[Federal Register Volume 69, Number 96 (Tuesday, May 18, 2004)]
[Proposed Rules]
[Pages 28093-28094]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-11199]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
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 

  Federal Register / Vol. 69, No. 96 / Tuesday, May 18, 2004 / Proposed 
Rules  

[[Page 28093]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NE-67-AD]
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: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for GE CF34-3A, CF34-3A2, CF34-1A, CF34-3A1, CF34-3B, and CF34-3B1 
series turbofan engines. This proposed AD would require 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 22,000 CSN for 
CF34-3A, CF34-3A2, CF34-1A, CF34-3A1, and CF34-3B1 engines. This 
proposed AD results from an updated low-cycle fatigue (LCF) analysis 
performed on certain HPC forward spools. We are proposing 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: We must receive any comments on this proposed AD by July 19, 
2004.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD:
     By mail: Federal Aviation Administration (FAA), New 
England Region, Office of the Regional Counsel, Attention: Rules Docket 
No. 2003-NE-67-AD, 12 New England Executive Park, Burlington, MA 01803-
5299.
     By fax: (781) 238-7055.
     By e-mail: [email protected].
    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 AD docket, by appointment, 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:

Comments Invited

    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 ``AD Docket No. 2003-NE-67-AD'' in the 
subject line of your comments. If you want us to acknowledge receipt of 
your mailed comments, send us a self-addressed, stamped postcard with 
the docket number written on it; we will date-stamp your postcard and 
mail it back to you. We specifically invite comments on the overall 
regulatory, economic, environmental, and energy aspects of the proposed 
AD. If a person contacts us verbally, and that contact relates to a 
substantive part of this proposed AD, we will summarize the contact and 
place the summary in the docket. We will consider all comments received 
by the closing date and may amend the proposed AD in light of those 
comments.
    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 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.

Discussion

    In October 2003, GE made the FAA aware of its updated LCF analysis 
of HPC forward spools, P/Ns 6078T56P03 and 6078T56P04, used in CF34-3A, 
CF34-3A2, CF34-1A, CF34-3A1, CF34-3B, CF34-3B1 turbofan engines. HPC 
forward spools, P/Ns 6078T56P03 and 6078T56P04, installed in CF34-3A, 
CF34-3A2, CF34-1A, CF34-3A1, and CF34-3B1 turbofan engines, must be 
replaced before accumulating 22,000 CSN. The highest time HPC forward 
spool has accumulated fewer than 21,500 CSN in CF34-3A, CF34-3A2, CF34-
1A, CF34-3A1, or CF34-3B1 turbofan engines, to date.
    HPC forward spools, P/Ns 6078T56P03 and 6078T56P04, installed in 
CF34-3B engines, must be replaced before accumulating 20,000 CSN. The 
highest time HPC forward spool has accumulated fewer than 4,500 CSN in 
a CF34-3B engine, to date.
    We are proposing 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.

Relevant Service Information

    We have reviewed and approved the technical contents of GE Alert 
Service Bulletins (ASBs) No. 72-A0165 and No. 72-A0140, that describe 
procedures for disassembly and replacement of HPC compressor rotor 
spool stages 3-8.

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 
replacing HPC forward spools, P/Ns 6078T56P03 and 6078T56P04, before 
accumulating 22,000 CSN on CF34-3A, CF34-3A2, CF34-1A, CF34-3A1, and 
CF34-3B1 engines, and 20,000 CSN on CF34-3B engines.

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

[[Page 28094]]

affected by this proposed 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 proposed 
actions, and that the average labor rate is $65 per work hour. Required 
parts would 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 proposed AD to U.S. operators to be 
$74,420,000.

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-67-AD'' in your request.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, 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:

GE Aircraft Engines (GE): Docket No. 2003-NE-67-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by July 19, 
2004.

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 certain HPC forward spools 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 HPC forward spools, P/Ns 6078T56P03 and 6078T56P04, with 
more than 6,000 cycles-since-new (CSN), installed on CF34-3B 
engines, remove the spool from service and replace with a 
serviceable spool at next piece-part exposure, but no later than 
20,000 CSN.
    (g) For HPC forward spools, P/Ns 6078T56P03 and 6078T56P04, with 
more than 6,000 CSN, installed in CF34-3A, CF34-3A2, CF34-1A, CF34-
3A1, and CF34-3B1 engines, remove the spool from service and replace 
with a serviceable spool at next piece-part exposure, but no later 
than 22,000 CSN.

Definitions

    (h) For the purpose of this AD, the definition of piece-part 
exposure for the HPC forward spool is when the spool is completely 
disassembled.
    (i) For purposes of this AD, a spool with P/N 6078T56P03 is not 
a serviceable spool, and a spool with P/N 6078T56P04 and more than 0 
CSN is not a serviceable spool. All other spools are serviceable.

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) GE Alert Service Bulletins No. ASB 72-A0165 and No. ASB 72-
A0140, pertain to the subject of this AD.

    Issued in Burlington, Massachusetts, on May 11, 2004.
Francis A. Favara,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 04-11199 Filed 5-17-04; 8:45 am]
BILLING CODE 4910-13-P