[Federal Register Volume 67, Number 65 (Thursday, April 4, 2002)]
[Proposed Rules]
[Pages 16069-16071]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-8173]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NE-37-AD]
RIN 2120-AA64


Airworthiness Directives; CFM International CFM56-5B and -7B 
Series Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The Federal Aviation Administration (FAA) proposes to adopt a 
new airworthiness directive (AD) that is applicable to CFM 
International (CFMI) CFM56-5B and -7B series turbofan engines. This 
proposal would require retirement of stage 2 LPT nozzle segments and 
stage 3 LPT nozzle segments, listed in Table 1 of this proposed AD, 
from service before accumulating 25,000 cycles-since-new (CSN), or by 
October 31, 2008, whichever occurs earlier. This proposal would also 
require installation of new design (either new or reworked) nozzle 
segments, that would aid in containment of the LPT rotor in the event 
of LPT shaft failure. This proposal is prompted by a report of an LPT 
shaft failure caused by a hydromechanical unit (HMU) malfunction that 
induced a higher than anticipated LPT rotor overspeed. The actions 
specified by the proposed AD are intended to aid in containment of the 
LPT rotor in the event of LPT shaft failure, which could result in 
uncontained engine failure and damage to the airplane.

DATES: Comments must be received by June 3, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 2001-NE-37-AD, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments

[[Page 16070]]

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: ``[email protected]''. Comments sent via the Internet must contain the 
docket number in the subject line.
    The service information referenced in the proposed rule may be 
obtained from CFM International, Technical Publications Department, 1 
Neumann Way, Cincinnati, OH 45215; telephone (513) 552-2800; fax (513) 
552-2816. This information may be examined, by appointment, at the FAA, 
New England Region, Office of the Regional Counsel, 12 New England 
Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT: James Rosa, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, telephone (781) 238-7152; 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 action 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 action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2001-NE-37-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRM's

    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. 2001-NE-37-AD, 12 New England Executive 
Park, Burlington, MA 01803-5299.

Discussion

    On August 7, 2001, the FAA received a report of a CFM56-7B turbofan 
engine LPT shaft failure. CFMI determined that this failure was caused 
by an HMU malfunction that induced an LPT rotor overspeed. To aid in 
containment of the LPT rotor in the event of LPT shaft failure, the FAA 
proposes to require:
     Retirement of stage 2 LPT nozzle segments and stage 3 LPT 
nozzle segments, listed in Table 1 of this proposed AD, from service 
before accumulating 25,000 CSN, or by October 31, 2008, whichever 
occurs earlier. These limits are based on manufacturer's analysis.
     Installation of new design (either new or reworked) nozzle 
segments, that facilitate the axial clashing between the stage 3 LPT 
blades and stage 4 nozzle airfoils.

FAA's Determination of an Unsafe Condition and Proposed Actions

    Since an unsafe condition has been identified that is likely to 
exist or develop on other CFM International (CFMI) CFM56-5B and -7B 
series turbofan engines of the same type design, the proposed AD would 
require retirement of stage 2 LPT nozzle segments and stage 3 LPT 
nozzle segments, listed in Table 1 of this proposed AD, from service 
before accumulating 25,000 cycles-since-new, or by October 31, 2008, 
whichever occurs earlier. The proposed AD would also require 
installation of new design (either new or reworked) nozzle segments, 
that would aid in containment of the LPT rotor in the event of LPT 
shaft failure.

Economic Analysis

    There are approximately 3,187 CFM International (CFMI) CFM56-5B and 
-7B series engines of the affected design in the worldwide fleet. The 
FAA estimates that 910 engines installed on airplanes of U.S. registry 
would be affected by this proposed AD. The FAA also estimates that it 
would take approximately 10 work hours per engine to perform the 
proposed actions, and that the average labor rate is $60 per work hour. 
Required parts would cost approximately $34,984 per engine. Based on 
these figures, the total cost of the proposed AD on U.S. operators is 
estimated to be $32,381,440.

Regulatory Analysis

    This proposed 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 proposed rule.
    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 adding the following new 
airworthiness directive:

CFM International: Docket No. 2001-NE-37-AD.

Applicability

    This airworthiness directive (AD) is applicable to CFM 
International (CFMI) CFM56-5B and -7B series turbofan engines. These 
engines are installed on, but not limited to Boeing 737-600, -700, -
800, and -900; and Airbus A319, A320, and A321 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

[[Page 16071]]

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

    Compliance with this AD is required before accumulating 25,000 
cycles-since-new on the parts listed in Table 1 of this AD, or by 
October 31, 2008, whichever occurs earlier, unless already done.
    To aid in containment of the LPT rotor in the event of LPT shaft 
failure, which could result in uncontained engine failure and damage 
to the airplane, do the following:
    (a) Retire from service stage 2 LPT nozzle segments and stage 3 
LPT nozzle segments listed in the following Table 1, and install new 
design (either new or reworked) nozzle segments:

   Table 1.--Stage 2 and Stage 3 LPT Nozzle Segment Part Numbers To Be
                                 Retired
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         Nozzle segments                        Part numbers
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(1) Stage 2......................  338-109-104-0, 338-109-105-0, 338-109-
                                    106-0, 338-109-204-0, 338-109-205-0,
                                    338-109-206-0, 338-109-304-0, 338-
                                    109-305-0, 338-109-306-0.
(2) Stage 3......................  338-109-702-0, 338-109-802-0.
------------------------------------------------------------------------

    (b) Information on reworking stage 2 LPT nozzle segments and 
stage 3 LPT nozzle segments, listed in Table 1 of this AD, can be 
found in CFM International Service Bulletins (SB's) 720328, dated 
May 25, 2000, for CFM56-5 series engines, and SB 720241, dated May 
25, 2000, for CFM56-7 series engines.

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 Manager, Engine Certification Office (ECO). 
Operators must submit their request 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

    (d) Special flight permits may be issued in accordance with 
Secs. 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.

    Issued in Burlington, Massachusetts, on March 29, 2002.
Robert G. Mann,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 02-8173 Filed 4-3-02; 8:45 am]
BILLING CODE 4910-13-P