[Federal Register Volume 65, Number 114 (Tuesday, June 13, 2000)]
[Rules and Regulations]
[Pages 37009-37011]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-14017]
[[Page 37009]]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-ANE-32-AD; Amendment 39-11760; AD 2000-11-12]
RIN 2120-AA64
Airworthiness Directives; General Electric Company CF6-45/50
Series Turbofan Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: This amendment adopts a new airworthiness directive (AD) that
is applicable to General Electric Company CF6-45/50 series turbofan
engines. This AD requires initial and repetitive inspections for cracks
in the stage 14 high pressure compressor (HPC) disk lock slots, and
removal from service of certain disks, at the first piece-part level or
HPC rotor disassembly level exposure, after 6,000 cycles since new
(CSN). This amendment is prompted by reports of stage 14 HPC disk lock
slot cracks discovered during shop fluorescent penetrant inspections.
The actions specified by this AD are intended to prevent stage 14 HPC
disk failure, which could result in an uncontained engine failure and
damage to the aircraft.
DATES: Effective date August 14, 2000.
The incorporation by reference of certain publications listed in
the rule is approved by the Director of the Federal Register as of
August 14, 2000.
ADDRESSES: The service information referenced in this AD may be
obtained from General Electric Company via Lockheed Martin Technology
Services, 10525 Chester Road, Suite C, Cincinnati, Ohio 45215,
telephone (513) 672-8400, fax (513) 672-8422. 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: William S. Ricci, Aerospace Engineer,
Engine Certification Office, FAA, Engine and Propeller Directorate, 12
New England Executive Park, Burlington, MA 01803-5299; telephone (781)
238-7742, fax (781) 238-7199.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) to include an airworthiness
directive (AD) that is applicable to General Electric Company CF6-45/50
series turbofan engines was published in the Federal Register on
October 26, 1999 (64 FR 57606). That action proposed to require initial
and repetitive inspections for cracks in the stage 14 high pressure
compressor (HPC) disk lock slots, and removal from service of certain
disks, at the first piece-part level or HPC rotor disassembly level
exposure, after 6,000 cycles since new (CSN).
Comments Received
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
Cost Impact
Two comments suggest that the financial impact is not
representative of the replacement cost of the disk since the disk is no
longer in production or stocked and the replacement cost of the stage
11-14 spool shaft is more than $250,000. The FAA does not agree. Over
the course of the inspection program, the availabilty of HPC rear
shafts, and not the availability of stage 14 disks, is expected to be
the limiting factor, requiring the installation of the stage 11-14
spool shaft. In addition, the estimate of economic impact was based on
the lost life of the stage 14 disk only.
Reporting Period
One comment suggests that the time limit for reporting the results
of inspections that equal or exceed the reject criteria be increased
from within five days of the inspection to within ten days of the
inspection. The FAA does not agree. Based on the potential criticality
of a reject finding, five days is considered reasonable and is
consistent with reporting requirements in ADs dealing with other
critical rotating parts. Carriers can make arrangements with inspection
facilities to report reject findings directly to the FAA if reporting
to the carrier first would cause a delay in reporting to the FAA.
Reports can be made to the FAA by fax on weekends and holidays. The FAA
has included the telephone and fax numbers for the ECO in paragraph (h)
of the Compliance Section.
Consistent Wording
One comment asks that the FAA use consistent wording with regard to
the term ``rotor module level exposure.'' The FAA agrees. The term
``rotor module level exposure'' has been changed to ``rotor disassembly
level exposure'' in the Summary and in paragraphs (f) and (i) (1) of
the Compliance Section.
Replacement of the Fan Forward Case
One comment requests that the FAA add a provision for the
definition of an engine shop visit to paragraph (i) for ``Introduction
of an engine into a shop solely for replacement of the fan forward
case.'' The FAA agrees. To be consistent with AD 99-24-15, the 3-9
spool AD, paragraph (i)(3)(iv), ``Introduction of an engine into a shop
solely for replacement of the fan forward case,'' has been inserted
into the compliance section of this AD and the paragraph previously
numbered (I) (3) (iv) has been renumbered (i)(3)(v).
Effective Date
One comment notes that the effective date should be changed so that
it is consistent with the schedule provided by the service bulletin.
The FAA does not agree. The rulemaking process is a formal legal course
of action that does not include provisions for coordinating effective
dates with manufacturers' service bulletins.
Support of the AD as Written
Three comments support the AD as written.
Conclusion
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.
Economic Analysis
There are approximately 1,538 engines of the affected design in the
worldwide fleet. The FAA estimates that 460 engines installed on
aircraft of U.S. registry would be affected by this proposed AD, that
it would take approximately 22 work hours per engine to accomplish the
proposed actions, and that the average labor rate is $60 per work hour.
Required parts would cost approximately $3,600 per engine. Based on
these figures, the total cost impact of the proposed AD on U.S.
operators is estimated to be $2,263,200.
Regulatory Impact
This rule does not have federalism implications, as defined in
Executive Order 13132, because it does not have a substantial direct
effect 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. Accordingly,
the
[[Page 37010]]
FAA has not consulted with state authorities prior to publication of
this rule.
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 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. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
2000-11-12 General Electric Company: Amendment 39-11760. Docket 98-
ANE-32-AD.
Applicability: General Electric Company (GE) Model CF6-45/50
series turbofan engines, installed on but not limited to Airbus
Industrie A300 series, Boeing Company 747 series, and McDonnell
Douglas Corporation DC-10 series airplanes
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 (j) 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 stage 14 high pressure compressor (HPC) disk
failure, which could result in uncontained engine failure and damage
to the aircraft, accomplish the following:
Inspections
(a) Perform initial inspections of HPC stage 14 disks, part
numbers (P/N's) 9080M34P03, 9080M34P04, 9080M34P05 and 9349M91P04,
with serial number (SN) prefixes GWN, MPO, RRY, and SNL, and disk
SN's SNE00001 through SNE00017, and disk SN's SNE01101 through
SNE01110, in accordance with paragraphs 2.A. through 2.B. of GE CF6-
50 ASB No. 72-A1144, dated March 19, 1998, or ASB No. 72-A1144,
Revision 1, dated May 13, 1999, and the following schedule:
(1) Inspect disks with 6,500 cycles since new (CSN) or less on
the effective date of this AD before accumulating 9,800 CSN.
(2) Inspect disks with more than 6,500 CSN on the effective date
of this AD no later than the next engine shop visit (ESV) after the
effective date of this AD or before accumulating an additional 3,300
cycles-in-service (CIS) after the effective date of this AD,
whichever occurs first.
(b) Perform repetitive inspections of HPC stage 14 disks, P/N's
9080M34P03, 9080M34P04, 9080M34P05 and 9349M91P04, with SN prefixes
GWN, MPO, RRY, and SNL, and disk SN's SNE00001 through SNE00017, and
disk SN's SNE01101 through SNE01110, in accordance with paragraphs
2.A. through 2.B. of GE CF6-50 ASB No. 72-A1144, dated March 19,
1998, or ASB No. 72-A1144, Revision 1, dated May 13, 1999, and the
following schedule:
(1) For disks with less than 9,800 CSN at the time of the last
inspection, perform repetitive inspections no later than 9,800 CSN
or before accumulating 3,300 cycles since last inspection (CSLI),
whichever occurs later.
(2) For disks with 9,800 CSN or greater at the time of the last
inspection, perform repetitive inspections no later than 3,300 CSLI.
(c) Perform initial inspections of HPC stage 14 disks, P/N's
9080M34P03, 9080M34P04, 9080M34P05 and 9349M91P04 with SN prefixes
SNG and SNE, except disk SN's SNE00001 through SNE00017 and SNE01101
through SNE01110, in accordance with paragraphs 2.A. through 2.B. of
GE CF6-50 ASB No. 72-A1144, dated March 19, 1998, or ASB No. 72-
A1144, Revision 1, dated May 13, 1999, and the following schedule:
(1) Inspect disks with 4,200 CSN or less on the effective date
of this AD before accumulating 7,500 CSN.
(2) Inspect disks with more than 4,200 CSN but less than 9,000
CSN on the effective date of this AD at the next ESV after the
effective date of this AD, before accumulating an additional 3,300
CIS after the effective date of this AD, or before accumulating
11,000 CSN, whichever occurs first.
(3) Inspect disks with 9,000 CSN or greater on the effective
date of this AD, at the next ESV after the effective date of this
AD, or before accumulating an additional 2,000 CIS after the
effective date of this AD, whichever occurs first.
(d) Perform repetitive inspections of HPC stage 14 disks, P/N's
9080M34P03, 9080M34P04, 9080M34P05 and 9349M91P04 with SN prefixes
SNG and SNE, except disk SN's SNE00001 through SNE00017 and SNE01101
through SNE01110, in accordance with paragraphs 2.A. through 2.B. of
GE CF6-50 ASB No. 72-A1144, dated March 19, 1998, or ASB No. 72-
A1144, Revision 1, dated May 13, 1999, and the following schedule:
(1) For disks with less than 7,500 CSN at the time of the last
inspection, perform repetitive inspections no later than 7,500 CSN
or before accumulating 3,300 CSLI, whichever occurs later.
(2) For disks with 7,500 CSN or greater at the time of the last
inspection, perform repetitive inspections no later than 3300 CSLI.
Removal From Service
(e) Remove from service prior to further flight stage 14 HPC
disks that equal or exceed the reject criteria established by GE
CF6-50 ASB 72-A1144, dated March 19, 1998, or ASB No. 72-A1144,
Revision 1, dated May 13, 1999.
(f) Remove from service, HPC stage 14 disks, P/N's 9080M34P03,
9080M34P04, 9080M34P05 and 9349M91P04 with SN prefixes SNG and SNE,
except disk SN's SNE00001 through SNE00017 and SNE01101 through
SNE01110, with greater than 6,000 CSN after the effective date of
this AD, at the next piece-part level exposure or at the next HPC
rotor disassembly level exposure after the effective date of this
AD.
Terminating Action
(g) Replacement of the stage 14 HPC disk, P/N's 9080M34P03,
9080M34P04, 9080M34P05, 9349M91P04, with a stage 11-14 spool shaft
is terminating action for the inspection requirements of this AD.
Reporting Requirements
(h) Report the results of inspections that equal or exceed the
reject criteria within five days of the inspection to: Manager,
Engine Certification Office, FAA, Engine and Propeller Directorate,
12 New England Executive Park, Burlington, MA 01803-5299, telephone,
(781) 238-7141, fax, (781) 238-7199. The following information must
be included in the report:
(1) HPC Stage 14 rotor disk P/N,
(2) HPC Stage 14 rotor disk SN,
(3) HPC Stage 14 rotor disk CSN,
(4) HPC Stage 14 rotor disk CSLI, and
(5) Date and location of inspection.
Reporting requirements have been approved by the Office of
Management and Budget (OMB) and assigned OMB control number 2120-
0056.
Definitions
(i) For the purpose of this AD, the following definitions apply:
(1) HPC Rotor disassembly occurs if any of the HPC Rotor bolted
flange joints are separated, such as the Stage 2 joint to accomplish
the Stage 3-9 Spool inspection.
[[Page 37011]]
(2) Piece-part exposure is defined as disassembly and removal of
the stage 14 disk from the HPC rotor structure, regardless of any
blades, locking lugs, bolts or balance weights assembled to the
disk.
(3) An engine shop visit is defined as the introduction of an
engine into a shop when a major engine flange is separated. The
following maintenance actions are not considered engine shop visits
for the purpose of this AD:
(i) Introduction of an engine into a shop solely for removal or
replacement of the Stage 1 Fan Disk;
(ii) Introduction of an engine into a shop solely for
replacement of the Turbine Rear Frame;
(iii) Introduction of an engine into a shop solely for
replacement of the Accessory Gearbox or Transfer Gearboxes;
(iv) Introduction of an engine into a shop solely for
replacement of the Fan Forward Case.
(v) Introduction of an engine into a shop for any combination of
exceptions specified in paragraphs (i)(3)(i) through (i)(3)(iv);
Alternative Methods of Compliance
(j) 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 request 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.
Incorporation by Reference
(k) The inspections shall be done in accordance with paragraphs
2.A. through 2.B. of GE CF6-50 ASB No. 72-A1144, dated March 19,
1998, or ASB No. 72-A1144, Revision 1, dated May 13, 1999, 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 Company via
Lockheed Martin Technology Services, 10525 Chester Road, Suite C,
Cincinnati, Ohio 45215, telephone (513) 672-8400, fax (513) 672-
8422. 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.
Special Flight Permit
(l) Special flight permits may be issued in accordance with
Secs. 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.
Effective Date of This AD
(m) This amendment becomes effective on August 14, 2000.
Issued in Burlington, Massachusetts, on May 25, 2000.
Thomas A. Boudreau,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 00-14017 Filed 6-12-00; 8:45 am]
BILLING CODE 4910-13-U