[Federal Register Volume 60, Number 71 (Thursday, April 13, 1995)]
[Rules and Regulations]
[Pages 18729-18731]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-9133]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 90-ANE-25; Amendment 39-9186; AD 91-10-03 R1]
Airworthiness Directives; General Electric Company (GE) CF6-45
and CF6-50 Series Turbofan Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment revises an existing airworthiness directive
(AD), applicable to General Electric Company (GE) CF6-45 and CF6-50
series turbofan engines, that currently requires repetitive inspections
of high pressure compressor (HPC) rear shafts, and also requires
installation of a certain rear shaft flange bolt configuration . This
amendment clarifies that engines with a Parts Manufacturer Approval
(PMA) bolt part number (P/N) installed must accomplish the inspection
requirements of the AD, and allow the installation of the PMA bolt in
lieu of the GE bolt. This amendment is prompted by the omission of the
PMA bolt P/N from the current AD requirements. The actions specified by
this AD are intended to prevent an HPC rear shaft fracture, which could
result in an inflight engine shutdown and an uncontained engine
failure.
DATES: Effective April 28, 1995.
The incorporation by reference of certain publications listed in
the regulations was approved by the Director of the Federal Register as
of June 17, 1991.
Comments for inclusion in the Rules Docket must be received on or
before June 12, 1995.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), New England Region, Office of the Assistant Chief
Counsel, Attention: Rules Docket No. 90-ANE-25, 12 New England
Executive Park, Burlington, MA 01803-5299.
The service information referenced in this AD may be obtained from
General Electric Company, Technical Publications Department, 1 Neumann
Way, Cincinnati, OH 45215. This information may be examined 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.
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 (617)
238-7138, fax (617) 238-7199.
SUPPLEMENTARY INFORMATION: On March 18, 1991, the Federal Aviation
Administration (FAA) issued AD 91-10-03, Amendment 39-6956 (56 FR
19920, May 1, 1991), applicable to General Electric Company (GE) CF6-45
and CF6-50 series turbofan engines, to require repetitive inspections
of high pressure compressor (HPC) rear shafts, and installation of a
certain rear shaft flange bolt configuration. That action was prompted
by reports of 35 HPC rear shafts found cracked in the bolt hole area.
That condition, if not corrected, could result in an HPC rear shaft
fracture, which could result in an inflight engine shutdown and an
uncontained engine failure.
Since the issuance of that AD, the FAA has determined that Parts
Manufacturer Approval (PMA) Production Approval Listing, Supplement No.
27, authorizes the use of Valley-Todeco (VT) bolt, Part Number (P/N)
VCD0016, in lieu of GE bolt, P/N 1375M69P01. Since VT bolt, P/N
VCD0016, and GE bolt, P/N 1375M69P01, are identical in design,
paragraphs (a)(1)(v), (a)(2), and (a)(2)(v) of AD 91-10-03 should also
apply to HPC rear shafts that are installed with VT bolt, P/N VCD0016.
The FAA has reviewed and approved the technical contents of GE
Service Bulletin (SB) No. 72-958, Revision 1, dated October 18, 1990,
that describes
[[Page 18730]]
procedures for inspection of HPC rear shafts.
Since an unsafe condition has been identified that is likely to
exist or develop on other engines of this same type design, this AD
revises AD 91-10-03 to continue the inspection requirements of the
current AD, but adds HPC rear shafts that are installed with VT bolt,
P/N VCD0016, to paragraphs (a)(1)(v), (a)(2), and (a)(2)(v). The
actions are required to be accomplished in accordance with the service
bulletin described previously.
Since a situation exists that requires the immediate adoption of
this regulation, it is found that notice and 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 90-ANE-25.'' 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. App. 1354(a), 1421 and 1423; 49 U.S.C.
106(g); and 14 CFR 11.89.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing Amendment 39-6956 (56 FR
19920, May 1, 1991) and by adding a new airworthiness directive,
Amendment 39-9186, to read as follows:
91-10-03 R1 General Electric Company: Amendment 39-9186. Docket 90-
ANE-25. Revises AD 91-10-03, Amendment 39-6956.
Applicability: General Electric Company (GE) CF6-45 and CF6-50
series turbofan engines installed on, but not limited to, McDonnell
Douglas DC-10 series, Boeing 747 series, and Airbus A300 series
aircraft.
Note: This 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 use the authority provided in paragraph (e) to
request approval from the FAA. This approval may address either no
action, if the current configuration eliminates the unsafe
condition, or different actions necessary to address the unsafe
condition described in this AD. Such a request should include an
assessment of the effect of the changed configuration on the unsafe
condition addressed by this AD. In no case does the presence of any
modification, alteration, or repair remove any engine from the
applicability of this AD.
Compliance: Required as indicated, unless accomplished
previously.
To prevent a high pressure compressor (HPC) rear shaft fracture,
which could result in an inflight engine shutdown and an uncontained
engine failure, accomplish the following:
(a) Fluorescent penetrant inspect HPC rear shafts, Part Numbers
(P/N) 9127M58P03, 9079M63P12, 9079M63P15, 9079M63P16, 9079M63P17,
9079M63P18, and 9079M63P19, in accordance with the Accomplishment
Instructions of GE Service Bulletin (SB) No. 72-958, Revision 1,
dated October 18, 1990, as follows:
(1) For HPC rear shafts currently installed with hook bolts, P/N
9012M99G10, 9114M95G07, and 9114M95G10, inspect in accordance with
the following schedule:
(i) For shafts which have not been previously inspected and have
10,000 cycles since new (CSN) or greater on the effective date of
this airworthiness directive (AD), inspect within the next 1,500
cycles in service (CIS) after the effective date of this AD.
(ii) For shafts which have not been previously inspected and
have less than 10,000 CSN on the effective date of this AD, inspect
within the next 2,500 CIS from the effective date of this AD, or
before accumulating 7,500 CSN, whichever occurs later. However, no
shaft may exceed 11,500 CSN prior to inspection.
(iii) For shafts that have been previously inspected and have
3,000 cycles since last inspection (CSLI) or less on the effective
date of this AD, reinspect within 4,500 CSLI, or before accumulating
7,500 CSN, whichever occurs later.
(iv) For shafts that have been previously inspected and have
greater than 3,000 CSLI on the effective date of this AD, reinspect
within the next 1,500 CIS from the effective date of this AD, or
before accumulating 7,500 CSN, whichever occurs later.
(v) Remove from service, HPC rear shaft hook bolts identified in
(a)(1) of this AD, after any inspection performed in accordance with
paragraph (a)(1) of this AD, and replace with new tapered turn-
around bolts, P/N 1375M69P01 or VCD0016.
(2) For HPC rear shafts installed with turn-around bolts, P/N
9249M54P01, or tapered turn-around bolts, P/N 1375M69P01 or
[[Page 18731]]
VCD0016, inspect in accordance with the following schedule:
(i) For shafts which have not been previously inspected and have
6,500 CSN or greater on the effective date of this AD, inspect
within the next 2,500 CIS after the effective date of this AD.
(ii) For shafts which have not been previously inspected and
have less than 6,500 CSN on the effective date of this AD, inspect
prior to accumulating 9,000 CSN.
(iii) For shafts that have been previously inspected and have
3,500 CSLI or less on the effective date of this AD, reinspect
within 6,000 CSLI, or before accumulating 9,000 CSN, whichever
occurs later.
(iv) For shafts that have been previously inspected and have
greater than 3,500 CSLI on the effective date of this AD, reinspect
within the next 2,500 CIS from the effective date of this AD, or
before accumulating 9,000 CSN, whichever occurs later.
(v) Remove from service, HPC rear shaft turn-around bolts
identified in paragraph (a)(2) of this AD, after any inspection
performed in accordance with paragraph (a)(2) of this AD, and
replace with new tapered turn-around bolts, P/N 1375M69P01 or
VCD0016.
Note: Information concerning the tapered turn-around bolt noted
in paragraph (a) of this AD can be found in GE SB No. 72-877.
(b) Remove from service, prior to further flight, any shafts
found cracked at inspection.
(c) Thereafter, for shafts which have been inspected in
accordance with paragraph (a) of this AD, reinspect in accordance
with the Accomplishment Instructions of GE SB No. 72-958, Revision
1, dated October 18, 1990, at intervals not to exceed 6,000 CSLI.
(d) Compliance with paragraph (a) of AD 91-10-03 satisfies the
corresponding requirements of paragraph (a) of this AD.
(e) An alternative method of compliance or adjustment of the
initial 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: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Engine Certification Office.
(f) 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.
(g) The actions required by this AD shall be done in accordance
with the following service document:
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Document No. Pages Revision Date
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GE SB No. 72-958........... 1-2 1........... Oct. 18, 1990.
3-6 Original.... Aug. 15, 1990.
Total pages: 6.
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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 as of June 17, 1991. Copies may be obtained from General Electric
Company, Technical Publications Department, 1 Neumann Way,
Cincinnati, OH 45215. 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.
(h) This amendment becomes effective on April 28, 1995.
Issued in Burlington, Massachusetts, on April 4, 1995.
James C. Jones,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 95-9133 Filed 4-11-95; 11:45 am]
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