[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]


=======================================================================
-----------------------------------------------------------------------

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.

-----------------------------------------------------------------------

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:

------------------------------------------------------------------------
          Document No.             Pages   Revision          Date       
------------------------------------------------------------------------
CFM56-7B SB No. 73-016..........     1-6          2  August 10, 1998.   
------------------------------------------------------------------------

    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

[[Page 50484]]

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]
BILLING CODE 4910-13-U