[Federal Register: March 31, 2006 (Volume 71, Number 62)]
[Proposed Rules]
[Page 16246-16248]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr31mr06-24]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2006-24145; Directorate Identifier 2006-NE-06-AD]
RIN 2120-AA64
Airworthiness Directives; General Electric Company CF6-45 and
CF6-50 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) CF6-45 and CF6-50 series
turbofan engines. This proposed AD would require inspecting and
reworking certain forward and aft center bodies of the long fixed core
exhaust nozzle (LFCEN) assembly. This proposed AD results from reports
of separation of LFCEN assembly forward and aft center bodies, due to
high imbalance engine conditions during flight. We are proposing this
AD to prevent the forward and aft center body of the LFCEN assembly
from separating, leading to additional damage to the engine and
airplane, possible damage to other airplanes, and to objects on the
ground.
DATES: We must receive any comments on this proposed AD by May 30,
2006.
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: 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-2006-24145;
Directorate Identifier 2006-NE-06-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.). 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 http://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
[[Page 16247]]
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
Since 1975, 45 events of forward and aft center bodies separating
from the engine have been reported. GE's investigation of the earlier
events identified nut plate corrosion, and loose and missing fasteners
as causes for the center body separations. In 1987, GE issued Service
Bulletin (SB) No. CF6-50 S/B 78-216 to inspect for these conditions and
add improved fasteners. In 2001, GE issued a Fleet Highlight and an All
Operators Wire to remind operators of the availability of SB No. CF6-50
S/B 78-216. In 2003, GE issued SB No. CF6-50 S/B 78-241 for improved
fastener torque.
In 2000, two separation events occurred. Investigation by GE and
the FAA determined that bird strikes or other similar events can result
in high engine imbalance conditions. These conditions can result in
high stress and movement at the joint between the forward and aft
center bodies, degrading the structural integrity of the joint, and
separating the center bodies from the engine.
GE and the FAA determined that additional improvements are
necessary to ensure structural integrity of the center body joints
during high imbalance events. GE completed certification in 2004 of
improved forward and aft center bodies. GE's improvement adds doublers,
larger nuts and bolts, and higher strength corrosion resistant nut
plates.
This condition, if not corrected, could result in the forward and
aft center body of the LFCEN assembly separating, leading to additional
damage to the engine and airplane, possible damage to other airplanes,
and to objects on the ground.
Relevant Service Information
We have reviewed and approved the technical contents of GE SB No.
CF6-50 S/B 78-0242, dated September 26, 2005, that identifies
disassembly, inspection, rework, and reassembly procedures for the
forward and aft center body, to add doublers, larger nuts and bolts,
and higher strength corrosion resistant nut plates.
FAA's Determination and Requirements of the Proposed AD
We 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 will require
reworking the forward and aft center bodies to add doublers, larger
nuts and bolts, and higher strength corrosion resistant nut plates.
This rework is required the next time the forward center body and aft
center body are removed from the engine after the effective date of
this proposed AD. 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 238 CF6-45 and CF6-
50 series turbofan engines installed on airplanes of U.S. registry. We
also estimate that it would take about 22 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 $6,000 per engine. Based
on these figures, we estimate the total cost of the proposed AD to U.S.
operators to be $1,846,880.
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-2006-24145; Directorate
Identifier 2006-NE-06-AD.
Comments Due Date
(a) The Federal Aviation Administration (FAA) must receive
comments on this airworthiness directive (AD) action by May 30,
2006.
Affected ADs
(b) None.
Applicability
(c) This AD applies to General Electric Company (GE) CF6-45A,
CF6-45A2, CF6-50C, CF6-50C1, CF6-50C2, CF6-50C2B, CF6-50C2D, CF6-
50E, CF6-50E1, CF6-50E2, and CF6-50E2B series turbofan engines with
long fixed core exhaust nozzle (LFCEN) assembly forward center body,
part number (P/N) 1313M55G01 or G02, P/N 9076M28G09 or G10, and aft
center body P/N 1313M56G01 or 9076M46G05, installed. These engines
are installed on, but not limited to, Airbus A300 series, Boeing 747
series, McDonnell Douglas DC-10 series, and DC-10-30F (KC-10A, KDC-
10) airplanes.
Unsafe Condition
(d) This AD results from reports of separation of LFCEN assembly
forward and
[[Page 16248]]
aft center bodies, due to high imbalance engine conditions during
flight. We are issuing this AD to prevent the forward and aft center
body of the LFCEN assembly from separating, leading to additional
damage to the engine and airplane, possible damage to other
airplanes, and to objects on the ground.
Compliance
(e) You are responsible for having the actions required by this
AD performed the next time the forward and aft center bodies are
removed from the engine after the effective date of this AD, unless
the actions have already been done.
(f) Rework the forward and aft center bodies to add doublers,
larger nuts and bolts, and higher strength corrosion resistant nut
plates. Use paragraph 3, Accomplishment Instructions, of GE Service
Bulletin No. CF6-50 S/B 78-0242, dated September 26, 2005, to
identify the procedures required to do these actions.
Definition
(g) For the purposes of this AD, ``next time the forward and aft
center bodies are removed from the engine'' includes when the center
bodies are removed from the engine to take the engine off-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.
Issued in Burlington, Massachusetts, on March 27, 2006.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. E6-4702 Filed 3-30-06; 8:45 am]
BILLING CODE 4910-13-P