[Federal Register: September 19, 2007 (Volume 72, Number 181)]
[Proposed Rules]
[Page 53498-53501]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr19se07-25]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2007-29227; Directorate Identifier 2007-NM-100-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-
100B SUD, 747-200B, 747-200C, 747-300, 747-400, 747-400D, and 747SR
Series Airplanes
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 Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B,
747-200C, 747-300, 747-400, 747-400D, and 747SR series airplanes. For
certain airplanes, this proposed AD would require a material type
inspection to determine if the lower forward corner reveal of the
number 3 main entry doors (MEDs) is a casting. If the reveals are
castings, this proposed AD would require repetitive inspection of the
reveals for cracking, and corrective action if necessary. If the
reveals are not castings, this proposed AD would require a detailed
inspection of the reveals for a sharp edge and repetitive inspection of
the reveals for cracking, and corrective action if necessary. For
certain other airplanes, this AD would require only a detailed
inspection of the reveals for a sharp edge and repetitive inspection of
the reveals for cracking, and corrective action if necessary. For
certain other airplanes, this AD would require repetitive inspection of
the reveals for cracking only, and corrective action if necessary. This
proposed AD results from reports of cracking and/or a sharp edge in the
lower forward corner reveal of the number 3 MEDs. We are proposing this
AD to detect and correct fatigue cracking of the lower forward corner
reveal of the number 3 MEDs, which could lead to the door escape slide
departing from the airplane when the door is opened and the slide is
deployed, and consequent injuries to passengers and crew using the door
escape slide during an emergency evacuation.
DATES: We must receive comments on this proposed AD by November 5,
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: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue, SE., Washington, DC 20590.
Fax: (202) 493-2251.
Hand Delivery: Room W12-140 on the ground floor of the
West Building, 1200 New Jersey Avenue, SE., 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: Ivan Li, Aerospace Engineer, Airframe
Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind
Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6437;
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-
29227; Directorate Identifier 2007-NM-100-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 Operations office between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays. The
Docket Operations office (telephone (800) 647-5527) is located on the
ground floor of the West 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
On June 30, 2004, we issued an NPRM, Docket No. FAA-2004-18583, to
address the identified unsafe condition. That NPRM was prompted by
reports from eight operators indicating that cracking of the lower
forward corner reveal of the number 3 main entry doors (MEDs) was found
on several Model 747 airplanes. Of the twelve reveals that were
cracked, eleven were made of cast 356 aluminum and one was made of
machined 6061 aluminum. The cause of the cracking of the reveals made
of cast 356 aluminum is fatigue. The cause of the cracking of the
reveal made of machined 6061 aluminum was a manufacturing defect, which
led to fatigue cracking.
Subsequent to issuing the NPRM, we have been working with the
manufacturer to ensure that the unsafe condition is adequately
addressed and appropriate service instructions are available. We have
also received new data showing other issues related to the unsafe
condition. In addition to the comments received for that NPRM, the data
include reports that forward corner reveals installed on certain
airplanes have a ``sharp edge'' detail at the forward edge, which could
lead to fatigue cracking, and that additional airplanes are affected by
the identified unsafe condition. We have determined from these data
that the corrective actions proposed by that NPRM are inadequate for
addressing the identified unsafe condition; therefore, we have
withdrawn that NPRM and are issuing this new proposed AD.
[[Page 53499]]
Explanation of Related AD
We have previously issued AD 2007-12-11, amendment 39-15089 (72 FR
31984, June 11, 2007), which applies to certain Boeing Model 747 series
airplanes. That AD requires repetitive inspections to detect cracks
and/or corrosion of the girt bar support fitting at certain main entry
doors (MED), and repair or replacement of the support fitting. That AD
also provides for various terminating actions for the repetitive
inspections. That AD also requires an inspection, for certain
airplanes, for correct installation of square and conical washers in
the girt bar support fitting; an inspection, for certain other
airplanes, to determine if the washers are installed; and related
investigative and corrective action if necessary.
Actions required by that AD are done in accordance with Boeing
Service Bulletin 747-53A2378, Revision 1, dated March 10, 1994; or
Boeing Service Bulletin 747-53A2378, Revision 3, dated August 11, 2005.
Accomplishment of the applicable repair in this proposed AD would
constitute compliance with the requirements of paragraph (q)(2)(ii) of
AD 2007-12-11 for the repair of the lower forward corner casting
(reveal) of the number 3 MEDs only.
Relevant Service Information
We have reviewed Boeing Special Attention Service Bulletin 747-53-
2460, Revision 1, dated February 13, 2007. The service bulletin
describes procedures for inspections of the lower forward corner reveal
of the number 3 MEDs, depending on the configuration of the airplane.
For airplanes identified as Group 3 airplanes: The service bulletin
describes procedures for a repetitive detailed inspection for cracking
of the lower forward corner reveals for cracking, and corrective action
if necessary. Corrective action includes replacing the reveal with a
new or reworked two-piece reveal, which would end the repetitive
inspections; or replacing the reveal with a new or reworked one-piece
machined aluminum reveal without a sharp edge, doing repetitive
inspections at a new compliance time after the replacement, and doing
corrective action if necessary.
For airplanes identified as Group 2 airplanes and Group 1,
Configuration 2 airplanes: The service bulletin describes procedures
for a repetitive detailed inspection of the lower forward corner
reveals for cracking, a one-time detailed inspection of the lower
forward corner reveals for a sharp edge, and corrective action if
necessary. The corrective actions include the following:
If no cracking and no sharp edge are found: Replace the
reveal with a new or reworked two-piece reveal, which would end the
repetitive inspections; or do repetitive detailed inspections at a new
compliance time, and corrective action if necessary (as specified above
in procedures for Group 3 airplanes).
If no cracking is found but a sharp edge is found: Replace
the reveal with a new or reworked two-piece reveal, which would end the
repetitive inspections; or replace the reveal with a new or reworked
one-piece machined aluminum reveal without a sharp edge, do the
repetitive detailed inspections at a new compliance time after doing
the replacement, and do corrective action if necessary (as specified
above in procedures for Group 3 airplanes).
If cracking is found: Replace the reveal with a new or
reworked two-piece reveal, which would end the repetitive inspection;
or replace the reveal with a new or reworked one-piece machined
aluminum reveal without a sharp edge, do the repetitive detailed
inspections at a new compliance time after doing the replacement, and
do corrective action if necessary (as specified above in procedures for
Group 3 airplanes).
For airplanes identified as Group 1, Configuration 1 airplanes: The
service bulletin describes procedures for a one-time material type
inspection to determine if the lower forward corner reveals are
castings. If the forward corner reveal is not a casting: Do a one-time
detailed inspection of the reveal for a sharp edge, repetitive
inspection of the reveal for cracking, and corrective action if
necessary (as specified above in procedures for Group 2 and Group 1,
Configuration 2 airplanes). If the reveal is a casting: Do repetitive
detailed inspections of the reveal for cracking, and corrective action
if necessary. Corrective actions include the following: Weld repair the
reveal and repeat the detailed inspection; replace the reveal with a
new or reworked two-piece reveal, which ends the repetitive
inspections; or replace the reveal with a new or reworked one-piece
machined aluminum reveal without a sharp edge, do the repetitive
inspections again at a new compliance time after the replacement, and
do corrective action if necessary (as specified above in procedures for
Group 2 and Group 1, Configuration 2 airplanes).
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, except as discussed under
``Difference Between the Proposed AD and the Service Bulletin.''
Difference Between the Proposed AD and the Service Bulletin
Although Step 5 of Figure 8 of the service bulletin specifies that
operators may accomplish the actions on forward corner reveals made of
cast 356 aluminum in accordance with ``an operator's equivalent
procedure,'' this proposed AD would require operators to accomplish
Step 5 of Figure 8 only in accordance with the procedures specified in
Boeing Standard Overhaul Practices Manual (SOPM) 20-20-02. An
``operator's equivalent procedure'' may be used only if approved as an
alternative method of compliance in accordance with paragraph (p) of
this AD.
The difference described above has been coordinated with the
manufacturer.
Costs of Compliance
There are about 715 airplanes of the affected design in the
worldwide fleet. The following table provides the estimated costs for
U.S. operators to comply with this proposed AD.
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Number of U.S.-
Action Work hours Average labor Cost per registered Fleet cost
rate per hour airplane airplanes
----------------------------------------------------------------------------------------------------------------
Inspections.................. 4 $80 $320, per 119 $38,080, per
inspection inspection
cycle. cycle.
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[[Page 53500]]
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-2007-29227; Directorate Identifier 2007-NM-
100-AD.
Comments Due Date
(a) The FAA must receive comments on this AD action by November
5, 2007.
Affected ADs
(b) Certain requirements of this AD terminate certain
requirements of AD 96-23-05, amendment 39-9810.
Applicability
(c) This AD applies to Boeing Model 747-100, 747-100B, 747-100B
SUD, 747-200B, 747-200C, 747-300, 747-400, 747-400D, and 747SR
series airplanes, certificated in any category, as identified in
Boeing Special Attention Service Bulletin 747-53-2460, Revision 1,
dated February 13, 2007, except airplanes that have been converted
to an all-cargo configuration. The requirements of this AD also
become applicable at the time when a converted airplane operating in
an all-cargo configuration is converted back to a passenger or
passenger/cargo configuration.
Unsafe Condition
(d) This AD results from reports of cracking and/or a sharp edge
in the lower forward corner reveal of the number 3 main entry doors
(MEDs). We are issuing this AD to detect and correct fatigue
cracking of the lower forward corner reveal of the number 3 MEDs,
which could lead to the door escape slide departing from the
airplane when the door is opened and the slide is deployed, and
consequent injuries to passengers and crew using the door escape
slide during an emergency evacuation.
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.
Service Bulletin Reference
(f) The term ``service bulletin,'' as used in this AD, means the
Accomplishment Instructions of Boeing Special Attention Service
Bulletin 747-53-2460, Revision 1, dated February 13, 2007.
Actions for Group 3 Airplanes
(g) For airplanes identified as Group 3 airplanes in the service
bulletin: Before the accumulation of 10,000 total flight cycles, or
within 1,000 flight cycles after the effective date of this AD,
whichever occurs later, do a detailed inspection for cracking of the
lower forward corner reveals in accordance with Part 8 of the
service bulletin.
(1) If no cracking is found, repeat the inspection thereafter at
intervals not to exceed 6,000 flight cycles until a new or reworked
two-piece reveal is installed in accordance with Part 2 of the
service bulletin. No further action is required by this paragraph
for that location only after the replacement.
Note 1: For the purpose of this AD, a one-piece machined
aluminum reveal may be reworked into a two-piece reveal in
accordance with Part 7 of the service bulletin after it was verified
to be crack free and without a sharp edge in accordance with Part 5
of the service bulletin, or after it was confirmed to be crack free
in accordance with Part 5 of the service bulletin and reworked to
remove a sharp edge in accordance with Part 6 of the service
bulletin.
(2) If cracking is found, do the replacement specified in
paragraph (g)(2)(i) or (g)(2)(ii) of this AD.
(i) Before further flight, replace the reveal with a new or
reworked two-piece reveal in accordance with Part 2 of the service
bulletin. No further action is required by this paragraph for that
location only after the replacement.
(ii) Before further flight, replace the reveal with a new or
reworked one-piece machined aluminum reveal without a sharp edge in
accordance with Part 3 of the service bulletin. Within 10,000 flight
cycles after doing the replacement, do the inspection specified in
paragraph (g) of this AD and repeat the inspection thereafter at
intervals not to exceed 6,000 flight cycles until a new or reworked
two-piece reveal is installed in accordance with Part 2 of the
service bulletin. No further action is required by this paragraph
for that location only after the replacement with a two-piece
reveal.
Note 2: For the purpose of this AD, a one-piece machined
aluminum reveal with a sharp edge may be reworked into a one-piece
machined aluminum reveal without a sharp edge in accordance with
Part 6 of the service bulletin after it was confirmed to be crack
free in accordance with Part 5 of the service bulletin. After the
sharp edge was removed, the one-piece machined aluminum reveal
without a sharp edge may be further reworked into a two-piece reveal
in accordance with Part 7 of the service bulletin.
Actions for Group 2 Airplanes and Group 1, Configuration 2 Airplanes
(h) For airplanes identified as Group 2 airplanes in the service
bulletin: Before the accumulation of 1,500 total flight cycles, or
within 1,000 flight cycles after the effective date of this AD,
whichever occurs later, do the inspection specified in paragraph (j)
of this AD.
(i) For airplanes identified as Group 1, Configuration 2
airplanes in the service bulletin: Within 1,500 flight cycles after
the lower forward corner reveal was last replaced or 1,000 flight
cycles after the effective date of this AD, whichever occurs later,
do the inspection specified in paragraph (j) of this AD.
(j) At the applicable times specified in paragraphs (h) and (i)
of this AD: Do a detailed inspection of the lower forward corner
reveals for cracking and a sharp edge in accordance with Part 5 of
the service bulletin.
(1) If no cracking and no sharp edge is found, before the
accumulation of another
[[Page 53501]]
10,000 flight cycles on the lower forward corner reveal, do the
detailed inspection for cracking specified in paragraph (j) of this
AD and inspect thereafter at intervals not to exceed 6,000 flight
cycles, until a new or reworked two-piece reveal is installed in
accordance with Part 2 of the service bulletin. No further action is
required by this paragraph for that location only after the
replacement.
(2) If no cracking is found but a sharp edge is found, do the
action specified in paragraph (j)(2)(i) or (j)(2)(ii) of this AD.
(i) Before further flight, replace the lower forward corner
reveal with a new or reworked two-piece reveal, in accordance with
Part 2 of the service bulletin. No further action is required by
this paragraph for that location only after the replacement.
(ii) Before further flight, replace the reveal with a new or
reworked one-piece machined aluminum reveal without a sharp edge, in
accordance with Part 3 of the service bulletin. Within 10,000 flight
cycles after doing the replacement, do the actions specified in
paragraph (j) of this AD, except for the inspection for a sharp
edge.
(3) If cracking is found, do the action specified in paragraph
(j)(3)(i) or (j)(3)(ii) of this AD.
(i) Before further flight, replace the reveal with a new or
reworked two-piece reveal, in accordance with Part 2 of the service
bulletin. No further action is required by this paragraph for that
location only after the replacement.
(ii) Before further flight, replace the lower forward corner
reveal with a new or reworked one-piece machined aluminum reveal
without a sharp edge, in accordance with Part 3 of the service
bulletin. Within 10,000 flight cycles after doing the replacement,
do the actions specified in paragraph (j) of this AD, except for the
inspection for a sharp edge.
Actions for Group 1, Configuration 1 Airplanes
(k) For airplanes identified as Group 1, Configuration 1
airplanes in the service bulletin: Before the accumulation of 1,500
total flight cycles, or within 1,000 flight cycles after the
effective date of this AD, whichever occurs later, do a material
type inspection to determine if the lower forward corner reveals are
castings, in accordance with the service bulletin.
(1) If the forward corner reveal is not a casting: Before
further flight, do the actions specified in paragraph (j) of this
AD, except for the inspection for a sharp edge.
(2) If the forward corner reveal is a casting: Before the
accumulation of 7,000 total flight cycles, within 2,000 flight
cycles after the effective date of this AD, or within 3,000 flight
cycles since the forward corner reveal was inspected in accordance
with Boeing Service Bulletin 747-53A2378, whichever is later, do a
detailed inspection for cracking of the lower forward corner reveal,
in accordance with Part 1 of Boeing Special Attention Service
Bulletin 747-53-2460, Revision 1, dated February 13, 2007.
(i) If no cracking is found: Repeat the inspection specified in
paragraph (k)(2) of this AD thereafter at intervals not to exceed
3,000 flight cycles until a new or reworked two-piece lower forward
corner reveal is installed in accordance with Part 2 of the service
bulletin. No further action is required by this paragraph for that
location only after the replacement.
(ii) If cracking is found: Do the actions specified in paragraph
(k)(2)(ii)(A), (k)(2)(ii)(B), or (k)(2)(ii)(C) of this AD.
(A) Before further flight, weld repair the reveal in accordance
with Part 4 of the service bulletin. Repeat the inspection specified
in paragraph (k)(2) of this AD thereafter at intervals not to exceed
3,000 flight cycles until a new or reworked two-piece reveal is
installed in accordance with Part 2 of the service bulletin.
(B) Before further flight, replace the reveal with a new or
reworked two-piece reveal, in accordance with Part 2 of the service
bulletin. No further action is required by this paragraph for that
location only after the replacement.
(C) Before further flight, replace the reveal with a new or
reworked one-piece machined aluminum reveal without a sharp edge, in
accordance with Part 3 of the service bulletin. Within 10,000 flight
cycles after doing the replacement, do the actions specified in
paragraph (j) of this AD, except for the inspection for a sharp
edge.
Operator's Equivalent Procedure
(l) Although Step 5 of Figure 8 of the service bulletin
specifies that operators may accomplish the actions in accordance
with ``an operator's equivalent procedure,'' this AD requires
operators to accomplish Step 5 of Figure 8 in accordance with only
the procedures specified in Boeing Standard Overhaul Practices
Manual (SOPM) 20-20-02 as given in the service bulletin. An
``operator's equivalent procedure'' may be used only if approved as
an alternative method of compliance in accordance with paragraph (p)
of this AD.
Compliance With AD 2007-12-11 for MED 3 Only
(m) Accomplishment of the applicable repair required by this AD
constitutes compliance with the repair of the lower forward corner
casting (reveal) of the number 3 MEDs only, as required by paragraph
(q)(2)(ii) of AD 2007-12-11 (which specifies the actions be done in
accordance with Boeing Service Bulletin 747-53A2378, Revision 1,
dated March 10, 1994; or Boeing Service Bulletin 747-53A2378,
Revision 3, dated August 11, 2005). Accomplishment of the actions of
this AD does not terminate the remaining requirements of AD 2007-12-
11.
Parts Installation
(n) As of the effective date of this AD, no person may install a
door lower forward corner reveal made of cast 356 aluminum on any
airplane at a location specified by this AD.
(o) As of the effective date of this AD, no person may install a
door lower forward corner reveal made of machined 6061 aluminum on
any airplane at a location specified by this AD, unless it has been
confirmed/reworked to be without a sharp edge in accordance with the
service bulletin.
Alternative Methods of Compliance (AMOCs)
(p)(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.
(3) An AMOC that provides an acceptable level of safety may be
used for any repair required by this AD, if it is approved by an
Authorized Representative for the Boeing Commercial Airplanes
Delegation Option Authorization Organization who has been authorized
by the Manager, Seattle ACO, to make those findings. For a repair
method to be approved, the repair must meet the certification basis
of the airplane, and the approval must specifically refer to this
AD.
Issued in Renton, Washington, on September 10, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E7-18420 Filed 9-18-07; 8:45 am]
BILLING CODE 4910-13-P