Airworthiness Directives; GE Aircraft Engines (GE) CF34-3A, CF34-3A2, CF34-1A, CF34-3A1, CF34-3B, and CF34-3B1 Series Turbofan Engines

[Federal Register Volume 69, Number 245 (Wednesday, December 22, 2004)]
[Rules and Regulations]
[Pages 76610-76611]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-27948]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NE-67-AD; Amendment 39-13914; AD 2004-26-02]
RIN 2120-AA64


Airworthiness Directives; GE Aircraft Engines (GE) CF34-3A, CF34-
3A2, CF34-1A, CF34-3A1, CF34-3B, and CF34-3B1 Series 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 
CF34-3A, CF34-3A2, CF34-1A, CF34-3A1, CF34-3B, and CF34-3B1 series 
turbofan engines. This AD requires removal from service of certain high 
pressure compressor (HPC) forward spools, at the first piece-part level 
exposure after 6,000 cycles since new (CSN); but not later than 20,000 
CSN for CF34-3B engines, and not later than 22,000 CSN for CF34-3A, 
CF34-3A2, CF34-1A, CF34-3A1, and CF34-3B1 engines. This AD results from 
an updated low-cycle fatigue (LCF) analysis performed on certain HPC 
forward spools. We are issuing this AD to prevent LCF cracks and 
failure of the HPC forward spool, which could result in an uncontained 
engine failure and damage to the airplane.

DATES: This AD becomes effective January 26, 2005.

ADDRESSES: You may examine the AD docket at the FAA, New England 
Region, Office of the Regional Counsel, 12 New England Executive Park, 
Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Robert Grant, Aerospace Engineer, 
Engine Certification Office, FAA, Engine & Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (781) 
238-7757; 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 CF34-3A, CF34-3A2, 
CF34-1A, CF34-3A1, CF34-3B, and CF34-3B1 series turbofan engines. We 
published the proposed AD in the Federal Register on May 18, 2004 (69 
FR 28093). That action proposed to require removal from service of 
certain HPC forward spools, at the first piece-part level exposure 
after 6,000 CSN, but not later than 20,000 CSN for CF34-3B engines and 
not later than 22,000 CSN for CF34-3A, CF34-3A2, CF34-1A, CF34-3A1, and 
CF34-3B1 engines. That action results from GE updating the LCF analysis 
for these HPC forward spools.

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 one comment received.

Request for Definition Clarification of Serviceable HPC Forward Spool

    One commenter requests that we clarify the definition of a 
serviceable HPC forward spool. The commenter states that a 
clarification would ensure that operators are not led to believe that 
HPC forward spools installed in their engines are not serviceable based 
on the AD's definition of a serviceable HPC forward spool.
    We partially agree. As written in the proposal, the compliance 
requires replacing certain HPC forward spools with a serviceable HPC 
forward spool at next piece-part level exposure, and then defines what 
a serviceable HPC forward spool is and what it is not. We agree that 
this definition could cause confusion. We do not agree that a 
clarification to the existing definition is the best approach to ensure 
that the AD is understandable. For clarification, we have rewritten the 
compliance in the final rule to require operators to remove certain 
specific spools from service. We have also added a paragraph in the 
final rule to clarify that after the effective date of this AD, do not 
install any HPC forward spool, P/N 6078T56P03. We have also clarified 
the requirement that after the effective date of this AD, do not 
install any HPC forward spool, P/N 6078T56P04, with more than 0 CSN. We 
have also deleted from the final rule the definition which described 
serviceable spools.

Conclusion

    We have carefully reviewed the available data, including the 
comment 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 2,681 GE CF34-3A, CF34-3A2, CF34-1A, CF34-3B and 
CF34-3B1 series turbofan engines of the affected design in the 
worldwide fleet. We estimate that 1,826 engines installed on airplanes 
of U.S. registry would be affected by this AD. We also estimate that 
59% of the replacements will not be done at piece-part exposure, and 
will require approximately 650 work hours per engine to perform the 
actions, and that the average labor rate is $65 per work hour. Required 
parts will cost about $16,000 per engine (a prorated cost of the unused 
spool life to the original life). Based on these figures, we estimate 
the total cost of the AD to U.S. operators to be $74,420,000.

[[Page 76611]]

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

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-67-AD'' in your request.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

Adoption of the Amendment

0
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 (AD):

2004-26-02 GE Aircraft Engines (GE): Amendment 39-13914. Docket No. 
2003-NE-67-AD.

Effective Date

    (a) This AD becomes effective January 26, 2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to GE CF34-3A, CF34-3A2, CF34-1A, CF34-3A1, 
CF34-3B, and CF34-3B1 series turbofan engines with high pressure 
compressor (HPC) forward spool, part number (P/N) 6078T56P03 or 
6078T56P04, installed. These engines are installed on, but not 
limited to, Bombardier series Business Jet Model CL-600-2A12 (CL-
601), Bombardier series Business Jet Model CL-600-2B16 (CL-601-3A, 
CL-601-3R, and CL-604), and Bombardier series Regional Jet Model CL-
600-2B19 (Regional Jet Series 100 and 440) airplanes.

Unsafe Condition

    (d) This AD results from an updated low-cycle fatigue (LCF) 
analysis performed on HPC forward spools, P/Ns 6078T56P03 and 
6078T56P04, by GE. We are issuing this AD to prevent LCF cracks and 
failure of the HPC forward spool, which could result in an 
uncontained engine failure and damage to the airplane.

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.

HPC Spool Replacement

    (f) For CF34-3B engines, remove from service HPC forward spools, 
P/Ns 6078T56P03 and 6078T56P04 at the first piece-part exposure 
after 6,000 cycles-since-new (CSN), but no later than 20,000 CSN.
    (g) For CF34-3A, CF34-3A2, CF34-1A, CF34-3A1, and CF34-3B1 
engines, remove from service HPC forward spools, P/Ns 6078T56P03 and 
6078T56P04 at the first piece-part exposure after 6,000 CSN, but no 
later than 22,000 CSN.
    (h) After the effective date of this AD:
    (1) Do not install any HPC forward spool, P/N 6078T56P03.
    (2) Do not install any HPC forward spool, P/N 6078T56P04, with 
more than 0 CSN.

Definition

    (i) For the purpose of this AD, the definition of piece-part 
exposure for the HPC forward spool is when the spool is completely 
disassembled.

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) None.

Related Information

    (l) None.

    Issued in Burlington, Massachusetts, on December 15, 2004.
Francis A. Favara,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 04-27948 Filed 12-21-04; 8:45 am]
BILLING CODE 4910-13-P

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