[Federal Register Volume 69, Number 131 (Friday, July 9, 2004)]
[Rules and Regulations]
[Pages 41389-41391]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-15508]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-18538; Directorate Identifier 2004-NE-29-AD; 
Amendment 39-13711; AD 2004-14-02]
RIN 2120-AA64


Airworthiness Directives; Rolls-Royce Corporation (Formerly 
Allison Engine Company, Allison Gas Turbine Division, and Detroit 
Diesel Allison) Models 250-C28, -C28B, and -C28C Turboshaft Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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[[Page 41390]]

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
Rolls-Royce Corporation (formerly Allison Engine Company, Allison Gas 
Turbine Division, and Detroit Diesel Allison) (RRC) models 250-C28, -
C28B, and -C28C turboshaft engines with certain serial number (SN) 
third-stage turbine wheels, part number (P/N) 6899383. This AD requires 
replacing certain SN third-stage turbine wheels, P/N 6899383, before 
reaching new reduced life limits. This AD results from three reports of 
third-stage turbine blade and shroud failures. We are issuing this AD 
to prevent loss of power and uncommanded engine shutdown due to failure 
of third-stage turbine blades and shrouds.

DATES: This AD becomes effective July 26, 2004.
    We must receive any comments on this AD by September 7, 2004.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590-001.
     Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    You may examine the comments on this AD in the AD docket on the 
Internet at http://dms.dot.gov.

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: On May 4, 2004, we became aware of three 
reports of third-stage turbine wheel blade and shroud failures on RRC 
model 250-C28 series turboshaft engines. Investigation by RRC revealed 
that high cycle fatigue caused the third-stage turbine blade and shroud 
failures. Investigation has also revealed that this high cycle fatigue 
condition is limited to a population of 73 third-stage turbine wheels 
that were manufactured and accepted with a blueprint variance. The 
turbine wheel original life limits were 4,550 operating hours and 6,000 
cycles-in-service. This condition, if not corrected, could result in 
loss of power and uncommanded engine shutdown due to failure of third-
stage turbine blades and shrouds.

FAA's Determination and Requirements of This AD

    The unsafe condition described previously is likely to exist or 
develop on other RRC 250-C28 series engines of the same type design. We 
are issuing this AD to prevent loss of power and uncommanded engine 
shutdown due to failure of third-stage turbine blades and shrouds. This 
AD requires replacing the third-stage turbine wheels, P/N 6899383, with 
SNs listed in the compliance section of this proposed AD at the 
following:
     For any turbine wheel with fewer than 250 operating hours 
time since new (TSN) on the effective date of the proposed AD, before 
accumulating 300 operating hours TSN; and
     For any turbine wheel with 250 or more operating hours TSN 
on the effective date of the proposed AD, before accumulating an 
additional 50 operating hours.

FAA's Determination of the Effective Date

    Since an unsafe condition exists that requires the immediate 
adoption of this AD, we have found that notice and opportunity for 
public comment before issuing this AD are impracticable, and that good 
cause exists for making this amendment effective in less than 30 days.

Docket Management System (DMS)

    We have implemented new procedures for maintaining AD dockets 
electronically. As of May 17, 2004, we posted new AD actions on the DMS 
and assigned a DMS docket number. We track each action and assign a 
corresponding Directorate identifier. The DMS docket No. is in the form 
``Docket No. FAA-2004-18538.'' Each DMS docket also lists the 
Directorate identifier (``Old Docket Number'') as a cross-reference for 
searching purposes.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety and was not preceded by notice and an opportunity for public 
comment; however, we invite you to submit any written relevant data, 
views, or arguments regarding this AD. Send your comments to an address 
listed under ADDRESSES. Include ``AD Docket No. FAA-2004-18538; 
Directorate Identifier 2004-NE-29-AD'' in the subject line of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify it.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this AD. Using the search function of the DMS web 
site, anyone can find and read the comments in any of our dockets, 
including the name of the individual who sent the comment (or signed 
the comment on behalf of an association, business, labor union, etc.). 
You may review the DOT's complete Privacy Act Statement in the Federal 
Register published on April 11, 2000 (65 FR 19477-78) or you may visit 
http://dms.dot.gov.
    We are reviewing the writing style we currently use in regulatory 
documents. We are interested in your comments on whether the style of 
this document is clear, and your suggestions to improve the clarity of 
our communications with you. You can get more information about plain 
language at http://www.faa.gov/language and http://www.plainlanguage.gov.

Examining the AD Docket

    You may examine the docket that contains the AD, any comments 
received, and any final disposition in person at the DMS Docket Offices 
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.

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 the regulation:
    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

[[Page 41391]]

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, Safety.

Adoption of the Amendment

0
Under the authority delegated to me by the Administrator, the Federal 
Aviation Administration amends part 39 of the Federal Aviation 
Regulations (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:

2004-14-02 Rolls-Royce Corporation (formerly Allison Engine Company, 
Allison Gas Turbine Division, and Detroit Diesel Allison): Amendment 
39-13711. Docket No. FAA-2004-18538; Directorate Identifier 2004-NE-
29-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective July 26, 
2004.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Rolls-Royce Corporation (formerly Allison 
Engine Company, Allison Gas Turbine Division, and Detroit Diesel 
Allison) (RRC) models 250-C28, -C28B, and -C28C turboshaft engines 
with third-stage turbine wheels, part number (P/N) 6899383, listed 
by serial number (SN) in the following Table 1:

          Table 1.--SNs of Affected Third Stage Turbine Wheels
------------------------------------------------------------------------
 
------------------------------------------------------------------------
          HX91922                  X523242                  X523281
          HX91923                  X523243                  X523283
          HX91925                  X523244                  X523284
          HX91926                  X523246                  X523287
          HX91928                  X523249                  X523288
          HX91929                  X523250                  X523289
          HX91930                  X523251                  X523290
          HX91932                  X523253                  X523291
          HX91934                  X523255                  X523292
          HX91936                  X523257                  X523293
          HX91937                  X523260                  X523294
          HX91939                  X523261                  X523295
          HX91940                  X523262                  X523296
          HX91960                  X523263                  X523297
          HX91962                  X523264                  X523298
          HX91966                  X523265                  X523300
          HX91976                  X523266                  X523305
          HX91977                  X523268                  X523309
          HX91979                  X523269                  X523313
          HX91980                  X523270                  X523315
          X523236                  X523271                  X523317
          X523237                  X523273                  X523319
          X523238                  X523276                  X523320
          X523239                  X523277                      N/A
          X523241                  X523278                      N/A
------------------------------------------------------------------------

    These engines are installed on, but not limited to, Bell 
Helicopter Textron 206L-1; Eurocopter Deutschland BO 105 LS A-1; and 
Eurocopter Canada BO 105 LS A-3 helicopters.

Unsafe Condition

    (d) This AD results from three reports of third-stage turbine 
wheel blade and shroud failures. We are issuing this AD to prevent 
loss of power and uncommanded engine shutdown due to failure of the 
third-stage turbine wheel blade and shroud.

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) For any third-stage turbine wheel with fewer than 250 
operating hours time since new (TSN) on the effective date of this 
AD, replace turbine wheel before accumulating 300 operating hours 
TSN.
    (g) For any third-stage turbine wheel with 250 or more operating 
hours TSN on the effective date of this AD, replace turbine wheel 
before accumulating an additional 50 operating hours.

Definition

    (h) For the purposes of this AD, a replacement third-stage 
turbine wheel is a turbine wheel that does not have a SN listed in 
this AD.
    (i) After the effective date of this AD, do not install third-
stage turbine wheels that are listed in Table 1 of this AD, into any 
engine.

Alternative Methods of Compliance

    (j) 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.

Special Flight Permits

    (k) Under 14 CFR 39.23, we are prohibiting special flight 
permits for this AD.

Material Incorporated by Reference

    (l) None.

Related Information

    (m) Rolls-Royce Corporation Alert Commercial Engine Bulletin No. 
CEB-A-72-2202, dated May 6, 2004, pertains to the subject of this 
AD.

    Issued in Burlington, Massachusetts, on July 1, 2004.
Francis A Favara,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 04-15508 Filed 7-8-04; 8:45 am]
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