[Federal Register: June 5, 2007 (Volume 72, Number 107)]
[Proposed Rules]
[Page 30999-31000]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr05jn07-17]
[[Page 30999]]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2007-28349; Directorate Identifier 2007-NM-025-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747-100B SUD, 747-200B,
747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, and 747SP
Series Airplanes
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 certain Boeing Model 747-100B SUD, 747-200B, 747-200C, 747-200F,
747-300, 747-400, 747-400D, 747-400F, and 747SP series airplanes. This
proposed AD would require reconfiguring the clamps of certain wire
bundles and applying insulating sealant to certain fasteners inside the
fuel tanks. This proposed AD results from fuel system reviews conducted
by the manufacturer. We are proposing this AD to prevent arcing inside
the fuel tanks in the event of a lightning strike or high-powered short
circuit, which could result in a fuel tank explosion or fire.
DATES: We must receive comments on this proposed AD by July 20, 2007.
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.
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.
Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle,
Washington 98124-2207, for the service information identified in this
proposed AD.
FOR FURTHER INFORMATION CONTACT: Sulmo Mariano, Aerospace Engineer,
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification
Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone
(425) 917-6501; fax (425) 917-6590.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to submit any relevant written data, views, or
arguments regarding this proposed AD. Send your comments to an address
listed in the ADDRESSES section. Include the docket number ``FAA-2007-
28349; Directorate Identifier 2007-NM-025-AD'' at the beginning 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
that 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 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 Docket
You may 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 located 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 Docket Management System
receives them.
Discussion
The FAA has examined the underlying safety issues involved in fuel
tank explosions on several large transport airplanes, including the
adequacy of existing regulations, the service history of airplanes
subject to those regulations, and existing maintenance practices for
fuel tank systems. As a result of those findings, we issued a
regulation titled ``Transport Airplane Fuel Tank System Design Review,
Flammability Reduction and Maintenance and Inspection Requirements''
(66 FR 23086, May 7, 2001). In addition to new airworthiness standards
for transport airplanes and new maintenance requirements, this rule
included Special Federal Aviation Regulation No. 88 (``SFAR 88,''
Amendment 21-78, and subsequent Amendments 21-82 and 21-83).
Among other actions, SFAR 88 requires certain type design (i.e.,
type certificate (TC) and supplemental type certificate (STC)) holders
to substantiate that their fuel tank systems can prevent ignition
sources in the fuel tanks. This requirement applies to type design
holders for large turbine-powered transport airplanes and for
subsequent modifications to those airplanes. It requires them to
perform design reviews and to develop design changes and maintenance
procedures if their designs do not meet the new fuel tank safety
standards. As explained in the preamble to the rule, we intended to
adopt airworthiness directives to mandate any changes found necessary
to address unsafe conditions identified as a result of these reviews.
In evaluating these design reviews, we have established four
criteria intended to define the unsafe conditions associated with fuel
tank systems that require corrective actions. The percentage of
operating time during which fuel tanks are exposed to flammable
conditions is one of these criteria. The other three criteria address
the failure types under evaluation: single failures, single failures in
combination with a latent condition(s), and in-service failure
experience. For all four criteria, the evaluations included
consideration of previous actions taken that may mitigate the need for
further action.
We have determined that the actions identified in this AD are
necessary to reduce the potential of ignition sources inside fuel
tanks, which, in combination with flammable fuel vapors, could result
in fuel tank explosions and consequent loss of the airplane.
We have received a report indicating that a certain type of
fastener used in the fuel tank walls of Model 747 airplanes is
insufficiently bonded to the airplane structure. Further, these
fasteners do not have sufficient electrical insulation applied inside
the fuel tanks to prevent arcing in the event of a lightning strike or
high-powered short circuit. This condition, if not corrected, could
result in a fuel tank explosion or fire.
[[Page 31000]]
Relevant Service Information
We have reviewed Boeing Special Attention Service Bulletin 747-57-
2326, dated January 4, 2007, which describes procedures for applying
insulating sealant to certain fasteners inside the main fuel tanks.
We have reviewed Boeing Special Attention Service Bulletin 747-57-
2327, Revision 1, dated July 10, 2006, which describes procedures for
reconfiguring the clamps of certain wire bundles by wrapping additional
Teflon sleeving around the wire bundles, installing new, larger clamps,
and sealing the ends of certain fasteners inside the auxiliary fuel
tank, main fuel tanks, and surge tanks.
Accomplishing the actions specified in the service information is
intended to adequately address the unsafe condition.
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. For this reason, we are proposing this AD,
which would require accomplishing the actions specified in the service
information described previously.
Costs of Compliance
There are about 707 airplanes of the affected design in the
worldwide fleet. This proposed AD would affect about 107 airplanes of
U.S. registry. Depending on airplane configuration, the proposed
actions would take between 106 and 448 work hours per airplane, at an
average labor rate of $80 per work hour. Required parts would cost
between $430 and $2,074 per airplane. Based on these figures, the
estimated cost of the proposed AD for U.S. operators is between $8,910
and $37,914 per airplane, or up to $4,056,798 for all airplanes.
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. 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 and placed it in the AD docket. 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, 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 Federal Aviation Administration (FAA) amends Sec. 39.13 by
adding the following new airworthiness directive (AD):
Boeing: Docket No. FAA-2007-28349; Directorate Identifier 2007-NM-
025-AD.
Comments Due Date
(a) The FAA must receive comments on this AD action by July 20,
2007.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Boeing Model 747-100B SUD, 747-200B, 747-
200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, and 747SP
series airplanes, certificated in any category; as identified in
Boeing Special Attention Service Bulletin 747-57-2327, Revision 1,
dated July 10, 2006; and Boeing Special Attention Service Bulletin
747-57-2326, dated January 4, 2007.
Unsafe Condition
(d) This AD results from fuel system reviews conducted by the
manufacturer. We are issuing this AD to prevent arcing inside the
fuel tanks in the event of a lightning strike or high-powered short
circuit, which could result in a fuel tank explosion or 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.
Change and Seal
(f) Within 60 months after the effective date of this AD, do the
actions required by paragraphs (f)(1) and (f)(2) of this AD.
(1) Reconfigure the wire bundle clamps and seal the ends of
certain fasteners inside the auxiliary fuel tank, main fuel tanks,
and surge fuel tanks; in accordance with the Accomplishment
Instructions of Boeing Special Attention Service Bulletin 747-57-
2327, Revision 1, dated July 10, 2006.
(2) Seal the ends of certain fasteners inside the main fuel
tanks, in accordance with the Accomplishment Instructions of Boeing
Special Attention Service Bulletin 747-57-2326, dated January 4,
2007.
Alternative Methods of Compliance (AMOCs)
(g)(1) 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.
(2) To request a different method of compliance or a different
compliance time for this AD, follow the procedures in 14 CFR 39.19.
Before using any approved AMOC on any airplane to which the AMOC
applies, notify your appropriate principal inspector (PI) in the FAA
Flight Standards District Office (FSDO), or lacking a PI, your local
FSDO.
Issued in Renton, Washington, on May 25, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E7-10760 Filed 6-4-07; 8:45 am]
BILLING CODE 4910-13-P