[Federal Register: September 9, 2002 (Volume 67, Number 174)]
[Rules and Regulations]               
[Page 57146-57147]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr09se02-4]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-ANE-64-AD; Amendment 39-12876; AD 97-09-02R1]
RIN 2120-AA64

 
Airworthiness Directives; CFM International CFM56 Series Turbofan 
Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment revises an existing airworthiness directive 
(AD) that is applicable to CFM International (CFMI) CFM56-5C series 
turbofan engines. This action establishes new life limits for certain 
low pressure turbine rotor (LPTR) stage 3 disks and all high pressure 
turbine rotor (HPTR) disks listed in the existing AD. This amendment is 
prompted by the results of an extensive life management program 
performed by the manufacturer. The actions specified in this AD are 
intended to prevent low-cycle-fatigue (LCF) failure of certain HPTR 
front shafts, HPTR front air seals, HPTR disks, booster spools, and 
LPTR stage 3 disks, which could result in an uncontained engine failure 
and damage to the airplane.

DATES: Effective September 24, 2002.
    Comments for inclusion in the Rules Docket must be received on or 
before November 8, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 95-ANE-64-AD, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may be inspected at 
this location, by appointment, between 8 a.m. and 4:30 p.m., Monday 
through Friday, except Federal holidays. Comments may also be sent via 
the Internet using the following address: ``9-ane-adcomment@faa.gov''. 
Comments sent via the Internet must contain the docket number in the 
subject line.

FOR FURTHER INFORMATION CONTACT: Glorianne Niebuhr, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (781) 
238-7132; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: On April 22, 1997, the FAA issued AD 97-09-
02, Amendment 39-9998 (62 FR 23642), applicable to CFMI CFM56-5C series 
turbofan engines, to reduce the LCF retirement lives of certain HPTR 
front shafts, HPTR front air seals, booster spools, HPTR disks, and 
LPTR stage 3 disks. That action was prompted by results of a refined 
life analysis performed by the manufacturer which revealed minimum 
calculated LCF lives lower than published LCF retirement lives. This 
condition could result in LCF failure of certain HPTR front shafts, 
HPTR front air seals, HPTR disks, booster spools, and LPTR stage 3 
disks, which could result in an uncontained engine failure and damage 
to the airplane. Since AD 97-09-02 was issued, the manufacturer 
conducted an extensive life management program for the LPTR stage 3 
disks installed in CFM56-5C2/G and -5C3/G engines and HPTR disks 
installed in all CFM56-5C series engines. This consisted of a mission 
cycle based on field data, an updated 2D heat transfer and stress 
analysis, and a 3D finite element analysis. The results indicated 
higher LCF retirement lives for certain LPTR stage 3 disks and all HPTR 
disks than the lives published in AD 97-09-02. Therefore, this revision 
establishes new life limits for LPTR stage 3 disks part numbers (P/N's) 
337-001-602-0 and 337-001-605-0 installed in CFM56-5C2/G and -5C3/G 
engines and HPTR disk P/N 1498M43P04 installed in all CFM56-5C series 
engines. Except for CFM56-5C4 engines, the LCF retirement lives for 
LPTR stage 3 disks part numbers (P/N's) 337-001-602-0 and 337-001-605-0 
are now extended to 20,000 cycles-since-new (CSN) in Chapter 05 of the 
CFM56-5C Engine Shop Manual, CFMI-TP.SM.8. The LCF retirement lives for 
HPTR disk part number 1498M43P04 are now extended to 7,800 cycles-
since-new (CSN) in Chapter 05 of the CFM56-5C Engine Shop Manual, CFMI-
TP.SM.8. The cyclic lives of these LPTR stage 3 disks installed in 
CFM56-5C4 engines, and the cyclic lives of HPTR front shafts P/N's 
1498M40P03, 1498M40P05, and 1498M40P06; HPTR front air seals, P/N's 
1523M34P02 and 1523M34P03; and booster spools, P/N 337-005-210-0, 
remain unchanged.

FAA's Determination of an Unsafe Condition and Required Actions

    Although these affected engine models are not used on any airplanes 
that are registered in the United States, the possibility exists these 
engine models could be used on airplanes that are registered in the 
United States in the future. This AD establishes new life limits for 
certain LPTR stage 3 disks and all HPTR disks listed in the existing 
AD.

Immediate Adoption of This AD

    Since there are currently no domestic operators of CFM56-5C series 
turbofan engines, notice and opportunity for prior public comment are 
unnecessary. Therefore, a situation exists that allows the immediate 
adoption of this regulation.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to

[[Page 57147]]

modify the 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 that summarizes each FAA-
public contact concerned with the substance of this AD will be filed in 
the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 95-ANE-64-AD.'' The postcard will be date stamped and 
returned to the commenter.

Regulatory Analysis

    This final rule does not have federalism implications, as defined 
in Executive Order 13132, because it 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. Accordingly, 
the FAA has not consulted with state authorities prior to publication 
of this final rule.
    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 the 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 
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.

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 removing Amendment 39-9998 (62 FR 
23642, May 1, 1997), and by adding a new airworthiness directive, 
Amendment 39-12876, to read as follows:

97-09-02R1 CFM International: Amendment 39-12876. Docket No. 95-ANE-
64-AD. Revises AD 97-09-02, Amendment 39-9998.

Applicability

    This airworthiness directive (AD) is applicable to CFM 
International (CFMI) CFM56-5C2/G, -5C3/G, and -5C4 series turbofan 
engines. These engines are installed on, but not limited to Airbus 
Industrie A340 series airplanes.

    Note 1: This 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 (i) 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

    Compliance with this AD is required as indicated, unless already 
done.
    To prevent a low-cycle-fatigue (LCF) failure of the high 
pressure turbine rotor (HPTR) front shaft, HPTR front air seal, HPTR 
disk, booster spool, and low pressure turbine rotor (LPTR) stage 3 
disk, which could result in an uncontained engine failure and damage 
to the airplane, do the following:
    (a) Remove from service HPTR front shafts, part numbers (P/N's) 
1498M40P03, 1498M40P05, and 1498M40P06, before accumulating 8,400 
cycles-since-new (CSN), and replace with a serviceable part.
    (b) Remove from service HPTR front air seals, P/N's 1523M34P02 
and 1523M34P03, before accumulating 4,000 CSN, and replace with a 
serviceable part.
    (c) Remove from service HPTR disks, P/N 1498M43P04, before 
accumulating 7,800 CSN, and replace with a serviceable part.
    (d) Remove from service booster spools, P/N 337-005-210-0, 
before accumulating 13,000 CSN, and replace with a serviceable part.
    (e) For CFM56-5C4 engines only, remove from service LPTR stage 3 
disks, P/N's 337-001-602-0 and 337-001-605-0, before accumulating 
7,000 CSN, and replace with a serviceable part.
    (f) For CFM56-5C2/G and -5C3/G engines only, remove from service 
LPTR stage 3 disks P/N's 337-001-602-0 and 337-001-605-0, before 
accumulating 20,000 CSN, and replace with a serviceable part.
    (g) This action establishes the new LCF retirement lives stated 
in paragraphs (a) through (f) of this AD, which are published in 
Chapter 05 of the CFM56-5C Engine Shop Manual, CFMI-TP.SM.8.
    (h) 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.

Alternative Methods of Compliance

    (i) 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 (ECO). 
The request must be forwarded through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, 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.

Special Flight Permits

    (j) Special flight permits may be issued in accordance with 
Sec. Sec.  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 done.

Effective Date

    (k) This amendment becomes effective on September 24, 2002.


    Issued in Burlington, Massachusetts, on August 29, 2002.
Francis A. Favara,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 02-22761 Filed 9-6-02; 8:45 am]
BILLING CODE 4910-13-P