[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
