[Federal Register Volume 63, Number 189 (Wednesday, September 30, 1998)]
[Rules and Regulations]
[Pages 52152-52155]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-25971]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-254-AD; Amendment 39-10751; AD 98-19-09]
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.
-----------------------------------------------------------------------
SUMMARY: This amendment supersedes an existing airworthiness directive
(AD), applicable to all Boeing Model 737-100, -200, -300, -400, and -
500 series airplanes, that currently 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. That AD was 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. This amendment expands
the inspection requirement to include additional airplanes. 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 October 15, 1998.
The incorporation by reference of 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, as listed in the regulations, was previously
approved by the Director of the Federal Register on June 29, 1998.
The incorporation by reference of Boeing Alert Service Bulletin
737-28A1120, Revision 1, dated May 28, 1998, as listed in the
regulations, is approved by the Director of the Federal Register as of
October 15, 1998.
Comments for inclusion in the Rules Docket must be received on or
before November 30, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 98-NM-254-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056.
The service information referenced in this AD 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: On June 12, 1998, the FAA issued AD 98-11-
52, amendment 39-10611 (63 FR 34271, June 24, 1998), applicable to all
Boeing 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 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. That action was 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 required by that 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.
Actions Since Issuance of Previous Rule
Since the issuance of that AD, the FAA has received reports of
severe chafing of the boost pump wiring (with wear of the primary wire
insulation between 40 percent and 80 percent) on Boeing Model 737
series airplanes that had accumulated between 29,000 and 35,000 total
flight hours. Some of these airplanes had accumulated fewer flight
hours than the number of flight hours specified as the inspection
threshold in AD 98-11-52.
In light of these findings, the FAA has determined that it is
necessary to expand the inspection requirement to include airplanes
that have accumulated between 20,000 and 30,000 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.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Alert Service Bulletin
737-28A1120, Revision 1, dated May 28, 1998. The procedures for
inspecting the fuel boost pump wiring and installing Teflon sleeving
are essentially identical to the procedures described in the original
version of the alert service bulletin (referenced in AD 98-11-52). The
only change effected by Revision 1 is to provide information concerning
revised rework instructions and optional parts and procedures.
Explanation of Requirements of Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of this same type design, this AD
supersedes AD 98-11-52 to continue to require 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 AD expands the inspection requirement to include
airplanes that have accumulated between 20,000 and 30,000 total flight
hours. The actions are required to be accomplished in accordance with
the alert service bulletin described previously. This AD also requires
that operators report findings of discrepancies to the manufacturer.
Possible Future Rulemaking Action
The FAA currently is considering further rulemaking action that
would supersede this action to additionally require inspection of Model
737 series airplanes that have accumulated less
[[Page 52153]]
than 20,000 total flight hours. However, the planned compliance time
for the inspection is sufficiently long so that notice and opportunity
for prior public comment will be practicable.
Determination of Rule's Effective Date
Since a situation exists that requires the immediate adoption of
this regulation, it is found that notice and opportunity for prior
public comment hereon are impracticable, and that good cause exists for
making this amendment effective in less than 30 days.
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-254-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 removing amendment 39-10611 (63 FR
34271, June 24, 1998), and by adding a new airworthiness directive
(AD), amendment 39-10751, to read as follows:
98-19-09 Boeing: Amendment 39-10751. Docket 98-NM-254-AD.
Supersedes AD 98-11-52, Amendment 39-10611.
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 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 (m)(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:
Inspections Required by AD 98-11-52
(a) For all airplanes that have accumulated 50,000 or more total
flight hours as of June 29, 1998 (the effective date of AD 98-11-52,
amendment 39-10611): Prior to further flight, remove the fuel boost
pump wiring from the in-tank conduit for the aft boost pumps in main
tanks numbers 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;
or Revision 1, dated May 28, 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 June 29, 1998, whichever occurs later, remove the fuel boost
pump wiring from the in-tank conduit for the aft boost pumps in main
tanks numbers 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;
or Revision 1, dated May 28, 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; or Revision 1, dated May
28, 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 June 29, 1998, 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 June 29, 1998, whichever occurs later.
(3) For all airplanes: Inspect prior to the accumulation of
50,000 total flight hours, or within 5 days after June 29, 1998,
whichever occurs later.
(d) For all airplanes: Prior to the accumulation of 30,000 total
flight hours or
[[Page 52154]]
within 45 days after June 29, 1998, whichever occurs later, remove
the fuel boost pump wiring from the in-tank conduit for the aft
boost pumps in main tanks numbers 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;
or Revision 1, dated May 28, 1998.
New Inspection Requirement
(e) For airplanes that have accumulated 20,000 or more total
flight hours and less than 30,000 total flight hours as of the
effective date of this AD: Within 60 days after the effective date
of this AD, remove the fuel boost pump wiring from the in-tank
conduit for the aft boost pumps in main tanks numbers 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; or Revision 1, dated May 28, 1998.
Corrective Actions
(f) 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 (f)(1), (f)(2), or (f)(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; or Revision 1, dated May 28, 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.
(g) 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
(g)(1) or (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;
or Revision 1, dated May 28, 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.
(h) 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 (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; or Revision 1, dated May 28, 1998.
(1) Verify the integrity of the conduit in accordance with the
instructions contained in NSC 03 or Revision 1 of the alert service
bulletin. And
(2) Accomplish either paragraph (h)(2)(i) or (h)(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.
(i) 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 (i)(1) and (i)(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; or Revision 1, dated May 28, 1998.
(1) Replace the conduit section where electrical arcing was
found. And
(2) Accomplish either paragraph (i)(2)(i) or (i)(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.
(j) 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 (f), (g), (h), or (i) 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; or Revision 1, dated May
28, 1998.
(k) Installation of Teflon sleeving over any electrical cable
that is new or has been inspected in accordance with paragraph (a),
(b), (c), (d), or (e) of this AD, constitutes terminating action for
the requirements of this AD.
(l) If any damage specified in paragraph (g), (h), or (i) 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), (d), or (e) of this AD, as applicable, accomplish
paragraphs (l)(1) and (l)(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, NSC 02, dated May 8, 1998, and NSC 03, dated May 9,
1998; or Revision 1, dated May 28, 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 June 29, 1998, 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.
(m)(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.
(m)(2) Alternative methods of compliance, approved previously in
accordance with AD 98-11-52 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.
(n) Special flight permits may be issued in accordance with
Secs. 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.
(o) Except as provided in paragraph (k)(2) of this AD, the
actions shall be done in accordance with Boeing Alert Service
Bulletin 737-28A1120, dated April 24, 1998, as revised by Notice of
Status Change NSC 01, dated May 7, 1998, Notice of Status Change NSC
02, dated May 8, 1998, and Notice of Status Change NSC 03, dated May
9, 1998; or Boeing Alert Service Bulletin 737-28A1120, Revision 1,
dated May 28, 1998.
(1) The incorporation by reference of Boeing Alert Service
Bulletin 737-28A1120, Revision 1, dated May 28, 1998, as listed in
the regulations, is approved by the Director of the Federal Register
as of October 15, 1998.
(2) The incorporation by reference of Boeing Alert Service
Bulletin 737-28A1120,
[[Page 52155]]
dated April 24, 1998, as revised by Notice of Status Change NSC 01,
dated May 7, 1998, Notice of Status Change NSC 02, dated May 8,
1998, and Notice of Status Change NSC 03, dated May 9, 1998, was
approved previously by the Director of the Federal Register as of
June 29, 1998 (63 FR 34271, June 24, 1998).
(3) 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.
(p) This amendment becomes effective on October 15, 1998.
Issued in Renton, Washington, on September 23, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-25971 Filed 9-29-98; 8:45 am]
BILLING CODE 4910-13-U
