[Federal Register Volume 69, Number 207 (Wednesday, October 27, 2004)]
[Rules and Regulations]
[Pages 62571-62574]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-23929]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NE-43-AD; Amendment 39-13835; AD 2004-22-07]
RIN 2120-AA64


Airworthiness Directives; General Electric Company (GE) CF6-80C2 
Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for GE 
CF6-80C2 turbofan engines with certain part number (P/N) high pressure 
turbine stage 2 nozzle guide vanes (HPT S2 NGVs) installed. This AD 
requires flex borescope inspections of HPT S2 NGVs installed in CF6-
80C2 turbofan engines. This AD results from an uncontained engine 
failure due to HPT S2 NGV distress. We are issuing this AD to prevent 
blade separation from HPT S2 NGV distress, which could result in an 
uncontained engine failure.

DATES: This AD becomes effective December 1, 2004. The Director of the 
Federal Register approved the incorporation by reference of certain 
publications listed in the regulations as of December 1, 2004.

ADDRESSES: You can get the service information identified in this AD 
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.
    You may examine the AD docket at the FAA, New England Region, 
Office of the Regional Counsel, 12 New England Executive Park, 
Burlington, MA. You may examine the service information, at the FAA, 
New England Region, Office of the Regional Counsel, 12 New England 
Executive Park, Burlington, MA; or at the National Archives and Records 
Administration (NARA). For information on the availability of this 
material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

[[Page 62572]]


FOR FURTHER INFORMATION CONTACT: Eugene Triozzi, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA; telephone (781) 238-7148; 
fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39 
with a proposed AD. The proposed AD applies to GE CF6-80C2 turbofan 
engines with certain P/N HPT S2 NGVs installed. We published the 
proposed AD in the Federal Register on November 18, 2003 (68 FR 65000). 
That action proposed to require flex borescope inspections of certain 
P/N HPT S2 NGVs installed in CF6-80C2A1, -80C2A2, -80C2A3, -80C2A5, -
80C2A5F, -80C2A8, -80C2B1, -80C2B1F, -80C2B2, -80C2B2F, -80C2B4, -
80C2B4F, -80C2B5F, -80C2B6, -80C2B6F, -80C2B6FA, -80C2B7F, and -80C2D1F 
turbofan engines.
    Examining the AD Docket: You may examine the AD Docket (including 
any comments and service information), by appointment, between 8 a.m. 
and 4:30 p.m., Monday through Friday, except Federal holidays. See 
ADDRESSES for the location.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments received.

Requests To Limit the Required Inspections

    Seven commenters ask that we limit the inspections required by the 
proposed AD to those parts listed in paragraph 1.C.(6) of GE Service 
Bulletin (SB) No. CF6-80C2 S/B 72-0952, Revision 6, dated May 5, 2003, 
and that we revise Table 1 of the proposed AD to clarify the affected 
parts. The commenters state that those parts are the population 
recommended by the Manufacturer. We agree. We revised the applicability 
paragraph and Table 1 of the final rule for consistency with GE SB No. 
CF6-80C2 S/B 72-0952, Revision 6, dated May 5, 2003. We also clarified 
the applicability of certain P/Ns in Table 1 by adding, ``Insert, P/N 
1957M40G01 or P/N 1957M40G02, was installed during modification or 
repair,'' to those parts.
    Six commenters ask that we limit the inspections required by the 
proposed AD to areas of critical stress such as the leading edge and 
outer fillet areas of the HPT nozzle airfoil as specified in Paragraph 
3.B.(3) of GE SB No. CF6-80C2 S/B 72-0952, Revision 6, dated May 5, 
2003. The commenters feel that the proposed AD requires inspecting HPT 
blades as well as the nozzles, but that the cracking of the nozzles is 
the primary cause of failure of the HPT blade. The commenters feel that 
the proposed AD requires inspecting noncritical areas of nozzles. We 
agree. We revised paragraph (f) of the final rule to state ``Flex-
borescope inspect the NGVs following paragraphs 3.B.(3) through 3.B.(5) 
of the * * *.'' We also deleted paragraphs (f)(1) through (f)(3)(ii) 
because they applied to HPT S2 NGVs that have not been repaired.

Requests for a Drawdown Allowance and Credit for Inspections Already 
Done

    Five commenters ask that we provide an appropriate drawdown 
allowance for engines that have exceeded the threshold for the initial 
inspection, or provide credit for inspections that have already been 
done. The commenters feel that some engines might have already exceeded 
the initial limits. We agree that credit should be given for 
inspections that were performed before the effective date of the final 
rule, however, the proposed AD already provides for that credit by 
stating in paragraph (e) of the proposed AD ``You are responsible for 
having the actions required by this AD performed within the compliance 
times specified, unless the actions have already been done''. We 
changed paragraph (f)(2) of the final rule to state ``For engines 
listed in paragraphs (f)(1)(i) and (f)(1)(ii) of this AD that are 
already beyond the initial inspection thresholds, inspect at or before 
accumulating an additional 200 CSO after the effective date of this 
AD.''

Request To Add CF6-80C2B8F to the Applicability

    Two commenters ask us to add the CF6-80C2B8F engine model to the 
Applicability. The commenters state that the engine model was in the SB 
before we issued the NPRM. We agree. We have added the CF6-80C2B8F 
engine model to the Applicability of the final rule.

Request To Withdraw the NPRM

    Two commenters ask us to withdraw the NPRM because they do not feel 
there is an issue with safety of flight. One commenter states that they 
have not removed any engines for this cause. The other commenter states 
that the engine fragments that exited the engine via holes in the low 
pressure turbine case were small and caused only minor damage to the 
airplane. We do not agree. We identified an unsafe condition after an 
uncontained engine failure. We provided a discussion of the cause of 
the uncontained engine failure and how the condition could affect other 
engines of the same type design. We are issuing this AD to prevent 
future occurrences of the same unsafe condition.

Request To Change Blade Failure to Blade Separation

    One commenter asks us to change ``blade failure'' to ``blade 
separation.'' The commenter states this is consistent with using the 
term failure when the failure of the part is the primary cause. We 
agree. We have changed ``blade failure'' to ``blade separation'' in the 
final rule.

Request To Change CSO to CSN

    One commenter asks us to state the inspection compliance times for 
new nozzles in paragraph (f)(2)(i) through (iii) in terms of ``CSN.'' 
The commenter feels this will clarify the requirements. We agree that 
the change would have clarified the requirements of the original NPRM. 
However, based on previous comments, the final rule will apply only to 
repaired or modified nozzles and the paragraphs that the commenter asks 
us to change will not be included in the final rule.

Requests To Limit Reinspection Requirements

    Two commenters ask us to limit the reinspection requirements in 
paragraph (g) for the outer fillet to Figure 5, sheets 1 and 2 of GE SB 
No. CF6-80C2 S/B 72-0952, Revision 6, dated May 5, 2003. The commenters 
state that those sheets are the specific inspection requirements for 
cracking in the outer fillet. We agree. We added ``Sheets 1 and 2'' to 
paragraph (g) of the final rule.

Requests To Change the Reinspection intervals

    Several commenters ask us to change the reinspection intervals that 
are incorporated by reference in paragraph (g). The commenters feel 
that the requirement to ``reinspect at the next regular S2 Blade 
Inspection'' as stated in Figure 5 of GE SB No. CF6-80C2 S/B 72-0952, 
Revision 6, dated May 5, 2003, might be misleading. Although the next 
regular S2 Blade Inspection should coincide with 250 cycles-since-last-
inspection (CSLI) for CF6-80C2D1F engines with 5.0 or more cycles per 
flight leg and 400 CSLI for all other engines, the lack of specific 
cyclic limits might cause confusion. We agree. We added new paragraphs 
(h), (h)(1), and (h)(2) to the final rule to define the next regular S2 
Blade Inspection as cyclic limits of 250 and 400 CSLI respectively.

[[Page 62573]]

Request To Delete or Change the Paragraph Relating To Operation as More 
Than One Engine Configuration

    Two commenters ask us to delete or change paragraph (h) of this AD, 
``Engines Operated as More than One Engine Model Configuration (Thrust 
Level).'' Both commenters feel that we should delete paragraph (h) 
because the inspections are limited to repaired nozzles. One commenter 
also feels that we need a provision for engines that have operated at 
different thrust levels (i.e., reconfigured from one model to another 
model) before the initial inspection. We agree. We changed paragraph 
(i) of the final rule to require performing the initial inspection at 
the lowest applicable inspection threshold, and reinspection intervals 
associated with the current engine model configuration.

Conclusion

    We have carefully reviewed the available data, including the 
comments received, and determined that air safety and the public 
interest require adopting the AD with the changes described previously. 
We have determined that these changes will neither increase the 
economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

    There are about 1,100 GE CF6-80C2 turbofan engines of the affected 
design in the worldwide fleet. We estimate that this AD will affect 300 
of these engines installed on airplanes of U.S. registry. We also 
estimate that it will take about 2 work hours per engine to perform the 
inspections on engines that exhibit no damage, and therefore require no 
mapping of damage, and that the average labor rate is $65 per work 
hour. Based on these figures, we estimate the total cost of this AD to 
U.S. operators to be $39,000.

Regulatory Findings

    We have determined that this AD will not have federalism 
implications under Executive Order 13132. This AD will 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.
    For the reasons discussed above, I certify that this AD:
    (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.
    We prepared a summary of the costs to comply with this AD and 
placed it in the AD Docket. You may get a copy of this summary by 
sending a request to us at the address listed under ADDRESSES. Include 
``AD Docket No. 2003-NE-43-AD'' in your request.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 14 CFR part 
39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive:

2004-22-07 General Electric Company: Amendment 39-13835. Docket No. 
2003-NE-43-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective December 
1, 2004.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to General Electric Company (GE) CF6-80C2A1, 
-80C2A2, -80C2A3, -80C2A5, -80C2A5F, -80C2A8, -80C2B1, -80C2B1F, -
80C2B2, -80C2B2F, -80C2B4, -80C2B4F, -80C2B5F, -80C2B6, -80C2B6F, -
80C2B6FA, -80C2B7F, -80C2B8F, and -80C2D1F turbofan engines, with 
the part numbers (P/Ns) of high pressure turbine (HPT) stage 2 
nozzle guide vanes (HPT S2 NGVs) listed in the following Table 1, 
installed:

                     Table 1.--Affected HPT S2 NGVs
------------------------------------------------------------------------
              HPT S2 NGV:                         Provided that:
------------------------------------------------------------------------
P/N 1347M66G03, P/N 1347M66G04, and P/   Insert, P/N 1957M40G01 or P/N
 Ns 1815M81G01 through 1815M81G07.        1957M40G02, was installed
                                          during repair.
P/Ns 9373M80G07 through 9373M80G22, and  Insert, P/N 1957M40G01 or P/N
 P/Ns 9373M80G25 through 9373M80G32.      1957M40G02, was installed
                                          during repair, or NGV was
                                          repaired by GE between April
                                          1, 1998 through September 30,
                                          1999.
P/Ns 9373M80G33 through 9373M80G36.....  Part was repaired.
P/Ns 2080M38G01 through 2080M38G16, and  Insert, P/N 1957M40G01 or P/N
 P/Ns 2080M38G19 through 2080M38G24.      1957M40G02, was installed
                                          during modification or repair.
P/Ns 2080M19G01 through 2080M19G04, P/   Insert, P/N 1957M40G01 or P/N
 Ns 2080M19G07 through 2080M19G16, P/Ns   1957M40G02, was installed
 2080M19G19 through 2080M19G46, P/Ns      during modification or repair.
 2080M19G49 through 2080M19G70, and P/
 Ns 2080M19G73 through 2080M19G80.
------------------------------------------------------------------------

    These engines are installed on, but not limited to, Airbus A300, 
Airbus A310, Boeing 747, Boeing 767, and McDonnell Douglas MD-11 
airplanes.

Unsafe Condition

    (d) This AD results from an uncontained engine failure due to 
HPT S2 NGV distress. We are issuing this AD to prevent blade 
separation from HPT S2 NGV distress, which could result in an 
uncontained engine failure.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Initial Flex Borescope Inspection of NGVs

    (f) Flex-borescope inspect the NGVs following paragraph 3.B.(3) 
through 3.B.(5) of Accomplishment Instructions of GE Service 
Bulletin (SB) No. CF6-80C2 S/B 72-0952, Revision 6, dated May 5, 
2003, as follows:

[[Page 62574]]

Initial Inspection Thresholds

    (1) For all P/N NGVs, initial-inspect after the effective date 
of this AD at the following applicable initial inspection 
thresholds:
    (i) For CF6-80C2A2, -80C2B2, and -80C2B2F engines, inspect at or 
before accumulating 1,600 HPT cycles-since-overhaul (CSO).
    (ii) For CF6-80C2A1, -80C2A3, -80C2A5, -80C2A5F, -80C2A8, -
80C2B1, -80C2B1F, -80C2B4, -80C2B4F, -80C2B5F, -80C2B6, -80C2B6F, -
80C2B6FA, -80C2B7F, -80C2B8F, and -80C2D1F engines, inspect at or 
before accumulating 800 CSO.
    (2) For engines listed in paragraphs (f)(1)(i) and (f)(1)(ii) of 
this AD that are already beyond the initial inspection thresholds, 
inspect at or before accumulating an additional 200 CSO after the 
effective date of this AD.

Reinspection

    (g) Reinspect or remove from service NGVs following the 
Conditions and Reinspection intervals listed in the ``Inspection 
Table for Cracking in the Airfoil Outer Fillet'', Figure 5, Sheets 1 
and 2, of GE SB No. CF6-80C2 S/B 72-0952, Revision 6, dated May 5, 
2003.
    (h) If the recommendation contained in Figure 5, Sheets 1 and 2, 
of GE SB No. CF6-80C2 S/B 72-0952, Revision 6, dated May 5, 2003, 
states ``reinspect at next regular S2 Blade inspection,'' then for 
the purposes of this AD, the next regular S2 Blade Inspection must 
be within the following intervals:
    (1) For CF6-80C2D1F engines with 5.0 or more cycles per flight 
leg, the next regular S2 Blade inspection means within 250 cycles-
since-last-inspection (CSLI).
    (2) For all other engines listed in paragraph (c) of this AD, 
the next regular S2 Blade inspection means within 400 CSLI.

Engines Operated as More Than One Engine Model Configuration (Thrust 
Level)

    (i) For NGVs installed in engines operated as more than one 
engine model configuration (thrust level), use the lowest applicable 
initial inspection threshold, and use the reinspection intervals 
associated with the current engine model.

Alternative Methods of Compliance

    (j) The Manager, Engine Certification Office, has the authority 
to approve alternative methods of compliance for this AD if 
requested using the procedures found in 14 CFR 39.19.

Material Incorporated by Reference

    (k) You must use GE Service Bulletin No. CF6-80C2 S/B 72-0952, 
Revision 6, dated May 5, 2003, to perform the inspections and 
removals required by this AD. The Director of the Federal Register 
approved the incorporation by reference of this service bulletin in 
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You can get a 
copy 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. You can review copies 
at the FAA, New England Region, Office of the Regional Counsel, 12 
New England Executive Park, Burlington, MA; or at the National 
Archives and Records Administration (NARA). For information on the 
availability of this material at NARA, call 202-741-6030, or go to: 
http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

Related Information

    (l) None.

    Issued in Burlington, Massachusetts, on October 20, 2004.
Francis A. Favara,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 04-23929 Filed 10-26-04; 8:45 am]
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