[Federal Register Volume 69, Number 224 (Monday, November 22, 2004)]
[Proposed Rules]
[Pages 67867-67869]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-25794]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-19648; Directorate Identifier 2004-NE-31-AD]
RIN 2120-AA64


Airworthiness Directives; Rolls-Royce Corporation (formerly 
Allison Engine Company) 250-B17B, -B17C, -B17D, -B17E, -C20, -C20B, -
C20F, -C20J, -C20S, and -C20W Turboprop and Turboshaft Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for Rolls-Royce Corporation (RRC) (formerly Allison Engine Company) 
250-B17B, -B17C, -B17D, -B17E, -C20, -C20B, -C20F, -C20J, -C20S, and -
C20W turboprop and turboshaft engines that do not have turbine energy 
absorbing ring, part number (P/N) 23035175, installed. This proposed AD 
would require installation of a turbine energy absorbing ring in the 
plane of the 1st stage turbine wheel. This proposed AD may also require 
installation of 1st stage turbine nozzles, 2nd stage turbine nozzles, 
and a gas producer support assembly, all modified to allow for 
installation of the turbine energy absorbing ring. This proposed AD 
results from an unacceptable rate of uncontained 1st stage turbine 
wheel failures. We are proposing this AD to minimize the risk of 
uncontained 1st stage turbine wheel fragments from causing damage to 
the aircraft or damage to the second engine on twin-engine 
installations which could lead to loss of control and loss of the 
aircraft.

DATES: We must receive any comments on this proposed AD by January 21, 
2005.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
    <bullet> DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
    <bullet> Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
    <bullet> Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590-001.
    <bullet> Fax: (202) 493-2251.
    <bullet> 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 can get the service information identified in this proposed 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 comments on this proposed AD in the AD docket 
on the Internet at http://dms.dot.gov.

FOR FURTHER INFORMATION CONTACT: Melissa T. Bradley, Aerospace 
Engineer, Chicago Aircraft Certification Office, FAA, 2300 East Devon 
Avenue, Des Plaines, IL 60018-4696; telephone (847) 294-8110; fax (847) 
294-7834.

SUPPLEMENTARY INFORMATION:

Docket Management System (DMS)

    We have implemented new procedures for maintaining AD dockets 
electronically. As of May 17, 2004, we post new AD actions on the DMS 
and assign 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-200X-XXXXX.'' Each DMS docket also lists the 
Directorate identifier (``Old Docket Number'') as a cross-reference for 
searching purposes.

Comments Invited

    We invite you to submit any written relevant data, views, or 
arguments regarding this proposal. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2004-19648; 
Directorate Identifier 2004-NE-31-AD'' in the subject line of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    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 proposed 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.

Examining the AD Docket

    You may examine the docket that contains the proposal, 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.

Discussion

    RRC conducted an analysis of uncontained 1st stage turbine wheel 
failures and the effects on aircraft. The 1st stage turbine wheel can 
fail as a result of in-service damage or gas producer tiebolt failure. 
The in-service damage is caused primarily by thermal fatigue to the 
turbine wheels during hot starts but has also been linked to improper 
alignment of the combustion liner and oil fires.
    The manufacturer developed a turbine energy absorbing ring to 
render turbine wheel fragments non-hazardous. We have determined the 
present rate of hazardous 1st stage turbine wheel

[[Page 67868]]

failures is unacceptable. This condition, if not corrected, could 
result in hazardous uncontained 1st stage turbine wheel fragments 
causing damage to the airframe and the second engine on twin-engine 
installations which could lead to loss of control and loss of the 
aircraft.

Relevant Service Information

    We have reviewed and approved the technical contents of RRC Alert 
Commercial Engine Bulletin No. CEB-A-1255, Revision 4, dated September 
29, 2004, that describes procedures for installing a turbine energy 
absorbing ring in the plane of the 1st stage turbine wheel. We have 
also reviewed and approved the technical contents of RRC Alert 
Commercial Engine Bulletin No. CEB-A-1254, Revision 3, dated May 21, 
2004, that describes procedures for modifying and installing a certain 
P/N gas producer support assembly. We have also reviewed and approved 
the technical contents of RRC Alert Commercial Engine Bulletin No. CEB-
A-1253, Revision 4, dated May 21, 2004, that describes procedures for 
modifying and installing a certain P/N 1st stage turbine nozzle, and 
certain P/N 2nd stage turbine nozzle. The actions required by RRC Alert 
Commercial Engine Bulletin No. CEB-A-1254 and No. CEB-A-1253, if 
necessary, must be done before or simultaneously with the actions of 
Alert Commercial Engine Bulletin No. CEB-A-1255.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other products 
of this same type design. We are proposing this AD, which would require 
installation of a turbine energy absorbing ring. The proposed AD would 
require that these actions be done using Alert Commercial Engine 
Bulletin No. CEB-A-1255.

Costs of Compliance

    There are about 13,299 RRC 250-B17B, -B17C, -B17D, -B17E, -C20, -
C20B, -C20F, -C20J, -C20S, and -C20W turboprop and turboshaft engines 
of the affected design in the worldwide fleet. We estimate that 5,000 
engines installed on helicopters of U.S. registry require the 
installation of a turbine energy absorbing ring. Of those 5,000 
engines, we also estimate that 4,000 engines require installation of a 
gas producer support assembly, 1st stage turbine nozzle, and 2nd stage 
turbine nozzle. It takes about 16 work hours per engine to install the 
turbine energy absorbing ring, 35 work hours to install the gas 
producer support assembly, and 20 work hours to install the 1st stage 
turbine nozzle, and 2nd stage turbine nozzle. The average labor rate is 
$65 per work hour. Required turbine energy absorbing rings cost about 
$10,765 per engine. Required gas producer support assemblies cost about 
$2,500 per engine. Required 1st stage turbine nozzles and 2nd stage 
turbine nozzles cost about $1,000 per engine. Based on these figures, 
we estimate the total cost of the proposed AD to U.S. operators to be 
$87,325,000.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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 proposed 
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. Would 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 proposal 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.

The Proposed Amendment

    Under the authority delegated to me by the Administrator, the 
Federal Aviation Administration proposes to amend 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.


Sec.  39.13  [Amended]

    2. The FAA amends Sec.  39.13 by adding the following new 
airworthiness directive:

Rolls-Royce Corporation (formerly Allison Engine Company): Docket 
No. FAA-2004-19648; Directorate Identifier 2004-NE-31-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by January 21, 
2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Rolls-Royce Corporation (RRC) (formerly 
Allison Engine Company) 250-B17B, -B17C, -B17D, -B17E, -C20, -C20B, 
-C20F, -C20J, -C20S, and -C20W turboprop and turboshaft engines that 
do not have turbine energy absorbing ring, part number 23035175, 
installed. These engines are installed on, but not limited to, the 
following aircraft:

Agusta A109
Agusta A109A
Agusta A109A II
B-N Group BN-2T
Bell 206A
Bell 206B
Bell 206L
Eurocopter Deutchland BO-105C
Eurocopter Deutchland BO-105S
Eurocopter France AS355E
Eurocopter France AS355F
Eurocopter France AS355F1
Eurocopter France AS355F2
FH-1100 Manufacturing Corp FH-1100
MDHI 369D
MDHI 369E
MDHI 369HM
MDHI 369HS
MDHI 369HE
SIAI Marchetti s.r.l. SF600

Unsafe Condition

    (d) This AD results from an unacceptable rate of uncontained 1st 
stage turbine wheel failures. We are issuing this AD to minimize the 
risk of uncontained 1st stage turbine wheel fragments from causing 
damage to the aircraft or damage to the second engine on twin-engine 
installations which could lead to loss of control and loss of the 
aircraft.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed at the next time the gas producer turbine rotor is 
disassembled for any reason, or within 1,750 hours time-since-last-
overhaul, time-since-new, time-since-last-heavy-maintenance, or 
time-since-last-hot section inspection after the effective date of 
this AD, whichever occurs first, but no later than October 31, 2011, 
unless already done.

Required Actions

    (f) If not already installed, install a modified gas producer 
support assembly to provide installation of the turbine energy 
absorbing ring. Use paragraph 2. of RRC Alert Commercial Engine 
Bulletin No. CEB-A-1254, Revision 3, dated May 21, 2004, to do the 
modification and installation.
    (g) If not already installed, install a modified 1st stage 
turbine nozzle, 2nd stage turbine nozzle, and gas producer support 
assembly to provide installation of the turbine energy absorbing 
ring. Use paragraph 2. of RRC Alert Commercial Engine Bulletin

[[Page 67869]]

No. CEB-A-1253, Revision 4, dated May 21, 2004, to do the 
modification and installation.
    (h) Install a turbine energy absorbing ring in the plane of the 
1st stage turbine wheel. Use paragraphs 2.A. and 2.B. of RRC Alert 
Commercial Engine Bulletin No. CEB-A-1255, Revision 4, dated 
September 29, 2004, to do the installation.

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.

    Issued in Burlington, Massachusetts, on November 16, 2004.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 04-25794 Filed 11-19-04; 8:45 am]
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