[Federal Register Volume 64, Number 194 (Thursday, October 7, 1999)]
[Proposed Rules]
[Pages 54589-54591]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-26210]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-ANE-38-AD]
RIN 2120-AA64
Airworthiness Directives; CFM International (CFMI) CFM56-2, -2A,
-2B, -3, -3B, -3C, -5, -5B, -5C, and -7B Series Turbofan Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the supersedure of an existing
airworthiness directive (AD), applicable to certain CFM International
(CFMI) CFM56 series turbofan engines, that currently requires revisions
to the Engine Time Limits section of applicable Engine Shop Manuals
(ESMs) to include required enhanced inspection of selected critical
life-limited parts at each piece-part exposure. This action would add
more CFM56 engine models to the AD's applicability and introduce
additional inspections. This proposal is prompted by additional focused
inspection procedures that have been developed by the manufacturer. The
actions specified by this proposed AD are intended to prevent critical
life-limited rotating engine part failure, which could result in an
uncontained engine failure and damage to the airplane.
DATES: Comments must be received by December 6, 1999.
ADDRESSES: Submit comments to the Federal Aviation Administration
(FAA), New England Region, Office of the Regional Counsel, Attention:
Rules Docket No. 98-ANE-38-AD, 12 New England Executive Park,
Burlington, MA 01803-5299. Comments may also be sent via the Internet
using the following address: ``[email protected]''. Comments sent
via the Internet must contain the docket number in the subject line.
Comments may be inspected at this location between 8:00 a.m. and 4:30
p.m., Monday through Friday, except Federal holidays.
FOR FURTHER INFORMATION CONTACT: Robert Ganley, Aerospace Engineer,
Engine Certification Office, FAA, Engine and Propeller Directorate, 12
New England Executive Park, Burlington, MA 01803-5299; telephone (781)
238-7138, fax (781) 238-7199.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the
proposed rule by submitting such written data, views, or arguments as
they may desire. Communications should identify the Rules Docket number
and be submitted to the address
[[Page 54590]]
specified above. All communications received on or before the closing
date for comments, specified above, will be considered before taking
action on the proposed rule. The proposals contained in this notice may
be changed in light of the comments received.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed rule. All
comments submitted will be available, both before and after the closing
date for comments, in the Rules Docket for examination by interested
persons. A report summarizing each FAA-public contact concerned with
the substance of this proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 98-ANE-38-AD.'' The postcard will be date stamped and
returned to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, New England Region, Office of the Regional Counsel,
Attention: Rules Docket No. 98-ANE-38-AD, 12 New England Executive
Park, Burlington, MA 01803-5299.
Discussion
On April 2, 1999, the Federal Aviation Administration (FAA) issued
airworthiness directive (AD) 99-08-16, Amendment 39-11122 (64 FR 17962,
April 13, 1999), to require revisions to the Engine Time Limits section
of the applicable Engine Shop Manuals (ESMs) for CFM International
(CFMI) CFM56-2, -2A, -2B, -3, -3B, and -3C series turbofan engines to
include required enhanced inspection of selected critical life-limited
parts at each piece-part exposure. That AD was prompted by an FAA study
of in-service events involving uncontained failures of critical
rotating engine parts that indicated the need for improved inspections.
That condition, if not corrected, could result in critical life-limited
rotating engine part failure, which could result in an uncontained
engine failure and damage to the airplane.
New Inspection Procedures
Since the issuance of that AD, CFMI has developed additional
focused inspection procedures. This proposal would add the CFM56-5, -
5B, -5C, and -7B series engines to the AD's applicability. This
proposal would also extend the currently required fluorescent penetrant
inspections (FPI) and bore/dovetail eddy current inspections (ECI) to
fan disks installed on the newly affected models, and extend the
currently required high pressure turbine (HPT) disk FPI on the newly
affected models as well. In addition, this AD would add, for all
affected CFM56 engine models, HPT disk bore ECI. Finally, for all
affected CFM56 engine models, this AD would add HPT front rotating air
seal FPI, bore ECI, and bolthole ECI or focused FPI.
Proposed Actions
Since an unsafe condition has been identified that is likely to
exist or develop on other products of this same type design, the
proposed AD would supersede AD 99-08-16 to add more CFM56 engine models
to the AD's applicability and introduce additional inspections. The
inspections would be required at each piece-part opportunity.
Economic Analysis
There are approximately 6,953 engines of the affected design in the
worldwide fleet. The FAA estimates that 2,453 engines installed on
airplanes of U.S. registry would be affected by this proposed AD, that
it would take approximately 30 work hours per engine for the fan disk
inspection, 13 work hours for the HPT disk inspection, and 13 work
hours for the HPT front rotating air seal inspection. The average labor
rate is $60 per work hour. Using average shop visitation rates, 554 fan
disks, 891 HPT disks, and 563 HPT front rotating air seals are expected
to be affected per year. The total estimated annual cost of the
proposed new inspections on US operators is approximately $2,131,320,
or $870 per engine.
Regulatory Impact
The regulations proposed herein would not have substantial direct
effects 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. Therefore, in
accordance with Executive Order 12612, it is determined that this
proposal would not have sufficient federalism implications to warrant
the preparation of a Federalism Assessment.
For the reasons discussed above, I certify that this 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) if promulgated, 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. A copy of the draft
regulatory evaluation prepared for this action is contained in the
Rules Docket. A copy of it may be obtained by contacting the Rules
Docket at the location provided under the caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by removing Amendment 39-11122 (64 FR
17962, April 13, 1999), and by adding a new airworthiness directive, to
read as follows:
CFM International: Docket No. 98-ANE-38-AD. Supersedes AD 99-08-16,
Amendment 39-11122.
Applicability: CFM International (CFMI) CFM56-2, -2A, -2B, -3, -
3B, -3C, -5, -5B, -5C, and -7B series turbofan engines, installed on
but not limited to McDonnell Douglas DC-8 series, Boeing 737 series,
Airbus Industrie A319, A320, A321, and A340 series, as well as
Boeing E-3, E-6, and KC-135 (military) series airplanes.
Note 1: This airworthiness directive (AD) applies to each engine
identified in the preceding applicability provision, regardless of
whether it has been modified, altered, or repaired in the area
subject to the requirements of this AD. For engines that have been
modified, altered, or repaired so that the performance of the
requirements of this AD is affected, the owner/operator must request
approval for an alternative method of compliance in accordance with
paragraph (c) of this AD. The request should include an assessment
of the effect of the modification, alteration, or repair on the
unsafe condition addressed by this AD; and, if the unsafe condition
has not been eliminated, the request should include specific
proposed actions to address it.
Compliance: Required as indicated, unless accomplished
previously. To prevent critical life-limited rotating engine part
failure, which could result in an uncontained engine failure and
damage to the airplane, accomplish the following:
[[Page 54591]]
Inspections
(a) Within the next 30 days after the effective date of this AD,
revise the Time Limits section (chapter 05-11-00) of Engine Shop
Manual (ESM) CFMI-TP.SM.4, for CFM56-2 series engines, ESM CFMI-
TP.SM.6, for CFM56-2A/-2B series engines, ESM CFMI-TP.SM.5, for
CFM56-3/-3B/-3C series engines, ESM CFMI-TP.SM.7 for CFM56-5 series
engines, ESM CFMI-TP.SM.9 for CFM56-5B series engines, ESM CFMI-
TP.SM.8 for CFM56-5C series engines, and ESM CFMI-TP.SM.10 for
CFM56-7B series engines, and for air carrier operations, revise the
approved continuous airworthiness maintenance program, by adding the
following:
``MANDATORY INSPECTIONS
(1) Perform inspections of the following parts at each piece-
part opportunity in accordance with the Inspection/Check section
instructions provided in the applicable manual sections listed
below:
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Engine manual
Engine models Part name section Inspection
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All................................... Fan Disk (All Part Number 72-21-03 Disk Fluorescent Penetrant
(P/N)). Inspection (FPI) and Disk
Bore and Dovetail Eddy
Current Inspection (ECI).
CFM56-2/-2A/-B/-3/-3B/-3C............. High Pressure Turbine 72-52-02 Disk FPI and Disk Bore and
(HPT) Disk (All P/N). Bold Hole(s) ECI.
CFM56-5/-5B/-5C/-7B................... HPT Disk (All P/N)....... 72-52-02 Disk FPI and Disk Bore ECI.
CFM56-2A/-2B/-3/-3B/-3C............... HPT Front Rotating Air 72-52-03 Disk FPI and Disk Bore and
Seal (All P/N). Bolt Hole(s) ECI.
CFM56-5/-5B/-5C/-7B................... HPT Front rotating Air 72-52-03 Disk FPI and Disk Bore ECI
Seal (All P/N). and Disk Bolt Hole(s)
Focused FPI.
CFM56-2............................... HPT Front Rotating Air 72-52-03 Disk FPI and Disk Bore ECI
Seal (All P/N). and Disk Bolt Hole(s) ECI or
focused FPI as applicable.
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(2) For the purposes of these mandatory inspections, piece-part
opportunity means:
(i) The part is considered completely disassembled when
accomplished in accordance with the disassembly instructions in the
manufacturer's engine manual; and
(ii) The part has accumulated more than 100 cycles in service
since the last piece-part opportunity inspection, provided that the
part was not damaged or related to the cause for its removal from
the engine.''
(b) Except as provided in paragraph (c) of this AD, and
notwithstanding contrary provisions in section 43.16 of the Federal
Aviation Regulations (14 CFR 43.16), these mandatory inspections
shall be performed only in accordance with the Time Limits section
of the manufacturer's ESM.
Alternative Methods of Compliance
(c) An alternative method of compliance or adjustment of the
compliance time that provides an acceptable level of safety may be
used if approved by the Engine Certification Office (ECO). Operators
shall submit their requests through an appropriate FAA Principal
Maintenance Inspector (PMI), who may add comments and then send it
to the ECO.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this airworthiness directive,
if any, may be obtained from the ECO.
Ferry Flights
(d) Special flight permits may be issued in accordance with
sections 21.197 and 21.199 of the Federal Aviation Regulations (14
CFR 21.197 and 21.199) to operate the airplane to a location where
the requirements of this AD can be accomplished.
Continuous Airworthiness Maintenance Program
(e) FAA-certificated air carriers that have an approved
continuous airworthiness maintenance program in accordance with the
record keeping requirement of Sec. 121.369(c) of the Federal
Aviation Regulations (14 CFR 121.369(c)) of this chapter must
maintain records of the mandatory inspections that result from
revising the Time Limits section of the applicable ESM and the air
carrier's continuous airworthiness program. Alternately,
certificated air carriers may establish an approved system of record
retention that provides a method for preservation and retrieval of
the maintenance records that include the inspections resulting from
this AD, and include the policy and procedures for implementing this
alternate method in the air carrier's maintenance manual required by
Sec. 121.369(c) of the Federal Aviation Regulations (14 CFR
121.369(c)); however, the alternate system must be accepted by the
appropriate PMI and require the maintenance records be maintained
either indefinitely or until the work is repeated. Records of the
piece-part inspections are not required under Sec. 121.380(a)(2)(vi)
of the Federal Aviation Regulations [14 CFR 121.380(a)(2)(vi)]. All
other operators must maintain the records of mandatory inspections
required by the applicable regulations governing their operations.
Note 3: The requirements of this AD have been met when the ESM
changes are made and air carriers have modified their continuous
airworthiness maintenance plans to reflect the requirements in the
applicable ESM.
Issued in Burlington, Massachusetts, on September 30, 1999.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 99-26210 Filed 10-6-99; 8:45 am]
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