[Federal Register Volume 60, Number 32 (Thursday, February 16, 1995)]
[Rules and Regulations]
[Pages 8930-8932]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-3248]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 94-ANE-11; Amendment 39-9138; AD 95-03-01]
Airworthiness Directives; General Electric Company CF6 Series
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 General Electric Company (GE) CF6-45/-50/-80A
series turbofan engines, that currently requires a one-time ultrasonic
and eddy current inspection of the high pressure compressor rotor
(HPCR) stage 3-9 spool for cracks. This amendment retains the
inspection requirements of the current AD, but would accelerate the
inspection schedule, and introduce a repetitive inspection requirement.
This amendment is prompted by a review of the inspection results to
date, which indicate that the crack occurrence rate is higher than
initially projected. The actions specified by this AD are intended to
prevent an uncontained HPCR stage 3-9 spool failure, which could result
in damage to the aircraft.
DATES: Effective March 20, 1995.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of March 20, 1995.
ADDRESSES: The service information referenced in this AD may be
obtained from General Electric Aircraft Engines, CF6 Distribution
Clerk, Room 132, 111 Merchant Street, Cincinnati, OH 45246. This
information may be 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: Robert J. 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: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) by superseding airworthiness
directive (AD) 91-20-01, Amendment 39-8035 (56 FR 55230), which is
applicable to General Electric Company (GE) CF6-45/-50/-80A series
turbofan engines, was published in the Federal Register on May 3, 1994
(59 FR 22769). That action proposed to retain the one-time ultrasonic
and eddy current inspection of the high pressure compressor rotor
(HPCR) stage 3-9 spool for cracks as required in the current AD, but
would accelerate the inspection schedule, and introduce a repetitive
ultrasonic and eddy current inspection requirement in accordance with
GE CF6-50 Service Bulletin (SB) No. 72-1000, Revision 2, dated
September 9, 1993, and GE CF6-80A SB No. 72-583, Revision 4, dated
September 15, 1993.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
Two commenters support the rule as proposed.
One commenter states that the repetitive inspection interval of
3,500 cycles in service (CIS) in compliance paragraph (b) of the
proposed rule should be replaced with 4,000 CIS in [[Page 8931]] order
to avoid premature engine removals. The FAA concurs that this change
will avoid some engine removals while not decreasing the level of
safety provided by the proposed rule. Accordingly, the FAA has made
this change in the final rule.
Although no comments were received regarding compliance paragraphs
(a)(3), (a)(4), (c)(2), and (d), the FAA has replaced 3,500 CIS with
4,000 CIS in these paragraphs to maintain consistency.
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 462 GE CF6-45/-50/-80A series engines of
the affected design in the worldwide fleet. The FAA estimates that 67
engines installed on aircraft of U.S. registry will be affected by this
AD, that it will take approximately 584 work hours per engine to
accomplish the required actions, and that the average labor rate is $55
per work hour. Required parts will cost approximately $127,412 per
engine. Based on these figures, and assuming that 3 of the inspected
spools will require replacement, the total cost impact of the AD on
U.S. operators is estimated to be $2,534,276.
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 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 39-8035 (56 FR
55230; October 25, 1991) and by adding a new airworthiness directive to
read as follows:
95-03-01 General Electric Company: Amendment 39-9138. Docket 94-
ANE-11. Supersedes AD 91-20-01, Amendment 39-8035.
Applicability: General Electric Company (GE) CF6-45/-50/-80A
series turbofan engines installed on, but not limited to, Airbus
A300 and A310 series, Boeing 747 and 767 series, and McDonnell
Douglas DC-10 series aircraft.
Compliance: Required as indicated, unless accomplished
previously.
To prevent an uncontained high pressure compressor rotor (HPCR)
stage 3-9 spool failure, which could result in damage to the
aircraft, accomplish the following:
(a) Eddy current and ultrasonic inspect GE CF6-45/-50 HPCR stage
3-9 spools, Part Number (P/N) 9136M89G02, 9136M89G03, 9136M89G06,
9136M89G08, 9253M85G01, 9253M85G02, 9273M14G01, and 9331M29G01, with
serial numbers (S/N) listed in Table 2 of GE CF6-50 Service Bulletin
(SB) No. 72-1000, Revision 2, dated September 9, 1993, as follows:
(1) For spools that have not been previously inspected in
accordance with GE CF6-50 SB No. 72-888, Original, Revision 1,
Revision 2, Revision 3, or Revision 4, or GE CF6-50 SB No. 72-1000,
Original, Revision 1, or Revision 2, inspect in accordance with
paragraph 2.C of GE CF6-50 SB No. 72-1000, Revision 2, dated
September 9, 1993, at the next engine shop visit, or by 30 days
after the effective date of this AD, whichever occurs earlier.
(2) For spools that have been inspected in accordance with GE
CF6-50 SB No. 72-888, Original, Revision 1, or Revision 2, inspect
in accordance with paragraph 2.D of GE CF6-50 SB No. 72-1000,
Revision 2, dated September 9, 1993, at the next engine shop visit,
or by 30 days after the effective date of this AD, whichever occurs
earlier.
(3) For spools that have been inspected in accordance with GE
CF6-50 SB No. 72-888, Original, Revision 1, or Revision 2, and GE
CF6-50 SB No. 72-1008, Original, inspect in accordance with
paragraph 2.D of GE CF6-50 SB No. 72-1000, Revision 2, dated
September 9, 1993, at the next piece-part exposure, or within 4,000
cycles in service (CIS) since inspected in accordance with GE CF6-50
SB No. 72-1008, Original, whichever occurs earlier.
(4) For spools that have been inspected in accordance with GE
CF6-50 SB No. 72-888, Revision 3, or Revision 4, or GE CF6-50 SB No.
72-1000, Original, Revision 1, or Revision 2, inspect in accordance
with paragraph 2.D of GE CF6-50 SB No. 72-1000, Revision 2, dated
September 9, 1993, at the next piece-part exposure, or within 4,000
CIS since inspected in accordance with, GE CF6-50 SB No. 72-888,
Revision 3, or Revision 4, or GE CF6-50 SB No. 72-1000, Original,
Revision 1, or Revision 2, whichever occurs earlier.
(b) Thereafter, for spools that have been inspected in
accordance with paragraph (a) of this AD, reinspect in accordance
with paragraph 2.D of GE CF6-50 SB No. 72-1000, Revision 2, dated
September 9, 1993, at intervals not to exceed 4,000 CIS since the
last inspection.
(c) Eddy current and ultrasonic inspect GE CF6-80A HPCR 3-9
spool, P/N 9136M89G10, with S/N's listed in Table 2 of GE CF6-80A SB
No. 72-583, Revision 4, dated September 15, 1993, as follows:
(1) For spools that have not been previously inspected in
accordance with GE CF6-80A SB No. 72-500, Original, Revision 1,
Revision 2, Revision 3, or Revision 4, or GE CF6-80A SB No. 72-583,
Original, Revision 1, Revision 2, Revision 3, or Revision 4, inspect
in accordance with paragraph 2.C of GE CF6-80A SB No. 72-583,
Revision 4, dated September 15, 1993, at the next engine shop visit,
or by 30 days after the effective date of this AD, whichever occurs
earlier.
(2) For spools that have been previously inspected in accordance
with GE CF6-80A SB No. 72-500, Revision 3, or Revision 4, or GE CF6-
80A SB No. 72-583, Original, Revision 1, Revision 2, Revision 3, or
Revision 4, inspect in accordance with paragraph 2.D of GE CF6-80A
SB No. 72-583, Revision 4, dated September 15, 1993, at the next
piece-part exposure, or within 4,000 CIS since inspected in
accordance with GE CF6-80A SB No. 72-500, Revision 3, or Revision 4,
or GE CF6-80A SB No. 72-583, Original, Revision 1, Revision 2,
Revision 3, or Revision 4, whichever occurs earlier.
(d) Thereafter, for spools that have been inspected in
accordance with paragraph (c) of this AD, reinspect in accordance
with paragraph 2.D of GE CF6-80A SB No. 72-583, Revision 4, dated
September 15, 1993, at intervals not to exceed 4,000 CIS since the
last inspection.
(e) Remove from service prior to further flight HPCR stage 3-9
spools that meet or exceed the reject criteria established in
Section 2.C and 2.D, as applicable, of GE CF6-50 SB No. 72-1000,
Revision 2, dated September 9, 1993, and GE CF6-80A SB No. 72-583,
Revision 4, dated September 15, 1993, as appropriate.
(f) For the purpose of this AD, an engine shop visit is defined
as the induction of an [[Page 8932]] engine into a shop for
maintenance involving the separation of any major flange.
(g) For the purpose of this AD, piece-part exposure is defined
as disassembly and removal of the stage 3-9 spool from the HPCR
rotor.
(h) 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: Information concerning the existence of approved
alternative method of compliance with this AD, if any, may be
obtained from the Engine Certification Office.
(i) 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.
(j) The actions required by this AD shall be done in accordance
with the following service bulletins:
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Document No. Pages Revision Date
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GE CF6-50, SB No. 72-1000... 1-37 2 Sept. 9, 1993.
Total pages: 37.......
GE CF6-80A SB No. 72-583.... 1-34 4 Sept. 15, 1993.
Total pages: 34.......
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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 General Electric Aircraft
Engines, CF6 Distribution Clerk, Room 132, 111 Merchant Street,
Cincinnati, OH 45246. 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.
(k) This amendment becomes effective on March 20, 1995.
Issued in Burlington, Massachusetts, on January 31, 1995.
Donald F. Perrault,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 95-3248 Filed 2-15-95; 8:45 am]
BILLING CODE 4910-13-P
