[Federal Register: January 3, 2005 (Volume 70, Number 1)]
[Proposed Rules]
[Page 51-53]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr03ja05-16]
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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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[[Page 51]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2004-19945; Directorate Identifier 2004-NM-22-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747-200B, 747-200C, 747-
200F, 747-300, and 747SR Series Airplanes Equipped with General
Electric (GE) CF6-45 or -50 Series Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for certain Boeing Model 747-200B, 747-200C, 747-200F, 747-300, and
747SR series airplanes, equipped with GE CF6-45 or -50 series engines.
This proposed AD would require modifying the side cowl assemblies on
the engines by replacing existing wear plates with new extended wear
plates and installing new stop fittings. This proposed AD is prompted
by reports of a gap at the interface of the lower portion of the side
cowl and the aft flange of the thrust reverser. We are proposing this
AD to prevent an excessive quantity of air from entering the fire zone
that surrounds the engine, which in the event of an engine fire, could
result in an inability to control or extinguish the fire.
DATES: We must receive comments on this proposed AD by February 17,
2005.
ADDRESSES: Use one of the following addresses to submit comments 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.
By 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.
For service information identified in this proposed AD, contact
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.
You can examine the contents of this AD docket on the Internet at
http://dms.dot.gov, or in person at the Docket Management Facility,
U.S. Department of Transportation, 400 Seventh Street SW., room PL-401,
on the plaza level of the Nassif Building, Washington, DC. This docket
number is FAA-2004-19945; the directorate identifier for this docket is
2004-NM-22-AD.
FOR FURTHER INFORMATION CONTACT: Dan Kinney, Aerospace Engineer,
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification
Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone
(425) 917-6499; fax (425) 917-6590.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to submit any written relevant data, views, or
arguments regarding this proposed AD. Send your comments to an address
listed under ADDRESSES. Include ``Docket No. FAA-2004-19945;
Directorate Identifier 2004-NM-22-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 submitted 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
that website, 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 can review DOT's complete Privacy Act Statement in the
Federal Register published on April 11, 2000 (65 FR 19477-78), or you
can visit http://dms.dot.gov.
Examining the Docket
You can examine the AD docket on the Internet at http://dms.dot.gov
, or in person at the Docket Management Facility office
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is on the plaza level of the Nassif Building at the DOT street
address stated in the ADDRESSES section. Comments will be available in
the AD docket shortly after the DMS receives them.
Discussion
We have received reports indicating that a gap may form at the
interface of the lower portion of the side cowl and the aft flange of
the thrust reverser on certain Boeing Model 747-200B, 747-200C, 747-
200F, 747-300, and 747SR series airplanes, equipped with General
Electric CF6-45 or -50 series engines. The gap forms when high engine
thrust is applied, but may not always close when thrust is reduced. The
gap is attributed to axial deflection of the engine case combined with
the difference in the rate of expansion due to heat between the
aluminum frame of the thrust reverser and the titanium frame of the
engine. The gap may allow an excessive quantity of air into the nacelle
surrounding the engine, which is a fire zone that is equipped with fire
detection, containment, and extinguishing provisions. However, excess
air in the area could defeat some or all of the fire protection
provisions. This condition, if not corrected, could result in an
inability to control or extinguish an engine fire.
Relevant Service Information
We have reviewed Boeing Service Bulletin 747-71-2300, Revision 1,
dated October 30, 2003. The service bulletin describes procedures for
modifying the side cowl assemblies on the engines by replacing existing
wear plates with new extended wear plates and installing new stop
fittings. The procedures for replacing the existing wear plates include
performing open-hole high frequency eddy current (HFEC)
[[Page 52]]
inspections for cracking of existing fastener holes, and creating new
fastener holes and plugging existing holes if necessary. The procedures
for installing the new stop fittings involves installing brackets,
channels, and wear pads; replacing existing fasteners with new
fasteners if necessary; performing open-hole HFEC inspections for
cracking of fastener holes; and oversizing fastener holes and
installing different-sized fasteners if necessary. Accomplishing the
actions specified in the service information is intended to adequately
address the unsafe condition.
Boeing Service Bulletin 747-71-2300, Revision 1, refers to Boeing
Service Letter 747-SL-71-045-C, dated April 10, 2003, as the applicable
source of service information for doing certain recommended actions.
Among other actions, Boeing Service Letter 747-SL-71-045-C describes
procedures for improving the aerodynamic smoothness of the side cowl
assemblies by removing bulb seals that may have been installed on the
trailing edge of the fan thrust reverser in accordance with a previous
issue of Boeing Service Letter 747-SL-71-045. The procedures for
removing the bulb seals include plugging open holes on the trailing
edge of the fan thrust reverser, and adjusting the cowl latches if
necessary.
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 airplanes
of this same type design. Therefore, we are proposing this AD, which
would require modifying the side cowl assemblies on the engines by
replacing existing wear plates with new extended wear plates, and
installing new stop fittings. The proposed AD would require you to use
the service information described previously to perform these actions,
except as discussed under ``Differences Between the Proposed AD and
Service Information.''
Differences Between the Proposed AD and Service Information
Section 1.B., ``Concurrent Requirements,'' of Boeing Service
Bulletin 747-71-2300, Revision 1, states that the service bulletin
``assumes that the cowls have had wear plates installed per Service
Bulletin 747-54-2093.'' We have determined that Boeing Service Bulletin
747-71-2300, Revision 1, refers to Boeing Service Bulletin 747-54-2093
only because Boeing Service Bulletin 747-71-2300, Revision 1, removes
certain parts that may have been installed according to Boeing Service
Bulletin 747-54-2093. We have discussed this matter with Boeing and
have determined that the Accomplishment Instructions in Boeing Service
Bulletin 747-71-2300, Revision 1, are effective regardless of whether
Boeing Service Bulletin 747-54-2093 has been done. In light of this
information, this proposed AD would not require the actions in Boeing
Service Bulletin 747-54-2093.
Boeing Service Bulletin 747-71-2300, Revision 1, also ``assumes''
that one certain airplane has been modified to have a narrower trailing
edge strip. We have determined that the subject airplane has been
modified; thus, this proposed AD would not require this modification.
As described previously, Boeing Service Bulletin 747-71-2300,
Revision 1, recommends that bulb seals installed previously in
accordance with a previous issue of Boeing Service Letter 747-SL-71-045
be removed in accordance with Boeing Service Letter 747-SL-71-045-C,
dated April 10, 2003. If the bulb seals were previously installed,
paragraph (g) of this proposed AD would require you to remove them
concurrent with or before further flight after accomplishing the
actions in Boeing Service Bulletin 747-71-2300, Revision 1.
Costs of Compliance
This proposed AD would affect about 38 airplanes of U.S. registry
and 140 airplanes worldwide. The following table provides the estimated
costs for U.S. operators to comply with this proposed AD.
Estimated Costs
----------------------------------------------------------------------------------------------------------------
hours
Average labor
Action Work hours labor rate Parts Cost per Fleet cost rate
per hour airplane airplane
per hour
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Modification per Boeing Service 72 $65 $25,736 $30,416 $1,155,808
Bulletin 747-71-2300, Revision 1......
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Authority for This Rulemaking
The FAA's authority to issue rules regarding aviation safety is
found in Title 49 of the United States Code. 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.
This rulemaking is promulgated under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701, ``General
requirements.'' Under that section, the FAA is charged 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
proposed AD.
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. 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 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
Accordingly, under the authority delegated to me by the
Administrator,
[[Page 53]]
the FAA 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 (AD):
Boeing: Docket No. FAA-2004-19945; Directorate Identifier 2004-NM-
22-AD. Comments Due Date.
(a) The Federal Aviation Administration (FAA) must receive
comments on this AD action by February 17, 2005.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Boeing Model 747-200B, 747-200C, 747-
200F, 747-300, and 747SR series airplanes; certificated in any
category; equipped with General Electric CF6-45 or -50 series
engines.
Unsafe Condition
(d) This AD was prompted by reports of a gap at the interface of
the lower portion of the side cowl and the aft flange of the thrust
reverser. We are issuing this AD to prevent an excessive quantity of
air from entering the fire zone that surrounds the engine, which, in
the event of an engine fire, could result in an inability to control
or extinguish the fire.
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.
Modification
(f) Within 24 months after the effective date of this AD: Modify
the side cowl assemblies on the engines by replacing existing wear
plates with new extended wear plates and installing new stop
fittings, by doing all actions according to the Accomplishment
Instructions of Boeing Service Bulletin 747-71-2300, Revision 1,
dated October 30, 2003. Any applicable corrective actions must be
done before further flight.
On Condition: Removal of Bulb Seals and Other Specified Actions
(g) If bulb seals were installed on the trailing edge of the fan
thrust reverser in accordance with Boeing Service Letter 747-SL-71-
045: Concurrent with or before further flight after accomplishing
paragraph (f) of this AD, remove the bulb seals, plug the open holes
in the trailing edge of the fan thrust reverser, and adjust the cowl
latches as applicable, in accordance with Boeing Service Letter 747-
SL-71-045-C, dated April 10, 2003.
Alternative Methods of Compliance (AMOCs)
(h) The Manager, Seattle Aircraft Certification Office (ACO),
FAA, has the authority to approve AMOCs for this AD, if requested in
accordance with the procedures found in 14 CFR 39.19.
Issued in Renton, Washington, on December 20, 2004.
Kevin M. Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 04-28667 Filed 12-30-04; 8:45 am]
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