[Federal Register: May 13, 2003 (Volume 68, Number 92)]
[Rules and Regulations]
[Page 25488-25489]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr13my03-6]
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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
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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.
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(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]
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