[Federal Register Volume 62, Number 182 (Friday, September 19, 1997)]
[Proposed Rules]
[Pages 49179-49180]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-24911]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-ANE-29-AD]
RIN 2120-AA64
Airworthiness Directives; CFM International CFM56-5B/2P Series
Turbofan Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to CFM International (CFMI) CFM56-5B/
2P series turbofan engines. This proposal would require a reduction of
the low cycle fatigue (LCF) retirement life for certain low pressure
turbine (LPT) cases. This proposal is prompted by the results of a
refined life analysis performed by the manufacturer which revealed
minimum calculated LCF lives significantly lower than the published LCF
retirement life. The actions specified by the proposed AD are intended
to prevent a LCF failure of the LPT case, which could result in damage
to the aircraft.
DATES: Comments must be received by November 18, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), New England Region, Office of the Assistant Chief
Counsel, Attention: Rules Docket No. 97-ANE-29-AD, 12 New England
Executive Park, Burlington, MA 01803-5299. 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 J. 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 in triplicate to the address 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 97-ANE-29-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 Assistant Chief Counsel,
Attention: Rules Docket No. 97-ANE-29-AD, 12 New England Executive
Park, Burlington, MA 01803-5299.
Discussion
This proposed airworthiness directive (AD) is applicable to CFM
International (CFMI) CFM56-5B/2P series turbofan engines. A study
performed by the manufacturer using updated lifing analyses based on
recent engine test results revealed that certain low pressure turbine
(LPT) cases have minimum calculated low cycle fatigue (LCF) lives which
are significantly lower than the published LCF retirement life. This
condition, if not corrected, could result in a LCF failure of the LPT
case, which could result in damage to the aircraft.
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 require a reduction of the LCF retirement life for
certain LPT cases.
There are approximately 18 engines of the affected design in the
worldwide fleet. The manufacturer has advised the FAA that there are no
engines installed on U.S. registered aircraft that would be affected by
this AD. Therefore, there is no associated cost impact on U.S.
operators as a result of this AD. However, should an affected engine be
imported on an aircraft and placed on the U.S. registry in the future,
and assuming that the parts cost is proportional to the reduction of
the LCF retirement life, the required parts would cost approximately
$40,423 per engine. Based on these figures, the total cost impact of
the proposed AD is estimated to be $40,423 per engine.
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,
[[Page 49180]]
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), 40101, 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
CFM International: Docket No. 97-ANE-29-AD.
Applicability: CFM International (CFMI) CFM56-5B1/2P, -5B2/2P, -
5B3/2P, and -5B4/2P turbofan engines, installed with low pressure
turbine (LPT) case, Part Number
(P/N) 338-117-004-0, installed on but not limited to Airbus A320 and
A321 series aircraft.
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 (e) 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 a low cycle fatigue (LCF) failure of the LPT case,
which could result in damage to the aircraft, accomplish the
following:
(a) Remove from service LPT case, P/N 338-117-004-0, and replace
with a serviceable part, as follows:
(1) For CFM56-5B2/2P and -5B3/2P engines, prior to accumulating
10,500 cycles.
(2) For CFM56-5B1/2P and -5B4/2P engines, prior to accumulating
15,500 cycles.
(b) This action establishes the new LCF retirement lives of
10,500 and 15,500 cycles for the engines stated in paragraphs (a)(1)
and (a)(2) of this AD, which are published in Chapter 05 of CFM56-5B
Engine Shop Manual, CFMI-TP.SM.9.
(c) For the purpose of this AD, a ``serviceable part'' is one
that has not exceeded its respective new life limit as set out in
this AD.
(d) Except as provided in paragraph (e) of this AD, no
alternative replacement times may be approved for LPT case, P/N 338-
117-004-0.
(e) 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 Manager, Engine Certification Office. The
request should be forwarded through an appropriate FAA Principal
Maintenance Inspector, who may add comments and then send it to the
Manager, Engine Certification Office.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this airworthiness directive,
if any, may be obtained from the Engine Certification Office.
(f) 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 aircraft to a location where
the requirements of this AD can be accomplished.
Issued in Burlington, Massachusetts, on September 12, 1997.
Mark C. Fulmer,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 97-24911 Filed 9-18-97; 8:45 am]
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