[Federal Register Volume 63, Number 183 (Tuesday, September 22, 1998)]
[Rules and Regulations]
[Pages 50482-50484]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-25007]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-ANE-55-AD; Amendment 39-10761; AD 98-19-20]
RIN 2120-AA64
Airworthiness Directives; CFM International CFM56-7B and -7B/2
Series Turbofan Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment adopts a new airworthiness directive (AD) that
is applicable to CFM International CFM56-7B and -7B/2 series turbofan
engines. This action requires initial and repetitive inspections of
certain hydromechanical unit (HMU) overspeed governor (OSG) spool
valves for out-of-specification conditions or the presence of heavy
contact or galling on the spool valve, and optional installation of an
improved HMU as a terminating action to the inspections. This amendment
is prompted by a report of a flameout that occurred on a flight test
engine due to a failed HMU OSG spool valve shaft. The actions specified
in this AD are intended to prevent failure of the HMU OSG spool valve
shaft, and subsequent engine flameout.
DATES: Effective October 7, 1998.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of October 7, 1998.
Comments for inclusion in the Rules Docket must be received on or
before October 7, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), New England Region, Office of the Regional
Counsel, Attention: Rules Docket No. 98-ANE-55-AD, 12 New England
Executive Park, Burlington, MA 01803-5299. Comments may also be sent
via the Internet using the following address: ``9-ad-
[email protected]''. Comments sent via the Internet must contain
the docket number in the subject line.
The service information referenced in this AD may be obtained from
CFM International, Technical Publications Department, 1 Neumann Way,
Cincinnati, OH 45215; telephone (513) 552-2981, fax (513) 552-2816.
This information may be examined at the FAA, New England Region, Office
of the Regional 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.
FOR FURTHER INFORMATION CONTACT: Robert Ganley, Aerospace Engineer,
Engine Certification Office, FAA, Engine and Propeller Directorate, 12
New England Executive Park, Burlington, MA 01803-5299; telephone (781)
238-7138; fax (781) 238-7199.
SUPPLEMENTARY INFORMATION: The Federal Aviation Administration (FAA)
has received a report of an engine flameout on a CFM International
CFM56-7B series turbofan flight test engine. Due to the similarity of
the engines, CFM56-7B/2 series engines could also be affected.
Investigation revealed that the flameout occurred as a result of a
failed hydromechanical unit (HMU) overspeed governor (OSG) spool valve
shaft. The shaft failed as a result of the spinning spool's contact
with the valve sleeve inner diameter. Further investigation revealed
out-of-specification conditions may exist that can contribute to rotor
contact. This condition, if not corrected, could result in a failure of
the HMU OSG spool valve shaft, and subsequent engine flameout.
The FAA has reviewed and approved the technical contents of CFM
International CFM56-7B Service Bulletin (SB) No. 73-016, Revision 2,
dated August 10, 1998, that describes procedures for inspection of HMU
OSG spool valves for out-of-specification conditions or the presence of
heavy contact or galling on the spool valve.
Since an unsafe condition has been identified that is likely to
exist or develop on other engines of the same type design, this AD is
being issued to prevent a failure of the HMU OSG spool valve shaft, and
subsequent engine flameout. This AD requires initial and repetitive
inspections of HMU OSG spool valves for out-of-specification conditions
or the presence of heavy contact or galling on the spool valve. The
optional installation of an improved HMU, Part Number (P/N) 1853M56P06
(AlliedSignal P/N 442098), constitutes terminating action to the
inspection requirements. The actions are required to be accomplished in
accordance with the SB described previously.
Since a situation exists that requires the immediate adoption of
this regulation, it is found that notice and
[[Page 50483]]
opportunity for prior public comment hereon are impracticable, and that
good cause exists for making this amendment effective in less than 30
days.
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 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 notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 98-ANE-55-AD.'' The postcard will be date stamped and
returned to the commenter.
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.
The FAA has determined that this regulation is an emergency
regulation that must be issued immediately to correct an unsafe
condition in aircraft, and is not a ``significant regulatory action''
under Executive Order 12866. It has been determined further that this
action involves an emergency regulation under DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979). If it is determined
that this emergency regulation otherwise would be significant under DOT
Regulatory Policies and Procedures, a final regulatory evaluation will
be prepared and placed in the Rules Docket. A copy of it, if filed, 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 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
98-19-20 CFM International: Amendment 39-10761. Docket 98-ANE-55-
AD.
Applicability: CFM International CFM56-7B and -7B/2 series
turbofan engines, with hydromechanical unit (HMU), Part Number (P/N)
1853M56P04 (AlliedSignal P/N 442008) or 1853M56P05 (Allied Signal P/
N 442026), installed. These engines are installed on, but not
limited to Boeing 737-600/-700/-800 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 (d) 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 failure of the HMU overspeed governor (OSG) spool
valve shaft, and subsequent engine flameout, accomplish the
following:
(a) Inspect HMU, P/N 1853M56P04 (AlliedSignal P/N 442008) and
1853M56P05 (Allied Signal P/N 442026), in accordance with CFM
International Service Bulletin (SB) No. 73-016, Revision 2, dated
August 10, 1998, as follows:
(1) For engines with HMUs that have not been previously
inspected in accordance with any revision level of CFM International
SB No. 73-016, inspect prior to accumulating 300 hours time since
new.
(2) For engines with HMUs that have been previously inspected in
accordance with any revision level of CFM International SB No. 73-
016, inspect within 300 hours time in service (TIS) since the last
inspection in accordance with the SB.
(b) Thereafter, for HMUs that have been inspected in accordance
with paragraph (a) of this AD, inspect the HMU at intervals not to
exceed 300 hours TIS since the last inspection in accordance with
CFM International SB No. 73-016, Revision 2, dated August 10, 1998.
Note 2: The inspections required in paragraphs (a) and (b) of
this AD have been published in Chapter 05 of the CFM56-7B series
Engine Shop Manual, CFMI-TP.SM.10.
(c) Installation of HMU, P/N 1853M56P06 (AlliedSignal P/N
442098), constitutes terminating action to the inspection
requirements of this AD.
(d) 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.
Operators shall submit their requests 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 methods of compliance with this airworthiness directive,
if any, may be obtained from the Engine Certification Office.
(e) 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.
(f) The actions required by this AD shall be done in accordance
with the following CFM International SB:
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Document No. Pages Revision Date
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CFM56-7B SB No. 73-016.......... 1-6 2 August 10, 1998.
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Total pages: 6.
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 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
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Regional 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.
(g) This amendment becomes effective on October 7, 1998.
Issued in Burlington, Massachusetts, on September 11, 1998.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 98-25007 Filed 9-21-98; 8:45 am]
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