[Federal Register Volume 63, Number 179 (Wednesday, September 16, 1998)]
[Rules and Regulations]
[Pages 49423-49425]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-24644]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-ANE-50-AD; Amendment 39-10758; AD 98-14-51]
RIN 2120-AA64
Airworthiness Directives; CFM International CFM56-7B Series
Turbofan Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule, request for comments.
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SUMMARY: This document publishes in the Federal Register an amendment
adopting Airworthiness Directive (AD) T98-14-51 that was sent
previously to all known U.S. owners and operators of CFM International
CFM56-7B series turbofan engines by individual telegrams. This AD
requires checks of the Accessory Gearbox (AGB)/Transfer Gearbox (TGB)
Magnetic Chip Detector (MCD) for abnormal magnetic particles that
indicate a pending starter gearshaft failure, and, removal from service
of suspect starter gearshafts and replacement with serviceable parts.
This amendment is prompted by reports of 2 inflight engine shutdowns
due to uncontained failures of the AGB starter gearshafts. The actions
specified by this AD are intended to prevent a dual inflight engine
shutdown event, which could result in a forced landing and loss of the
aircraft.
DATES: Effective October 1, 1998, to all persons except those persons
to whom it was made immediately effective by telegraphic AD T98-14-51,
issued July 2, 1998, which contained the requirements of this
amendment.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of October 1, 1998.
Comments for inclusion in the Rules Docket must be received on or
before November 16, 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-50-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 applicable service information 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; or at the Office of the Federal
Register, 800 North Capitol Street, NW., Suite 700, Washington, DC
20001.
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 (781) 238-7132, fax (781) 238-7199.
SUPPLEMENTARY INFORMATION: On July 2, 1998, the Federal Aviation
Administration (FAA) issued telegraphic airworthiness directive (AD)
T98-14-51, applicable to CFM International (CFMI) CFM56-7B series
turbofan engines, which requires checks of the Accessory Gearbox (AGB)/
Transfer Gearbox (TGB) Magnetic Chip Detector (MCD) for abnormal
magnetic
[[Page 49424]]
particles that indicate a pending starter gearshaft failure, and,
removal from service of suspect starter gearshafts and replacement with
serviceable parts. That action was prompted by reports of 2 inflight
engine shutdowns on CFM56-7B series turbofan engines installed on
Boeing 737-700 series aircraft. The cause of the inflight engine
shutdowns were due to uncontained failures of the AGB starter
gearshafts. The investigation revealed that the gearshafts failed due
to inadequate fatigue capability caused by high residual tensile
stresses introduced during the manufacturing process, coupled with the
elimination of shotpeening in the gearshaft hub. The manufacturing
process has since been modified. The starter gearshaft, part number (P/
N) 340-055-202-0, involved in the events are part of a lot of 237 parts
manufactured. All of the production engines currently in revenue
service or as spares incorporate these suspect starter gearshafts. The
engines have been identified by engine serial number (ESN) in Table 1
of CFMI CFM56-7B Service Bulletin (SB) No. 72-130, dated June 29, 1998,
and the suspect starter gearshafts have also been identified by serial
number (S/N) in that table. Currently, all revenue service Boeing 737-
700 and 737-800 series aircraft have the suspect starter gearshafts
installed in both engines; therefore, this condition, if not corrected,
could result in a dual inflight engine shutdown event, which could
result in a forced landing and loss of the aircraft.
The FAA has reviewed and approved the technical contents of CFMI
CFM56-7B SB No. 72-130, dated June 29, 1998, that describes procedures
for removal from service of suspect starter gearshafts and replacement
with serviceable parts; and CFMI CFM56-7B SB No. 72-132, dated July 2,
1998, that describes procedures for checks of the AGB/TGB MCD for
abnormal magnetic particles that indicate a pending starter gearshaft
failure.
Since the unsafe condition described is likely to exist or develop
on other engines of the same type design, the FAA issued Telegraphic AD
T98-14-51 to prevent a dual inflight engine shutdown event. The AD
requires, prior to further flight, a check of the AGB/TGB MCD on the
No. 2 engine of the aircraft for abnormal magnetic particles that
indicate a pending starter gearshaft failure. If abnormal magnetic
particles are discovered, this AD requires, prior to further flight,
removal from service of the starter gearshaft and replacement with a
serviceable part not identified by S/N in Table 1 of CFMI CFM56-7B SB
No. 72-130, dated June 29, 1998. The required actions are required for
the No. 2 engine first because the AGB is located on the inboard side
of the No. 2 engine. An uncontained starter gearshaft failure on the
No. 2 engine would expose the aircraft to a higher risk of damage than
an uncontained starter gearshaft failure on the No. 1 engine. This AD
also requires, on the next calendar day after checking the No. 2 engine
of the aircraft, an AGB/TGB MCD check of the No. 1 engine of the
aircraft, and, if necessary, removal from service of starter
gearshafts. Thereafter, the AGB/TGB MCD checks must be alternated,
every other calendar day, between the No. 2 and No. 1 engines of the
aircraft.
This AD also requires, within 350 hours time in service (TIS) after
the effective date of this AD, or by August 1, 1998, whichever occurs
first, on aircraft with two affected engines installed identified by
ESN in Table 1 of CFMI CFM56-7B SB No. 72-130, dated June 29, 1998, on
the No. 2 engine of that aircraft, removal from service of suspect
starter gearshafts and replacement with a serviceable part not
identified by S/N in Table 1 of that SB. On aircraft with only one
affected engine identified by ESN in Table 1 of that SB, this AD
requires removal from service of suspect starter gearshafts and
replacement with a serviceable part not identified by S/N in Table 1 of
that SB within 725 hours TIS after the effective date of this AD, or by
September 1, 1998, whichever occurs first. Installation of replacement
serviceable starter gearshafts constitutes terminating action to the
repetitive AGB/TGB MCD checks. The calendar end-dates were determined
based upon risk analysis and parts availability.
Finally, this AD requires reporting to the Engine Certification
Office of the FAA within 5 working days of replacement of the starter
gearshaft; if the ESN listed in Table 1 of CFMI CFM56-7B SB No. 72-130,
dated June 29, 1998, does not directly correspond to the adjoining
starter gearshaft serial number, in order to verify that all affected
parts have been removed from service. The actions are required to be
accomplished in accordance with the Accomplishment Instructions in the
SBs described previously.
Since it was found that immediate corrective action was required,
notice and opportunity for prior public comment thereon were
impracticable and contrary to the public interest, and good cause
existed to make the AD effective immediately by individual telegrams
issued on July 2, 1998, to all known U.S. owners and operators of CFMI
CFM56-7B series turbofan engines. These conditions still exist, and the
AD is hereby published in the Federal Register as an amendment to
Sec. 39.13 of part 39 of the Federal Aviation Regulations (14 CFR part
39) to make it effective to all persons.
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-50-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
[[Page 49425]]
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:
98-14-51 CFM International: Amendment 39-10758. Docket 98-ANE-50-AD.
Applicability: CFM International (CFMI) CFM56-7B series turbofan
engines, identified by engine serial number (ESN) in CFMI CFM56-7B
Service Bulletin (SB) No. 72-130, dated June 29, 1998. These engines
are installed on but not limited to Boeing 737-600, 737-700, and
737-800 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 (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: Required as indicated, unless accomplished
previously.
To prevent a possible dual inflight engine shutdown event, which
could result in a forced landing and loss of the aircraft,
accomplish the following:
(a) Prior to further flight, check the accessory gearbox (AGB)/
transfer gearbox (TGB) magnetic chip detector (MCD) on the No. 2
engine of the aircraft for abnormal magnetic particles that indicate
a pending starter gearshaft failure, in accordance with CFMI CFM56-
7B SB No. 72-132, dated July 2, 1998, as follows:
(1) If magnetic particles are found to be abnormal in accordance
with CFMI CFM56-7B SB No. 72-132, dated July 2, 1998, prior to
further flight, remove from service starter gearshafts, part number
(P/N) 340-055-202-0, and replace with a serviceable part not
identified by S/N in Table 1 of CFMI CFM56-7B SB No. 72-130, dated
June 29, 1998.
(2) On the next calendar day after checking the No. 2 engine of
the aircraft, perform an AGB/TGB MCD check of the No. 1 engine of
the aircraft, and, if necessary, remove from service starter
gearshafts and replace with serviceable parts in accordance with
paragraph (a)(1) of this AD.
(3) Thereafter, perform AGB/TGB MCD checks alternately, every
other calendar day, between the No. 2 and No. 1 engines of the
aircraft, and, if necessary, remove from service starter gearshafts
and replace with serviceable parts in accordance with paragraph
(a)(1) of this AD.
(b) Within 350 hours time in service (TIS) after the effective
date of this AD, or by August 1, 1998, whichever occurs first, on
aircraft with two affected engines installed identified by ESN in
Table 1 of CFMI CFM56-7B SB No. 72-130, dated June 29, 1998, remove
from service suspect starter gearshafts on the No. 2 engine and
replace with a serviceable part not identified by S/N in Table 1 of
that SB.
(c) Within 725 hours TIS after the effective date of this AD, or
by September 1, 1998, whichever occurs first, on aircraft with only
one affected engine identified by ESN in Table 1 of CFMI CFM56-7B SB
No. 72-130, dated June 29, 1998, remove from service suspect starter
gearshafts and replace with a serviceable part not identified by S/N
in Table 1 of that SB.
(d) Installation of serviceable starter gearshafts not
identified by S/N in Table 1 of CFMI CFM56-7B SB No. 72-130, dated
June 29, 1998, constitutes terminating action to the repetitive AGB/
TGB MCD checks required by paragraph (a) of this AD.
(e) Report to the Manager of the Engine Certification Office of
the FAA within 5 working days of replacement of the starter
gearshaft if the ESN listed in Table 1 of CFMI CFM56-7B SB No. 72-
130, dated June 29, 1998, does not directly correspond to the
adjoining starter gearshaft serial number to verify that all
affected parts have been removed from service. The address is:
Manager, Engine Certification Office, FAA, Engine and Propeller
Directorate, 12 New England Executive Park, Burlington, MA 01803-
5299; fax (781) 238-7199. Reporting requirements have been approved
by the Office of Management and Budget and assigned OMB control
number 2120-0056.
(f) 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 2: Information concerning the existence of approved
alternative methods of compliance with this airworthiness directive,
if any, may be obtained from the Engine Certification Office.
(g) The actions required by this AD shall be accomplished in
accordance with the following CFMI SBs:
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Document No. Pages Date
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CFM56-7B SB No. 72-130............. 1-33 June 29, 1998.
Total pages: 33.
CFM56-7B SB No. 72-132............. 1-12 July 2, 1998.
Total pages: 12.
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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 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 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.
(h) This amendment becomes effective October 1, 1998, to all
persons except those persons to whom it was made immediately
effective by telegraphic AD T98-14-51, issued July 2, 1998, which
contained the requirements of this amendment.
Issued in Burlington, Massachusetts, on September 8, 1998.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 98-24644 Filed 9-15-98; 8:45 am]
BILLING CODE 4910-13-U