[Federal Register: July 1, 2004 (Volume 69, Number 126)]
[Proposed Rules]
[Page 39877-39880]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr01jy04-34]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2004-18515; Directorate Identifier 2004-NE-12-AD]
RIN 2120-AA64
Airworthiness Directives; Rolls-Royce Corporation (Formerly
Allison Engine Company, Allison Gas Turbine Division, and Detroit
Diesel Allison) 250-B and 250-C Series Turbofan 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) 250-B and 250-C series turbofan and
turboshaft engines with certain part numbers (PNs) of compressor
adaptor couplings manufactured by Alcor Engine Company (Alcor), EXTEX
Ltd. (EXTEX), RRC, and Superior Air Parts (SAP) installed. This
proposed AD would require operators to remove from service affected
compressor adaptor couplings. This proposed AD results from nine
reports of engine shutdown caused by compressor adaptor coupling
failure. We are proposing this AD to reduce the risk of failure of the
compressor adaptor coupling and subsequent loss of all engine power.
DATES: We must receive any comments on this proposed AD by August 30,
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 proposed AD in the AD docket
on the Internet at http://dms.dot.gov.
[[Page 39878]]
FOR FURTHER INFORMATION CONTACT: Robert Baitoo, Aerospace Engineer, Los
Angeles Aircraft Certification Office, FAA, Transport Airplane
Directorate, 3960 Paramount Blvd., Lakewood, CA 90712-4137; telephone:
(562) 627-5245, fax: (562) 627-5210, for questions about Alcor, EXTEX,
or SAP compressor adaptor couplings; and 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, for questions about RRC compressor adaptor couplings.
SUPPLEMENTARY INFORMATION:
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-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-2004-18515;
Directorate Identifier 2004-NE-12-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.
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 that affect 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 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
The FAA has received reports of nine RRC 250-B and 250-C series
turbofan and turboshaft engines that have experienced failure of the
compressor adaptor coupling in service. Each failure has resulted in
total loss of engine power, with three of the events resulting in
accidents. The engines are installed in mostly single-engine
helicopters, along with several turboprop airplanes. Alcor, EXTEX, and
SAP each independently manufactured compressor adaptor couplings, under
Parts Manufacturer Approval (PMA) authority. RRC manufactured
compressor adaptor couplings under type and production certificate
authority.
While the precise mechanism of coupling failure is still under
investigation, enough evidence has been collected to conclude that the
four individual part designs could have unsatisfactory rates of failure
in service, and should be removed from service as recommended and
substantiated by each individual part manufacturer.
Each of the four manufacturers is responsible for its own
independent component design, design substantiation, component
manufacture, and development of a field management plan for its fleet.
EXTEX is handling field management of affected couplings made by SAP,
under an agreement between the two manufacturers.
Compliance requirements in this proposed AD have been developed
based on the FAA's consideration of those individual field management
plans and corresponding substantiation. The condition described
previously, if not corrected, could result in failure of the compressor
adaptor coupling and subsequent loss of all engine power.
With respect to the field management plans, design and production
approval holders are expected to have a comprehensive understanding of
the system that the component is installed in and the consequences of
failure of that specific component design. Also, design and production
approval holders are expected to effectively collect and review service
data and assess risk to support continued operational safety of their
components in service. The different manufacturers of compressor
adaptor couplings have conducted their own independent data reviews and
risk assessments, with varying outcomes. These varying outcomes have
generated different compliance requirements in this proposed AD, for
users of each manufacturer's compressor adaptor coupling.
FAA's Determination and Requirements of the Proposed AD
We have evaluated all pertinent information available from field
reports and from the four manufacturers' safety assessments and have
identified an unsafe condition that is likely to exist or develop in
other RRC 250-B17, -B17B, -B17C, -B17D, -B17E, 250-C20, -C20B, -C20F, -
C20J, -C20S, and -C20W series turbofan and turboshaft engines that have
any of the following compressor adaptor couplings installed:
Alcor: P/Ns 23039791AL and 23039791AL-1/-2/-3.
EXTEX: P/Ns A23039791, E23039791, E23039791-1/-2/-3,
EH23039791, and EH23039791-1/-2/-3.
RRC: P/Ns 23039791-1/-2/-3.
SAP: P/N A23039791.
We are proposing this AD, which would:
Remove from service affected Alcor compressor adaptor
couplings using the schedule specified in the compliance section of
this proposed AD. The related Alcor safety assessment and
recommendations are based on a significant number of service part
inspections and engineering judgment.
Remove from service affected EXTEX and SAP compressor
adaptor couplings using the schedule specified in the compliance
section of this proposed AD. The related EXTEX and SAP safety
assessments and recommendations are based on a significant number of
service part inspections and engineering judgment.
Remove from service affected RRC compressor adaptor
couplings using the schedule specified in the compliance section of
this proposed AD. The related RRC safety assessment and recommendations
are based on a significant number of service part inspections,
component tests, and
[[Page 39879]]
manufacturing and overhaul assembly analysis, and engineering analysis.
Costs of Compliance
There are about 9,000 RRC 250-B and 250-C series turbofan and
turboshaft engines of the affected design in the worldwide fleet. We
estimate that 6,000 engines installed on helicopters and airplanes of
U.S. registry would be affected by this proposed AD. We also estimate
that it would take about 3 work hours per engine to perform the
proposed actions when done at time of rotor disassembly, and that the
average labor rate is $65 per work hour. Required parts would cost
about $1,601 per engine. Based on these figures, we estimate the total
cost of the proposed AD to U.S. operators to be $10,776,000.
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, Allison
Gas Turbine Division, and Detroit Diesel Allison): Docket No. FAA-
2004-18515; Directorate Identifier 2004-NE-12-AD.
Comments Due Date
(a) The Federal Aviation Administration (FAA) must receive
comments on this airworthiness directive (AD) action by August 30,
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) 250-B17, -B17B, -B17C, -B17D, -B17E, 250-C20, -C20B, -C20F,
-C20J, -C20S, and -C20W series turbofan and turboshaft engines with
the compressor adaptor couplings installed listed in the following
Table 1:
Table 1.--Affected Compressor Adaptor Couplings
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Manufacturer Affected part numbers
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Alcor Engine Company (Alcor) P/Ns 23039791AL; 23039791AL-
1/-2/-3;
EXTEX Ltd. (EXTEX)........................ A23039791; E23039791;
E23039791-1/-2/-3;
EH23039791; EH23039791-1/-2/
-3.
Rolls-Royce Corporation (RRC) 23039791-1/-2/-3
Superior Air Parts (SAP).................. A23039791
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These engines are installed on, but not limited to, the aircraft
in the following Table 2:
Table 2.--Applicable Aircraft
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Helicopters
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Agusta Models
A109, A109A, A109A II Bell Models
206A, 207B, 206L Enstrom Models
TH-28, 480, 480B Eurocopter France Models
AS355E, AS355F, AS355F1, AS355F2
Eurocopter Deutschland Models
BO-105C, BO-105S
MDHI Models
369D, 369E, 369H, 369HM, 369HS, 369HE
Schweizer Model 269D
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Airplanes
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B-N Group Ltd. Model
BN-2T
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Unsafe Condition
(d) This AD results from nine reports of engine shutdown caused
by compressor adaptor coupling 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.
Alcor Compressor Adaptor Couplings
(f) Remove Alcor compressor adaptor couplings, P/Ns 23039791AL,
23039791AL-1, -2, and -3 from service as follows:
(1) For couplings with 600 or more operating hours-since-new as
of the effective date of this AD, or the operating hours are unknown
and cannot be determined, remove couplings from service at next
access but not to exceed 50 additional operating hours.
(2) For couplings with fewer than 600 operating hours-since-new
on the effective date of this AD, remove couplings from service at
next access but not to exceed 649 operating hours-since-new.
EXTEX and SAP Compressor Adaptor Couplings
(g) Remove EXTEX and SAP compressor adaptor couplings, P/Ns
A23039791, E23039791, E23039791-1, -2, and -3, EH23039791, and
EH23039791-1, -2, and -3, from service as follows:
(1) For couplings with operating hours that are unknown and
cannot be determined, remove couplings from service at next access
but not to exceed 50 additional operating hours.
(2) For couplings with 600 or more operating hours-since-new as
of the effective date of this AD, remove couplings from service at
next access but not to exceed 100 additional operating hours.
(3) For couplings with fewer than 600 operating hours-since-new
on the effective date of this AD, remove couplings from service at
next access but not to exceed 150 additional operating hours.
RRC Compressor Adaptor Couplings
(h) Remove RRC compressor adaptor couplings, P/Ns 23039791-1, -
2, and -3 from service at next access but not later than March 1,
2012.
Installation Requirements for Compressor Adaptor Couplings
(i) Machine the compressor impeller as follows:
(1) Machine the inside diameter (ID) to accept the next larger
size outside diameter (OD) compressor adaptor coupling.
(2) For example, if a -1 coupling was removed, a -2 coupling
must be installed.
(3) If a -3 coupling is removed, a new impeller is required.
[[Page 39880]]
(4) A fit of 0.0000 to -0.0018 inch must be achieved. No
fretting is allowed on the impeller after machining.
(5) Due to previous fretting, an impeller with a -1 coupling
removed might have to be machined for a -3 coupling. Plating of the
impeller ID is not allowed.
(6) Fluorescent penetrant inspect the impeller.
(7) Install a new compressor adaptor coupling, P/N 23076559-2 or
-3; or
(8) If a new impeller is installed, then install compressor
adaptor coupling, P/N 23076559-1.
(9) Heating of the impeller per the engine overhaul manual is
required to install the coupling to achieve the target fit specified
in the following Table 3:
Table 3.--Impeller-to-Coupling Target Fit
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Impeller ID New Adaptor Adaptor OD Fit (Interference)
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(i) 0.900 to 0.899 inch.............. 23076559-1............. 0.9000 to 0.9008 inch.. 0.0000 to -0.0018 inch.
(ii) 0.902 to 0.901 inch............. 23076559-2............. 0.9020 to 0.9028 inch.. 0.0000 to -0.0018 inch.
(iii) 0.904 to 0.903 inch............ 23076559-3............. 0.9040 to 0.9048 inch.. 0.0000 to -0.0018 inch.
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Definition
(j) For the purposes of this AD, next access is defined as when
the compressor module is separated from the engine and disassembled
for any reason.
Alternative Methods of Compliance
(k) The Manager, Los Angeles Aircraft Certification Office, has
the authority to approve alternative methods of compliance for
Alcor, EXTEX, and SAP adaptor couplings addressed in this AD if
requested using the procedures found in 14 CFR 39.19. The Manager,
Chicago Aircraft Certification Office, has the authority to approve
alternative methods of compliance for RRC adaptor couplings
addressed in this AD if requested using the procedures found in 14
CFR 39.19.
Material Incorporated by Reference
(l) None.
Related Information
(m) Alcor SLB No. 814-3-1, Revision C, dated April 28, 2004,
EXTEX Alert Service Bulletin T-081, Revision B, dated May 4, 2004,
and RRC CEB-A-1392 and CEB-A-1334, dated September 9, 2003, pertain
to the subject of this AD.
Issued in Burlington, Massachusetts, on June 25, 2004.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification
Service.
[FR Doc. 04-14945 Filed 6-30-04; 8:45 am]
BILLING CODE 4910-13-P