[Federal Register: November 14, 2008 (Volume 73, Number 221)]
[Rules and Regulations]
[Page 67368-67372]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr14no08-4]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2008-0414; Directorate Identifier 2007-NM-095-AD;
Amendment 39-15714; AD 2008-22-17]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-
100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D,
747-400F, and 747SR Series Airplanes
AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).
ACTION: Final rule.
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SUMMARY: The FAA is superseding an existing airworthiness directive
(AD) that applies to certain Boeing Model 747 series airplanes. That AD
currently requires repetitive inspections for cracking and corrosion of
all exposed surfaces of the carriage spindles (including the inner bore
and aft links) of the trailing edge flaps, and additional inspection
and corrective action if necessary. That AD also currently requires
repetitive overhaul of the carriage spindle and aft link, which
terminates the repetitive inspections. This new AD adds a repetitive
inspection to detect broken parts, and revises the overhaul threshold
and repetitive intervals. This AD results from analysis that showed
additional inspections should be done to prevent the loss of a flap,
and that the flight-hour-based interval should be revised to a flight-
cycle-based interval, because the greatest loads on the spindles happen
during takeoff and landing. We are issuing this AD to detect and
correct failed carriage spindles or aft links of the inboard or
outboard trailing edge flaps. Such failure could cause the flap to
depart the airplane, reducing the flightcrew's ability to maintain the
safe flight and landing of the airplane.
DATES: This AD becomes effective December 19, 2008.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in the AD as of December 19,
2008.
ADDRESSES: For service information identified in this AD, contact
Boeing Commercial Airplanes, P.O. Box 3707,
[[Page 67369]]
Seattle, Washington 98124-2207; telephone 206-544-9990; fax 206-766-
5682; e-mail DDCS@boeing.com; Internet http://www.myboeingfleet.com.
Examining the AD Docket
You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Management Facility
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The AD docket contains this AD, the regulatory evaluation,
any comments received, and other information. The address for the
Docket Office (telephone 800-647-5527) is the Document Management
Facility, U.S. Department of Transportation, Docket Operations, M-30,
West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE.,
Washington, DC 20590.
FOR FURTHER INFORMATION CONTACT: Gary Oltman, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425)
917-6443; fax (425) 917-6590.
SUPPLEMENTARY INFORMATION:
Discussion
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to include an AD that supersedes AD 90-17-19, amendment 39-
6705 (55 FR 33280, August 15, 1990). The existing AD applies to certain
Boeing Model 747 series airplanes. That NPRM was published in the
Federal Register on April 28, 2008 (73 FR 22845). That NPRM proposed to
retain the requirements of the existing AD but to add a repetitive
inspection to detect broken parts, and revise the overhaul threshold
and repetitive intervals.
Comments
We provided the public the opportunity to participate in the
development of this AD. We have considered the comments that have been
received on the NPRM.
Support for the NPRM
Boeing has reviewed the NPRM and concurs with the contents of the
proposed rule. Northwest Airlines (NWA) has no technical objection to
the AD.
Requests To Revise Inspection Threshold
The Hong Kong Civil Aviation Department, and Air Transport
Association (ATA), on behalf of its member NWA, request that we revise
the inspection threshold for the inspection for broken parts proposed
in paragraph (i) of the NPRM. The commenters point out that the NPRM
stated the first inspection should be done at the earlier of 12 months
or 400 flight cycles after the effective date of the AD; however,
Boeing Service Bulletin 747-27-2280, Revision 6, dated February 14,
2008, specifies doing that inspection at the later of those two times.
We agree with the commenters. It was our intent that the compliance
threshold should match that of the Boeing Service Bulletin 747-27-2280,
Revision 6. We have revised paragraph (i) of the AD as requested.
Request To Clarify Compliance Times
ATA on behalf of NWA, requests that we revise paragraph (j),
``Repetitive Overhauls,'' of the NPRM to clarify the compliance
threshold for the initial overhaul for carriage assemblies previously
overhauled in accordance with the requirements of AD 90-17-19. NWA
requests that we specify that the compliance threshold is measured from
the completion of the overhaul mandated by AD 90-17-19 for carriages/
assemblies previously overhauled.
We agree that the compliance times can be clarified, although we do
not agree that it is necessary to change the AD in this regard.
Paragraph (j) of the NPRM specifies doing the initial overhaul at the
later of the applicable thresholds specified in paragraph 1.E.,
``Compliance,'' of Boeing Service Bulletin 747-27-2280, Revision 6,
dated February 14, 2008; or 48 months after the effective date of the
AD. Paragraph 1.E. of the service bulletin includes notes (a) and (e).
Note (a) states, ``Compliance Time and Repeat Interval applies to each
new or overhauled carriage or aft link from the time it enters service,
regardless of whether the part is removed and installed on another
airplane.'' Note (e) states, ``The initial overhaul must be
accomplished prior to terminating the repetitive overhauls at the
compliance times specified in FAA AD 90-17-19.'' These notes provide
the information requested by the commenter. It is the intent of this
new AD that if the initial or repetitive overhaul required by AD 90-17-
19 is due prior to ``48 months after the effective date of this AD,''
the compliance time for the initial carriage overhaul will not be
affected by the new requirements of this AD. However, if the initial or
repetitive carriage overhaul required by AD 90-17-19 is due subsequent
to ``48 months after the effective date of this AD,'' the required
carriage overhauls are governed by the new compliance times of this AD.
Specifically, the compliance time for carriages with sleeved journals
is to accomplish the initial overhaul within 6000 flight cycles or 8
years, whichever occurs first, since new or since completion of the
overhaul mandated by AD 90-17-19; and the compliance time for carriages
with chrome-plated forward and aft journals is to accomplish the
initial overhaul within 9000 flight cycles or 8 years, whichever occurs
first, since new or since completion of the overhaul mandated by AD 90-
17-19. We have not changed the AD in this regard.
Request To Revise Optional Terminating Action
Japan Airlines (JAL) requests that we refer to the latest aft
links. JAL explains that the latest aft links do not require a repeat
overhaul, and points out that the latest aft links are not shown in
Boeing Service Bulletin 747-27-2371, dated December 20, 2000 (we
referred to this service bulletin in paragraph (k) of the NPRM as the
source of service information for the optional terminating action of
replacing the existing 4340M aft link with a new corrosion resistant
steel (CRES) aft link). JAL states that the latest aft links are shown
in paragraph 3.B.5. of Boeing Service Bulletin 747-27-2280, Revision 6,
dated February 14, 2008.
We agree that the newest aft links do not require a repeat overhaul
and that a note in paragraph 3.B.5. of Boeing Service Bulletin 747-27-
2280, Revision 6, refers to these links. Therefore, we have revised
paragraph (k) of this AD to state that replacing the existing 4340M aft
link with a new CRES aft link in accordance with the Accomplishment
Instructions of Boeing Service Bulletin 747-27-2371, dated December 20,
2000, or with an aft link specified in paragraph 3.B.5. of the
Accomplishment Instructions of Boeing Service Bulletin 747-27-2280,
Revision 6, dated February 14, 2008, terminates the repetitive
inspection requirements of paragraph (f) of this AD and the repetitive
overhaul requirements of paragraphs (g) and (j) of this AD for that aft
link only.
Request To Revise Repetitive Intervals
All Nippon Airways (ANA) requests that we use the results of a
Boeing analysis, using ANA flight data as a basis, to change intervals
in the NPRM for Boeing Model 747-400D series airplanes, or provide the
intervals as an alternative method of compliance (AMOC). ANA states
that it operates five Boeing Model 747-400 series airplanes, for which
the maximum takeoff weight
[[Page 67370]]
(MTOW) is 899,600 pounds, and 11 Boeing Model 747-400D series airplanes
for which the MTOW is 599,600 pounds. ANA believes that the loads on
the spindles must be smaller for the Model 747-400D series airplanes
because of the difference between the takeoff and landing weights. ANA
requests that Boeing develop for Model 747-400D series airplanes
different repetitive intervals for the flap carriage overhaul and the
general visual inspection. ANA makes this request because the
repetitive flap carriage overhaul must be done every two to three C-
checks (3 to 4.5 years) and the general visual inspection must be done
every 2 months, thus requiring a lot of manpower and costs. ANA
provided no analysis to justify this requested increase.
We disagree with the request to change the AD to include revised
intervals for Boeing Model 747-400D series airplanes. The intervals for
inspection proposed in the NPRM were based on analysis provided by the
manufacturer. In the absence of any analysis showing the differences in
landing weights for these spindles, there is no evidence that
increasing the intervals would provide an acceptable level of safety.
However, as ANA noted, under the provisions of paragraph (m) of the AD,
we will consider requests for approval of an AMOC if sufficient data
are submitted to substantiate that the change to the intervals would
provide an acceptable level of safety. We have not changed the AD in
this regard.
Conclusion
We reviewed the available data, including the comments received,
and determined that air safety and the public interest require adopting
the AD with the changes described previously. We determined that these
changes will not increase the economic burden on any operator or
increase the scope of the AD.
Costs of Compliance
There are about 925 airplanes of the affected design in the
worldwide fleet, which includes 160 airplanes of U.S. registry. The
following table provides the estimated costs for U.S. operators to
comply with this AD. The average labor rate is $80 per work hour.
Estimated Costs
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Action Work hours Parts Cost per airplane Fleet cost
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Inspection and overhaul (required Between 120 and 140, $0 Between $9,600 and Between $1,536,000
by AD 90-17-19). per flap per cycle. $11,200, per flap and $1,792,000, per
per overhaul cycle. flap per cycle.
Repetitive inspection for broken 2, per inspection 0 $160, per inspection $25,600, per
parts (new action). cycle. cycle. inspection cycle.
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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 AD will not have federalism
implications under Executive Order 13132. This AD will 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 this AD:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866;
(2) Is not a ``significant rule'' under 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 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, Incorporation by
reference, Safety.
Adoption of the Amendment
0
Accordingly, under the authority delegated to me by the Administrator,
the FAA amends 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
0
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]
0
2. The Federal Aviation Administration (FAA) amends Sec. 39.13 by
removing amendment 39-6705 (55 FR 33280, August 15, 1990) and by adding
the following new airworthiness directive (AD):
2008-22-17 Boeing: Amendment 39-15714. Docket No. FAA-2008-0414;
Directorate Identifier 2007-NM-095-AD.
Effective Date
(a) This AD becomes effective December 19, 2008.
Affected ADs
(b) This AD supersedes AD 90-17-19.
Applicability
(c) This AD applies to all Boeing Model 747-100, 747-100B, 747-
100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D,
747-400F, and 747SR series airplanes, certificated in any category.
Unsafe Condition
(d) This AD results from analysis that showed that additional
inspections should be done to prevent the loss of a flap, and that
the flight-hour-based interval should be revised to a flight-cycle-
based interval, because the greatest loads on the spindles happen
during takeoff and landing. We are issuing this AD to detect and
correct failed carriage spindles or aft links of the inboard or
outboard trailing edge flaps. Such failure could cause the flap to
depart the airplane, reducing the flightcrew's ability to maintain
the safe flight and landing of the airplane.
[[Page 67371]]
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.
Requirements of AD 90-17-19
Repetitive Inspections
(f) For all airplanes except those airplanes on which the
repetitive overhauls required by paragraph B. of AD 90-17-19 are
being accomplished as of the effective date of this AD: Prior to the
accumulation of 30,000 flight hours or 8 years on each new or
previously overhauled flap carriage spindle, whichever occurs first,
remove the aft link and thrust collars from the trailing edge flaps'
carriage spindles and perform a detailed inspection of all exposed
surfaces of the carriage spindles, including inner bore, and aft
links to detect cracking and corrosion, in accordance with the
Accomplishment Instructions of Boeing Service Bulletin 747-27-2280,
Revision 3, dated November 30, 1989.
Note 1: For the purposes of this AD, a detailed inspection is:
``An intensive examination of a specific item, installation, or
assembly to detect damage, failure, or irregularity. Available
lighting is normally supplemented with a direct source of good
lighting at an intensity deemed appropriate. Inspection aids such as
mirror, magnifying lenses, etc., may be necessary. Surface cleaning
and elaborate procedures may be required.''
(1) If no cracking or corrosion is found, repeat the inspections
required by paragraph (f) of this AD at intervals not to exceed 12
months until the carriage spindles are overhauled in accordance with
paragraph (g) of this AD.
(2) If a cracked carriage spindle or aft link is found, prior to
further flight, replace the part(s) in accordance with the service
bulletin.
(3) If corrosion is found on any part of the carriage spindle/
aft link assembly, but not on the other assembly on the same flap,
perform a repetitive general visual inspection in accordance with
the service bulletin at intervals not to exceed 2 months. Overhaul
or replace corroded parts in accordance with the service bulletin
within 36 months after detection of the corrosion.
(4) If corrosion is found on any part of both carriage spindle/
aft link assemblies on the same flap, prior to further flight,
overhaul or replace the part(s) in accordance with the service
bulletin or repair in accordance with the procedures specified in
paragraph (m) of this AD.
Note 2: For the purposes of this AD, a general visual inspection
is: ``A visual examination of an interior or exterior area,
installation, or assembly to detect obvious damage, failure, or
irregularity. This level of inspection is made from within touching
distance unless otherwise specified. A mirror may be necessary to
ensure visual access to all surfaces in the inspection area. This
level of inspection is made under normally available lighting
conditions such as daylight, hangar lighting, flashlight, or
droplight and may require removal or opening of access panels or
doors. Stands, ladders, or platforms may be required to gain
proximity to the area being checked.''
Initial and Repetitive Overhauls
(g) For all airplanes: Prior to the accumulation of 8 years or
30,000 flight hours on any new or previously overhauled flap
carriage spindle, whichever occurs later, remove the carriage
spindle and aft link, and overhaul in accordance with the
Accomplishment Instructions of Boeing Service Bulletin 747-27-2280,
Revision 3, dated November 30, 1989. Repeat the overhaul thereafter
at intervals not to exceed 8 years or 30,000 flight hours, whichever
occurs earlier. Accomplishment of initial overhaul required by this
paragraph terminates the requirements of paragraph (f) of this AD.
New Requirements of This AD
Terminating Requirements
(h) The actions specified in paragraphs (i) and (j) of this AD
must be accomplished in their entirety, at the specified compliance
times, to terminate the requirements of paragraphs (f) and (g) of
this AD. There is no terminating action for the requirements of
paragraphs (i) and (j) of this AD.
Repetitive Inspection for Broken Parts
(i) For all airplanes: Within 12 months or 400 flight cycles
after the effective date of this AD, whichever occurs later, do a
general visual inspection of all eight carriage spindles and aft
links to detect a broken carriage spindle or broken aft link, and do
all applicable corrective actions before further flight. Repeat the
inspection thereafter at intervals not to exceed 400 flight cycles.
Do all actions in accordance with the Accomplishment Instructions of
Boeing Service Bulletin 747-27-2280, Revision 6, dated February 14,
2008. For airplanes identified in Note (d) of Table 1 in paragraph
1.E., ``Compliance,'' of Boeing Service Bulletin 747-27-2280,
Revision 6, dated February 14, 2008, the initial compliance time and
repetitive interval for a flap may be extended to 1,000 flight
cycles when new carriages are installed at both the inboard and
outboard carriage locations on the flap.
Repetitive Overhauls
(j) For all airplanes: At the later of the times specified in
paragraph (j)(1) or (j)(2) of this AD, remove the carriage spindle
and aft link, and overhaul in accordance with the Accomplishment
Instructions of Boeing Service Bulletin 747-27-2280, Revision 6,
dated February 14, 2008. Repeat the overhaul thereafter at the
applicable repeat interval specified in paragraph 1.E.,
``Compliance,'' of Boeing Service Bulletin 747-27-2280, Revision 6,
dated February 14, 2008.
(1) The applicable threshold specified in paragraph 1.E.
``Compliance,'' of Boeing Service Bulletin 747-27-2280, Revision 6,
dated February 14, 2008.
(2) Within 48 months after the effective date of this AD.
Optional Terminating Action
(k) For Groups 1 and 3 airplanes identified in Boeing Service
Bulletin 747-27-2280, Revision 6, dated February 14, 2008: Replacing
the existing 4340M aft link with a new corrosion resistant steel
(CRES) aft link in accordance with the Accomplishment Instructions
of Boeing Service Bulletin 747-27-2371, dated December 20, 2000, or
with an aft link specified in paragraph 3.B.5. of the Accomplishment
Instructions of Boeing Service Bulletin 747-27-2280, Revision 6,
dated February 14, 2008, terminates the repetitive inspection
requirements of paragraph (f) of this AD, and the repetitive
overhaul requirements of paragraphs (g) and (j) of this AD for that
aft link only. The repetitive inspections for broken parts required
by paragraph (i) of this AD cannot be terminated.
Credit for Actions Done Using Previous Revision of Service Bulletin
(l) Actions done before the effective date of this AD in
accordance with Boeing Service Bulletin 747-27-2280, Revision 4,
dated April 26, 2001, are acceptable for compliance with the
corresponding requirements of paragraphs (f) and (g) of this AD.
Actions done before the effective date of this AD in accordance with
Boeing Service Bulletin 747-27-2280, Revision 5, dated April 5,
2007, are acceptable for compliance with the corresponding
requirements of paragraphs (i) and (j) of this AD.
Alternative Methods of Compliance (AMOCs)
(m)(1) The Manager, Seattle Aircraft Certification Office (ACO),
FAA, ATTN: Gary Oltman, Aerospace Engineer, Airframe Branch, ANM-
120S, 1601 Lind Avenue, SW., Renton, Washington 98057-3356;
telephone (425) 917-6443; fax (425) 917-6590; has the authority to
approve AMOCs for this AD, if requested using 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) AMOCs approved previously in accordance with AD 90-17-19 are
approved as AMOCs for the corresponding provisions of this AD.
(4) Adjustments to the compliance times approved previously in
accordance with AD 90-17-19 are not approved for the corresponding
provisions of this AD.
(5) 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.
Material Incorporated by Reference
(n) You must use the applicable service information identified
in Table 1 of this AD to perform the actions that are required by
this AD, unless the AD specifies otherwise.
[[Page 67372]]
If you accomplish the optional terminating actions specified by this
AD, you must use the service information identified in Table 2 of
this AD to perform those actions, unless the AD specifies otherwise.
Table 1--Material Incorporated by Reference for Actions Required in this
AD
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Revision
Service Bulletin level Date
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Boeing Service Bulletin 747-27-2280. 3 Nov. 30, 1989.
Boeing Service Bulletin 747-27-2280. 6 Feb. 14, 2008.
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Boeing Service Bulletin 747-27-2280, Revision 3, dated November
30, 1989, contains the following effective pages:
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Revision
Page No. level shown Date shown on page
on page
------------------------------------------------------------------------
1-26............................... 3 Nov. 30, 1989.
27-29.............................. 2 Mar. 23, 1989.
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Table 2--Material Incorporated by Reference for the Optional Terminating
Action in this AD
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Service Bulletin Revision level Date
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Boeing Service Bulletin 747-27- 6................ Feb. 14, 2008.
2280.
Boeing Service Bulletin 747-27- Original......... Dec. 20, 2000.
2371.
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(1) The Director of the Federal Register approved the
incorporation by reference of these documents in accordance with 5
U.S.C. 552(a) and 1 CFR part 51.
(2) Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle,
Washington 98124-2207; telephone 206-544-9990; fax 206-766-5682; e-
mail DDCS@boeing.com; Internet https://www.myboeingfleet.com; for a
copy of this service information.
(3) You may review copies of the service information that is
incorporated by reference at the FAA, Transport Airplane
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the
National Archives and Records Administration (NARA). For information
on the availability of this material at NARA, call 202-741-6030, or
go to: http://www.archives.gov/federal_register/code_of_federal_
regulations/ibr_locations.html.
Issued in Renton, Washington, on October 20, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E8-25761 Filed 11-13-08; 8:45 am]
BILLING CODE 4910-13-P