Airworthiness Directives; General Electric Company CF6-50C Series Turbofan Engines, 19661-19662 [E6-5645]

Agencies

• Federal Aviation Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 71, Number 73 (Monday, April 17, 2006)]
[Proposed Rules]
[Pages 19661-19662]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E6-5645]


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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.

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Federal Register / Vol. 71, No. 73 / Monday, April 17, 2006 / 
Proposed Rules

[[Page 19661]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-24171; Directorate Identifier 2006-NE-08-AD]
RIN 2120-AA64


Airworthiness Directives; General Electric Company CF6-50C Series 
Turbofan Engines

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

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain General Electric Company (GE) CF6-50C series turbofan 
engines. This proposed AD would require reworking the forward fan 
stator case and installing a fan module secondary containment shield. 
This proposed AD results from reports of uncontained fan blade failures 
causing damage and separation of airplane hydraulic lines. We are 
proposing this AD to prevent uncontained fan blade failures, which can 
result in separation of airplane hydraulic lines, damage to critical 
airplane systems, and possible loss of airplane control.

DATES: We must receive any comments on this proposed AD by June 16, 
2006.

ADDRESSES: Use one of the following addresses to comment on this 
proposed AD.
     DOT Docket Web site: Go to https://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to https://
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 https://dms.dot.gov.

FOR FURTHER INFORMATION CONTACT: Karen Curtis, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803; telephone (781) 238-
7192; 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-2006-24171; 
Directorate Identifier 2006-NE-08-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 https://
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.). You may review the DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78) or you 
may visit https://dms.dot.gov.

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 Office 
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

    In the service history of the CF6-50C series turbofan engine, there 
have been more than 40 fan blade failure events. In two of these 
events, fragments were uncontained, impacting airplane hydraulic lines. 
In another of these events, the fan case bulged, separating a hydraulic 
line. Failure of fan blades can result from material defects, foreign 
object ingestion, or bird ingestion. Fan blade uncontainment can result 
depending on the size and kinetic energy of the released fan blade 
fragments, the impact location, and the design capability and integrity 
of the containment structure. Continued safe flight and landing might 
be compromised if uncontained fan blade fragments impact critical 
airplane system components, such as hydraulic lines. This condition, if 
not corrected, could result in uncontained fan blade failures, which 
can result in separation of airplane hydraulic lines, damage to 
critical airplane systems, and possible loss of airplane control.

Relevant Service Information

    We have reviewed and approved the technical contents of GE Service 
Bulletin (SB) No. CF6-50 S/B 72-0985, Revision 1, dated September 15, 
1998 (Airbus) and GE SB No. CF6-50 S/B 72-0986, Revision 1, dated 
September 15, 1998 (McDonnell Douglas). These SBs describe procedures 
for reworking the forward fan stator case and installing a fan module 
secondary containment shield.

Differences Between the Proposed AD and the Manufacturer's Service 
Information

    The SBs recommend compliance at the operator's convenience. We

[[Page 19662]]

determined that a stricter compliance schedule is necessary. The 
European Aviation Safety Agency issued AD 2004-0007, on December 15, 
2004, which required compliance by December 14, 2005. However, due to 
insufficient parts availability, we propose to require compliance no 
later than June 30, 2007.

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 engines of 
this same type design. We are proposing this AD, which would require 
reworking certain CF6-50C forward fan stator cases and installing 
secondary containment shields at the next engine shop visit after the 
effective date of the proposed AD, but no later than June 30, 2007.
    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 226 CF6-50C series 
turbofan engines installed on airplanes of U.S. registry. We also 
estimate that it would take about 2.5 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 $9,451 per engine. Based on these 
figures, we estimate the total cost of the proposed AD to U.S. 
operators to be $2,181,126.

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-2006-24171; Directorate 
Identifier 2006-NE-08-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by June 16, 
2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to General Electric Company (GE) CF6-50C, 
CF6-50C1, CF6-50C2, CF6-50C2B, CF6-50C2F, and CF6-50C2R turbofan 
engines, with a forward fan stator case, part number 9064M53G04, 
GO5, G06, G07, G08, G09, G10, G12, or G13, installed. These engines 
are installed on, but not limited to, Airbus A300, McDonnell Douglas 
DC-10 series, and DC-10-30F (KC-10A, KDC-10) airplanes.

Unsafe Condition

    (d) This AD results from reports of uncontained fan blade 
failures causing damage and separation of airplane hydraulic lines. 
We are issuing this AD to prevent uncontained fan blade failures, 
which can result in separation of airplane hydraulic lines, damage 
to critical airplane systems, and possible loss of airplane control.

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) At the next engine shop visit after the effective date of 
this AD, but no later than June 30, 2007, rework the forward fan 
stator case and install the fan module secondary containment shield.
    (1) For engines on Airbus 300 series airplanes, use paragraph 3, 
Accomplishment Instructions, of GE SB No. CF6-50 S/B 72-0985, dated 
December 2, 1991 or Revision 1, dated September 15, 1998, to do the 
rework and installation.
    (2) For engines on McDonnell Douglas airplanes, use paragraph 3, 
Accomplishment Instructions, of GE Service Bulletin (SB) No. CF6-50 
S/B 72-0986, dated December 2, 1991 or Revision 1, dated September 
15, 1998, to do the rework and installation.
    (g) The rework and installation specified in paragraphs (f)(1) 
through (f)(2) of this AD can also be done on-wing.

Alternative Methods of Compliance

    (h) 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

    (i) European Aviation Safety Agency airworthiness directive 
2004-0007, dated December 15, 2004, also addresses the subject of 
this AD.

    Issued in Burlington, Massachusetts, on April 11, 2006.
Francis A. Favara,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. E6-5645 Filed 4-14-06; 8:45 am]
BILLING CODE 4910-13-P