97-2854. Airworthiness Directives; Boeing Model 747 and 757 Series Airplanes  

  • [Federal Register Volume 62, Number 26 (Friday, February 7, 1997)]
    [Rules and Regulations]
    [Pages 5748-5752]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 97-2854]
    
    
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    DEPARTMENT OF TRANSPORTATION
    14 CFR Part 39
    
    [Docket No. 96-NM-57-AD; Amendment 39-9922; AD 97-03-17]
    RIN 2120-AA64
    
    
    Airworthiness Directives; Boeing Model 747 and 757 Series 
    Airplanes
    
    AGENCY: Federal Aviation Administration, DOT.
    
    ACTION: Final rule.
    
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    SUMMARY: This amendment adopts a new airworthiness directive (AD), 
    applicable to all Boeing Model 747 and 757 series airplanes, that 
    requires repetitive visual inspections to detect discrepancies of the 
    wire terminal assembly, electrical connector, and wire insulation on 
    the fuel pump; and replacement of the fuel pump with a new fuel pump, 
    if necessary. This amendment also requires repetitive insulation 
    resistance tests of the fuel pump wiring. This amendment is prompted by 
    reports of fuel leaks at the fuel boost and override/jettison pumps due 
    to corrosion. The actions specified by this AD are intended to prevent 
    such a fuel leakage, which could result in a fire at the location of 
    the affected fuel pump.
    
    DATES: Effective March 14, 1997.
        The incorporation by reference of certain publications listed in 
    the regulations is approved by the Director of the Federal Register as 
    of March 14, 1997.
    
    ADDRESSES: 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 Federal 
    Aviation Administration (FAA), Transport Airplane Directorate, Rules 
    Docket, 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: G. Michael Collins, Aerospace 
    Engineer, Seattle Aircraft Certification Office, Propulsion Branch, 
    ANM-140S, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., 
    Renton, Washington 98055-4056; telephone (206) 227-2689; fax (206) 227-
    1181.
    
    SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
    Aviation Regulations (14 CFR part 39) to include an airworthiness 
    directive (AD) that is applicable to all Boeing Model 747 and 757 
    series airplanes was published in the Federal Register on August 14, 
    1996 (61 FR 42195). That action proposed to require a visual inspection 
    to detect discrepancies of the wire terminal assembly, electrical 
    connector, and wire insulation on the fuel pump; and replacement of the 
    fuel pump with a new fuel pump, if necessary. That action also proposed 
    to require repetitive insulation resistance tests of the fuel pump 
    wiring.
        Interested persons have been afforded an opportunity to participate 
    in the making of this amendment. Due consideration has been given to 
    the comments received.
    
    Support for the Proposal
    
        One commenter supports the proposed AD.
    
    Request To Allow Credit for Use of Previous Versions of Service 
    Bulletins
    
        Several commenters request that the proposal be revised to provide 
    credit to those operators who have already initiated the inspections in 
    accordance with the original versions of Boeing Service Bulletins 747-
    28A2194 and 757 28A0043. One of these commenters, states that Revision 
    1 of both of these service bulletins, which are referenced in the 
    proposal, contain essentially the same inspection and test procedures 
    of the subject fuel pumps as is contained the original versions.
        The FAA concurs partially with the commenters' request:
        The FAA finds that both the original version and Revision 1 of 
    Boeing Service Bulletin 757 28A0043, which is applicable to Model 757 
    series airplanes, contain essentially identical inspection procedures. 
    Therefore, operators of those airplanes will be given credit for any 
    inspections conducted in accordance with the original version of the 
    service bulletin accomplished prior to the effective date of this AD. 
    The final rule has been revised to indicate this.
        However, the FAA finds that Revision 1 of Boeing Service Bulletin 
    747-28A2194, which is applicable to Model 747 series airplanes, is 
    substantively different from the original version, in that Revision 1 
    adds a continuity check of the pin 4 bonding strap internal to the pump 
    (the pump ground wire). Although the manufacturer asserts that this 
    continuity check ``does not affect the result of the key insulation 
    resistance test which determines the condition of the pump connector,'' 
    the FAA maintains that the continuity check is an important step, 
    without which the resistance test cannot be considered adequate. 
    Therefore, operators who previously have performed the resistance tests 
    in accordance with the original version of that service bulletin will 
    not be granted credit for those tests as compliance with the applicable 
    requirements of this AD.
    
    Request To Clarify Applicability of Requirements to New Airplanes
    
        One commenter requests that the proposal be revised to clarify what 
    inspection actions would be required of new airplanes that are 
    delivered after the effective date of the AD. The commenter states that 
    the proposal is not clear whether the AD applies to these new airplanes 
    or not, and, if it does apply, when the first inspection is required.
        The FAA does not consider that any further clarification of the 
    applicability of the AD is necessary. The applicability statement of 
    the AD clearly indicates that it is applicable to ``all Model 747 and 
    757 airplanes.'' This includes airplanes delivered now or in the 
    future; it is not limited to any range of existing airplanes. Since the 
    configuration of the subject area on all of these airplanes, from the 
    earliest manufactured to the most recent, is similar, all are subject 
    to the unsafe condition addressed by this AD.
        To clarify the commenter's concern as to when the first inspection 
    of new airplanes is required, the FAA points out that any airplane that 
    is manufactured and/or delivered after 120 days after the effective 
    date of this AD, will have to be inspected in accordance with the AD 
    prior to its delivery, as required by the Federal Aviation Regulations 
    (FAR). The AD stipulates in its compliance provisions that the actions 
    are required at the time specified in the AD, ``unless [those actions 
    have been] accomplished previously.'' The inspection of the pumps that 
    is conducted previous to the delivery of the new airplanes is 
    considered to be the initial inspection required by the AD.
    
    Request To Extend Compliance Time for Initial Inspection
    
        Several commenters request that the proposal be revised to extend 
    the proposed compliance time of 120 days for the initial inspection to 
    as much as 9 months. Most of these commenters are airline operators, 
    and request the extension in order to accommodate the inspection during 
    their regular maintenance schedules. One of these
    
    [[Page 5749]]
    
    commenters requests that the initial inspection interval be based on 
    how many hours have accumulated on the affected fuel pump. Another 
    commenter requests that the compliance time be stated as ``the 
    operator's next `C'-check'' for new airplanes delivered after the 
    effective date of the AD. Several commenters request an extension 
    because they are concerned that an ample number of spare fuel pumps 
    will not be available to support the affected fleet, should it be 
    necessary to replace all pumps within the proposed 120-day compliance 
    period.
        The FAA does not concur with the commenters' requests to extend the 
    compliance time. In developing an appropriate compliance time for this 
    action, the FAA considered not only the degree of urgency associated 
    with addressing the subject unsafe condition, but the availability of 
    necessary parts and the practical aspect of conducting the required 
    inspections within an interval of time that parallels normal scheduled 
    maintenance for the majority of affected operators. The FAA also took 
    into account the manufacturer's recommendation (specified in the 
    referenced Boeing service bulletin) that the first inspection to be 
    conducted ``at the next maintenance time when manpower and equipment 
    are available.'' The FAA finds that, for the majority of affected 
    operators, some scheduled maintenance will occur within the 120-day 
    compliance period.
        As for the commenters' concern that the availability of an ample 
    number of replacement parts will be a problem, the FAA has received no 
    indication to substantiate that parts will not be available during the 
    compliance period. The FAA has been advised that there is a 60-day 
    turnaround time for ordering retrofit pumps from at least one vendor; 
    this should provide enough time for operators to obtain parts within 
    the 120-day compliance time for the initial inspection.
        In light of these factors, the FAA finds no technical justification 
    for delaying the initiation of inspections any further. The FAA has 
    determined that the 120-day compliance time for accomplishing the 
    initial inspection is not only appropriate, but warranted.
    
    Request To Extend Repetitive Inspection Intervals
    
        Several commenters request that the proposal be revised to extend 
    the intervals for repetitive visual inspections of the pumps from the 
    proposed ``5,000 hours or 18 months, whichever occurs first.'' Some 
    commenters request that the interval be specified as ``every `C'-
    check;'' others request that it be ``every 8,000 flight hours.'' The 
    commenters indicate that such extensions would allow the inspections to 
    be conducted during regularly scheduled maintenance intervals. One 
    commenter requests that the repetitive inspection interval be extended 
    for airplanes equipped with permanently mounted fuel vapor sensors that 
    can detect leaked fuel and fuel vapor in the vicinity of the pump.
        The FAA does not concur with the commenters' requests to extend the 
    repetitive inspection interval. Based on the fact that the subject 
    problem is associated with corrosion, the FAA considers that a 5,000 
    flight hour/18-month interval represents the maximum time allowable for 
    the affected airplanes to continue to operate prior to accomplishing 
    the required inspections without compromising safety. Since maintenance 
    schedules may vary from operator to operator, there would be no 
    assurance that the inspection (and any necessary replacement) would be 
    accomplished during that maximum interval. Therefore, to specify the 
    interval as a ``C''-check would not be appropriate.
        The FAA cannot concur with the commenter who requested an extension 
    if a permanently mounted fuel vapor sensor is installed, since the 
    device has not been approved by the FAA for use in the affected 
    airplanes for the specific purpose of detecting fuel leaks near a fuel 
    booster pump. Since the certification process for approval of such a 
    device may take many months, the FAA considers that, for the time 
    being, revising the requirements of the AD in relation to the use of 
    such a device is not appropriate.
    
    Request To Specify Flight Hours in Compliance Time Intervals
    
        One commenter requests that the proposal be revised to indicate 
    that the various inspections and tests are required to be performed at 
    intervals stated in terms of ``flight hours.'' The proposal stated 
    these compliance times in terms of ``hours.''
        The FAA concurs, since this was the intent of those requirements. 
    (The word ``flight'' was inadvertently omitted from the published 
    version of the proposal.) The final rule has been corrected to indicate 
    that the initial inspection is to be repeated at intervals not to 
    exceed 5,000 flight hours or 18 months, whichever occurs first; and the 
    insulation resistance test is to be repeated at intervals not to exceed 
    500 flight hours.
    
    Request To Allow Replacement With Other Than ``New'' Fuel Pumps
    
        Several commenters request that the proposal be revised to allow 
    the installation of other than ``new'' fuel pumps whenever replacement 
    of the pump is required. These commenters point out that the reference 
    to ``new'' fuel pump in the provisions of the proposed AD literally 
    excludes the use of a refurbished or overhauled pump. Since both an 
    overhauled and a new pump are airworthy, the commenters request that 
    either be allowed to be installed as replacement parts. Another 
    commenter points out that the use of the word ``new'' may create the 
    misunderstanding that a replacement pump must be a ``new model'' or a 
    later configuration.
        The FAA concurs with the commenters' request, and has revised the 
    provisions in the final rule to indicate that discrepant fuel pumps 
    must be replaced with ``new or serviceable'' pumps.
    
    Request To Delete Resistance Test on Replacement Pumps
    
        Several commenters request that the proposal be revised to delete 
    the requirement to perform an insulation resistance test of the fuel 
    pump wiring after a fuel pump is replaced. The commenters maintain that 
    the insulation resistance test provided in the Component Maintenance 
    Manual (CMM) is more stringent than that provided in the referenced 
    Boeing service bulletins. Several of these commenters (both U.S. and 
    non-U.S. operators) state that all of the spare pumps in their 
    inventories must pass an insulation resistance test in accordance with 
    the CMM before they are put on the shelf. The commenters assert that, 
    to require another resistance test immediately after a spare is 
    installed as a replacement pump, is needlessly redundant.
        The FAA does not concur with the commenters' request. While some 
    operators may be conducting the resistance tests on the spares in their 
    inventory, the FAA has no assurance that all operators are doing so. 
    The FAA cannot assume that all operators, worldwide, are following such 
    procedures. Further, the FAA has determined that the resistance test 
    procedures described in the referenced Boeing service bulletins are 
    both adequate and appropriate for detecting the sort of reduced 
    resistance that would pose safety concerns. In light of these factors, 
    the FAA finds no reason to delete the requirement for a
    
    [[Page 5750]]
    
    resistance test of replaced fuel pumps prior to flight.
    
    Request To Allow Continued Flight if Replacement Pump is 
    Unavailable
    
        One commenter requests that paragraph (a)(1)(i) of the proposal be 
    revised to allow continued flight if the resistance measurement is less 
    than or equal to 1 megohms and a new unit is not available. The 
    proposal would require that the fuel pump be replaced prior to further 
    flight. This commenter suggests that a pump that fails the insulation 
    resistance test could be deactivated and the airplane be allowed to 
    continue in service in accordance with the Minimum Equipment List (MEL) 
    under the guidelines contained in sections 2-28-22-1 and 2-28-22-2 of 
    the Boeing Dispatch Deviation Guide, Document D630N002. The failed pump 
    should then be replaced as soon as a new unit is available.
        The FAA does not concur with the commenter's request. The actions 
    specified by this AD are intended to prevent fuel leakage in the area 
    of the fuel boost and override pumps; such leakage could result in a 
    fire at the location of the affected fuel pump. Based on the safety 
    implications associated with this unsafe condition, the FAA has 
    determined that, if a pump is found to be defective during the 
    inspections required by this AD, that pump must be replaced and the 
    airplane must not continue to operate until the pump is replaced. The 
    FAA finds no technical justification to permit further flight without 
    an operative pump. Where there are differences between an AD and an 
    MEL, the AD prevails.
        Further, as indicated earlier, the FAA is not aware of any problem 
    regarding obtaining replacement pumps as needed to comply with this AD. 
    If operators are concerned about the availability of replacement parts, 
    they should schedule the required inspections so that another pump is 
    always available if needed for replacement.
    
    Request To Clarify Need for Fuel Pump Ground Continuity Check
    
        One commenter requests clarification as to whether a continuity 
    check of the fuel pump ground wire is required as part of the 
    insulation resistance test. The commenter does not consider the 
    proposal to be clear on this.
        The FAA considers that the requirement to conduct the continuity 
    check was implicit in the proposal. The procedures for conducting the 
    continuity check are clearly iterated in the same paragraph of the 
    Accomplishment Instructions (of both Boeing service bulletins 
    referenced in the proposal) as the procedures for the insulation 
    resistance test. Since the continuity check of the ground wire is 
    unquestionably a part of the required resistance test, it is required 
    to be conducted for compliance with this AD. (As stated previously, the 
    FAA considers the check to be an important step, without which the 
    resistance test cannot be considered adequate.) To make this eminently 
    clear to operators, however, the FAA has added NOTE 3 to paragraph (a) 
    of the final rule to indicate that the continuity check of the pump 
    ground wire is part of the insulation resistance test.
    
    Request To Revise Criteria of Insulation Resistance Test
    
        One commenter requests that paragraphs (a)(1)(ii), (a)(1)(iii), 
    (a)(2)(ii), and (a)(2)(iii) be revised to specify that ``all'' 
    resistance measurements must be greater than the indicated value in 
    order to allow the continuation of inspections (rather than replacement 
    of the fuel pump). There are three resistances to be measured, one per 
    power pin, and all of them should register between 1 and 5 megohms or 
    more than 5 megohms to be considered acceptable for remaining on the 
    airplane. However, the wording in the proposal states that inspections 
    are to be repeated if ``any'' resistance measurement is greater than 
    the specific value; this implies that only one of the three power pins 
    must meet this resistance requirement. The referenced service bulletin 
    instructions specify that ``all`` of the pins should meet the 
    requirement.
        The FAA concurs that revision is necessary. It was the intent of 
    the FAA to make the requirements of the AD as parallel as possible to 
    the instructions and recommendations of the manufacturer's reference 
    service bulletin. The final rule has been revised accordingly.
    
    Request To Allow Use of Alternative Equipment for Testing
    
        One commenter requests that the proposal be revised to indicate 
    that use of testing equipment, other than that specified in the 
    referenced Boeing service bulletins, is permitted when accomplishing 
    the required inspections. The commenter first points out that the 
    AVTRON Model T477W bonding meter called out in the Accomplishment 
    Instructions of Boeing Service Bulletin 757-28A0043, Revision 1, does 
    not measure the full range of acceptable resistance values (10 megohms 
    or less). The commenter requests that use of this meter not be 
    required. Additionally, the commenter states that it is nearly 
    impossible to accomplish the resistance checks by pressing the meter 
    probes against the electrical contacts of the motor. To facilitate 
    obtaining these measurements, the commenter recommends, instead, the 
    use of a break-out box with a connector that mates to the pump; the 
    commenter has used this method successfully on eight airplanes in its 
    fleet. The commenter also states that other options are available, such 
    as adapter leads for meter probes, and the proposal should reference 
    these.
        The FAA does not consider that a revision to the requirements of 
    the AD is necessary. As for use of the AVTRON bonding meter, Boeing has 
    reiterated to the FAA that this ohmmeter is perfectly appropriate for 
    measuring low resistances, and is currently the only ohmmeter that can 
    be used in areas where there is the potential existence of flammable 
    fluids. As for the use of a break-out box or other equipment not 
    specified in the referenced Boeing service bulletins, the FAA cannot 
    comment without further data. However, under the provisions of 
    paragraph (c) of the final rule, the FAA may approve requests for use 
    of alternative methods of compliance if data are submitted to 
    substantiate that such methods would provide an acceptable level of 
    safety.
    
    Request for Terminating Action
    
        Two commenters request that the proposed rule be revised to include 
    terminating action for the repetitive inspections.
        The FAA cannot concur with these commenters, since a terminating 
    action does not currently exist. The addressed unsafe condition is 
    related to the problems associated with corrosion that occurs in the 
    fuel pump assembly; unless the materials of the components themselves 
    are changed to more corrosion-resistant materials, or unless the design 
    of the assembly itself is totally reconfigured, there likely will be no 
    terminating action in the very near future. However, via the reporting 
    requirement included in this AD, the FAA will continue to monitor the 
    on-going condition of this area within the fleet. If conditions 
    warrant, the FAA may consider additional rulemaking action to ensure 
    further improvements of the pump assembly.
    
    Request for Extension of Reporting Requirement
    
        Two commenters request that paragraph (b) of the proposal be 
    revised to extend the time for submitting the initial inspection 
    results from the proposed 10 days to 30 days.These commenters indicate 
    that, due to the sheer volume of data required,
    
    [[Page 5751]]
    
    especially of operators with large fleets, additional time will be 
    needed to prepare a complete and comprehensive report of findings.
        The FAA concurs and has revised paragraph (b) of the final rule 
    accordingly.
        The FAA has also revised paragraph (b) to indicate that operators 
    who already accomplished the initial inspection prior to the effective 
    date of the AD should submit the report within 30 days after the 
    effective date.
    
    Request To Specify Additional Service Information
    
        Crane Company, Hydro-Aire Division, which the manufacturer of the 
    fuel boost and override pumps, requests that the proposal be revised to 
    cite Crane's Service Information Letter (SIL) 989-9-8, dated July 22, 
    1996, as an additional source of appropriate service instructions. This 
    commenter states that the SIL provides detailed instructions regarding 
    replacement of the connectors that exhibit resistance lower than the 
    acceptable limits specified in the referenced Boeing service bulletins.
        The FAA does not concur. The SIL provides instructions for 
    repairing existing fuel pumps that require the replacement of 
    electrical connectors. This information could be used for pump repair, 
    but the FAA does not consider it necessary for accomplishing the 
    actions required by this AD. The FAA finds that the information 
    contained in the reference Boeing service bulletins is sufficient for 
    conducting those actions properly.
    
    Conclusion
    
        After careful review of the available data, including the comments 
    noted above, the FAA has determined that air safety and the public 
    interest require the adoption of the rule with the changes previously 
    described. The FAA has determined that these changes will neither 
    increase the economic burden on any operator nor increase the scope of 
    the AD.
    
    Cost Impact
    
        There are approximately 1,084 Model 747 series airplanes and 716 
    Model 757 series airplanes of the affected design in the worldwide 
    fleet. Of these airplanes, 242 Model 747 series airplanes and 462 Model 
    757 series airplanes are of U.S. registry and will be affected by this 
    AD.
        For the 242 Model 747 series airplanes, it will take approximately 
    18 work hours per airplane to accomplish the required actions, at an 
    average labor rate of $60 per work hour. Based on these figures, the 
    cost impact of the AD on U.S. operators of Model 747 series airplanes 
    is estimated to be $261,360, or $1,080 per airplane.
        For the 462 Model 757 series airplanes, it will take approximately 
    12 work hours per airplane to accomplish the required actions, at an 
    average labor rate of $60 per work hour. Based on these figures, the 
    cost impact of the AD on U.S. operators of Model 757 series airplanes 
    is estimated to be $332,640, or $720 per airplane.
        The cost impact figures discussed above are based on assumptions 
    that no operator has yet accomplished any of the requirements of this 
    AD action, and that no operator would accomplish those actions in the 
    future if this AD were not adopted.
    
    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.
        For the reasons discussed above, I certify that this action (1) is 
    not a ``significant regulatory action'' under Executive Order 12866; 
    (2) is not a ``significant rule'' under DOT Regulatory Policies and 
    Procedures (44 FR 11034, February 26, 1979); and (3) will not have a 
    significant economic impact, positive or negative, on a substantial 
    number of small entities under the criteria of the Regulatory 
    Flexibility Act. A final evaluation has been prepared for this action 
    and it is contained in the Rules Docket. A copy of it 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:
    
    97-03-17  Boeing: Amendment 39-9922. Docket 96-NM-57-AD.
    
        Applicability: All Model 747 and 757 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 (c) 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 fuel leakage at the fuel boost and override/jettison 
    pumps, which could result in a fire at the location of the affected 
    fuel pump, accomplish the following:
        (a) Within 120 days after the effective date of this AD, perform 
    a visual inspection to detect discrepancies (i.e., fuel leak, heat 
    discoloration, and damage) of the wire terminal assembly, electrical 
    connector, and wire insulation on the fuel pump, in accordance with 
    Boeing Service Bulletin 747-28A2194, Revision 1, dated January 18, 
    1996 (for Model 747 series airplanes), or Boeing Service Bulletin 
    757-28A0043, Revision 1, dated January 18, 1996 (for Model 757 
    series airplanes), as applicable.
    
        Note 2: Inspections accomplished prior to the effective date of 
    this AD in accordance with Boeing Service Bulletin 757-280043, dated 
    November 7, 1995, are considered acceptable for compliance with the 
    requirements of this paragraph.
    
        (1) If no discrepancy is detected, prior to further flight, 
    perform an insulation resistance test of the fuel pump wiring, in 
    accordance with the Accomplishment Instructions of the applicable 
    service bulletin.
    
        Note 3: Each insulation resistance test of the fuel pump wiring 
    includes a continuity check of the fuel pump ground wire, as 
    specifically indicated in the Accomplishment Instructions of the 
    applicable Boeing service bulletin(s).
    
        (i) If any resistance measurement is less than or equal to 1 
    megohms, prior to further flight, replace the fuel pump with a new 
    or serviceable fuel pump, in accordance with the applicable service 
    bulletin. Prior to further flight following accomplishment of the 
    replacement, repeat the insulation resistance test.
        (ii) If all resistance measurements are greater than 1 megohm, 
    but one or more are less than 5 megohms: Repeat the visual 
    inspection and insulation resistance test within 500 flight hours, 
    or replace the fuel
    
    [[Page 5752]]
    
    pump with a new or serviceable fuel pump. Prior to further flight 
    following accomplishment of the replacement, repeat the insulation 
    resistance test.
        (iii) If all resistance measurements are greater than or equal 
    to 5 megohms, repeat the visual inspection and insulation resistance 
    test within 5,000 flight hours or 18 months, whichever occur first.
        (2) If any discrepancy is detected, prior to further flight, 
    replace the fuel pump with a new or serviceable fuel pump, in 
    accordance with the applicable service bulletin. Prior to further 
    flight following accomplishment of the replacement, perform an 
    insulation resistance test of the fuel pump wiring, in accordance 
    with the Accomplishment Instructions of the applicable service 
    bulletin.
        (i) If any resistance measurement is less than or equal to 1 
    megohms, prior to further flight, replace the fuel pump with a new 
    or serviceable fuel pump, in accordance with the applicable service 
    bulletin. Prior to further flight following accomplishment of the 
    replacement, repeat the insulation resistance test.
        (ii) If all resistance measurements are greater than 1 megohm, 
    but one or more are less than 5 megohms: Repeat the visual 
    inspection and insulation resistance test within 500 flight hours, 
    or replace the fuel pump with a new or serviceable fuel pump. Prior 
    to further flight following accomplishment of the replacement, 
    repeat the insulation resistance test.
        (iii) If all resistance measurements are greater than or equal 
    to 5 megohms, repeat the visual inspection and insulation resistance 
    test within 5,000 flight hours or 18 months, whichever occur first.
        (b) Within 30 days after accomplishing the initial visual 
    inspection required by paragraph (a) of this AD, or within 30 days 
    after the effective date of this AD, whichever is later, submit a 
    report of the inspection results (both positive and negative 
    findings) to the Manager, Seattle Aircraft Certification Office 
    (ACO), 1601 Lind Avenue, SW., Renton, Washington 98055-4056; 
    telephone (206) 227-2180; fax (206) 227-1181. 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.
        (c) 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, Transport Airplane Directorate. 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.
    
        Note 4: Information concerning the existence of approved 
    alternative methods of compliance with this AD, if any, may be 
    obtained from the Seattle ACO.
    
        (d) 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.
        (e) Except as specified in NOTE 2 of this AD, the actions shall 
    be done in accordance with Boeing Service Bulletin 747-28A2194, 
    Revision 1, dated January 18, 1996 (for Model 747 series airplanes); 
    or Boeing Service Bulletin 757-28A0043, Revision 1, dated January 
    18, 1996 (for Model 757 series airplanes); as applicable. 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.
        (f) This amendment becomes effective on March 14, 1997.
    
        Issued in Renton, Washington, on January 30, 1997.
    Darrell M. Pederson,
    Acting Manager, Transport Airplane Directorate, Aircraft Certification 
    Service.
    [FR Doc. 97-2854 Filed 2-6-97; 8:45 am]
    BILLING CODE 4910-13-P
    
    
    

Document Information

Effective Date:
3/14/1997
Published:
02/07/1997
Department:
Transportation Department
Entry Type:
Rule
Action:
Final rule.
Document Number:
97-2854
Dates:
Effective March 14, 1997.
Pages:
5748-5752 (5 pages)
Docket Numbers:
Docket No. 96-NM-57-AD, Amendment 39-9922, AD 97-03-17
RINs:
2120-AA64: Airworthiness Directives
RIN Links:
https://www.federalregister.gov/regulations/2120-AA64/airworthiness-directives
PDF File:
97-2854.pdf
CFR: (1)
14 CFR 39.13