[Federal Register Volume 69, Number 35 (Monday, February 23, 2004)]
[Rules and Regulations]
[Pages 8098-8100]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-3679]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2004-NE-06-AD; Amendment 39-13485; AD 2004-04-04]
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 adopting a new airworthiness directive (AD) for 
General Electric Company (GE) CF34-8E series turbofan engines, with 
certain serial number (SN) master variable geometry (VG) actuators 
installed. This AD requires initial and repetitive reviews of the 
airplane computer systems for master VG actuator fault messages. This 
AD also requires replacement of actuators reported faulty by the Full 
Authority Digital Engine Control (FADEC). This AD results from nine 
reports of CF34-8C master VG actuator electrical signal faults, one 
report of which was a dual-channel fault, resulting in the FADEC 
commanding the engine power to idle. We are issuing this AD to prevent 
VG master actuator dual-channel electrical signal faults which will 
cause an uncommanded reduction of thrust to idle with a subsequent loss 
of the ability to advance thrust above idle; and which could result in 
a multi-engine loss of thrust if

[[Page 8099]]

dual-channel faults occur on more than one engine simultaneously.

DATES: This AD becomes effective March 9, 2004. The Director of the 
Federal Register approved the incorporation by reference of certain 
publications listed in the regulations as of March 9, 2004.
    We must receive any comments on this AD by April 23, 2004.

ADDRESSES: Use one of the following addresses to submit comments on 
this AD:
     By mail: The 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.
     By fax: (781) 238-7055.
     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, by appointment, at the FAA, New 
England Region, Office of the Regional Counsel, 12 New England 
Executive Park, Burlington, MA. You may examine the service 
information, by appointment, at the FAA, New England Region, Office of 
the Regional Counsel, 12 New England Executive Park, Burlington, MA; or 
at the Office of the Federal Register, 800 North Capitol Street, NW., 
suite 700, Washington, DC.

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: In September of 2002, GE, the manufacturer 
of CF34-8E series turbofan engines, replaced its supplier of dual-
channel linear variable differential transformers (LVDTs), installed on 
the master VG actuator, part number 4120T02P02. Since that changing of 
suppliers, nine master VG actuators, installed on CF34-8C engines, with 
LVDTs produced by the new supplier have been reported with single-
channel electrical signal faults sent to the MDC and to the FADEC. The 
CF34-8E engines use the same part number VG master actuator as the 
CF34-8C series engines, and the same service experience is expected. 
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 on-going investigation has revealed LVDT coil 
wire deformation and breakage, caused by thermal expansion of potting 
material. The affected master VG actuators are identified by serial 
numbers (SNs) APM238AE, and SNs APM242AE and up. A dual-channel LVDT 
failure that occurs at a certain phase of flight will result in a 
single engine loss of thrust control. VG master actuators with dual-
channel LVDT failures that occur simultaneously on multiple engines 
will cause a multi-engine loss of thrust control.

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 1, dated 
February 10, 2004, 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 VG master actuator dual-
channel electrical signal faults:
     Which will cause an uncommanded reduction of 
thrust to idle with a subsequent loss of the ability to advance thrust 
above idle; and
     Which could result in a multi-engine loss of 
thrust if dual-channel faults occur on more than one engine 
simultaneously.
    This AD 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. This AD also requires the same reviews, repetitively, 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.

Changes to 14 CFR Part 39--Effect on the AD

    On July 10, 2002, we issued a new version of 14 CFR part 39 (67 FR 
47998, July 22, 2002), which governs our AD system. This regulation now 
includes material that relates to special flight permits, alternative 
methods of compliance, and altered products. This material previously 
was included in each individual AD. Since this material is included in 
14 CFR part 39, we will not include it in future AD actions.

Interim Action

    These actions are interim actions and we may take further 
rulemaking actions in the future.

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.
    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 with you. You can get more information about plain 
language at http://www.faa.gov/language and http://www.plainlanguage.gov.

[[Page 8100]]

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.

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.

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 adding the following new airworthiness 
directive:

2004-04-04 General Electric Company: Amendment 39-13485. Docket No. 
2004-NE-06-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective March 9, 
2004.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to General Electric Company (GE) CF34-8E 
series turbofan engines, with master variable geometry (VG) 
actuators, part number (P/N) 4120T02P02, serial number (SN) 
APM238AE, and SNs APM242AE and up. These engines are installed on, 
but not limited to, Embraer 170 series airplanes.

Unsafe Condition

    (d) This AD results from nine reports of CF34-8C master VG 
actuator electrical signal faults, one report of which was a dual-
channel fault, resulting in the Full Authority Digital Engine 
Control (FADEC) commanding the engine power to idle. We are issuing 
this AD to prevent VG master actuator dual-channel electrical signal 
faults:
    (1) Which will cause an uncommanded reduction of thrust to idle 
with a subsequent loss of the ability to advance thrust above idle; 
and
    (2) Which could result in a multi-engine 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) Before installation of a replacement VG actuator, P/N 
4120T02P02 with SNs APM238AE, APM242AE and up, confirm that the 
actuator is new, or if used, confirm that records show that the 
linear variable differential transformer (LVDT), installed on the 
master VG actuator, has been replaced since last actuator use.

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 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 1, dated February 10, 2004. The 
specific review instructions are dependent 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 1, dated February 10, 
2004. The specific review instructions are dependent on the version 
of FADEC software installed at the time of the review, as detailed 
in the ASB.

Alternative Methods of Compliance

    (i) 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

    (j) 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 the 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

    (k) You must use GE Alert Service Bulletin No. CF34-8E-AL S/B 
75-A0001, Revision 1, dated February 10, 2004, to perform the 
reviews and actuator dispositions required by this AD. The Director 
of the Federal Register approved the incorporation by reference of 
this service bulletin in accordance with 5 U.S.C. 552(a) and 1 CFR 
part 51. 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 Federal Aviation Administration 
(FAA), New England Region, Office of the Regional Counsel, 12 New 
England Executive Park, Burlington, MA 01803-5299; or at the Office 
of the Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.

Related Information

    (l) AD 2003-26-05 also addresses the same unsafe condition, but 
for GE CF34-8C1 series and CF34-8C5 series turbofan engines.

    Issued in Burlington, Massachusetts, on February 13, 2004.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 04-3679 Filed 2-20-04; 8:45 am]
BILLING CODE 4910-13-P