FR Doc 03-331

[Federal Register: January 13, 2003 (Volume 68, Number 8)]
[Rules and Regulations]
[Page 1519-1521]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr13ja03-4]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NE-44-AD; Amendment 39-13016; AD 2003-01-05]
RIN 2120-AA64

Airworthiness Directives; General Electric Co. CF6-80A Series
Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that
is applicable to General Electric Co. (GE) CF6-80A series turbofan
engines. This action requires the following initial and repetitive
inspections of certain part number (P/N) stage 1 high pressure turbine
(HPT) rotor disks for cracks:
[sbull] Etch preparations and fluorescent penetrant inspections.
[sbull] Visual inspections.
[sbull] Eddy current inspections.

This amendment is prompted by a Boeing 767 airplane recently
experiencing a stage 1 HPT rotor disk separation resulting in
uncontained engine failure. The actions specified in this AD are
intended to detect cracks in the bottoms of the dovetail slots that
could propagate to failure of the disk and cause an uncontained engine
failure.

DATES: Effective January 28, 2003. The incorporation by reference of
certain publications listed in the rule is approved by the Director of
the Federal Register as of January 28, 2003.
Comments for inclusion in the Rules Docket must be received on or
before March 14, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), New England Region, Office of the Regional
Counsel, Attention: Rules Docket No. 2002-NE-44-AD, 12 New England
Executive Park, Burlington, MA 01803-5299. Comments may be inspected at
this location, by appointment, between 8 a.m. and 4:30 p.m., Monday
through Friday, except Federal holidays. Comments may also be sent via
the Internet using the following address: ``9-ane-adcomment@faa.gov''.
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
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, by
appointment, 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: Anthony W. Cerra Jr., Aerospace
Engineer, Engine Certification Office, FAA, Engine and Propeller
Directorate, 12 New England Executive Park, Burlington, MA 01803-5299;
telephone: (781) 238-7128, fax: (781) 238-7199.

SUPPLEMENTARY INFORMATION: On December 8, 2002, a Boeing 767-200
equipped with GE CF6-80A series engines experienced an uncontained
failure of a stage 1 HPT rotor disk during climb. The results of the
investigation indicate that the stage 1 HPT rotor disk failure was the
result of a crack that initiated in an aft corner edge of the bottom of
a dovetail slot. The crack propagated in fatigue to critical crack
size, and subsequently resulted in disk rupture and separation.
In September 2000, a U.S. operator experienced a similar
uncontained failure of the stage 1 HPT rotor disk during a ground
maintenance run of a CF6-80C2 engine. The investigation of that failure
had indicated that a crack initiated in the dovetail slot bottom aft
edge. The root cause of the crack initiation remains unknown. However,
cracks, burrs, or damage sustained in the dovetail slot bottom corner
radii from improper handling and processing during new part manufacture
and/or during maintenance were suspect for the September 2000 event. AD
2001-10-07, which became effective on June 28, 2001, was issued to
mandate inspections of the CF6-80C2 stage 1 HPT rotor disk dovetail
slot bottoms.
Since 1995, shop level inspections have found eleven stage 1 HPT
rotor disks from CF6-80A series engines and CF6-80C2 series engines
with crack-like indications in the dovetail slot bottoms. These
indications resulted from material inclusions, toolmarks, broach burrs,
and unknown causes. Of these eleven disks, three have been CF6-80A
series engine stage 1 HPT rotor disks, with cracks in the dovetail slot
bottom aft corner radius. Of the three that have been -80A series
engine disks, two indications were associated with non-propagating
broaching burrs occurring during manufacture, while no root cause was
identified for the third. Only the third disk had crack propagation.
The failure of the disk involved in the recent CF6-80A series
engine event was also caused by a crack that initiated in the dovetail
slot bottom aft edge. This event is still under investigation.
Therefore, this final rule; request for comments is an interim action
until a root cause is established for the crack initiation and/or
additional corrective actions are identified. The actions specified by
this AD are intended to detect cracks in the bottoms of the dovetail
slots that could propagate to failure of the disk and cause an
uncontained engine failure. This condition, if not corrected, could
result in stage 1 HPT rotor disk separation resulting in uncontained
engine failure.

Manufacturer's Service Information

The FAA has reviewed and approved the technical contents of GE
Service Bulletin (SB) CF6-80A S/B 72-0779, dated March 20, 2002 that
describes procedures for etch preparation, fluorescent penetrant,
visual, and eddy current inspections of the following stage 1 HPT rotor
disks P/N's used on CF6-80A, -80A1, -80A2, and -80A3 series turbofan
engines:

[[Page 1520]]

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9234M67G22 9234M67G24 9234M67G25 9234M67G26
9362M58G02 9362M58G06 9362M58G07 9362M58G09
9367M45G02 9367M45G04 9367M45G09 N/A
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Differences Between This AD and the Manufacturer's Service Information

SB CF6-80A S/B 72-0779, dated March 20, 2002, only requires a one-
time inspection at the next exposure of disks that have accumulated
operating cycles, and requires no inspection of new disks that have not
yet accumulated operating cycles. This AD requires initial and
repetitive inspections of the affected P/N's of stage 1 HPT rotor
disks, as specified in the following paragraph.

FAA's Determination of an Unsafe Condition and Required Actions

Since an unsafe condition has been identified that is likely to
exist or develop on other GE CF6-80A, -80A1, -80A2, and -80A3 series
turbofan engines of the same type design, this AD is being issued to
detect cracks in the bottoms of the dovetail slots that could propagate
to failure of the disk and cause an uncontained engine failure. This AD
requires:
[sbull] For stage 1 HPT rotor disks not currently installed in
engines, before further flight, inspection of disk dovetail slot
bottoms. Any disk that meets or exceeds the reject criteria of SB CF6-
80A S/B 72-0779, dated March 20, 2002, is not to be installed into any
engine.
[sbull] For stage 1 HPT rotor disks that have been inspected in
accordance with SB CF6-80A S/B 72-0779, dated March 20, 2002, before
the effective date of this AD, inspection of the disk dovetail slot
bottoms at each piece-part exposure of the disk, and replacement of
disks as necessary.
[sbull] For stage 1 HPT rotor disks that have not been inspected in
accordance with SB CF6-80A S/B 72-0779, dated March 20, 2002, before
the effective date of this AD, inspection of the disk dovetail slot
bottoms at next engine shop visit, and each piece-part exposure of the
disk, and replacement of disks as necessary.
[sbull] A mandatory reporting requirement which mandates that
within 5 calendar days of an inspection, any results that equal or
exceed the reject criteria be reported to the FAA's Engine and
Propeller Directorate, Engine Certification Office.
The actions are required to be done in accordance with the service
bulletin described previously.

Interim Actions

The actions specified in the AD are considered interim actions and
further action is anticipated based on the continuing investigation of
the stage 1 HPT rotor disk cracking.

Immediate Adoption of This AD

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 action must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 2002-NE-44-AD.'' The postcard will be date stamped and
returned to the commenter.

Regulatory Analysis

This final rule does not have federalism implications, as defined
in Executive Order 13132, because it would 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 FAA has not consulted with state authorities prior to publication
of this final rule.
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:

2003-01-05 General Electric Co.: Amendment 39-13016. Docket No.
2002-NE-44-AD.

Applicability

This airworthiness directive (AD) is applicable to General
Electric Co. (GE) CF6-

[[Page 1521]]

80A, -80A1, -80A2, and -80A3 series turbofan engines with the stage
1 high pressure turbine (HPT) rotor disks part numbers (P/N's)
listed in the following Table 1:

Table 1.--Stage 1 HPT Rotor Disks P/N's Affected
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These engines are installed on, but not limited to, Airbus
Industrie A310 and Boeing 767 airplanes.

Note 1: 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 request approval for an
alternative method of compliance in accordance with paragraph (g) 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

Compliance with this AD is required as indicated, unless already
done.
To detect cracks in the bottoms of the dovetail slots that could
propagate to failure of the disk and cause an uncontained engine
failure, do the following in accordance with paragraphs 3.A. through
3.C.(10)(h) of the Accomplishment Instructions of GE Service
Bulletin (SB) CF6-80A S/B 72-0779, dated March 20, 2002:
(a) For stage 1 HPT rotor disks not currently installed in
engines, before further flight, inspect the disk dovetail slot
bottoms. Do not install any disk that meets or exceeds the reject
criteria of the above service bulletin, into any engine.
(b) For stage 1 HPT rotor disks that have been inspected in
accordance with the above service bulletin before the effective date
of this AD, inspect the disk dovetail slot bottoms at each piece-
part exposure of the disk, and replace disk as necessary.
(c) For stage 1 HPT rotor disks that have not been inspected in
accordance with the above service bulletin before the effective date
of this AD, inspect the disk dovetail slot bottoms at next engine
shop visit, and each piece-part exposure of the disk, and replace
disk as necessary.

Definitions

(d) An engine shop visit is defined as the induction of an
engine into a shop, where the separation of a major engine flange
will occur after the effective date of this AD.
(e) Piece-part exposure is defined as:
(1) The part being considered completely disassembled, when done
in accordance with the disassembly instructions of the
manufacturer's or other FAA-approved engine manual; AND
(2) The part has accumulated more than 100 cycles-in-service
since the last piece-part opportunity inspection, provided that the
part was not damaged or related to the cause for its removal from
the engine.

Reporting Requirements

(f) Report within 5 calendar days of inspection the results of
inspections that equal or exceed the reject criteria to: Engine
Certification Office, FAA, Engine and Propeller Directorate, 12 New
England Executive Park, Burlington, MA 01803-5299; telephone (781)
238-7128; fax (781) 238-7199. Reporting requirements have been
approved by the Office of Management and Budget (OMB) control number
2120-0056. Be sure to include the following information:
(1) Engine model in which the stage 1 HPT rotor disk was
installed.
(2) Disk Part Number.
(3) Disk Serial Number.
(4) Disk Cycles-Since-New.
(5) Disk Cycles-Since-Last Inspection.
(6) Date and Location of Inspection.

Note 2: The FAA recommends recording the inspection results on
GE Form 1653-1, found in GE SB CF6-80A S/B 72-0779, dated March 20,
2002, and sending the data to GE Airline Support Engineering.

Alternative Methods of Compliance

(g) 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 (ECO).
Operators must submit their requests through an appropriate FAA
Principal Maintenance Inspector, who may add comments and then send
it to the Manager, ECO.

Note 3: Information concerning the existence of approved
alternative methods of compliance with this airworthiness directive,
if any, may be obtained from the ECO.

Special Flight Permits

(h) Special flight permits may be issued in accordance with
Sec. Sec. 21.197 and 21.199 of the Federal Aviation Regulations (14
CFR 21.197 and 21.199) to operate the airplane to a location where
the requirements of this AD can be done.

Documents That Have Been Incorporated by Reference

(i) The inspections must be done in accordance with General
Electric Co. Service Bulletin CF6-80A S/B 72-0779, dated March 20,
2002. 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.

Effective Date

(j) This amendment becomes effective on January 28, 2003.

Issued in Burlington, Massachusetts, on January 2, 2003.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification
Service.
[FR Doc. 03-331 Filed 1-10-03; 8:45 am]

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