[Federal Register Volume 64, Number 70 (Tuesday, April 13, 1999)]
[Rules and Regulations]
[Pages 17951-17954]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-8863]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-ANE-49-AD; Amendment 39-11119; AD 99-08-13]
RIN 2120-AA64


Airworthiness Directives; General Electric Company CF6-80A, CF6-
80C2, and CF6-80E1 Series Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), that 
requires revisions to the Life Limits Section of the manufacturer's 
Instructions for Continued Airworthiness (ICA) for General Electric 
Company (GE) CF6-80A, CF6-80C2 and CF6-80E1 series turbofan engines to

[[Page 17952]]

include required enhanced inspection of selected critical life-limited 
parts at each piece-part exposure. This AD also requires that an air 
carrier's approved continuous airworthiness maintenance program 
incorporate these inspection procedures. This amendment is prompted by 
a Federal Aviation Administration (FAA) study of in-service events 
involving uncontained failures of critical rotating engine parts that 
indicated the need for improved inspections. The improved inspections 
are needed to identify those critical rotating parts with conditions, 
which if allowed to continue in service, could result in uncontained 
failures. The actions specified by this AD are intended to prevent 
critical life-limited rotating engine part failure, which could result 
in an uncontained engine failure and damage to the airplane.

DATES: Effective May 13, 1999.

ADDRESSES: The information contained in this AD may be examined at the 
FAA, New England Region, Office of the Regional Counsel, 12 New England 
Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Karen Curtis, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (781) 
238-7192, 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 GE CF6-80A, CF6-80C2 and CF6-80E1 
series turbofan engines was published in the Federal Register on July 
28, 1998 (63 FR 40223). That action proposed to require within the next 
30 days after the effective date of this AD, revisions to the Life 
Limits section of the Engine Manuals, and, for air carriers, their 
approved continuous airworthiness maintenance program. The manufacturer 
of CF6-80A, CF6-80C, and CF6-80E1 series turbofan engines, has provided 
the FAA with a detailed proposal that identifies and prioritizes the 
critical life-limited rotating engine parts with the highest potential 
to hazard the airplane in the event of failure, along with instructions 
for enhanced, focused inspection methods. These enhanced inspections 
will be conducted at piece-part opportunity, as defined in this AD, 
rather than at specific inspection intervals.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    Four commenters note that some of the tasks and subtasks that are 
referenced in the Notice for Proposed Rule Making (NPRM) require visual 
and dimensional inspections in addition to the nondestructive 
inspections identified as part of the enhanced inspection initiative. 
The commenters recommend that the final rule be revised to reflect only 
those tasks or subtasks that are intended to be mandated by the AD. The 
FAA concurs. The requested changes are consistent with the enhanced 
inspection initiative. The compliance section of this final rule has 
been changed to reference only the tasks and subtasks of the mandated 
inspections.
    One commenter notes that the chapter referenced for the CF6-80A 
high pressure turbine (HPT) stage 1 disk inspection in the table in 
paragraph (a) of the NPRM is in error. The commenter recommends 
changing the final rule to reference the correct chapter (72-53-02 
instead of 72-53-03). The FAA concurs. The chapter reference for the 
CF6-80A HPT stage 1 disk in the table in paragraph (a) of the 
compliance section of this AD has been changed to reference chapter 72-
53-02.
    One commenter notes that the work hours that are stated in the 
preamble for the HPT rotor stage 1 and stage 2 disk inspections are 
less than the commenter's estimate. The commenter recommends that the 
final rule be revised to note 18 hours instead of 8 hours for the 
mandated inspections. The FAA does not concur. The FAA has reviewed the 
work hour estimate that includes 3 hours for eddy current inspection 
and 5 hours for fluorescent-penetrant inspection (FPI) for each HPT 
rotor disk for a total of 16 hours for the two HPT rotor disks. The FAA 
believes that 8 hours is a conservative estimate for a part of average 
cleanliness that's being inspected under typical shop conditions.
    No other comments were received on the economic analysis contained 
in the NPRM. Based on that analysis, the FAA has determined that the 
annual per engine cost of $308 does not create a significant economic 
impact on small entities.
    One commenter requests that the FAA link the conduct of mandatory 
inspections on whether the subject part was removed from an engine 
while the engine was installed on the airplane or while the engine was 
removed and in an overhaul shop. The commenter wishes to exempt those 
parts that are removed from installed engines from the focused 
inspections. The FAA does not concur. The mandatory inspections are 
based on a single trigger. The trigger is a part being completely 
disassembled using the engine manual instructions (piece-part 
opportunity), and is not dependent on whether an engine is installed on 
the airplane. This final rule mandates that the definition of piece-
part opportunity appears in the mandatory section of each affected 
engine manual. This final rule further mandates that an operator's 
continuous airworthiness maintenance program be modified to capture 
those engine manual changes.
    Several commenters ask that the FAA clarify the record keeping 
aspects of the mandatory inspections resulting from the required 
changes to the Original Equipment Manufacturer's manual and operator's 
continuous airworthiness maintenance program. One commenter believes 
that paragraph (e) of the proposed AD is unclear and suggests that it 
be revised by eliminating the word ``or'' from the first sentence and 
beginning a second sentence with ``In lieu of the record. * * *'' Two 
commenters state that the AD should be revised to clearly specify which 
types of maintenance records must be retained (i.e., inspection 
results, defect reporting requirements, date of performed maintenance, 
signature of the person performing the maintenance). These commenters 
believe that these revisions are necessary in order to avoid potential 
differences in interpretation between the air carriers and the FAA. 
And, one commenter states that the AD should clarify that there is no 
need for a special form to comply with the AD record keeping 
requirements. The FAA concurs in part. Generally, record keeping 
requirements are addressed in other regulations and this AD does not 
change those requirements. In order to allow flexibility from operator 
to operator, the FAA does not agree that the AD itself specify the 
precise nature of the records that will result from the required 
changes to the manufacturer's manual and operator's maintenance 
program. The FAA has, however, revised Paragraph (e) of this AD to 
clarify record keeping aspects of the new mandatory inspections.
    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.
    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

[[Page 17953]]

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, 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:

99-08-13  General Electric Company: Amendment 39-11119. Docket 98-
ANE-49-AD.
    Applicability: General Electric Company CF6-80A, CF6-80C2 and 
CF6-80E1 series turbofan engines, installed on but not limited to 
Airbus A300, A310, and A330 series, Boeing 747 and 767 series, and 
McDonnell Douglas MD-11 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 (c) 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 critical life-limited rotating engine part 
failure, which could result in an uncontained engine failure and 
damage to the airplane, accomplish the following:
    (a) Within the next 30 days after the effective date of this AD, 
revise the manufacturer's Life Limits Section of the Instructions 
for Continued Airworthiness (ICA), and for air carrier operations 
revise the approved continuous airworthiness maintenance program, by 
adding the following:

``MANDATORY INSPECTIONS

    (1) Perform inspections of the following parts at each piece-
part opportunity in accordance with the instructions provided in the 
applicable manual provisions:

----------------------------------------------------------------------------------------------------------------
       Part Nomenclature              Part number (P/N)                Inspect per engine manual chapter
----------------------------------------------------------------------------------------------------------------
For CF6-80A Engines:
    Fan Rotor Disk Stage 1.....  All........................  72-21-03, paragraph 3, Fluorescent-Penetrant
                                                               Inspect; and 72-21-03, paragraph 4, Eddy Current
                                                               Inspect.
    High Pressure Turbine Rotor  All........................  72-53-02, paragraph 3, Fluorescent-Penetrant
     Stage 1 Disk/Shaft.                                       Inspect Disk/Shaft per 70-32-02; and 72-53-02,
                                                               paragraph 6, Eddy Current Inspection.
    High Pressure Turbine Rotor  All........................  72-53-06, paragraph 3, Fluorescent-Penetrant
     Stage 2 Disk.                                             Inspection; and 72-53-06, paragraph 6, Eddy
                                                               Current Inspection of Rim Boltholes for Cracks.
For CF6-80C2 Engines:
    Fan Rotor Disk Stage 1.....  All........................  Task 72-21-03-200-000-004, Fluorescent-Penetrant
                                                               Inspection; and Task 72-21-03-200-000-008, Eddy
                                                               Current Inspect Fan Rotor Disk Stage 1 Bore,
                                                               Forward and Aft Hub Faces, and Bore Radii.
    High Pressure Turbine (HPT)  All........................  Task 72-53-02-200-000-001, Fluorescent-Penetrant
     Rotor Stage 1 Disk/Shaft.                                 Inspect the HPT Rotor Stage 1 Disk/Shaft; and
                                                               Task 72-53-02-200-000-005, Eddy Current
                                                               Inspection.
    High Pressure Turbine (HPT)  All........................  Task 72-53-06-200-000-002, Fluorescent-Penetrant
     Rotor Stage 2 Disk.                                       Inspect the Stage 2 Disk; and Task 72-53-06-200-
                                                               000-006, Eddy Current Inspection of the HPTR
                                                               Stage 2 Rim Boltholes.
For CF6-80E1 Engines:
    Stage 1 Disk, Fan Rotor....  All........................  Task 72-21-03-230-051, Fluorescent-Penetrant
                                                               Inspection; and Task 72-21-03-250-051 or 72-21-03-
                                                               250-052, Eddy Current Inspection.
    High Pressure Turbine (HPT)  All........................  Task 72-53-02-230-051, Fluorescent-Penetrant
     Rotor Stage 1 Disk/Shaft.                                 Inspection; and Task 72-53-02-200-001-005, Eddy
                                                               Current Inspection.
    High Pressure Turbine (HPT)  All........................  Task 72-53-06-230-051, Fluorescent-Penetrant
     Rotor Stage 2 Disk.                                       Inspection; and Task 72-53-06-200-001-006, Eddy
                                                               Current Inspection of the HPTR Stage 2 Rim
                                                               Boltholes.
----------------------------------------------------------------------------------------------------------------

    (2) For the purposes of these mandatory inspections, piece-part 
opportunity means:
    (i) The part is considered completely disassembled when done in 
accordance with the disassembly instructions in the manufacturer's 
engine manual; and
    (ii) 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.''
    (b) Except as provided in paragraph (c) of this AD, and 
notwithstanding contrary provisions in Sec. 43.16 of the Federal 
Aviation Regulations (14 CFR 43.16), these mandatory inspections 
shall be performed only in accordance with the Life Limits Section 
of the manufacturer's ICA.
    (c) 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 (PMI), 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.


[[Page 17954]]


    (d) 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 aircraft to a location where 
the requirements of this AD can be accomplished.
    (e) FAA-certificated air carriers that have an approved 
continuous airworthiness maintenance program in accordance with the 
recordkeeping requirement of Sec. 121.369 (c) of the Federal 
Aviation Regulations [14 CFR 121.369 (c)] of this chapter must 
maintain records of the mandatory inspections that result from 
revising the Life Limits section of the ICA and the air carrier's 
continuous airworthiness program. Alternately, certificated air 
carriers may establish an approved system of record retention that 
provides a method for preservation and retrieval of the maintenance 
records that include the inspections resulting from this AD, and 
include the policy and procedures for implementing this alternate 
method in the air carrier's maintenance manual required by 
Sec. 121.369 (c) of the Federal Aviation Regulations [14 CFR 121.369 
(c)]; however, the alternate system must be accepted by the 
appropriate PMI and require the maintenance records be maintained 
either indefinitely or until the work is repeated. Records of the 
piece-part inspections are not required under Sec. 121.380(a)(2)(vi) 
of the Federal Aviation Regulations [14 CFR 121.380(a)(2)(vi)]. All 
other Operators must maintain the records of mandatory inspections 
required by the applicable regulations governing their operations.

    Note 3: The requirements of this AD have been met when the 
engine manual changes are made and operators have modified their 
continuous airworthiness maintenance plans to reflect the 
requirements in the engine manuals.

    (f) This amendment becomes effective on May 13, 1999.

    Issued in Burlington, Massachusetts, on April 2, 1999.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 99-8863 Filed 4-12-99; 8:45 am]
BILLING CODE 4910-13-U