[Federal Register Volume 63, Number 121 (Wednesday, June 24, 1998)]
[Rules and Regulations]
[Pages 34271-34274]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-16308]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-178-AD; Amendment 39-10611; AD 98-11-52]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-100, -200, -300, -400, 
and -500 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This document publishes in the Federal Register an amendment 
adopting airworthiness directive (AD) T98-11-52 that was sent 
previously to all known U.S. owners and operators of Boeing Model 737-
100, -200, -300, -400, and -500 series airplanes by individual 
telegrams. This AD requires removal of the fuel boost pump wiring in 
the conduits of the wing and center fuel tanks; an inspection to detect 
damage of the wiring, and corrective action, if necessary; and eventual 
installation of teflon sleeving over the electrical cable. This action 
is prompted by reports of severe wear of the fuel boost pump wiring due 
to chafing between the wiring and the surrounding conduit inside the 
fuel tank; pin-hole-sized holes in the conduit that appear to be the 
result of arc-through of the conduit; and exposure of the main tank 
boost pump wire conductor inside a conduit and signs of arcing to the 
wall of the conduit. The actions specified by this AD are intended to 
detect and correct chafing and electrical arcing between the fuel boost 
pump wiring and the surrounding conduit, which, if not corrected, could 
result in arc-through of the conduit, and consequent fire or explosion 
of the fuel tank.

DATES: Effective June 29, 1998, to all persons except those persons to 
whom it was made immediately effective by telegraphic AD T98-11-52, 
issued on May 14, 1998, which contained the requirements of this 
amendment.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of June 29, 1998.
    Comments for inclusion in the Rules Docket must be received on or 
before August 24, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-178-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.
    The applicable service information may be obtained from Boeing 
Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-
2207. This information may be examined at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the 
Office of the Federal Register, 800 North Capitol Street, NW., suite 
700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Dorr Anderson, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate, 
Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 227-2684; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION:

Issuance of Telegraphic AD T98-10-51

    On May 7, 1998, the FAA issued telegraphic AD T98-10-51, applicable 
to all Model 737-100, -200, -300, -400, and -500 series airplanes, to 
require removal of the fuel boost pump wiring in the conduits of the 
wing fuel tanks; a one-time detailed visual inspection to detect damage 
of the wiring; reinstallation of the wiring with teflon sleeving, or 
replacement of damaged wiring with new wiring and teflon sleeving; and 
submission of damaged parts to Boeing. Telegraphic AD T98-10-51 was 
prompted by reports of severe wear of the fuel boost pump wiring due to 
chafing between the in-tank fuel boost pump wiring and the surrounding 
conduit inside the fuel tank, and pin-hole-sized holes in two sections 
of the fuel boost pump conduit that appeared to be the result of arc-
through of the conduit. The actions required by that telegraphic AD 
were intended to detect and correct such chafing, which could result in 
arc-through of the conduit, and consequent fire or explosion of the 
fuel tank.

Issuance of Telegraphic AD T98-11-51

    On May 10, 1998, the FAA issued telegraphic AD T98-11-51, which is 
applicable to all Model 737-100, -200, -300, -400, and -500 series 
airplanes. That AD superseded telegraphic AD T98-10-51 to continue to 
require removal of the fuel boost pump wiring in the conduits of the 
wing fuel tanks; a detailed visual inspection to detect damage of the 
wiring; and corrective action, if necessary. Additionally, that 
telegraphic AD required eventual installation of teflon sleeving over 
the electrical cable, which terminated the requirements of the 
telegraphic AD.
    Telegraphic AD T98-11-51 was prompted by a report indicating that 
the left main tank boost pump power wire conductor was exposed at three 
areas inside the conduit. At least one of the areas exhibited signs of 
arcing to the wall of the conduit. In addition, several reports of 
severe chafing had been received since the issuance of telegraphic AD 
T98-10-51. The actions required by telegraphic AD T98-11-51 were 
intended to detect and correct chafing and electrical arcing between 
the fuel boost pump wiring and the surrounding conduit, which, if not 
corrected, could result in arc-through of the conduit, and consequent 
fire or explosion of the fuel tank.
    In telegraphic AD T98-11-51, the FAA required inspection of 
airplanes that had accumulated between 40,000 and 50,000 total flight 
hours based on the significance of the problems on the high-time 
airplanes reported at that time, and the lack of available data for 
airplanes that had accumulated between 40,000 and 50,000 total flight 
hours. However, the FAA indicated in that telegraphic AD that it would 
continue to monitor inspection reports to determine whether an 
adjustment to the compliance time was warranted.

Issuance of Telegraphic AD T98-11-52

    Since the issuance of telegraphic AD T98-11-51, the FAA has 
received inspection results indicating that exposed copper wire and 
significant chafing was found on other Model 737-200 series airplanes 
that had accumulated flight hours below those specified in earlier 
reports.
    The FAA has determined that it is necessary to expand the 
inspection requirement to airplanes that have accumulated less than 
40,000 total flight hours. This is necessary to ensure that these 
airplanes have not also developed a problem with chafing and electrical 
arcing between the fuel boost pump wiring and the surrounding conduit.
    When telegraphic AD T98-11-51 superseded telegraphic AD T98-10-51, 
the FAA had received inspection reports indicating that the center fuel 
tank boost pump wiring was not showing chafing and did not present a 
safety of flight problem on Model 737-100 and -200 series airplanes. 
(It should be noted that the center fuel tank boost pump wiring

[[Page 34272]]

is located in the main tanks, not within the center fuel tank itself.) 
As a result, the requirement for inspection of the center fuel tank 
boost pump wiring on Model 737-100 and -200 series airplanes was 
removed in telegraphic AD T98-11-51. Inspection results received since 
the issuance of telegraphic AD T98-11-51 indicate that chafing has 
occurred in the center fuel tank boost pump wiring of some Model 737-
100 and -200 series airplanes. Telegraphic AD T98-11-52 restores the 
requirement to inspect the center fuel tank boost pump wiring on all 
affected models.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletin 
737-28A1120, dated April 24, 1998, as revised by Notices of Status 
Change NSC 01, dated May 7, 1998, NSC 02, dated May 8, 1998, and NSC 
03, dated May 9, 1998. The alert service bulletin describes procedures 
for removal of the fuel boost pump wiring in the conduits of the wing 
fuel tanks and center fuel tanks; an inspection to detect damage of the 
wiring; and corrective action, if necessary. (The corrective actions 
include replacing the wiring or conduit with new or serviceable parts.) 
This alert service bulletin also describes procedures for eventual 
installation of teflon sleeving over the electrical cable. The NSC's 
provide information concerning optional parts and procedures.

Explanation of Requirements of the Rule

    Since the unsafe condition described is likely to exist or develop 
on other airplanes of the same type design, the FAA issued telegraphic 
AD T98-11-52 to detect and correct chafing and electrical arcing 
between the fuel boost pump wiring and the surrounding conduit, which, 
if not corrected, could result in arc-through of the conduit, and 
consequent fire or explosion of the fuel tank. This AD supersedes 
telegraphic AD T98-11-51 to continue to require removal of the fuel 
boost pump wiring in the conduits of the wing fuel tanks; a detailed 
visual inspection to detect damage of the wiring; and corrective 
action, if necessary. Additionally, this AD continues to require 
eventual installation of teflon sleeving over the electrical cable, 
which terminates the requirements of the AD.
    This AD requires inspection of airplanes that have accumulated less 
than 40,000 total flight hours. In addition, this AD adds a requirement 
for inspection of the fuel boost pump wiring in the conduits of the 
center fuel tanks on Model 737-100 and -200 series airplanes that have 
accumulated 40,000 or more total flight hours.
    The actions are required to be accomplished in accordance with 
alert service bulletin and notices of status change described 
previously.
    Since it was found that immediate corrective action was required, 
notice and opportunity for prior public comment thereon were 
impracticable and contrary to the public interest, and good cause 
existed to make the AD effective immediately by individual telegrams 
issued on May 14, 1998, to all known U.S. owners and operators of all 
Boeing Model 737-100, -200, -300, -400, and -500 series airplanes. 
These conditions still exist, and the AD is hereby published in the 
Federal Register as an amendment to section 39.13 of the Federal 
Aviation Regulations (14 CFR 39.13) to make it effective to all 
persons.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this rule by 
submitting such written data, views, or arguments as they may desire. 
Communications shall identify the Rules Docket number and be submitted 
in triplicate to the address specified under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the rule. All comments submitted will be 
available, both before and after the closing date for comments, in the 
Rules Docket for examination by interested persons. A report that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 98-NM-178-AD.'' The postcard will be date stamped and 
returned to the commenter.

Regulatory Impact

    The regulations adopted herein will not have substantial direct 
effects 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. Therefore, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, may be obtained from the Rules Docket at the 
location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new 
airworthiness directive:

98-11-52  BOEING: Amendment 39-10611. Docket 98-NM-178-AD.

    Applicability: All Model 737-100, -200, -300, -400, and -500 
series airplanes, certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability

[[Page 34273]]

provision, regardless of whether it has been modified, altered, or 
repaired in the area subject to the requirements of this AD. For 
airplanes that have been modified, altered, or repaired so that the 
performance of the requirements of this AD is affected, the owner/
operator must request approval for an alternative method of 
compliance in accordance with paragraph (l)(1) of this AD. The 
request should include an assessment of the effect of the 
modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To detect and correct chafing and electrical arcing between the 
fuel boost pump wiring and the surrounding conduit, which, if not 
corrected, could result in arc-through of the conduit, and 
consequent fire or explosion of the fuel tank, accomplish the 
following:
    (a) For all airplanes that have accumulated 50,000 or more total 
flight hours as of the effective date of this AD: Prior to further 
flight, remove the fuel boost pump wiring from the in-tank conduit 
for the aft boost pumps in main tanks #1 and #2, and perform a 
detailed visual inspection to detect damage of the wiring, in 
accordance with the procedures specified in Boeing Alert Service 
Bulletin 737-28A1120, dated April 24, 1998, as revised by Notices of 
Status Change NSC 01, dated May 7, 1998, NSC 02, dated May 8, 1998, 
and NSC 03, dated May 9, 1998.
    (b) For all airplanes that have accumulated less than 50,000 
total flight hours as of receipt of telegraphic AD T98-11-51: Prior 
to the accumulation of 40,000 total flight hours, or within 14 days 
after the effective date of this AD, whichever occurs later, remove 
the fuel boost pump wiring from the in-tank conduit for the aft 
boost pumps in main tanks #1 and #2, and perform a detailed visual 
inspection to detect damage of the wiring, in accordance with the 
procedures specified in Boeing Alert Service Bulletin 737-28A1120, 
dated April 24, 1998, as revised by Notices of Status Change NSC 01, 
dated May 7, 1998, NSC 02, dated May 8, 1998, and NSC 03, dated May 
9, 1998.
    (c) For all airplanes: Remove the fuel boost pump wiring from 
the in-tank conduit for the center tank left and right boost pumps, 
and perform a detailed visual inspection to detect damage of the 
wiring, in accordance with the procedures specified in Boeing Alert 
Service Bulletin 737-28A1120, dated April 24, 1998, as revised by 
Notices of Status Change NSC 01, dated May 7, 1998, NSC 02, dated 
May 8, 1998, and NSC 03, dated May 9, 1998. Accomplish the 
inspection at the earliest of the times specified in paragraphs 
(c)(1), (c)(2), and (c)(3).
    (1) For Model 737-300, -400, and -500 series airplanes: Inspect 
prior to the accumulation of 40,000 total flight hours, or within 14 
days after the effective date of this AD, whichever occurs later.
    (2) For Model 737-100 and -200 series airplanes: Inspect prior 
to the accumulation of 40,000 total flight hours, or within 10 days 
after the effective date of this AD, whichever occurs later.
    (3) For all airplanes: Inspect prior to the accumulation of 
50,000 total flight hours, or within 5 days after the effective date 
of this AD, whichever occurs later.
    (d) For all airplanes: Prior to the accumulation of 30,000 total 
flight hours or within 45 days after the effective date of this AD, 
whichever occurs later, remove the fuel boost pump wiring from the 
in-tank conduit for the aft boost pumps in main tanks #1 and #2, and 
the center tank left and right boost pumps, and perform a detailed 
visual inspection to detect damage of the wiring, in accordance with 
the procedures specified in Boeing Alert Service Bulletin 737-
28A1120, dated April 24, 1998, as revised by Notices of Status 
Change NSC 01, dated May 7, 1998, NSC 02, dated May 8, 1998, and NSC 
03, dated May 9, 1998.
    (e) If red, yellow, blue, or green wire insulation cannot be 
seen through the outer jacket of the electrical cable during any 
inspection required by this AD: Prior to further flight, accomplish 
paragraph (e)(1), (e)(2), or (e)(3) of this AD in accordance with 
procedures specified in Boeing Alert Service Bulletin 737-28A1120, 
dated April 24, 1998, as revised by Notices of Status Change NSC 01, 
dated May 7, 1998, NSC 02, dated May 8, 1998, and NSC 03, dated May 
9, 1998.
    (1) Install teflon sleeving over the electrical cable, and 
reinstall the cable. Or
    (2) Reinstall the electrical cable without teflon sleeving over 
the cable. Within 500 flight hours after accomplishment of the 
reinstallation, repeat the inspection described in paragraph (d) of 
this AD; and install teflon sleeving over the cable. Or
    (3) Replace the electrical cable with new cable without teflon 
sleeving. Within 18 months or 6,000 flight hours, whichever occurs 
first, repeat the inspection specified in paragraph (d) of this AD, 
and install teflon sleeving over the cable.
    (f) If red, yellow, blue, or green wire insulation can be seen 
through the outer jacket of the electrical cable during any 
inspection required by this ad, but no evidence of electrical arcing 
is found: Prior to further flight, accomplish either paragraph 
(f)(1) or (f)(2) of this AD in accordance with the procedures 
specified in Boeing Alert Service Bulletin 737-28A1120, dated April 
24, 1998, as revised by Notices of Status Change NSC 01, dated May 
7, 1998, NSC 02, dated May 8, 1998, and NSC 03, dated May 9, 1998.
    (1) Replace the damaged electrical cable with a new cable, 
install teflon sleeving over the cable, and reinstall the cable. Or
    (2) Replace the electrical cable with a new cable without teflon 
sleeving. Within 18 months or 6,000 flight hours, whichever occurs 
first, repeat the inspection described in paragraph (d) of this AD; 
and install teflon sleeving over the cable.
    (g) If any evidence of electrical arcing but no evidence of fuel 
leakage is found on the removed electrical cable during any 
inspection required by this AD: Prior to further flight, accomplish 
paragraphs (g)(1) and (g)(2) of this AD in accordance with the 
procedures specified in Boeing Alert Service Bulletin 737-28A1120, 
dated April 24, 1998, as revised by Notices of Status Change NSC 01, 
dated May 7, 1998, NSC 02, dated May 8, 1998, and NSC 03, dated May 
9, 1998.
    (1) Verify the integrity of the conduit in accordance with the 
instructions contained in NSC 03 to the alert service bulletin. And
    (2) Accomplish either paragraph (g)(2)(i) or (g)(2)(ii) of this 
AD in accordance with the alert service bulletin.
    (i) Replace the damaged electrical cable with a new cable, 
install teflon sleeving over the cable, and reinstall the cable. Or
    (ii) Replace the electrical cable with a new cable without 
teflon sleeving. Within 18 months or 6,000 flight hours, whichever 
occurs first, repeat the inspection described in paragraph (d) of 
this AD; and install teflon sleeving over the cable.
    (h) If any evidence of fuel is found on the removed electrical 
cable during any inspection required by this AD: Prior to further 
flight, accomplish paragraphs (h)(1) and (h)(2) of this AD in 
accordance with the procedures specified in Boeing Alert Service 
Bulletin 737-28A1120, dated April 24, 1998, as revised by Notices of 
Status Change NSC 01, dated May 7, 1998, NSC 02, dated May 8, 1998, 
and NSC 03, dated May 9, 1998.
    (1) Replace the conduit section where electrical arcing was 
found. And
    (2) Accomplish either paragraph (h)(2)(i) or (h)(2)(ii) of this 
AD.
    (i) Replace the damaged electrical cable with a new cable, 
install teflon sleeving over the cable, and reinstall the cable. Or
    (ii) Replace the electrical cable with a new cable without 
teflon sleeving. Within 18 months or 6,000 flight hours, whichever 
occurs first, repeat the inspection described in paragraph (d) of 
this AD; and install teflon sleeving over the cable.
    (i) For Groups 1 and 2 airplanes, as identified in Boeing Alert 
Service Bulletin 737-28A1120, dated April 24, 1998: Concurrent with 
the first accomplishment of corrective action in accordance with 
paragraph (e), (f), (g), or (h) of this AD, as applicable, replace 
the case ground wire with a new wire in accordance with Boeing Alert 
Service Bulletin 737-28A1120, dated April 24, 1998; as revised by 
Notices of Status Change NSC 01, dated May 7, 1998, NSC 02, dated 
May 8, 1998, and NSC 03, dated May 9, 1998.
    (j) Installation of teflon sleeving over any electrical cable 
that is new or has been inspected in accordance with paragraph (a), 
(b), (c), or (d) of this AD, constitutes terminating action for the 
requirements of this AD.
    (k) If any damage specified in paragraph (f), (g), or (h) of 
this AD is found during any inspection required by this AD, within 
10 days after accomplishing the inspection required by paragraph 
(a), (b), (c), or (d) of this AD, as applicable, accomplish 
paragraphs (k)(1) and (k)(2) of this AD. Information collection 
requirements contained in this regulation have been approved by the 
Office of Management and Budget (OMB) under the provisions of the 
Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have 
been assigned OMB Control Number 2120-0056.
    (1) Submit any damaged electrical cables and conduits to Boeing, 
in accordance with Boeing Alert Service Bulletin 737-28A1120, dated 
April 24, 1998, as revised by Notices of Status Change NSC 01, dated 
May 7, 1998,

[[Page 34274]]

NSC 02, dated May 8, 1998, and NSC 03, dated May 9, 1998; include 
the serial number of the airplane, the number of total flight hours 
and flight cycles accumulated on the airplane, and the location of 
the electrical cable on the airplane.
    (2) For airplanes that are inspected after the effective date of 
this AD, submit the serial number of the airplane, the number of 
total flight hours and flight cycles accumulated on the airplane, 
and the location of the electrical cable on the airplane to the 
Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport 
Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056; fax (425) 227-1181.
    (l)(1) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Seattle ACO. Operators shall submit 
their requests through an appropriate FAA Principal Maintenance 
Inspector, who may add comments and then send it to the Manager, 
Seattle ACO.
    (l)(2) Alternative methods of compliance, approved previously in 
accordance with telegraphic AD T98-10-51 or telegraphic AD T98-11-51 
are approved as alternative methods of compliance with this AD.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

    (m) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.
    (n) The actions shall be done in accordance with Boeing Alert 
Service Bulletin 737-28A1120, dated April 24, 1998, as revised by 
Notices of Status Change NSC 01, dated May 7, 1998, NSC 02, dated 
May 8, 1998, and NSC 03, dated May 9, 1998. This incorporation by 
reference was approved by the Director of the Federal Register in 
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, 
Seattle, Washington 98124-2207. Copies may be inspected at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington; or at the Office of the Federal Register, 800 North 
Capitol Street, NW., suite 700, Washington, DC.
    (o) This amendment becomes effective on June 29, 1998, to all 
persons except those persons to whom it was made immediately 
effective by telegraphic AD T98-11-52, issued on May 14, 1998, which 
contained the requirements of this amendment.

    Issued in Renton, Washington, on June 12, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-16308 Filed 6-23-98; 8:45 am]
BILLING CODE 4910-13-U