 Fmt 4700 Sfmt 4700 56865 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 have 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 that this AD: (1) Is not a ‘‘significant regulatory action’’ under Executive Order 12866; (2) Is not a ‘‘significant rule’’ under 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 summary of the costs to comply with this AD and placed it in the AD Docket. You may get a copy of this summary at the address listed under ADDRESSES. 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 Federal Aviation Administration amends 14 CFR part 39 as follows: I PART 39—AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: I Authority: 49 U.S.C. 106(g), 40113, 44701. § 39.13 [Amended] 2. The FAA amends § 39.13 by adding the following new airworthiness directive: I E:\FR\FM\28SER1.SGM 28SER1 56866 Federal Register / Vol. 71, No. 188 / Thursday, September 28, 2006 / Rules and Regulations 2006–20–07 Rolls-Royce Corporation (formerly Allison Engine Company, Allison Gas Turbine Division, and Detroit Diesel Allison): Amendment 39– 14776. Docket No. FAA–2005–23392; Directorate Identifier 2005–NE–47–AD. Effective Date (a) This airworthiness directive (AD) becomes effective November 2, 2006. Affected ADs (b) None. Applicability (c) This AD applies to Rolls-Royce Corporation (RRC) models 250–C30, –C30G, –C30G/2, –C30M, –C30P, –C30R, –C30R/1, –C30R/3, –C30R/3M, –C30S, –C30U, –C40B, –C47B, and –C47M turboshaft engines, with a third-stage turbine wheel, part number (P/N) 6898663 or P/N 23065843 installed, or a fourth-stage turbine wheel, P/N 6892764 or P/N 23066744, installed. These engines are installed on, but not limited to, Bell 206L– 3, Bell 206L–4, Bell 230, Bell 407, Bell 430, MDHI 369F, MDHI 369FF, MDHI 600N, and Sikorsky S–76A helicopters. Unsafe Condition (d) This AD results from analysis by RRC of failures of third-stage turbine wheels. We are issuing this AD to prevent loss of power, possible engine shutdown, or uncontained failure. Compliance (e) You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done. (f) Within 30 days after the effective date of this AD, record each time the third- and fourth-stage turbine wheels enter into the speed range between ‘‘Event Threshold’’ and ‘‘Maximum Overspeed Transient’’. Use paragraph 2.A. through 2.A.(5) of the Accomplishment Instructions and the applicable Figures 1 through 5 of RRC Alert Commercial Engine Bulletins (CEBs) No. CEB A–72–3272, No. CEB A–72–5048, and No. CEB A–72–6054 (combined in one document), all Revision 2, dated June 27, 2006, to determine the speed range. (g) Remove and retire any third-stage turbine wheel or fourth-stage turbine wheel after the sixth time the wheel enters into the speed range between ‘‘Event Threshold’’ and ‘‘Maximum Overspeed Transient’’. jlentini on PROD1PC65 with RULES Third- and Fourth-Stage Turbine Wheel Life Limits (h) The retirement criteria in this AD are in addition to the existing third- and fourthstage turbine wheel hour and cycle life limits. You must retire the wheels when you exceed any published life limit (transient speed excursions, hours, or cycles). Alternative Methods of Compliance (i) The Manager, Chicago Aircraft Certification Office, has the authority to approve alternative methods of compliance for this AD if requested using the procedures found in 14 CFR 39.19. Related Information (j) None. VerDate Aug<31>2005 17:21 Sep 27, 2006 Jkt 208001 Material Incorporated by Reference (k) You must use Rolls-Royce Corporation Alert Commercial Engine Bulletins No. CEB A–72–3272, No. CEB A–72–5048, and No. CEB A–72–6054 (combined in one document), all Revision 2, dated June 27, 2006, to perform the actions required by this AD. The Director of the Federal Register approved the incorporation by reference of this service bulletin in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Rolls-Royce Corporation, P.O. Box 420, Indianapolis, IN 46206–0420; telephone (317) 230–6400; fax (317) 230–4243 for a copy of this service information. You may review copies at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA; or 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: https:// www.archives.gov/federal-register/cfr/ibrlocations.html. Issued in Burlington, Massachusetts, on September 20, 2006. Francis A. Favara, Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. 06–8230 Filed 9–27–06; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 520 Oral Dosage Form New Animal Drugs; Neomycin AGENCY: Food and Drug Administration, HHS. ACTION: Final rule. SUMMARY: The Food and Drug Administration (FDA) is amending the animal drug regulations to reflect approval of an abbreviated new animal drug application (ANADA) filed by Sparhawk Laboratories, Inc. The ANADA provides for use of neomycin sulfate soluble powder in livestock for the treatment and control of bacterial enteritis. This rule is effective September 28, 2006. FOR FURTHER INFORMATION CONTACT: John K. Harshman, Center for Veterinary Medicine (HFV–104), Food and Drug Administration, 7500 Standish Pl., Rockville, MD 20855, 301–827–0169, email: john.harshman@fda.hhs.gov. SUPPLEMENTARY INFORMATION: Sparhawk Laboratories, Inc., 12340 Santa Fe Trail Dr., Lenexa, KS 66215, filed ANADA 200–378 for the use of Neomycin Soluble Powder in cattle, swine, sheep, DATES: PO 00000 Frm 00014 Fmt 4700 Sfmt 4700 goats, and turkeys for the treatment and control of bacterial enteritis. Sparhawk Laboratories, Inc.’s Neomycin Soluble Powder is approved as a generic copy of NEOMIX 325 (neomycin sulfate) Soluble Powder, sponsored by Pharmacia & Upjohn Co., a Division of Pfizer, Inc., under NADA 11–315. The ANADA is approved as of August 31, 2006, and the regulations in 21 CFR 520.1484 and 520.1485 are amended to reflect the approval and a current format. The basis of approval is discussed in the freedom of information summary. In addition, a label statement warning against the use of these products in calves to be processed for veal was not codified at the time supplemental NADAs or ANADAs for oral neomycin products were approved. At this time, FDA is amending the animal drug regulations to reflect required food safety warning statements. In accordance with the freedom of information provisions of 21 CFR part 20 and 21 CFR 514.11(e)(2)(ii), a summary of safety and effectiveness data and information submitted to support approval of this application may be seen in the Division of Dockets Management (HFA–305), Food and Drug Administration, 5630 Fishers Lane, rm. 1061, Rockville, MD 20852, between 9 a.m. and 4 p.m., Monday through Friday. FDA has determined under 21 CFR 25.33(a)(1) that this action is of a type that does not individually or cumulatively have a significant effect on the human environment. Therefore, neither an environmental assessment nor an environmental impact statement is required. This rule does not meet the definition of ‘‘rule’’ in 5 U.S.C. 804(3)(A) because it is a rule of ‘‘particular applicability.’’ Therefore, it is not subject to the congressional review requirements in 5 U.S.C. 801–808. List of Subjects in 21 CFR Part 520 Animal drugs. Therefore, under the Federal Food, Drug, and Cosmetic Act and under authority delegated to the Commissioner of Food and Drugs and redelegated to the Center for Veterinary Medicine, 21 CFR part 520 is amended as follows: I PART 520—ORAL DOSAGE FORM NEW ANIMAL DRUGS 1. The authority citation for 21 CFR part 520 continues to read as follows: I Authority: 21 U.S.C. 360b. 2. Revise § 520.1484 to read as follows: I E:\FR\FM\28SER1.SGM 28SER1

Agencies

[Federal Register Volume 71, Number 188 (Thursday, September 28, 2006)]
[Rules and Regulations]
[Pages 56864-56866]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 06-8230]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-23392; Directorate Identifier 2005-NE-47-AD; 
Amendment 39-14776; AD 2006-20-07]
RIN 2120-AA64


Airworthiness Directives; Rolls-Royce Corporation Models 250-C30, 
250-C40, and 250-C47 Series Turboshaft Engines

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

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

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
Rolls-Royce Corporation (RRC) models 250-C30, 250-40, and 250-C47 
series turboshaft engines with a third-stage turbine wheel, part number 
(P/N) 6898663 or P/N 23065843 installed, or a fourth-stage turbine 
wheel, P/N 6892764 or P/N 23066744, installed. This AD adds an 
additional life limit for third- and fourth-stage turbine wheels. This 
AD results from analysis by RRC of failures of third-stage turbine 
wheels. We are issuing this AD to prevent loss of power, possible 
engine shutdown, or uncontained engine failure.

DATES: This AD becomes effective November 2, 2006. The Director of the 
Federal Register approved the incorporation by reference of certain 
publications listed in the regulations as of November 2, 2006.

ADDRESSES: You can get the service information identified in this AD 
from Rolls-Royce Corporation, P.O. Box 420, Indianapolis, IN 46206-
0420; telephone (317) 230-6400; fax (317) 230-4243.
    You may examine the AD docket on the Internet at https://dms.dot.gov 
or in Room PL-401 on the plaza level of the Nassif Building, 400 
Seventh Street, SW., Washington, DC.

FOR FURTHER INFORMATION CONTACT: John Tallarovic, Aerospace Engineer, 
Chicago Aircraft Certification Office, FAA, 2300 East Devon Avenue, Des 
Plaines, IL 60018-4696; telephone (847) 294-8180; fax (847) 294-7834.

SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39 
with a proposed AD. The proposed AD applies to RRC models 250-C30, 250-
40, and 250-C47 series turboshaft engines. We published the proposed AD 
in the Federal Register on January 25, 2006 (71 FR 4065). That action 
proposed to add an additional life limit for third- and fourth-stage 
turbine wheels.

Examining the AD Docket

    You may examine the docket that contains the AD, any comments 
received, and any final disposition in person at the Docket Management 
Facility Docket Office between 9 a.m. and 5 p.m., Monday through 
Friday, except Federal holidays. The Docket Office (telephone (800) 
647-5227) is located on the plaza level of the Department of 
Transportation Nassif Building at the street address stated in 
ADDRESSES. Comments will be available in the AD docket shortly after 
the DMS receives them.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments received.

Request to Correct Factual Errors

    One commenter, RRC, requests that we correct factual errors in the 
NPRM and revise the Discussion paragraph, to state that:
     Only third-stage turbine wheels actually failed in the 
past; and
     Only the third-stage turbine wheel (not the third-and-
fourth-stage turbine

[[Page 56865]]

wheels) could prematurely fail if operated too many times in the 
transient overspeed region.
    We agree with these factual corrections. We changed the AD by 
removing certain references to the fourth-stage turbine wheel and 
changing the AD to state that it results from analysis by RRC of 
failures of third-stage turbine wheels.

Final Rule Should Include the Lower-Speed Avoidance Range

    A private citizen states that the final rule should include the 
lower-speed avoidance range (68.4% to 87.1%) in addition to the high-
speed transient range, when counting speed excursions and retiring 
turbine wheels. The commenter gave three reasons for the request:
    First, that operation in the lower-speed avoidance range probably 
does more cumulative damage to the turbine wheel than operation in the 
high-speed excursion range. The commenter bases this on data that he 
claims shows higher stress levels at the low-speed transient range 
compared to the high-speed transient range.
    Second, the fact that the engine control unit does not record 
operation in the low-speed avoid range, emphasizes the importance to 
inform operators about the danger of cumulative damage.
    Third, the current commercial engine bulletin gives no information 
about cumulative damage in the low-speed avoid range. The commenter 
states that currently there is no warning to operators of the potential 
damage to turbine wheels operated for any length of time in the avoid 
range which may cause more cumulative damage than high-speed 
excursions.
    We do not agree. The supporting data the commenter provided 
includes information from a manufacturer development configuration that 
does not represent the current production configuration. The data also 
does not represent the manufacturer's current, more detailed, knowledge 
of the stresses on the turbine airfoils. Transients in the low-speed 
range do not need to be tracked and used to retire turbine wheels. The 
low-speed range from 22,000 rpm to 28,045 rpm is a speed range that is 
normally passed through transiently, during the start up and shutdown 
procedures. The rate of speed change during the start up or shutdown is 
high enough that no significant time is spent at any resonant speed and 
no significant dynamic stresses are encountered that would lead to 
damage. In comparison to the low-speed excursions, if an operational 
situation occurs that results in a speed excursion above the maximum 
continuous speed, the rate of change of speed goes from positive to 
negative as it accelerates up to the maximum speed before returning 
back to the continuous operating range. During this transition, speed 
may hold close to constant, or only change very slowly, for a number of 
seconds. In this case, there could be sufficient time for the dynamic 
stresses to build to their full resonant values and potentially cause 
some level of damage to a turbine wheel. This difference between a fast 
acceleration or deceleration through a resonant speed, and a potential 
slow motion or hold in a resonant speed is why counting of occurrences 
in the low speed range is unnecessary.
    Finally, the inclusion of a specific ``steady state operation 
prohibited'' speed avoid zone denotes that failure could occur if 
operation outside of the defined continuous operating range was 
performed. RRC SB No. CEB A-72-3272, CEB A-72-5048, and CEB A-72-6054 
(combined in one document), all Revision 2, dated June 27, 2006, 
clearly instruct operators to avoid the low-speed region. As stated 
above, this speed range is not of concern for normal transient 
operation of the engine. We did not change the AD.

Conclusion

    We have carefully 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 have determined that these changes will neither increase the 
economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

    We estimate that this AD will affect 1,300 engines installed on 
airplanes of U.S. registry. We also estimate that it will take about 42 
work-hours per engine to replace the third- and fourth-stage turbine 
wheels, and that the average labor rate is $65 per work-hour. Required 
parts will cost about $25,000 per engine. We estimate that only 10% of 
all turbine wheel replacements will result from operators exceeding the 
new transient overspeed event limits. Based on these figures, we 
estimate the total potential maximum cost of the AD to U.S. operators 
to be $3,604,900.

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 have 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 that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866;
    (2) Is not a ``significant rule'' under 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 summary of the costs to comply with this AD and 
placed it in the AD Docket. You may get a copy of this summary at the 
address listed under ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the Federal Aviation Administration 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:


[[Page 56866]]


2006-20-07 Rolls-Royce Corporation (formerly Allison Engine Company, 
Allison Gas Turbine Division, and Detroit Diesel Allison): Amendment 
39-14776. Docket No. FAA-2005-23392; Directorate Identifier 2005-NE-
47-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective November 
2, 2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Rolls-Royce Corporation (RRC) models 250-
C30, -C30G, -C30G/2, -C30M, -C30P, -C30R, -C30R/1, -C30R/3, -C30R/
3M, -C30S, -C30U, -C40B, -C47B, and -C47M turboshaft engines, with a 
third-stage turbine wheel, part number (P/N) 6898663 or P/N 23065843 
installed, or a fourth-stage turbine wheel, P/N 6892764 or P/N 
23066744, installed. These engines are installed on, but not limited 
to, Bell 206L-3, Bell 206L-4, Bell 230, Bell 407, Bell 430, MDHI 
369F, MDHI 369FF, MDHI 600N, and Sikorsky S-76A helicopters.

Unsafe Condition

    (d) This AD results from analysis by RRC of failures of third-
stage turbine wheels. We are issuing this AD to prevent loss of 
power, possible engine shutdown, or uncontained failure.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified unless the 
actions have already been done.
    (f) Within 30 days after the effective date of this AD, record 
each time the third- and fourth-stage turbine wheels enter into the 
speed range between ``Event Threshold'' and ``Maximum Overspeed 
Transient''. Use paragraph 2.A. through 2.A.(5) of the 
Accomplishment Instructions and the applicable Figures 1 through 5 
of RRC Alert Commercial Engine Bulletins (CEBs) No. CEB A-72-3272, 
No. CEB A-72-5048, and No. CEB A-72-6054 (combined in one document), 
all Revision 2, dated June 27, 2006, to determine the speed range.
    (g) Remove and retire any third-stage turbine wheel or fourth-
stage turbine wheel after the sixth time the wheel enters into the 
speed range between ``Event Threshold'' and ``Maximum Overspeed 
Transient''.

Third- and Fourth-Stage Turbine Wheel Life Limits

    (h) The retirement criteria in this AD are in addition to the 
existing third- and fourth-stage turbine wheel hour and cycle life 
limits. You must retire the wheels when you exceed any published 
life limit (transient speed excursions, hours, or cycles).

Alternative Methods of Compliance

    (i) The Manager, Chicago Aircraft Certification Office, has the 
authority to approve alternative methods of compliance for this AD 
if requested using the procedures found in 14 CFR 39.19.

Related Information

    (j) None.

Material Incorporated by Reference

    (k) You must use Rolls-Royce Corporation Alert Commercial Engine 
Bulletins No. CEB A-72-3272, No. CEB A-72-5048, and No. CEB A-72-
6054 (combined in one document), all Revision 2, dated June 27, 
2006, to perform the actions required by this AD. The Director of 
the Federal Register approved the incorporation by reference of this 
service bulletin in accordance with 5 U.S.C. 552(a) and 1 CFR part 
51. Contact Rolls-Royce Corporation, P.O. Box 420, Indianapolis, IN 
46206-0420; telephone (317) 230-6400; fax (317) 230-4243 for a copy 
of this service information. You may review copies at the FAA, New 
England Region, Office of the Regional Counsel, 12 New England 
Executive Park, Burlington, MA; or 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: https://
www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Burlington, Massachusetts, on September 20, 2006.
Francis A. Favara,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 06-8230 Filed 9-27-06; 8:45 am]
BILLING CODE 4910-13-P

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