[Federal Register Volume 68, Number 92 (Tuesday, May 13, 2003)]
[Rules and Regulations]
[Pages 25488-25489]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-11864]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NE-24-AD; Amendment 39-13144; AD 2003-10-01]
RIN 2120-AA64


Airworthiness Directives; General Electric Company CF6-6 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 
is applicable to General Electric (GE) CF6-6 series turbofan engines. 
This amendment requires a reduction of the cyclic life limit for 
certain high pressure turbine rotor (HPTR) rear shafts, and requires 
removing certain HPTR rear shafts from service before exceeding the 
new, lower cyclic life limit. In addition, this amendment requires 
removing from service certain HPTR rear shafts that currently exceed, 
or will exceed, the new, lower cyclic life limit according to the 
compliance schedule described in this AD. This amendment is prompted by 
an updated low-cycle-fatigue (LCF) analysis performed by the 
manufacturer that resulted in a lower cyclic life limit for certain 
HPTR rear shaft part numbers (PNs) installed in CF6-6 engines. The 
actions specified by this AD are intended to prevent cracks in HPTR 
rear shafts that could result in uncontained engine failure and damage 
to the airplane.

DATES: Effective June 17, 2003.

ADDRESSES: Information regarding this action may be examined, by 
appointment, at the Federal Aviation Administration (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 AD that is 
applicable to GE CF6-6 series turbofan engines was published in the 
Federal Register on January 8, 2003 (68 FR 1016). That action proposed 
to require a reduction of the cyclic life limit for certain HPTR rear 
shafts, and to require removing certain HPTR rear shafts from service 
before exceeding the new, lower cyclic life limit. In addition, that 
action proposed to require removing from service certain HPTR rear 
shafts that currently exceed, or will exceed, the new, lower cyclic 
life limit according to the compliance schedule described in that 
proposal.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were received on the 
proposal or the FAA's determination of the cost to the public. The FAA 
has determined that air safety and the public interest require the 
adoption of the rule as proposed.

Economic Analysis

    There are approximately 55 GE CF6-6 series turbofan engines of the 
affected design in the domestic fleet that would be affected by this 
AD. There are no foreign registered engines. There are no labor or 
parts costs associated with the implementation of this AD. Based on 
these figures, the total cost of the AD to U.S. operators is estimated 
to be $41,690 per engine, which is the cost of new rear shafts.

Regulatory Analysis

    This final rule does not have federalism implications, as defined 
in

[[Page 25489]]

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.
    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 the 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 
by contacting 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

0
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

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. Section 39.13 is amended by adding a new airworthiness directive to 
read as follows:

2003-10-01 General Electric Company: Amendment 39-13144. Docket No. 
2002-NE-24-AD.

    Applicability: This airworthiness directive (AD) is applicable 
to General Electric Company CF6-6 series turbofan engines. These 
engines are installed on, but not limited to McDonnell Douglas DC-10 
series 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 (e) 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 prevent cracks in high pressure turbine rotor (HPTR) rear 
shafts, which could result in uncontained engine failure and damage 
to the airplane, do the following:
    (a) Remove from service HPTR rear shafts, part numbers (P/Ns) 
9137M13G01/G02/G03, 9138M22G01/G02/G09/G10, 9138M25G02, and 
9687M22G04/G07/G10 in accordance with Table 1 as follows:

               Table 1.--HPTR Rear Shaft Removal Schedule
------------------------------------------------------------------------
If the rear shaft cycles-since-new
  (CSN) on the effective date of         Then remove the rear shaft
           this AD are:
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(1) Fewer than 5,000 CSN..........  Before exceeding 8,950 CSN.
(2) 5,000 CSN or more, but fewer    Within 3,950 additional cycles-in-
 than 8,950 CSN.                     service (CIS) from the effective
                                     date of this AD or before 11,550
                                     CSN, whichever occurs earlier.
(3) 8,950 CSN or more.............  At next HPTR rear shaft piece part
                                     exposure, or within 2,600
                                     additional CIS, whichever occurs
                                     earlier.
------------------------------------------------------------------------

    (b) After the effective date of this AD, do not install any HPTR 
rear shaft, P/Ns 9137M13G01/G02/G03, 9138M22G01/G02/G09/G10, 
9138M25G02, or 9687M22G04/G07/G10, that has 8,950 or more CSN into 
an engine.
    (c) Except as provided in paragraph (a) of this AD, this action 
establishes a new, cyclic life limit of 8,950 CSN for HPTR rear 
shaft P/Ns 9137M13G01/G02/G03, 9138M22G01/G02/G09/G10, 9138M25G02, 
and 9687M22G04/G07/G10 which is published in Chapter 05-11-03 of 
CF6-6 Engine Shop Manual, GEK 9266.

Definition

    (d) For the purpose of this AD, HPTR rear shaft piece-part 
exposure is defined as complete disassembly of the rear shaft from 
the HPTR structure using the manufacturer's engine manual.

Alternative Methods of Compliance

    (e) 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 request through an appropriate FAA 
Principal Maintenance Inspector, who may add comments and then send 
it to the Manager, ECO.

    Note 2: 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

    (f) 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.

Effective Date

    (g) This amendment becomes effective on June 17, 2003.

    Issued in Burlington, Massachusetts, on May 5, 2003.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 03-11864 Filed 5-12-03; 8:45 am]
BILLING CODE 4910-13-P