[Federal Register Volume 69, Number 98 (Thursday, May 20, 2004)]
[Rules and Regulations]
[Pages 29055-29058]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-11405]



[[Page 29055]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NE-26-AD; Amendment 39-13643; AD 2004-10-13]
RIN 2120-AA64


Airworthiness Directives; CFM International, S.A. CFM56-2-C, -3 
Series, and -5 Series Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), that 
applies to CFM International, S.A., CFM56-2-C, -3 series, and -5 series 
turbofan engines. This amendment requires removing from service main 
fuel pumps with bronze gear-stage bearings and installing main fuel 
pumps with bi-metal, aluminum/bronze bearings. This amendment results 
from several reports of main fuel pump bronze bearing failures. We are 
issuing this AD to prevent main fuel pump bearing failures resulting in 
fuel nozzle clogging, low pressure turbine (LPT) case burn-through, and 
damage to the airplane.

DATES: Effective June 24, 2004.

ADDRESSES: The service information referenced in this AD 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 
Federal Aviation Administration (FAA), New England Region, Office of 
the Regional Counsel, 12 New England Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Robert Green, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (781) 
238-7754; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an AD that applies to 
CFM International, S.A., CFM56-2-C, -3 series, and -5 series turbofan 
engines was published in the Federal Register on May 16, 2003, (68 FR 
26553). That action proposed to require removing from service main fuel 
pumps with bronze bearings and installing main fuel pumps with 
aluminum/bronze bearings.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Request To Update Service Bulletins to the Latest Revisions

    Two commenters request that the proposed terminating action 
reference main fuel pump configurations introduced in conjunction with 
FAA AD 2000-15-01. CFM56-3 Service Bulletin (SB) 73-0120, Revision 4, 
dated July 27, 2000, and CFM56-5 SB 73-0126, Revision 3, dated 
September 25, 2000, did not include the part configurations introduced 
by CFM56-3/3B/3C SB 73-A129 or CFM56-5 SB 73-A143. Comments were 
specifically related to CFM56-3/3B/3C SB 73-0120, Revision 4, and SB 
73-A129.
    The FAA agrees. Since the issuance of the proposed rule, CFM56-3 SB 
73-0120, Revision 4, dated July 27, 2000, and CFM56-5 SB 73-0126, 
Revision 3, dated September 25, 2000, have been revised to include 
hardware defined by CFM56-3/3B/3C SB 73-A129 and CFM56-5 SB 73-A143. 
The latest revisions of CFM56-2 SB 73-0104, CFM56-3 SB 73-0120, and 
CFM56-5 SB 73-0126 are referenced in the final rule.

Request for Additional Replacement Parts as Alternative Method of 
Compliance (AMOC)

    Three commenters request that additional replacement parts be 
specified as AMOCs. The commenters believe that dual-sourced parts can 
be less costly.
    The FAA does not agree. The AD does not make specific hardware 
replacement recommendations. The AD mandates that unserviceable parts 
be replaced with serviceable parts. The AD did not change as a result 
of this comment.

Main Fuel Pump Failure Mode Clarification

    One commenter provided additional information on the documented 
failure modes and requests that the Summary and Discussion statements 
be modified. The modification would note that the bi-metal bearing was 
introduced to prevent main fuel pump failures that result in a fuel 
flow degradation. This degradation could lead to diminished engine 
start or in-flight restart capability.
    The FAA agrees. The initial introduction of the bi-metal bearing 
was intended to address a specific failure mode that is not the subject 
of this AD. A further benefit of the bi-metal, aluminum/bronze bearings 
is that they are less likely to generate debris and create the unsafe 
condition that this AD addresses. The Summary paragraph in the AD has 
been modified to better describe the debris-related failure mode. We 
have noted the commenter's request to clarify the Discussion section of 
the NPRM; however, the Discussion section does not carry over to the 
final rule.

Request To Modify the Economic Analysis

    One commenter believes that the number of engines affected is 
incorrect. The commenter has provided additional information on the 
quantity of engines affected and the cost of incorporating bi-metal 
aluminum/bronze bearings. The commenter believes that there would be no 
additional labor or material costs for converting affected main fuel 
pumps because the conversion should occur within the scheduled 
refurbishment of the pump.
    The FAA partially agrees. We agree that the initial estimate of the 
number of engines affected was too high and that the assumption that an 
affected main fuel pump would be replaced with a new, zero-time part 
was unrealistic. However, we do not agree that all of the material 
costs associated with the conversion of a main fuel pump to a 
serviceable part would be achieved during regularly scheduled 
maintenance. The number of affected engines and total cost of 
incorporating the bi-metal bearings have been adjusted based on the 
estimated hardware consumption to date. The corrective action cost was 
also adjusted to reflect bearing incorporation by refurbishment. The 
bearing hardware has been treated as an incremental cost as there will 
be unscheduled conversions either because of forced main fuel pump 
removals or differing workscope practices. The Economic Analysis has 
been revised in the final rule.

Request To Clarify Part Number Effectivity for CFM56-2-C Engines

    One commenter requests that compliance paragraph (a)(2) end with 
the phrase ``if SB 73-081 is accomplished.'' The commenter believes 
that by adding this phrase the part numbers to be removed from service 
will be clarified.
    The FAA does not agree. Compliance paragraph (a)(2) states the 
following: ``For all CFM56-2-C series engines that have incorporated 
CFM International Service Bulletin (SB) (CFM56-2) 73-081 * * *''. The 
final rule did not change as a result of this comment.

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Request To Clarify Part Number Effectivity for CFM56-3 Engines

    One commenter requests that compliance paragraph (b)(3) end with 
the phrase ``if SB 73-087 is accomplished.'' The commenter believes 
that by adding this phrase, the part numbers to be removed from service 
will be clarified.
    The FAA does not agree. Compliance paragraph (b)(3) states the 
following: ``For all CFM56-3 series engines that have incorporated SB 
(CFM56-3) 73-087 * * *''. The final rule did not change as a result of 
this comment.
    One commenter requests that compliance paragraph (b)(3) include a 
phrase to reference the lack of compliance with CFM56-3 SB 73-120. The 
commenter believes that by adding the phrase ``but have not 
incorporated SB 73-120,'' as a qualification for Compliance paragraph 
(b)(3), the part numbers to be removed from service will be clarified.
    The FAA does not agree. The referenced part numbers in paragraph 
(b)(3) reflect the lack of compliance with CFM56-3 SB 73-120. The final 
rule did not change as a result of this comment.

Request To Modify the Compliance Statement

    One commenter requests that the compliance statement in the 
Regulatory section of the AD be changed from ``required at the next 
engine removal, engine module removal, or main fuel pump removal'' to 
``required at the next shop visit, or main fuel pump replacement.'' The 
commenter suggests that the next shop visit should be defined as 
removal from the aircraft for the purposes of maintenance and 
inspection except when removed for the purpose of performing field 
maintenance type activities at a maintenance facility in lieu of 
performing them on wing. The commenter suggests that a main fuel pump 
shop visit would be defined as removal of the pump for the purpose of 
sending it to a shop capable of performing the specified modification 
regardless of other planned pump maintenance. The commenter suggests 
that an engine module would be clarified as the fan, core, or low-
pressure turbine to avoid confusion with any other parts of the engine 
that might be referred to as a module. The commenter feels that these 
changes would allow easier scheduling of the required corrective 
actions.
    The FAA partially agrees. We agree that next engine shop visit or 
main fuel pump replacement is a better description of the intended 
threshold. However we do not agree with the proposed qualifications for 
each action. For simplification and to assure expedient incorporation 
at the first opportunity, we have revised the compliance statement to 
``next engine shop visit or main fuel pump replacement, whichever comes 
earlier.'' We have added a definitions paragraph (e) to the Regulatory 
Section that defines ``engine shop visit'' as any maintenance that 
includes the separation of an engine casing flange.

Request To Extend the Compliance Terminating Action Date

    Two commenters state that the compliance terminating action date 
will result in premature main fuel pump removals. One of the commenters 
requests that the compliance terminating action date of January 1, 
2007, be extended.
    The FAA disagrees. The corrective action compliance period allows 
for sufficient planning for main fuel pump replacement during regularly 
scheduled maintenance. The projected incorporation rate does not allow 
an extension of the terminating action date.

Request To Include Downstream Fuel Filter as an AMOC

    One commenter requests the corrective action requirement be revised 
to include the incorporation of a downstream fuel filter as an AMOC to 
preclude fuel nozzle clogging and related LPT overtemperature damages. 
The commenter referenced CFM56-3 SB 73-0134. The commenter states that 
together with the main fuel pump interstage filter, the addition of a 
downstream fuel filter will provide greater engine protection. The 
commenter also states that a downstream fuel filter is more economical 
than the proposed main fuel pump modification.
    The FAA does not agree. Analysis based on fleet experience 
indicates safety margins are maintained with the conversion of the bi-
metal, gear-stage bearings. Vendor data shows that the main fuel pump 
gear-stage bearings would normally be replaced during pump 
refurbishment. Recommending incorporation of the downstream fuel filter 
is not justified at this time. The AD did not change as a result of 
this comment.

Typographical Error Corrected for CFM56-2-C Engine

    After the issuance of the NPRM, we discovered that the CFM56-2-C 
engine had been incorrectly listed as CFM56-2C. We have corrected the 
engine model in the AD.

Regulatory Text Corrections

    Paragraph (a)(2) of the NPRM Regulatory text for the CFM56-2-C 
included pump part numbers (P/Ns) 301-778-801-0, 301-778-802-0, 301-
778-804-0, and 301-778-805-0 with pumps that had incorporated CFM56-2 
SB 73-081. Further review revealed these parts were originally CFM56-3 
hardware that could incorporate bronze bearings following CFM56-3 SB 
73-087. CFM56-2 SB 73-0070 subsequently released these parts for use on 
the CFM56-2-C engine. We have added a new Regulatory text paragraph 
(a)(3) in the AD to highlight that these pumps could incorporate bronze 
bearings by a CFM56-3 SB. The codification of paragraph (a) is changed 
from (a)(1), (2), (3), (4) to (a)(1), (2), (3), (4), and (5) in the AD 
as a result of this comment.
    The addition of Regulatory text paragraph (a)(3) in the AD results 
in the addition of Regulatory text paragraph (d)(3) in the AD. The 
codification of paragraph (d) is changed from (d)(1), (2), and (3) to 
(d)(1), (2), (3), and (4) in the AD.
    Paragraph (a)(3) of the NPRM Regulatory text for the CFM56-2-C 
inadvertently referenced CFM56-2-C SB 73-078 as defining P/N 301-779-
006-0. That SB is incorrect. The correct SB that defines P/N 301-779-
006-0 is CFM56-2 SB 73-A113. We have corrected the SB reference in the 
newly recodified paragraph (a)(4) of the AD.
    Paragraph (b)(2) of the NPRM Regulatory text for the CFM56-3 
inadvertently referenced CFM56-3 SB 73-082 as defining pump P/N 301-
779-006-0. That SB is incorrect. The correct SB that defines pump P/N 
301-779-006-0 is CFM56-3 SB 73-A129. We have corrected the SB reference 
in paragraph (b)(2) of the AD.
    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes described 
previously. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Economic Analysis

    There are approximately 6,160 CFM56-2-C, -3 series, and -5 series 
turbofan engines of the affected design in the worldwide fleet. The FAA 
estimates that 975 engines installed on airplanes of U.S. registry 
would be affected by this AD. Assuming an average incorporation rate of 
325 pumps per year and an incremental material cost of $8,000, the cost 
for U.S.

[[Page 29057]]

operators to replace the bronze bearings is estimated to be $2,600,000 
per year.

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

0
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

0
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]

0
2. Section 39.13 is amended by adding a new airworthiness directive to 
read as follows:

2004-10-13 CFM International, S.A.: Amendment 39-13643. Docket No. 
2002-NE-26-AD.

Applicability

    This airworthiness directive (AD) applies to CFM International, 
S.A. CFM56-2-C, -3 series, and -5 series turbofan engines. These 
engines are installed on, but not limited to, Airbus Industrie A319 
and A320, Boeing 737, and McDonnell Douglas DC-8 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 (f) 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 at the next engine shop 
visit, or main fuel pump replacement, whichever is earlier, after 
the effective date of this AD, but no later than January 1, 2007, 
unless already done.
    To prevent main fuel pump bearing failures resulting in fuel 
nozzle clogging, low pressure turbine (LPT) case burn-through, and 
damage to the airplane, do the following:

Main Fuel Pumps Installed on CFM56-2-C Engines

    (a) For CFM56-2-C engines, do the following:
    (1) Remove from service main fuel pumps part number (P/N) 301-
779-002-0.
    (2) For all CFM56-2-C series engines that have incorporated CFM 
International Service Bulletin (SB) (CFM56-2) 73-081, remove from 
service main fuel pumps P/N 301-776-101-0, P/N 301-776-102-0, P/N 
301-776-103-0, P/N 301-776-104-0, P/N 301-776-105-0, P/N 301-776-
106-0, P/N 301-776-108-0, P/N 301-776-109-0, P/N 301-776-110-0, P/N 
301-776-111-0, P/N 301-776-112-0, and P/N 301-776-113-0.
    (3) For all CFM56-2-C series engines that have incorporated SB 
(CFM56-3) 73-087, remove from service main fuel pumps P/N 301-778-
801-0, P/N 301-778-802-0, P/N 301-778-804-0, and P/N 301-778-805-0.
    (4) For all CFM56-2-C engines that have incorporated SB (CFM56-
2-C) 73-A113, remove from service main fuel pumps P/N 301-779-006-0.
    (5) Install a serviceable main fuel pump. Information on 
converting removed pumps into serviceable pumps can be found in SB 
(CFM56-2) 73-0104, Revision 3, dated December 17, 2003.

Main Fuel Pumps Installed on CFM56-3 Series Engines

    (b) For CFM56-3 series engines, do the following:
    (1) Remove main fuel pumps P/N 301-779-002-0.
    (2) For all CFM56-3 series engines that have incorporated SB 
(CFM56-3) 73-A129, remove from service main fuel pumps P/N 301-779-
006-0.
    (3) For all CFM56-3 series engines that have incorporated SB 
(CFM56-3) 73-087, remove from service main fuel pumps P/N 301-778-
801-0, P/N 301-778-802-0, P/N 301-778-804-0, and P/N 301-778-805-0.
    (4) Install a serviceable main fuel pump. Information on 
converting removed pumps into serviceable pumps can be found in SB 
(CFM56-3) 73-0120, Revision 5, dated December 17, 2003.

Main Fuel Pumps Installed on CFM56-5 Series Engines

    (c) For CFM56-5 series engines, do the following:
    (1) Remove main fuel pumps P/N 301-785-502-0.
    (2) For all CFM56-5 series engines that have incorporated SB 
(CFM56-5A) 73-A143, remove from service main fuel pumps P/N 301-785-
504-0.
    (3) Install a serviceable main fuel pump. Information on 
converting removed pumps into serviceable pumps can be found in SB 
(CFM56-5A) 73-0126, Revision 4, dated December 17, 2003.

Do Not Install Main Fuel Pumps

    (d) After the effective date of this AD, do not install the 
following P/N main fuel pumps onto any engine:
    (1) For all engines: P/N 301-779-002-0, P/N 301-779-006-0, P/N 
301-785-502-0, and P/N 301-785-504-0.
    (2) For CFM56-2-C engines that have incorporated SB (CFM56-2-C) 
73-081 but have not incorporated SB (CFM56-2-C) 73-0104: P/N 301-
776-101-0, P/N 301-776-102-0, P/N 301-776-103-0, P/N 301-776-104-0, 
P/N 301-776-105-0, P/N 301-776-106-0, P/N 301-776-108-0, P/N 301-
776-109-0, P/N 301-776-110-0, P/N 301-776-111-0, P/N 301-776-112-0, 
and P/N 301-776-113-0.
    (3) For CFM56-2-C engines that have incorporated SB (CFM56-3) 
73-087 but have not incorporated SB (CFM56-3) 73-0120: P/N 301-778-
801-0, P/N 301-778-802-0, P/N 301-778-804-0, and P/N 301-778-805-0.
    (4) For CFM56-3 series engines that have incorporated SB (CFM56-
3) 73-087 but have not incorporated SB (CFM56-3) 73-0120: P/N 301-
778-801-0, P/N 301-778-802-0, P/N 301-778-804-0, and P/N 301-778-
805-0.

Definition

    (e) An engine shop visit is defined as any maintenance that 
includes the separation of an engine casing flange.

Alternative Methods of Compliance (AMOC)

    (f) An AMOC 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

    (g) 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 aircraft to a location where 
the requirements of this AD can be done.

Documents That Have Been Incorporated by Reference

    (h) None.

[[Page 29058]]

Effective Date

    (i) This amendment becomes effective on June 24, 2004.

    Issued in Burlington, Massachusetts, on May 13, 2004.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 04-11405 Filed 5-19-04; 8:45 am]
BILLING CODE 4910-13-P