[Federal Register Volume 69, Number 183 (Wednesday, September 22, 2004)]
[Proposed Rules]
[Pages 56730-56733]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-21275]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-19144; Directorate Identifier 2003-NE-18-AD]
RIN 2120-AA64


Airworthiness Directives; General Electric Company (GE) CF6-80C2 
and CF6-80E1 Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain GE CF6-80C2 and CF6-80E1 turbofan engines. This proposed AD 
would require you to:
     Inspect the high pressure compressor rotor (HPCR) stage 
11-14 spool shaft for circumferential repair cuts, and
     Repair or replace the spool shaft if you find certain 
circumferential cuts.
    This proposed AD results from an updated stress analysis. We are 
proposing this AD to prevent failure of the HPCR stage 11-14 spool 
shaft due to low-cycle fatigue that could result in an uncontained 
engine failure.

DATES: We must receive any comments on this proposed AD by November 22, 
2004.

ADDRESSES: Use one of the following addresses to send comments on this 
proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590-001.
     Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    You can get the service information identified in this proposed 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 comments on this proposed AD in the AD docket 
on the Internet at http://dms.dot.gov.

FOR FURTHER INFORMATION CONTACT: Karen Curtis, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803; telephone (781) 238-
7192; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: We invite you to submit any written relevant 
data, views, or arguments regarding this proposal. Send your comments 
to an address listed under ADDRESSES. Include ``Docket No. FAA-2004-
19144; Directorate Identifier 2003-NE-18-AD'' in the subject line of 
your comments. We specifically invite comments on the overall 
regulatory, economic, environmental, and energy aspects of the proposed 
AD. We will consider all comments received by the closing date and may 
amend the proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of the 
DMS Web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You may review the DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78) or you 
may visit http://dms.dot.gov.
    We are reviewing the writing style we currently use in regulatory 
documents. We are interested in your comments on whether the style of 
this document is clear, and your suggestions to improve the clarity of 
our communications that affect you. You can get more information about 
plain language at http://www.faa.gov/language and http://www.plainlanguage.gov.

Examining the AD Docket

    You may examine the docket that contains the proposal, any comments 
received and, any final disposition in person at the DMS Docket Offices 
between 9 a.m. and 5 p.m., Monday

[[Page 56731]]

through Friday, except Federal holidays. The Docket Office (telephone 
(800) 647-5227) is located on the plaza level of the Department of 
Transportation Nassif Building at the street address stated in 
ADDRESSES. Comments will be available in the AD docket shortly after 
the DMS receives them.

Discussion

    In 1996, GE developed a circumferential cut repair to remove 
damaged material from seal wire grooves in the outer rim of HPCR stage 
11-14 spool shafts installed in certain CF6-80C2 and CF6-80E1 turbofan 
engines. The damage was due to wear of the seal wire from engine 
operation. At that time, analysis showed that there was no impact on 
spool shaft life from the repair geometry. GE performed updated stress 
analyses in 1999 and 2003. Those stress analyses showed that the 
circumferential cut geometry resulted in a high-stress concentration. 
This high-stress concentration could result in a service life that is 
lower than the published service life of the spool shaft, depending on 
the spool shaft part number (P/N) and location of the repair. GE 
reports that as many as 135 CF6-80C2 and CF6-80E1 HPCR 11-14 spool 
shafts have had this repair. This condition, if not corrected, could 
result in failure of the HPCR stage 11-14 spool shaft due to low-cycle 
fatigue that could result in an uncontained engine failure.

Relevant Service Information

    We have reviewed and approved the technical contents of GE Aircraft 
Engines (GEAE) Service Bulletins (SBs) CF6-80C2 S/B 72-1052, Revision 
01, dated February 5, 2004; and CF6-80E1 S/B 72-0232, Revision 01, 
dated February 5, 2004, that describe procedures for inspection and 
repair of the circumferential cuts in the seal wire grooves of the HPCR 
stage 11-14 spool shaft.

Differences Between the Proposed AD and the Manufacturer's Service 
Information

    This proposed AD does not require the operator to take further 
action when a circumferential cut repair is on the forward seal wire 
groove of the stage 14 disk of a CF6-80E1 or CF6-80C2 Group 2 spool 
shaft. GEAE, however, recommends repairing these disks at the next 
exposure, regardless of the number of cycles-since-repair.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other products 
of this same type design. We are proposing this AD, which would 
require:
     Inspection of the spool shaft for circumferential repair 
cuts at the next piece-part level exposure, but not to exceed a 
specific service cap specified in this proposed AD, and
     Repair or replacement of certain spool shafts.
    You must use the service information described previously to 
perform these proposed actions.

Costs of Compliance

    There are approximately 135 GE CF6-80C2 and CF6-80E1 turbofan 
engines of the affected design in the worldwide fleet. We estimate that 
27 engines installed on airplanes of U.S. registry would be affected by 
this proposed AD. We also estimate that it would take about 1 work hour 
per engine to inspect for the location of previous circumferential cut 
repairs and 5 work hours per engine to repair the spool shaft. We 
estimate that 24 engines would be repaired and that three spool shafts 
would be replaced. The average labor rate is $65 per work hour. Each 
replacement spool shaft would cost approximately $447,400. Based on 
these figures, we estimate the total cost of the proposed AD to U.S. 
operators to be $1,351,755.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD 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.
    For the reasons discussed above, I certify that the proposed 
regulation:
    1. Is not a ``significant regulatory action'' under Executive Order 
12866;
    2. Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979); and
    3. Would 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 proposal 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-18-AD'' in your request.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Under the authority delegated to me by the Administrator, the 
Federal Aviation Administration proposes to amend 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. The FAA amends Sec.  39.13 by adding the following new 
airworthiness directive:

General Electric Company: Docket No. FAA-2004-19144; Directorate 
Identifier 2003-NE-18-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by November 22, 
2004.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to certain GE CF6-80C2 and CF6-80E1 turbofan 
engines that have a high pressure compressor rotor (HPCR) stage 11-
14 spool shaft with a part number (P/N) listed in Table 1 of this AD 
and that had a seal wire groove repaired using a circumferential cut 
at a location specified in Table 2 of this AD. These engines are 
installed on, but not limited to, Airbus Industrie A300, A310, and 
A330 series airplanes and Boeing 747, 767, and MD-11 series 
airplanes.

              Table 1.--Stage 11-14 Spool Shaft P/Ns By Engine Model and Forging Group Designations
----------------------------------------------------------------------------------------------------------------
              Engine model                  Stage 11-14 spool shaft P/Ns         Forging group  designations
----------------------------------------------------------------------------------------------------------------
CF6-80C2................................  9380M30G07, 9380M30G08,           Group 1.
                                           9380M30G09, 9380M30G10,
                                           9380M30G12, 1509M71G02,
                                           1509M71G03, 1509M71G04, and
                                           1509M71G05.

[[Page 56732]]

 
CF6-80C2................................  1531M21G01, 1531M21G02,           Group 2.
                                           1531M21G04, 1509M71G06,
                                           1509M71G07, 1509M71G08,
                                           1509M71G11, 1509M71G12,
                                           1703M74G01, and 1703M74G03.
CF6-80E1................................  1509M71G11, 1509M71G12,           Not Applicable.
                                           1509M71G13, 1644M99G03,
                                           1703M74G01, and 1703M74G03.
----------------------------------------------------------------------------------------------------------------

Unsafe Condition

    (d) This AD results from an updated stress analysis. We are 
issuing this AD to prevent failure of the HPCR stage 11-14 spool 
shaft due to low-cycle fatigue that 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.

CF6-80C2 Engines

    (f) For CF6-80C2 series engines with HPCR stage 11-14 spool 
shaft serial numbers listed in 1.A.(2) of GE Aircraft Engines (GEAE) 
Service Bulletin (SB) No. CF6-80C2 S/B 72-1052, Revision 1, dated 
February 5, 2004, inspect the spool shaft for the location of the 
circumferential cut repair at the next piece-part exposure.
    (1) If the stage and location of the repair is specified in the 
engine records, inspect prior to exceeding the cycles-since-repair 
(CSR) limit specified in the column titled, Replace By (CSR), in 
Table 2.
    (2) If the stage or location of the repair is not known from the 
engine records, remove the spool shaft for inspection before 
exceeding 4,200 CSR for the Group 1 or before exceeding 10,000 CSR 
for Group 2. Use 3.A.(1) of the Accomplishment Instructions of GEAE 
SB No. CF6-80C2 S/B 72-1052, Revision 1, dated February 5, 2004, for 
the inspection. Table 2 follows:

  Table 2.--Repair and Replacement Limits for Spool Shafts by Forging Group and Location of the Circumferential
                                                   Cut Repair
----------------------------------------------------------------------------------------------------------------
                                                                   Location of
         Engine model             Forging group       Stage      circumferential    Repair by (CSR)   Replace by
                                  (from table 1)                    cut repair           limit       (CSR) limit
----------------------------------------------------------------------------------------------------------------
(1) CF6-80C2..................  Group 1..........           14  (i) Aft Seal Wire  3,600...........        4,200
                                                                 Groove--Not in
                                                                 Area X.
                                                                (ii) Aft Seal      None--Replace           4,200
                                                                 Wire Groove--In    spool.
                                                                 Area X.
                                                                (iii) Forward      7,100...........        7,100
                                                                 Seal Wire
                                                                 Groove--Not in
                                                                 Area X.
                                                                (iv) Forward Seal  None--Replace           7,100
                                                                 Wire Groove--In    spool.
                                                                 Area X.
(2) CF6-80C2..................  Group 1..........           13  (i) Aft Seal Wire  7,100...........        7,100
                                                                 Groove--Not in
                                                                 Area X.
                                                                (ii) Aft Seal      2,740...........        7,100
                                                                 Wire Groove--In
                                                                 Area X.
                                                                (iii) Forward      7,100...........        7,100
                                                                 Seal Wire
                                                                 Groove--Not in
                                                                 Area X.
                                                                (iv) Forward Seal  7,100...........        7,100
                                                                 Wire Groove--In
                                                                 Area X.
(3) CF6-80C2..................  Group 1..........           12  Aft Seal Wire      7,100...........        7,100
                                                                 Groove--In Area
                                                                 X.
(4) CF6-80C2..................  Group 2..........           14  (i) Aft Seal Wire  13,700..........       13,700
                                                                 Groove--Not in
                                                                 Area X.
                                                                (ii) Aft Seal      None--Replace          13,700
                                                                 Wire Groove--In    spool.
                                                                 Area X.
                                                                (iii) Forward      9,830...........       10,000
                                                                 Seal Wire
                                                                 Groove--In Area
                                                                 X.
(5) CF6-80C2..................  Group 2..........           13  (i) Aft Seal Wire  9,830...........       10,000
                                                                 Groove--In Area
                                                                 X.
                                                                (ii) Forward Seal  9,830...........       10,000
                                                                 Wire Groove--In
                                                                 Area X.
(6) CF6-80C2..................  Group 2..........           12  Aft Seal Wire      9,830...........       10,000
                                                                 Groove--In Area
                                                                 X.
(7) CF6-80E1..................  Not Applicable...           14  (i) Aft Seal Wire  11,600..........       11,600
                                                                 Groove--Not in
                                                                 Area X.
                                                                (ii) Aft Seal      None--Replace          11,600
                                                                 Wire Groove--In    spool.
                                                                 Area X.
                                                                (iii) Forward      8,080...........       11,600
                                                                 Seal Wire
                                                                 Groove--In Area
                                                                 X.
(8) CF6-80E1..................  Not Applicable...           13  (i) Aft Seal Wire  8,080...........       11,600
                                                                 Groove--In Area
                                                                 X.
                                                                (ii) Forward Seal  8,080...........       11,600
                                                                 Wire Groove--In
                                                                 Area X.
(9) CF6-80E1..................  Not Applicable...           12  Aft Seal Wire      8,080...........       11,600
                                                                 Groove--In Area
                                                                 X.
----------------------------------------------------------------------------------------------------------------

    (g) If you have a Group 2 spool shaft, and the circumferential 
cut repair is in the Stage 14 forward location, and not in Area X, 
no further action is required by this AD. However, GEAE recommends 
that you repair these spools at the next exposure of the spool 
shaft.

Replacement of the Spool Shaft

    (h) If the spool shaft exceeds the CSR limit in the column 
titled, Replace by (CSR), in Table 2 of this AD, replace the spool 
shaft within 420 cycles-in-service (CIS) after the effective date of 
this AD or within the published part life limit, whichever occurs 
first.

Repair of the Spool Shaft

    (i) You may repair the spool if the CSR on the spool shaft are 
fewer than or equal to the limit in the column titled, Repair by 
(CSR), in Table 2 of this AD. Use 3.B. of the Accomplishment 
Instructions of GEAE SB CF6-80C2 S/B 72-1052, Revision 01, dated 
February 5, 2004, for the repair.

CF6-80E1 Engines

    (j) For CF6-80E1 series engines with HPCR stage 11-14 spool 
shafts with SNs listed in 1.A.(2) of GEAE SB No. CF6-80E1 S/B 72-
0232, Revision 01, dated February 5, 2004, do the following:
    (1) Inspect the spool shaft for the location of the cut 
circumferential repair at the next piece-part exposure, but before 
exceeding 11,600 CSR. Use 3.A.(1) of the Accomplishment Instructions 
of GEAE SB No. CF6-80E1 S/B 72-0232, Revision 01, dated February 5, 
2004 for the inspection.
    (2) If the circumferential cut repair is in the Stage 14 forward 
location, and not in Area X, no further action is required by this 
AD. However, GEAE recommends that you repair these spools at the 
next exposure of the spool shaft.

[[Page 56733]]

Replacement of the Spool Shaft

    (k) If the CSR are higher than 11,600 CSR, replace the spool 
shaft within 420 CIS after the effective date of this AD or within 
the published part life limit, whichever occurs first.

Repair of the Spool Shaft

    (l) You may repair the spool if the CSR on the spool shaft are 
fewer than or equal to the limit in the column titled, Repair by 
(CSR), in Table 2 of this AD. Use 3.B. of the Accomplishment 
Instructions of GEAE SB CF6-80E1 S/B 72-0232, Revision 01, dated 
February 5, 2004, for the repair.

Alternative Methods of Compliance (AMOCs)

    (m) 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

    (n) None.

Related Information

    (o) None.

    Issued in Burlington, Massachusetts, on September 15, 2004.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 04-21275 Filed 9-21-04; 8:45 am]
BILLING CODE 4910-13-P