Airworthiness Directives; General Electric Company CF34-8E Series Turbofan Engines

[Federal Register Volume 70, Number 64 (Tuesday, April 5, 2005)]
[Rules and Regulations]
[Pages 17199-17201]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-6343]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2004-NE-06-AD; Amendment 39-14033; AD 2005-07-09]
RIN 2120-AA64


Airworthiness Directives; General Electric Company CF34-8E Series 
Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is superseding an existing airworthiness directive 
(AD) for General Electric Company (GE) CF34-8E series turbofan engines 
with certain serial number (SN) master variable geometry (VG) actuators 
installed. That AD currently requires initial and repetitive reviews of 
the airplane computer systems for master VG actuator fault messages. 
That AD also requires replacement of actuators reported faulty by the 
Full Authority Digital Engine Control (FADEC). This AD requires the 
same reviews. This AD also prohibits installation of affected master VG 
actuators onto any CF34-8E series turbofan engine after the effective 
date of the AD. This AD results from the need to add to the list of 
affected parts, master VG actuators made by a parts manufacturing 
approval (PMA) holder. We are issuing this AD to prevent dual-channel 
electrical signal faults in the master VG actuator which will cause an 
uncommanded reduction of thrust to idle with a subsequent loss of the 
ability to advance thrust above idle, and will result in a multiengine 
loss of thrust if dual-channel faults occur on more than one engine 
simultaneously.

DATES: Effective April 20, 2005. The Director of the Federal Register 
approved the incorporation by reference of certain publications listed 
in the regulations as of April 20, 2005.
    We must receive any comments on this AD by June 6, 2005.

ADDRESSES: Use one of the following addresses to submit comments on 
this AD:
    <bullet> By mail: Federal Aviation Administration (FAA), New 
England Region, Office of the Regional Counsel, Attention: Rules Docket 
No. 2004-NE-06-AD, 12 New England Executive Park, Burlington, MA 01803-
5299.
    <bullet> By fax: (781) 238-7055.
    <bullet> By e-mail: [email protected].
    You can get the service information referenced in this 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 at the FAA, New England Region, 
Office of the Regional Counsel, 12 New England Executive Park, 
Burlington, MA. You may examine the service information, 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, 
Aircraft Certification Office, FAA, Engine and Propeller Directorate, 
12 New England Executive Park, Burlington, MA; telephone (781) 238-
7757; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: On February 13, 2004, the FAA issued AD 
2004-04-04, Amendment 39-13485 (69 FR 8098, February 23, 2004). That AD 
requires initial and repetitive reviews of the airplane computer 
systems for master VG actuator fault messages of certain SN master VG 
actuators. That AD also requires replacement of actuators reported 
faulty by the FADEC. The background for that AD is as follows:
    In September of 2002, GE, the manufacturer of CF34-8E series 
turbofan engines, replaced its supplier

[[Page 17200]]

of dual-channel linear variable differential transformers (LVDTs), 
installed on the master VG actuator, part number 4120T02P02. Since that 
changing of suppliers, four master VG actuators, installed on CF34-8E 
engines, with LVDTs produced by the new supplier have been reported 
with single-channel electrical signal faults. The CF34-8E engines use 
the same part number VG master actuator as the CF34-8C series engines, 
which have experienced 54 LVDT faults in service, to date. One of these 
master VG actuators also experienced a failure of the second LVDT 
channel, seventeen days after the first single-channel fault report, 
resulting in the FADEC commanding the engine power to idle. The 
manufacturer's investigation revealed LVDT coil wire deformation and 
breakage, caused by thermal expansion of potting material. That 
condition, if not corrected, could result in dual channel electrical 
signal faults in the master VG actuator, which will cause an 
uncommanded reduction of thrust to idle with a subsequent loss of the 
ability to advance thrust above idle, and result in multiengine loss of 
thrust if dual-channel faults occur on more than one engine 
simultaneously, and possible loss of the airplane.

Actions Since AD 2004-04-04 Was Issued

    Since AD 2004-04-04 was issued, we learned that PMA holder, Arkwin 
Industries, Inc., has master VG actuators in service with affected 
LVDTs installed. The same unsafe condition described previously for 
master VG actuators, SN APM238AE, and SNs APM242AE and up, is likely to 
exist or develop on these PMA master VG actuators. The PMA actuators 
are identified by P/N 1211508-002, SN 238AE, and SNs 241AE and up. 
These actuators also have GE P/N 4120T02P02 marked on them.

Relevant Service Information

    We have reviewed and approved the technical contents of GE Alert 
Service Bulletin (ASB) No. CF34-8E-AL S/B 75-A0001, Revision 3, dated 
February 14, 2005, that describes procedures for initial and repetitive 
reviews of the airplane computer systems for fault messages, and 
replacement of actuators reported faulty by the FADEC.

FAA's Determination and Requirements of This AD

    The unsafe condition described previously is likely to exist or 
develop on other CF34-8E series turbofan engines of the same type 
design. We are issuing this AD to prevent dual-channel electrical 
signal faults in the master VG actuator, which will cause an 
uncommanded reduction of thrust to idle with a subsequent loss of the 
ability to advance thrust above idle, and will result in a multiengine 
loss of thrust if dual-channel faults occur on more than one engine 
simultaneously.
    This AD prohibits installation of any master VG actuator specified 
in this AD, onto any CF34-8E series turbofan engine after the effective 
date of the AD. This AD also requires an initial review within 10 days 
after the effective date of the AD, of the airplane computer systems 
for fault messages, and replacement of actuators reported faulty by the 
FADEC. Actuator hardware troubleshooting may be required to identify 
faulty actuators. Also, this AD requires the same repetitive reviews, 
at intervals not to exceed 10 days. Replacement of actuators reported 
faulty by the FADEC is required either before further flight or within 
10 days of the first fault occurrence, based on requirements defined in 
the service information described previously, for the actual fault 
reported. You must use the service information described previously to 
perform the actions required by this AD.

FAA's Determination of the Effective Date

    Since an unsafe condition exists that requires the immediate 
adoption of this AD, we have found that notice and opportunity for 
public comment before issuing this AD are impracticable, and that good 
cause exists for making this amendment effective in less than 30 days.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety and was not preceded by notice and an opportunity for public 
comment; however, we invite you to submit any written relevant data, 
views, or arguments regarding this AD. Send your comments to an address 
listed under ADDRESSES. Include ``AD Docket No. 2004-NE-06-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 rule 
that might suggest a need to modify it. If a person contacts us 
verbally, and that contact relates to a substantive part of this 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 AD 
in light of those comments.

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.

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 the 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. 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. 2004-NE-06-AD'' in your request.

[[Page 17201]]

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under 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. The FAA amends Sec.  39.13 by removing Amendment 39-13485 (69 FR 
8098, February 23, 2004), and by adding a new airworthiness directive, 
Amendment 39-14033, to read as follows:

2005-07-09 General Electric Company: Amendment 39-14033. Docket No. 
2004-NE-06-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective April 
20, 2005.

Affected ADs

    (b) This AD supersedes AD 2004-04-04, Amendment 39-13485.

Applicability

    (c) This AD applies to General Electric Company (GE) CF34-8E 
series turbofan engines with the master variable geometry (VG) 
actuators, GE part number (P/N) 4120T02P02, serial number (SN) 
APM238AE, and SNs APM242AE and up; and Arkwin Industries, Inc. Parts 
Manufacturer Approval (PMA) P/N 1211508-002, SN 238AE, and SNs 242AE 
and up installed. The Arkwin PMA parts are also marked with P/N 
4120T02P02. These engines are installed on, but not limited to, 
Embraer 170 series airplanes.

Unsafe Condition

    (d) This AD results from the need to add to the list of affected 
parts, master VG actuators made by PMA holder, Arkwin Industries, 
Inc. We are issuing this AD to prevent dual-channel electrical 
signal faults in the VG master actuator, which will cause an 
uncommanded reduction of thrust to idle with a subsequent loss of 
the ability to advance thrust above idle, and which will result in a 
multiengine loss of thrust if dual-channel faults occur on more than 
one engine simultaneously.

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.
    (f) After the effective date of this AD, do not install master 
VG actuators specified in this AD onto any engine.

Initial Review

    (g) Within 10 days after the effective date of this AD, 
initially review the airplane computer systems for fault messages, 
and replace actuators with faults reported by the full-authority 
digital electronic control (FADEC). Follow the review and 
replacement requirements of paragraph 3 of the Accomplishment 
Instructions of GE Alert Service Bulletin (ASB) No. CF34-8E-AL S/B 
75-A0001, Revision 3, dated February 14, 2005. The specific review 
instructions depend on the version of FADEC software installed at 
the time of the review, as detailed in the ASB.

Repetitive Review

    (h) At intervals not to exceed 10 days, repetitively review the 
computer systems for fault messages, and replace actuators with 
faults reported by the FADEC. Follow the review and replacement 
requirements of paragraph 3 of the Accomplishment Instructions of GE 
ASB No. CF34-8E-AL S/B 75-A0001, Revision 3, dated February 14, 
2005. The specific review instructions depend on the version of 
FADEC software installed at the time of the review, as detailed in 
the ASB.

Optional Terminating Action

    (i) As an optional terminating action to the repetitive reviews 
specified in this AD, replace the master VG actuator with a master 
VG actuator not specified in this AD.

Previous Credit

    (j) Previous credit is allowed for reviews and replacements of 
master VG actuators performed before the effective date of this AD, 
using paragraph 3 of GE ASB No. CF34-8E-AL S/B 75-A0001 Revision 1, 
dated February 10, 2004, or Revision 2, dated December 15, 2004, or 
Revision 3, dated February 14, 2005.

Alternative Methods of Compliance

    (k) 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.

Special Flight Permits

    (l) Under 39.23, the FAA imposes the following conditions and 
limitations on the issuance and use of Special Flight Permits for 
this AD:
    (1) If both engines report FADEC status messages, with dispatch 
classification the same as an actuator LVDT fault, at the same time, 
whether intermittent or continuous, at least one engine must be 
cleared of faults before further flight, even if none of the faults 
are VG actuator-related.
    (2) If both engines report FADEC status messages with dispatch 
classification the same as an actuator LVDT fault, at the same time, 
whether intermittent or continuous, the airplane computer systems 
must be reviewed for master VG actuator faults before further 
flight. If actuator faults are present for both engines, then at 
least one master VG actuator must be replaced before further flight.
    (3) If intermittent status messages are posted for both engines, 
with the same dispatch classification as LVDT faults, and the cause 
cannot be found, one of the actuators must be replaced before 
further flight.
    (4) If a master VG actuator with a single channel fault switches 
channels, the actuator must be replaced before further flight.

Material Incorporated by Reference

    (m) You must use GE Alert Service Bulletin No. CF34-8E-AL S/B 
75-A0001, Revision 3, dated February 14, 2005, to perform the 
reviews and actuator dispositions required by this AD. You can get a 
copy 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 review copies 
at the FAA, New England Region, Office of the Regional Counsel, 12 
New England Executive Park, Burlington, MA; or at the National 
Archives and Records Administration (NARA). For information on the 
availability of this material at NARA, call 202-741-6030, or go to: 
http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

Related Information

    (n) None.

    Issued in Burlington, Massachusetts, on March 25, 2005.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 05-6343 Filed 4-4-05; 8:45 am]
BILLING CODE 4910-13-P

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