[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
