[Federal Register Volume 72, Number 104 (Thursday, May 31, 2007)]
[Proposed Rules]
[Pages 30300-30302]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-10512]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
 
 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.
 
 ========================================================================
 

  Federal Register / Vol. 72, No. 104 / Thursday, May 31, 2007 / 
Proposed Rules  

[[Page 30300]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-25239; Directorate Identifier 2006-NE-23-AD]
RIN 2120-AA64


Airworthiness Directives; General Electric Company Aircraft 
Engine Group (GEAE) CF6-45A Series, CF6-50A, CF6-50C Series and CF6-50E 
Series Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for GEAE CF6-45A, 45A2, -50A, -50C, -50CA, -50C1, -50C2, -50C2B, -
50C2D, -50C2F, -50C2R, -50E, -50E1, -50E2, and -50E2B turbofan engines. 
This proposed AD would require replacing the compressor discharge 
pressure (CDP) restoring spring assembly on certain main engine 
controls (MECs) or re-marking MECs that already incorporate GEAE 
Service Bulletin (SB) No. CF6-50 S/B 73-0119, dated March 21, 2005. 
This proposed AD results from reports of five events involving 
fractured CDP restoring spring assemblies. We are proposing this AD to 
prevent loss of engine thrust control that could lead to loss of 
control of the airplane.

DATES: We must receive any comments on this proposed AD by July 30, 
2007.

ADDRESSES: Use one of the following addresses to comment on this 
proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590-0001.
     Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    You can get the service information identified in this proposed AD 
from General Electric Company via GE-Aviation, Attn: Distributions, 111 
Merchant St., Room 230, Cincinnati, Ohio 45246; telephone (513) 552-
3272; fax (513) 552-3329.
    You may examine the comments on this proposed AD in the AD docket 
on the Internet at http://dms.dot.gov.

FOR FURTHER INFORMATION CONTACT: Tara Chaidez, Aerospace Engineer, 
Engine Certification Office, FAA, Engine & Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803; telephone (781) 238-
7773; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send us any written relevant data, views, or 
arguments regarding this proposal. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2006-25239; 
Directorate Identifier 2006-NE-23-AD'' in the subject line of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of the 
DOT Web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.).

Examining the AD Docket

    You may examine the docket that contains the proposal, any comments 
received and, any final disposition in person at the DOT Docket Offices 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Office (telephone (800) 647-5227) is located on 
the plaza level of the Department of Transportation Nassif Building at 
the street address stated in ADDRESSES. Comments will be available in 
the AD docket shortly after the Docket Management Facility receives 
them.

Discussion

    We received reports of five field events since 2002, which involved 
fractured CDP restoring spring assemblies. Four events resulted in in-
flight shutdowns, and one event occurred during ground operation and 
resulted in an engine shutdown.
    Before 1996, the manufacturer of the spring assemblies welded some 
spring assemblies such that the gap between the spring and the curved 
spring seat exceeded 0.002 inch. Analysis shows that spring assemblies 
with gaps greater than 0.002 inch have high stresses in the spring and 
can fatigue in the heat affected zone of the weld.
    Fracture of the spring assembly could cause excessive fuel flow 
from the MEC, which could result in an uncommanded increase in engine 
thrust with loss of throttle control. This condition, if not corrected, 
could result in loss of engine thrust control that could lead to loss 
of control of the airplane.

Relevant Service Information

    We have reviewed and approved the technical contents of GEAE SB No. 
CF6-50 S/B 73-0119, Revision 02, dated March 9, 2007, that describes 
procedures for replacing the CDP restoring spring assembly and re-
marking the MEC data plate, and GEAE SB No. CF6-50 S/B 73-0120, dated 
March 21, 2007 that describes procedures for replacing the CDP 
restoring spring assembly.

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,

[[Page 30301]]

which would require replacing the CDP restoring spring assembly on 
certain MECs and re-marking MECs that already incorporate GEAE SB No. 
CF6-50 S/B 73-0119, dated March 21, 2005 or GEAE SB No. CF6-50 S/B 73-
0119, Revision 01, dated May 26, 2006. The proposed AD would require 
you to use the service information described previously to perform 
these actions.

Costs of Compliance

    We estimate that this proposed AD would affect 756 GEAE CF6-45A, -
50C, and -50E series turbofan engines installed on airplanes of U.S. 
registry. We also estimate that it would take about 40 work-hours per 
engine to perform the proposed actions, and that the average labor rate 
is $80 per work-hour. Required parts would cost about $1,787 per 
engine. Based on these figures, we estimate the total cost of the 
proposed AD to U.S. operators to be $3,770,172.

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 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 regulatory evaluation of the estimated costs to 
comply with this proposed AD. See the ADDRESSES section for a location 
to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    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:

    General Electric Company: Docket No. FAA-2006-25239; Directorate 
Identifier 2006-NE-23-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by July 30, 
2007.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to General Electric Company Aircraft Engine 
Group (GEAE) CF6-45A, 45A2, -50A, -50C, -50CA, -50C1, -50C2, -50C2B, 
-50C2D -50C2F, -50C2R, -50E, -50E1, -50E2, and -50E2B turbofan 
engines that have a main engine control (MEC) with a part number (P/
N) specified in Table 1 of this AD installed. These engines are 
installed on, but not limited to, Airbus A300 series airplanes, 
McDonnell Douglas DC-10, KC-10, and MD-10 series airplanes, and 
Boeing 747 series airplanes.

   Table 1.--Affected Woodward and GEAE P/Ns for MECs by Engine Model
                                 Series
------------------------------------------------------------------------
        Engine model series           Woodward  P/N         GEAE P/N
------------------------------------------------------------------------
CF6-50A, -50C, -50CA, -50C1, -               8062-275         9070M55P42
 50C2, -50C2B, -50C2D, -50C2F, -             8062-279         9070M55P44
 50C2R............................           8062-287         9070M55P49
                                             8062-289         9070M55P51
                                             8062-819        9070M55P101
                                             8062-822        9070M55P102
                                             8062-824        9070M55P103
                                             8062-823        9070M55P104
                                             8062-826        9070M55P105
                                             8062-827        9070M55P106
                                             8062-828        9070M55P107
                                             8062-829        9070M55P108
CF6-45A, -45A2, -50E, -50E1, -               8062-276         9187M29P10
 50E2, -50E2B.....................           8062-280         9187M29P11
                                             8062-290         9187M29P14
                                             8062-291         9187M29P15
                                             8062-817        9187M29P100
                                             8062-820        9187M29P101
                                             8062-896         9187M29P22
                                             8062-897         9187M29P23
                                             8062-898         9187M29P20
                                             8062-899         9187M29P21
------------------------------------------------------------------------


[[Page 30302]]

    (d) This AD results from reports of five events involving 
fractured compressor discharge pressure (CDP) restoring spring 
assembly. We are issuing this AD to prevent loss of engine thrust 
control that could lead to loss of control of 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.

Replacing the CDP Restoring Spring Assembly on CF6-50A Engines and -50C 
Series Engines

    (f) For CF6-50A model engines and -50C series engines that have 
an MEC that has a P/N listed in Table 1 of this AD, replace the CDP 
restoring spring assembly as follows in Table 2 of this AD:

                           Table 2.--Compliance Schedule for CF6-50A and -50C Engines
----------------------------------------------------------------------------------------------------------------
 If the CDP restoring spring assembly
             in your MEC                         Then                      By                      Use
----------------------------------------------------------------------------------------------------------------
(1) Was already replaced using GEAE    Re-mark the MEC........  The next time the MEC    Paragraph 3.A. of the
 CF6-50 S/B 73-0119, dated March 21,                             is routed for repair     Accomplishment
 2005.                                                           such as the next MEC     Instructions of SB No.
                                                                 shop visit.              CF6-50 S/B 73-0119,
                                                                                          Revision 02, dated
                                                                                          March 9, 2007.
(2) Was already replaced within        Replace the spring       The first MEC shop       Paragraph 3.A. of the
 10,000 or fewer hours time-in-         assembly and re-mark     visit or engine shop     Accomplishment
 service (TIS) before the effective     the MEC.                 visit after the MEC      Instructions of SB No.
 date of this AD, and the replacement                            exceeds 10,000 hours     CF6-50 S/B 73-0119,
 spring assembly (P/N 3018-248) had                              TIS, but do not exceed   Revision 02, dated
 zero hours TIS.                                                 20,000 hours TIS.        March 9, 2007.
(3) Has more then 10,000 hours TIS...  Replace the spring       The next MEC shop visit  Paragraph 3.A. of the
                                        assembly and re-mark     or engine shop visit     Accomplishment
                                        the MEC.                 whichever occurs first.  Instructions of SB No.
                                                                                          CF6-50 S/B 73-0119,
                                                                                          Revision 02, dated
                                                                                          March 9, 2007.
----------------------------------------------------------------------------------------------------------------

Replacing the CDP Restoring Spring Assembly on CF6-45A and -50E Series 
Engines

    (g) For CF6-45A series and -50E series engines that have an MEC 
that has a P/N listed in Table 1 of this AD, replace the CDP 
restoring spring assembly as follows in Table 3 of this AD:

                           Table 3.--Compliance Schedule for CF6-45A and -50E Engines
----------------------------------------------------------------------------------------------------------------
 If the CDP restoring spring assembly
             in your MEC                         Then                      By                      Use
----------------------------------------------------------------------------------------------------------------
(1) Was already replaced within        Replace the spring       The first MEC shop       Paragraph 3.A. of the
 10,000 or fewer hours time-in-         assembly and re-mark     visit or engine shop     Accomplishment
 service (TIS) before the effective     the MEC.                 visit after the MEC      Instructions of SB No.
 date of this AD, and the replacement                            exceeds 10,000 hours     CF6-50 S/B 73-0120,
 spring assembly (P/N 3018-248) had                              TIS, but do not exceed   dated March 21, 2007.
 zero hours TIS.                                                 20,000 hours TIS.
(2) Has more then 10,000 hours TIS...  Replace the spring       The next MEC shop visit  Paragraph 3.A. of the
                                        assembly and re-mark     or engine shop visit     Accomplishment
                                        the MEC.                 whichever occurs first.  Instructions of SB No.
                                                                                          CF6-50 S/B 73-0120,
                                                                                          dated March 21, 2007.
----------------------------------------------------------------------------------------------------------------

Definition

    (h) For the purpose of this AD, a shop visit is induction of the 
engine or MEC into the shop for any cause.

Installation Prohibition

    (i) After the effective date of the AD, do not install an MEC 
that:
    (1) Has not complied with SB No. CF6-50 S/B 73-0119, Revision 
02, dated March 9, 2007 or earlier revision, or SB No. CF6-50 S/B 
73-0120, dated March 21, 2007, or,
    (2) Has not had the CDP restoring spring replaced with a spring 
assembly, P/N 3018-248, or FAA-approved equivalent spring assembly, 
within the previous 10,000 hours of MEC operation.

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.

Related Information

    (k) None.

    Issued in Burlington, Massachusetts, on May 23, 2007.
Fran A. Favara,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
 [FR Doc. E7-10512 Filed 5-30-07; 8:45 am]
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