[Federal Register Volume 68, Number 112 (Wednesday, June 11, 2003)]
[Proposed Rules]
[Pages 34843-34847]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-14666]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
 
 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
 ========================================================================
 

  Federal Register / Vol. 68, No. 112 / Wednesday, June 11, 2003 / 
Proposed Rules  

[[Page 34843]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-78-AD]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Supplemental notice of proposed rulemaking; reopening of 
comment period.

-----------------------------------------------------------------------

SUMMARY: This document revises an earlier proposed airworthiness 
directive (AD), applicable to certain Boeing airplane models, that 
would have superseded an existing AD currently requiring either 
inspections for discrepancies of the fueling float switch wiring in the 
center fuel tank and follow-on actions, or deactivation of the float 
switch. The proposed AD would have removed the option to deactivate the 
float switch and would have required repetitive inspections for 
discrepancies of the float switch wiring and various other actions. 
This new action would require replacing the float switches in the 
center and wing fuel tanks with new, improved parts, installing a 
conduit liner system in the center fuel tank, and replacing conduit 
assemblies in the wing fuel tanks with new parts, which would terminate 
the existing requirements. For certain airplanes, this new action also 
would require replacing certain existing sections of the electrical 
conduit in the center fuel tank with new conduit. This new action also 
would add one additional airplane model to the applicability and remove 
another. These actions are necessary to prevent contamination of the 
fueling float switch by moisture or fuel, and chafing of the float 
switch wiring against the fuel tank conduit, which could present an 
ignition source inside the fuel tank that could cause a fire or 
explosion. These actions are intended to address the identified unsafe 
condition.

DATES: Comments must be received by July 7, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-78-AD, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056. Comments may be inspected at this location 
between 9 a.m. and 3 p.m., Monday through Friday, except Federal 
holidays. Comments may be submitted via fax to (425) 227-1232. Comments 
may also be sent via the Internet using the following address: [email protected]. Comments sent via fax or the Internet must contain 
``Docket No. 99-NM-78-AD'' in the subject line and need not be 
submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Airplane Group, PO Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Sherry Vevea, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone 
(425) 917-6514; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed 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 above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this action may be changed in 
light of the comments received.
    Submit comments using the following format:
    [sbull] Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
    [sbull] For each issue, state what specific change to the proposed 
AD is being requested.
    [sbull] Include justification (e.g., reasons or data) for each 
request.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 99-NM-78-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 99-NM-78-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    A proposal to amend part 39 of the Federal Aviation Regulations (14 
CFR part 39) to add an airworthiness directive (AD), applicable to 
certain Boeing Model 737-100, -200, -300, -400, and -500 series 
airplanes, was published as a notice of proposed rulemaking (NPRM) in 
the Federal Register on April 28, 2000 (65 FR 24889). That NPRM 
proposed to supersede AD 99-05-12, amendment 39-11060 (64 FR 10213, 
March 3, 1999). (A correction of that AD was published in the Federal 
Register on March 9, 1999 (64 FR 11533).) That proposal would have 
continued to require inspection of the fueling float switch wiring in 
the center fuel tank to detect discrepancies, accomplishment of 
corrective actions, and installation of double Teflon sleeving over the 
wiring of the float switch. That NPRM would

[[Page 34844]]

have eliminated deactivation of the float switch as an option for 
complying with the existing AD, and would have required, for all 
affected airplanes, repetitive inspections of the float switch wiring 
to detect discrepancies, replacement of the float switch and wiring if 
necessary, and replacement of the double Teflon sleeving. For certain 
airplanes, that NPRM also would have added a new requirement for 
inspection and installation of partial double Teflon sleeving in a 
certain area. That NPRM was prompted by a report indicating that 
chafing of the direct current (DC) powered float switch wiring 
insulation in the center fuel tank occurred on several airplanes. That 
condition, if not corrected, could result in arcing from the wiring to 
the in-tank conduit, which could present an ignition source inside the 
fuel tank and result in consequent fire/explosion.
    In the preamble to AD 99-05-12, we stated that the actions required 
by that AD were considered ``interim action'' and that we were 
considering further rulemaking action. We have now determined that 
further rulemaking action is indeed necessary, and this supplemental 
NPRM follows from that determination.

Actions Since Issuance of Previous Proposal

    Since the issuance of that NPRM, the FAA has reviewed and approved 
Boeing Alert Service Bulletin 737-28A1141, Revision 1, dated December 
19, 2002. That service bulletin describes procedures for replacing the 
existing float switches with new, improved float switches and 
installing a conduit liner system in the center fuel tanks, and 
replacing the float switches and conduit assemblies with new, improved 
float switches and conduit assemblies in the wing fuel tanks. The new, 
improved float switches are more resistant to contamination by fuel or 
moisture, and the new conduit assemblies for the float switch eliminate 
sharp bends within the conduit and include a conduit liner system that 
provides added protection against chafing of the float switch wiring. 
For airplanes on which the float switch for the center fuel tank was 
deactivated previously, the service bulletin also contains procedures 
for removal of placards and stencils associated with that deactivation. 
Accomplishment of the actions specified in the service bulletin is 
intended to adequately address the identified unsafe condition.

Other Relevant Rulemaking

    We have previously issued AD 2002-26-18, amendment 39-13006 (68 FR 
481, January 6, 2003), which applies to Boeing Model 737-600, -700, -
700C, -800, and -900 series airplanes. That AD requires replacement of 
the existing fueling float switch and conduit assemblies in the main 
and center fuel tanks with new, improved assemblies. This supplemental 
NPRM would require similar actions for Model 737-200, -200C, -300, -
400, and -500 series airplanes.

Comments

    Due consideration has been given to the comments received in 
response to the original NPRM. Certain comments are no longer relevant 
because of the issuance of the service bulletin described previously. 
Certain other comments have revealed a need for clarification, as 
explained below.

Support for the Original NPRM

    Two commenters support the original NPRM.

Request To Provide Credit for Actions Accomplished Previously

    One commenter requests that a statement be added to the proposed AD 
to clarify that credit is given for accomplishment of the proposed 
initial inspection and replacement prior to the effective date of this 
AD.
    Though the FAA concurs with the commenter's intent, the FAA does 
not concur that any change to the supplemental NPRM is necessary. 
Credit for actions accomplished previously is given by means of the 
phrase in the ``Compliance'' section of the AD, ``Required as 
indicated, unless accomplished previously.''

Request To Provide for Airplanes Grounded for Extended Period

    One commenter requests that the original NPRM be revised ``to be 
written in such a manner [that] would not require inspecting airplanes 
[that] have been grounded for an extended period, until they are 
prepared for return to service.''
    The FAA points out that no change to the supplemental NPRM is 
necessary to meet the intent of the commenter's request. Part 39.3 of 
the Federal Aviation Regulations (14 CFR 39.3) states that, ``No person 
may operate a product to which an airworthiness directive applies 
except in accordance with the requirements of that airworthiness 
directive.'' This regulation provides relief for airplanes that are not 
being operated because affected airplanes need only be in compliance 
prior to their return to service.

Explanation of Change Made to Restatement of AD 99-05-12

    As explained in the original NPRM, paragraph (a) of this 
supplemental NPRM, which is restated from AD 99-05-12, states that the 
paragraph applies to Model 737-200, -300, -400, and -500 series 
airplanes having line numbers 1 through 3108 inclusive. Paragraph (a) 
of AD 99-05-12 did not specify the line numbers affected by that 
paragraph. The FAA has determined that airplanes having line numbers 
3109 and subsequent had double Teflon sleeving installed over the 
wiring of the float switch during production. Therefore, it is not 
necessary for operators of these airplanes to accomplish paragraph (a) 
of this supplemental NPRM.

Explanation of Applicability of Supplemental NPRM

    Boeing Model 737-200C series airplanes are not specifically 
identified in the applicability of the existing AD or the original 
NPRM. However, certain Model 737-200C series airplanes are included in 
the effectivity listings of Boeing Alert Service Bulletins 737-28A1132 
and 737-28A1141, and those airplanes are subject to the actions 
specified in those service bulletins. Therefore, for Model 737-200C 
series airplanes, we have added a new paragraph (f) to this 
supplemental NPRM to require accomplishment of the actions required by 
paragraph (b) or (c) of this AD prior to the accumulation of 30,000 
flight hours, or within 30 days after the effective date of this AD, 
whichever is later. If the actions specified in paragraph (b) or (c) of 
this AD have already been accomplished before the effective date of the 
AD, no further action would be required by paragraph (f) of this AD.
    Also, Model 737-100 series airplanes have been removed from the 
applicability statement of this supplemental NPRM. These airplanes are 
not affected by the proposed actions and were inadvertently included in 
the original NPRM.

Explanation of Additional Changes to Original NPRM

    We have changed all references to ``detailed visual inspection'' in 
the original NPRM to ``detailed inspection'' in this supplemental NPRM.

Conclusion

    Since certain changes described previously expand the scope of the 
originally proposed rule, we have determined that it is necessary to 
reopen the comment period to provide additional opportunity for public 
comment.

[[Page 34845]]

Explanation of Proposed Requirements of Supplemental NPRM

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, this 
supplemental NPRM proposes to supersede AD 99-05-12 to continue to 
require inspection of the fueling float switch wiring in the center 
fuel tank to detect discrepancies, accomplishment of corrective 
actions, and installation of double Teflon sleeving over the wiring of 
the float switch. The supplemental NPRM would require replacement of 
the float switches with new, improved float switches and installation 
of a conduit liner system in the center fuel tank, and replacement of 
the float switches and conduit assemblies with new, improved float 
switches and conduit assemblies in the wing fuel tanks. This 
replacement would terminate the requirements of the existing AD. The 
float switch replacements would be required to be done in accordance 
with Boeing Alert Service Bulletin 737-28A1141, Revision 1. For certain 
airplanes, the supplemental NPRM would require replacement of certain 
sections of conduit in the center fuel tank with new conduit, in 
accordance with Boeing Alert Service Bulletin 737-28A1132, Revision 2, 
dated June 17, 1999.

Cost Impact

    There are approximately 2,886 Model 737-200, -200C, -300, -400, and 
-500 series airplanes of the affected design in the worldwide fleet. 
The FAA estimates that 1,111 airplanes of U.S. registry would be 
affected by this supplemental NPRM.
    The removal and inspection of the fueling float switch in the 
center fuel tank and installation of double Teflon sleeving, which is 
provided as one alternative for compliance with AD 99-05-12, takes 
approximately 18 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Required parts cost approximately $30 
per airplane. Based on these figures, the cost impact of the removal 
and inspection of the float switch and installation of double Teflon 
sleeving, if accomplished, is estimated to be $1,110 per airplane.
    The deactivation of the float switch and installation of 
``Caution'' signs that are provided as the other alternative for 
compliance with AD 99-05-12, takes approximately 3 work hours per 
airplane to accomplish, at an average labor rate of $60 per work hour. 
Based on these figures, the cost impact of the deactivation and 
installation, if accomplished, is estimated to be $180 per airplane.
    The new replacement of float switches and installation of a conduit 
liner in the center fuel tank, and the replacement of float switches 
and conduit assemblies in the wing fuel tanks, that are proposed in 
this supplemental NPRM would take approximately 62 work hours per 
airplane to accomplish, at an average labor rate of $60 per work hour. 
Required parts would cost between $3,633 and $5,061 per airplane. Based 
on these figures, the cost impact of the proposed replacement is 
estimated to be between $7,353 and $8,781 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the proposed requirements 
of this AD action, and that no operator would accomplish those actions 
in the future if this AD were not adopted. The cost impact figures 
discussed in AD rulemaking actions represent only the time necessary to 
perform the specific actions actually required by the AD. These figures 
typically do not include incidental costs, such as the time required to 
gain access and close up, planning time, or time necessitated by other 
administrative actions.

Regulatory Impact

    The regulations proposed herein would not have a substantial direct 
effect on the States, on the relationship between the national 
Government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, 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. A copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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 39-11060 (64 FR 
10213, March 3, 1999), corrected at 64 FR 11533, March 9, 1999, and by 
adding a new airworthiness directive (AD), to read as follows:

BOEING: Docket 99-NM-78-AD. Supersedes AD 99-05-12, Amendment 39-
11060.

    Applicability: Model 737-200, -200C, -300, -400, and -500 series 
airplanes; on which the center wing tanks are activated; excluding 
those airplanes equipped with center wing tank volumetric topoff 
systems, or alternating current (AC) powered center tank float 
switches; 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 (k)(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 prevent contamination of the fueling float switch by moisture 
or fuel, and chafing of the float switch wiring against the fuel 
tank conduit, which could present an ignition source inside the fuel 
tank that could cause a fire or explosion, accomplish the following:

Requirements of AD 99-05-12:

Compliance Time for Initial Action

    (a) For Model 737-200, -300, -400, and --500 series airplanes 
having line numbers (L/N) 1 through 3108 inclusive: Prior to the 
accumulation of 30,000 total flight hours, or within 30 days after 
March 18, 1999 (the effective date of AD 99-05-12, amendment 39-
11060), whichever occurs later, accomplish the requirements of 
paragraph (b) or (c) of this AD.

[[Page 34846]]

Initial Inspection: Procedures

    (b) Remove the fueling float switch and wiring from the center 
fuel tank and perform a detailed inspection of the float switch 
wiring to detect discrepancies (i.e., evidence of electrical arcing, 
exposure of the copper conductor, presence or scent of fuel on the 
electrical wires, or worn insulation), in accordance with Part 1 of 
the Accomplishment Instructions of Boeing Alert Service Bulletin 
737-28A1132, dated December 2, 1998; Revision 1, dated January 15, 
1999; or Revision 2, dated June 17, 1999. After the effective date 
of this AD, only Revision 2 may be used. Pay particular attention to 
the wire bundle where it passes through the wing pylon vapor seals 
and under the wire bundle clamps.

    Note 2: For the purposes of this AD, a detailed inspection is 
defined as: ``An intensive visual examination of a specific 
structural area, system, installation, or assembly to detect damage, 
failure, or irregularity. Available lighting is normally 
supplemented with a direct source of good lighting at intensity 
deemed appropriate by the inspector. Inspection aids such as mirror, 
magnifying lenses, etc., may be used. Surface cleaning and elaborate 
access procedures may be required.''

Initial Inspection: Follow-On Actions

    (1) If no discrepancy is detected, prior to further flight, 
accomplish either paragraph (b)(1)(i) or (b)(1)(ii) of this AD.
    (i) Measure the resistance between the wires and the float 
switch housing, in accordance with Boeing Alert Service Bulletin 
737-28A1132, dated December 2, 1998; Revision 1, dated January 15, 
1999; or Revision 2, dated June 17, 1999.
    (A) If the resistance is less than 200 megohms, prior to further 
flight, replace the float switch and wiring with a new float switch 
and wiring, and install double Teflon sleeving over the wiring of 
the float switch, in accordance with Boeing Alert Service Bulletin 
737-28A1132, dated December 2, 1998; Revision 1, dated January 15, 
1999; or Revision 2, dated June 17, 1999; or replace the float 
switch and wiring with a new, improved float switch and wiring in 
accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 737-28A1141, Revision 1, dated December 19, 2002. 
After the effective date of this AD, only a new, improved float 
switch and wiring may be installed. If a replacement float switch 
and wiring are not available, prior to further flight, accomplish 
the requirements specified in paragraphs (c) and (d) of this AD.
    (B) If the resistance is greater than or equal to 200 megohms, 
prior to further flight, blow dirt out of the conduit, install 
double Teflon sleeving over the wiring of the float switch, and 
reinstall the existing float switch, in accordance with Boeing Alert 
Service Bulletin 737-28A1132, dated December 2, 1998; Revision 1, 
dated January 15, 1999; or Revision 2, dated June 17, 1999.
    (ii) Replace the float switch and wiring with a new float switch 
and wiring, and install double Teflon sleeving over the wiring of 
the float switch, in accordance with Boeing Alert Service Bulletin 
737-28A1132, dated December 2, 1998; Revision 1, dated January 15, 
1999; or Revision 2, dated June 17, 1999; or replace the float 
switch and wiring with a new, improved float switch and wiring in 
accordance with the Accomplishment Instructions of Boeing Alert 
Service Bulletin 737-28A1141, Revision 1, dated December 19, 2002. 
After the effective date of this AD, only a new, improved float 
switch and wiring may be installed. If a replacement float switch 
and wiring are not available, prior to further flight, accomplish 
the requirements specified in paragraphs (c) and (d) of this AD.
    (2) If any worn insulation is detected, and if no copper 
conductor is exposed, and if no evidence of arcing is detected; 
accomplish the requirements specified in either paragraph (b)(1)(i) 
or (b)(1)(ii) of this AD.
    (3) If any electrical arcing or exposed copper conductor is 
detected, prior to further flight, accomplish either paragraph 
(b)(3)(i) or (b)(3)(ii) of this AD.
    (i) Replace any section of the electrical conduit where the 
arcing occurred with a new section, in accordance with Boeing Alert 
Service Bulletin 737-28A1132, dated December 2, 1998; Revision 1, 
dated January 15, 1999; or Revision 2, dated June 17, 1999; and 
accomplish the requirements specified in paragraph (b)(1)(ii) of 
this AD.
    (ii) Perform a detailed inspection to detect fuel leaks of the 
electrical conduit, in accordance with Boeing Alert Service Bulletin 
737-28A1132, dated December 2, 1998; Revision 1, dated January 15, 
1999; or Revision 2, dated June 17, 1999.
    (A) If no fuel leak is detected, prior to further flight, 
accomplish the requirements specified in paragraph (b)(1)(ii) of 
this AD. Repeat the inspection required by paragraph (b)(3)(ii) of 
this AD thereafter at intervals not to exceed 1,500 flight hours, 
until the replacement required by paragraph (b)(3)(ii)(B) of this AD 
is accomplished.
    (B) If any fuel leak is detected, prior to further flight, 
replace, with new conduit, any section of the electrical conduit 
where a leak is found, in accordance with Boeing Alert Service 
Bulletin 737-28A1132, dated December 2, 1998; Revision 1, dated 
January 15, 1999; or Revision 2, dated June 17, 1999. Prior to 
further flight after accomplishment of the replacement, accomplish 
the requirements specified in paragraph (b)(1)(ii) of this AD. 
Accomplishment of electrical conduit replacement constitutes 
terminating action for the repetitive inspection requirements of 
paragraph (b)(3)(ii)(A) of this AD.
    (4) If any presence or scent of fuel on the electrical wires is 
detected, prior to further flight, locate the source of the leak and 
replace the damaged conduit with a new conduit, in accordance with 
the alert service bulletin; and accomplish the requirements 
specified in either paragraph (b)(1)(i) or (b)(1)(ii) of this AD, 
unless accomplished previously in accordance with paragraph (b)(1), 
(b)(2), or (b)(3) of this AD.

Deactivation of Float Switch

    (c) Accomplish the requirements specified in either paragraph 
(c)(1) or (c)(2) of this AD, in accordance with Part 2 of the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
28A1132, dated December 2, 1998; Revision 1, dated January 15, 1999; 
or Revision 2, dated June 17, 1999.
    (1) Deactivate the center tank float switch (i.e., cut the two 
wires for the float switch at the splices on the front spar and cap 
and stow the four wire ends), paint a ``Caution'' sign that shows a 
conservative maximum fuel capacity for the center tank on the 
underside of the right-hand wing near the fueling station door, and 
install an INOP placard on the fueling panel.
    (2) Deactivate the center tank float switch (i.e., cut, stow, 
and splice the two wires for the float switch at the splices on the 
front spar), and paint a ``Caution'' sign that shows a conservative 
maximum fuel capacity for the center tank on the underside of the 
right-hand wing near the fueling station door.

Deactivation of Float Switch: Additional Requirements

    (d) For airplanes on which the requirements specified in 
paragraph (c) of this AD have been accomplished: Accomplish the 
requirements specified in paragraphs (d)(1), (d)(2), and (d)(3) of 
this AD.
    (1) Operators must ensure that airplane fueling crews are 
properly trained in accordance with the procedures specified in 
Boeing Telex M-7200-98-04486, dated December 1, 1998, or procedures 
approved by the FAA. This one-time training must be accomplished 
prior to utilizing the procedures specified in paragraph (d)(3) of 
this AD.
    (2) Prior to fueling the airplane, perform a check to verify 
that the fueling panel center tank quantity indicator is operative. 
Repeat this check thereafter prior to fueling the airplane. If the 
fueling panel center tank quantity indicator is not operative, prior 
to further flight, replace the fueling panel center tank quantity 
indicator with a serviceable part.
    (3) One of the two manual fueling procedures for the center fuel 
tank must be used for each fueling occurrence, in accordance with 
Boeing Telex M-7200-98-04486, dated December 1, 1998, or a method 
approved by the FAA.

    Note 3: For the purposes of this AD, the term ``the FAA,'' is 
defined in paragraph (d) of this AD as ``the cognizant Principal 
Maintenance Inspector (PMI).''


    Note 4: Where there are differences between Boeing Alert Service 
Bulletin 737-28A1132 and this AD, the AD prevails.

Deactivation of Float Switch: Dispatch

    (e) Dispatch with the center fuel tank float switch deactivated, 
in accordance with Boeing Alert Service Bulletin 737-28A1132, dated 
December 2, 1998; Revision 1, dated January 15, 1999; or Revision 2, 
dated June 17, 1999; is allowed until replacement float switches and 
wiring are available for installation or until the compliance time 
for the replacement required by paragraph (h) of this AD. Where 
there are differences between the Master Minimum Equipment List 
(MMEL) and the AD, the AD prevails.

[[Page 34847]]

New Requirements of this AD

Compliance Time for Initial Action for Model 737-200C Series Airplanes

    (f) For Model 737-200C series airplanes having L/Ns 1 through 
3108 inclusive: Prior to the accumulation of 30,000 total flight 
hours, or within 30 days after the effective date of this AD, 
whichever occurs later, accomplish the requirements of paragraph (b) 
or (c) of this AD. (If the actions specified in paragraph (b) or (c) 
of this AD have been accomplished before the effective date of this 
AD, no further action is required by this paragraph.) If the actions 
required by paragraph (h) of this AD are accomplished within the 
compliance time specified in this paragraph, operators are not 
required to do paragraph (b) or (c) of this AD.

Replacement of Conduit

    (g) For airplanes having L/Ns 1 through 3108 inclusive, on which 
the inspection required by paragraph (b)(3)(ii) of this AD has been 
accomplished prior to the effective date of this AD, and on which 
replacement of conduit specified in paragraph (b)(3)(ii)(B) has NOT 
been accomplished: Within 1,500 flight hours or 6 months after the 
effective date of this AD, whichever occurs first, replace, with new 
conduit, any section of the electrical conduit where arcing or a 
leak occurred, in accordance with the Accomplishment Instructions of 
Boeing Alert Service Bulletin 737-28A1132, Revision 2, dated June 
17, 1999. Such replacement of the conduit constitutes terminating 
action for the repetitive inspection requirements of paragraph 
(b)(3)(ii)(A) of this AD.

Replacement of Center and Wing Tank Float Switches

    (h) Within 2 years after the effective date of this AD, 
accomplish paragraphs (h)(1) and (h)(2) of this AD, as applicable. 
Except as provided by paragraph (j) of this AD, accomplishment of 
the actions in paragraphs (h)(1) and (h)(2) of this AD, as 
applicable, terminates the requirements of this AD.
    (1) For all airplanes: In the center fuel tank, replace the 
existing float switches with new, improved float switches, and 
install a conduit liner system; and in the wing fuel tanks, replace 
the existing float switches and conduit assemblies with new, 
improved float switches and conduit assemblies that include a liner 
system inside the conduit. Do these replacements in accordance with 
the Accomplishment Instructions of Boeing Alert Service Bulletin 
737-28A1141, Revision 1, dated December 19, 2002.
    (2) For airplanes subject to the repetitive inspections required 
by paragraph (b)(3)(ii)(A) of this AD, on which the electrical 
conduit in the center fuel tank has not been replaced as specified 
in paragraph (b)(3)(ii)(B) or (g) of this AD: Prior to or 
concurrently with the replacement of the float switch in the center 
fuel tank required by paragraph (h)(1) of this AD, replace, with new 
conduit, any section of the center fuel tank electrical conduit 
where arcing or a leak occurred, in accordance with the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
28A1132, Revision 2, dated June 17, 1999. Such replacement 
constitutes terminating action for the repetitive inspection 
requirements of paragraph (b)(3)(ii)(A) of this AD.

Credit for Previously Accomplished Actions

    (i) Replacement of float switches and conduit assemblies, and 
installations of conduit liner systems, as applicable, accomplished 
before the effective date of this AD in accordance with Boeing Alert 
Service Bulletin 737-28A1141, dated September 5, 2002, are 
considered acceptable for compliance with the corresponding action 
specified in this AD.

Parts Installation

    (j) As of the effective date of this AD, no person may install a 
float switch having part number F8300-146 on any airplane.

Alternative Method of Compliance

    (k)(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 Aircraft Certification 
Office (ACO), FAA. 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.
    (2) Alternative methods of compliance, approved previously in 
accordance with AD 99-05-12, amendment 39-11060, are approved as 
alternative methods of compliance with the corresponding 
requirements of this AD.

    Note 5: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permits

    (l) 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.

    Issued in Renton, Washington, on June 5, 2003.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-14666 Filed 6-10-03; 8:45 am]
BILLING CODE 4910-13-P