[Federal Register Volume 61, Number 251 (Monday, December 30, 1996)]
[Rules and Regulations]
[Pages 68570-68572]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-32435]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-ANE-47; Amendment 39-9854; AD 96-25-11]
RIN 2120-AA64


Airworthiness Directives; CFM International Model CFM56-3C-1 and 
CFM56-3B-2 Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to all CFM International (CFMI) CFM56-3C-1 and certain 
CFM56-3B-2 engines, that currently requires the removal from service of 
certain fan disk and fan blade hardware, and limits the use of CFM56-
3C-1 thrust levels. This amendment requires removal of additional fan 
blade hardware, requires an Airplane Flight Manual (AFM) revision to 
impose thrust level limitations for airplanes equipped with affected 
engines, and requires the installation of redesigned fan blades as a 
terminating action to the thrust level limitations of this AD. The 
existing AD requirements for certain CFM56-3B-2 engines are unchanged 
and carried over into this final rule AD. This amendment is prompted by 
the availability of redesigned fan blades that are not subject to the 
thrust level limitations, and the need to clarify the AD requirements 
by deleting references to specific AFMs. The actions specified by this 
AD are intended to prevent a fan blade failure that can result in 
complete loss of engine power.

DATES: Effective January 29, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of January 29, 1997.

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplanes, Publications Department, 
P.O. Box 3707, Seattle, WA 98124-2207; telephone (206) 544-9058, fax 
(206) 544-9178; and CFM International, Technical Publications 
Department, 1 Neumann Way, Cincinnati, OH 45215; telephone (513) 552-
2981, fax (513) 552-2816. This information may be

[[Page 68571]]

examined at the Federal Aviation Administration (FAA), New England 
Region, Office of the Assistant Chief Counsel, 12 New England Executive 
Park, Burlington, MA 01803-5299; or at the Office of the Federal 
Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Glorianne Messemer, Aerospace 
Engineer, Engine Certification Office, FAA, Engine and Propeller 
Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; 
telephone (617) 238-7132, fax (617) 238-7199.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 89-13-51, 
Amendment 39-6425 (55 FR 1401, January 16, 1990), which is applicable 
to all CFM International (CFMI) CFM56-3C-1 and certain CFM56-3B-2 model 
turbofan engines, was published in the Federal Register on October 16, 
1995 (60 FR 53550). That action proposed to require removal of 
additional fan blade hardware, thrust level limitations for airplanes 
equipped with affected engines, and the installation of redesigned fan 
blades as a terminating action to the thrust level limitations of this 
AD. The existing AD requirements for certain CFM56-3B-2 engines are 
unchanged and carried over into this final rule AD. The actions are 
required to be accomplished in accordance with Boeing Service Bulletin 
(SB) No. 737-71-1203, Revision 10, dated July 21, 1994, and CFMI CFM56-
3/-3B/-3C SB No. 72-543, Revision 4, dated July 29, 1992.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    One commenter states that incorrect fan blade part numbers, 
7M99P08, 9527M99P09, 9527M99P10, 9527M99P11, and 1285M39P01 were added 
to compliance paragraph (c). The FAA concurs and has revised this final 
rule accordingly.
    Two comments support the rule as proposed.
    Although no comments were received regarding the compliance end-
date noted in compliance paragraph (c), the FAA has replaced June 30, 
1996, with August 30, 1997, based on the anticipated effective date of 
this 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.
    There are approximately 289 CFMI CFM56-3C-1 and CFM56-3B-2 series 
engines of the affected design in the worldwide fleet. The FAA has been 
advised by the manufacturer that there are no engines 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.
    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 USC 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing Amendment 39-6425 (55 FR 
1401, January 16, 1990) and by adding a new airworthiness directive, 
Amendment 39-9854, to read as follows:

96-25-11  CFM International: Amendment 39-9854. Docket 95-ANE-47. 
Supersedes AD 89-13-51, Amendment 39-6425.

    Applicability: CFM International (CFMI) CFM56-3B-2 and CFM56-3C-
1 model turbofan engines installed on but not limited to Boeing 737 
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 (g) 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 fan blade failure that may result in complete loss of 
power, accomplish the following:
    (a) For CFM56-3C-1 model turbofan engines:
    (1) Prior to further flight, remove from service stage 1 fan 
disk Part Number (P/N) 335-014-511-0 that have operated at 
unrestricted CFM56-3C-1 thrust levels with fan blade P/N's 
9527M99P08, 9527M99P09, 9527M99P10, 9527M99P11, or 1285M39P01 and 
replace with a serviceable fan disk.
    (2) Prior to further flight, remove from service stage 1 fan 
blade P/N's 9527M99P08, 9527M99P09, 9527M99P10, 9527M99P11, and 
1285M39P01 that have operated at unrestricted CFM56-3C-1 thrust 
levels and replace with a serviceable fan blade.
    (b) For CFM56-3C-1 model turbofan engines equipped with fan 
blade P/N's 9527M99P08, 9527M99P09, 9527M99P10, 9527M99P11, or 
1285M39P01:
    (1) Prior to further flight, for aircraft that have not already 
complied with any of the revision levels 3 through 10 of Boeing 
Service Bulletin (SB) No. 737-71-1203, incorporate the provisions of 
Boeing SB No. 737-71-1203, Revision 10, dated July 21, 1994, as 
described in item III titled, ``Accomplishment Instructions'', part 
V, ``Airplane Wiring Modification for Operation at 22,000 Pounds 
Thrust Levels with two CFM56-3C-1 Engines Installed.''
    (2) Prior to further flight, revise the engine limitations 
section of the Boeing 737-400 series Airplane Flight Manuals (AFM) 
by adding the operational restrictions contained in Appendix I. This 
may be accomplished by inserting a copy of Appendix I of this AD in 
the AFM.
    (3) Operate engines at or below CFM56-3B-2 thrust levels, or in 
accordance with the limitations contained in Appendix I of this AD.

[[Page 68572]]

Appendix I--Operational Restrictions Referenced in Paragraphs 
(b)(2) and (b)(3)

    (a) Use of fan speed (N1) values for take-off and maximum 
continuous thrust levels at CFM56-3C-1 (23.5K) thrust levels are 
restricted.
    (b) The following limitations must be observed for all CFM56-3C-
1 (23.5K) operations:
    (1) Airport pressure altitude must be 2,500 feet or less for 
take-off.
    (2) The auto-throttle must be OFF and the thrust must be set 
manually for take-off.
    (3) Both power management controls (PMCs) must be operative for 
airplane dispatch.
    (4) Maximum take-off thrust for CFM56-3C-1 (23.5K) rating must 
not be used above 5,000 feet pressure altitude, or the 5-minute time 
limit, whichever occurs first.
    (5) Maximum continuous or maximum climb thrust for CFM56-3C-1 
(23.5K) rating must not be used above 10,000 feet pressure altitude.
    (6) LANDING:
    (i) For landing at destination airport or for less than maximum 
landing weight the CFM56-3B-2 (22K) go-around rating should be used.
    (ii) Go-around at CFM56-3C-1 (23.5K) rating should be used when 
returning to departure airport or diverting in an emergency 
situation providing airport pressure altitude is 2,500 feet or less 
and the landing weight is greater than maximum landing weight.

 End of Appendix I

    (c) For CFM56-3C-1 model turbofan engines equipped with fan 
blade P/N's 9527M99P08, 9527M99P09, 9527M99P10, 9527M99P11, or 
1285M39P01, install fan blade P/N's 1590M21P01, 1663M24P01, 
1663M24P02, 1663M24P03, 1663M24P04, or 1663M24P05 in accordance with 
CFMI CFM56-3/-3B/-3C SB No. 72-543, Revision 4, dated July 29, 1992, 
prior to August 30, 1997. The installation of new fan blades in 
accordance with this paragraph constitutes terminating action to the 
thrust level limitations required by paragraph (b) of this AD.
    (d) For CFM56-3B-2 model turbofan engines, Serial Number (S/N) 
725101, 725102, 725103, 725104, 725105, 725107, 725108, 725141, and 
725142:
    (1) Prior to further flight, remove from service stage 1 fan 
disk P/N 335-014-511-0 that have operated at unrestricted CFM56-3C-1 
thrust levels with fan blade P/N's 9527M99P08, 9527M99P09, 
9527M99P10, 9527M99P11, or 1285M39P01 and replace with a serviceable 
fan disk.
    (2) Prior to further flight, remove from service stage 1 fan 
blade P/N's 9527M99P08, 9527M99P09, 9257M99P10, 9257M99P11, and 
1285M39P01 that have operated at unrestricted CFM56-3C-1 thrust 
levels and replace with a serviceable fan blade.

     Note 2: Ground running for maintenance purposes should be 
conducted in accordance with CFM56-3B-2 rating limitations.
    (e) Fan disk removal, fan blade removal, and airplane wiring 
modifications done in accordance with AD 89-13-51 satisfies the 
corresponding requirements of paragraphs (a), (b), and (d) of this 
AD.
    (f) For the purpose of this AD, unrestricted CFM56-3C-1 thrust 
levels include operation at either of the following:
    (1) More than CFM56-3B-2 maximum take-off thrust above 5,000 
feet pressure altitude.
    (2) More than CFM56-3B-2 maximum continuous or maximum climb 
thrust above 10,000 feet pressure altitude.
    (g) 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 3: Information concerning the existence of approved 
alternative method of compliance with this AD, if any, may be 
obtained from the Engine Certification Office.

    (h) 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.
    (i) The actions required by this AD shall be done in accordance 
with the following SBs:

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         Document No.            Pages   Revision           Date        
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Boeing SB No. 737-71-1203.....     1-35        10  July 21, 1994.       
    Total pages: 35.                                                    
CFMI:                                                                   
  CFM56-3/-3B/-3C.............                                          
  SB No. 72-543...............     1-26         4  July 29, 1992        
    Total pages: 26.                                                    
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    This incorporation by reference was approved by the Director of 
the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR 
part 51. Copies may be obtained from Boeing Commercial Airplanes, 
Publications Department, P.O. Box 3707, Seattle, WA 98124-2207; 
telephone (206) 544-9058, fax (206) 544-9178; and CFM International, 
Technical Publications Department, 1 Neumann Way, Cincinnati, OH 
45215; telephone (513) 552-2981, fax (513) 552-2816. Copies may be 
inspected at the FAA, New England Region, Office of the Assistant 
Chief 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.
    (j) This amendment becomes effective on January 29, 1997.

    Issued in Burlington, Massachusetts, on December 4, 1996.
James C. Jones,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 96-32435 Filed 12-27-96; 8:45 am]
BILLING CODE 4910-13-U