AD Amdt-39-10286

final rule

Airworthiness Directives; CFM International CFM56-5B/2P Series Turbofan Engines

AD Number
Amdt-39-10286
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Docket No. 97-ANE-29-AD
FR Citation
63 FR 3031
Technical illustration of an aircraft turbine engine assembly
Problem area Engine

Applicability

TypeManufacturerModelDetails
engine CFM International CFM56-5B/2P Series Airworthiness Directives; CFM International CFM56-5B/2P Series Turbofan Engines

Unsafe Condition

A low cycle fatigue (LCF) failure of the low pressure turbine (LPT) case due to minimum calculated LCF lives significantly lower than the published retirement life.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Reduce the low cycle fatigue (LCF) retirement life for certain low pressure turbine (LPT) cases. Operators must comply with the revised life limits specified in the engine manufacturer's instructions.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Before further flight

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Affected Aircraft

CFM International CFM56-5B/2P series turbofan engines with certain low pressure turbine (LPT) cases affected by the refined life analysis.

AI-generated summary from the source AD text. Verify against the official source before acting.

Federal Register Abstract

This amendment adopts a new airworthiness directive (AD), applicable to CFM International (CFMI) CFM56-5B/2P series turbofan engines, that requires a reduction of the low cycle fatigue (LCF) retirement life for certain low pressure turbine (LPT) cases. This amendment 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 this AD are intended to prevent a LCF failure of the LPT case, which could result in damage to the aircraft.

Document Text

Show stored source text (verify against official source)
[Federal Register Volume 63, Number 13 (Wednesday, January 21, 1998)]
[Rules and Regulations]
[Pages 3031-3032]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 98-1326]



[[Page 3031]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-ANE-29-AD; Amendment 39-10286; AD 98-02-04]
RIN 2120-AA64


Airworthiness Directives; CFM International CFM56-5B/2P Series 
Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to CFM International (CFMI) CFM56-5B/2P series turbofan 
engines, that requires a reduction of the low cycle fatigue (LCF) 
retirement life for certain low pressure turbine (LPT) cases. This 
amendment 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 this AD are intended to prevent a LCF failure of 
the LPT case, which could result in damage to the aircraft.

DATES: Effective March 23, 1998.

ADDRESSES: This information may be examined at the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, 12 New England Executive Park, Burlington, MA; or at the 
Office of the Federal Register, 800 North Capitol Street, NW., suite 
700, Washington, DC.

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: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to CFM International (CFMI) CFM56-5B/
2P series turbofan engines was published in the Federal Register on 
September 19, 1997 (62 FR 49179). That action proposed to require a 
reduction of the low cycle fatigue (LCF) retirement life for certain 
low pressure turbine (LPT) cases.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comment received.
    One commenter supports the rule as proposed.
    After careful review of the available data, including the comment 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule as proposed.
    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 are 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 AD is 
estimated to be $40,423 per engine.
    The regulations adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under 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 under the criteria of the Regulatory 
Flexibility Act. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to 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

    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 adding the following new 
airworthiness directive:

98-02-04  CFM International: Amendment 39-10286. Docket 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.


[[Page 3032]]


    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.
    (g) This amendment becomes effective on March 23, 1998.

    Issued in Burlington, Massachusetts, on January 7, 1998.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 98-1326 Filed 1-20-98; 8:45 am]
BILLING CODE 4910-13-U

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