99-29329. Airworthiness Directives; Boeing Model 727-200 Series Airplanes  

  • [Federal Register Volume 64, Number 218 (Friday, November 12, 1999)]
    [Rules and Regulations]
    [Pages 61487-61491]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 99-29329]
    
    
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    DEPARTMENT OF TRANSPORTATION
    
    Federal Aviation Administration
    
    14 CFR Part 39
    
    [Docket No. 97-NM-227-AD; Amendment 39-11409; AD 99-23-13]
    RIN 2120-AA64
    
    
    Airworthiness Directives; Boeing Model 727-200 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 727-200 series airplanes, that requires 
    repetitive inspections to detect cracks in certain areas between the 
    upper and lower sills of the number 1 cargo door, and repair, if 
    necessary. This amendment is prompted by reports indicating that 
    fatigue cracks were found in certain structures adjacent to the number 
    1 cargo door cutout at the forward and aft doorway frames. The actions 
    specified by this AD are intended to detect and correct such fatigue 
    cracking, which could result in rapid decompression of the fuselage and 
    consequent reduced structural integrity of the airplane.
    
    DATES: Effective December 17, 1999.
        The incorporation by reference of certain publications listed in 
    the regulations is approved by the Director of the Federal Register as 
    of December 17, 1999.
    
    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: Walter Sippel, Aerospace Engineer, 
    Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle 
    Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
    Washington 98055-4056; telephone (425) 227-2774; fax (425) 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 727-200 series 
    airplanes was published in the Federal Register on July 15, 1998 (63 FR 
    38123). That action proposed to require repetitive inspections to 
    detect cracks in certain areas between the upper and lower sills of the 
    number 1 cargo door, and repair, if necessary.
    
    Explanation of Changes Made to the Proposal
    
        The FAA has revised this final rule to clarify the inspection 
    requirement contained in the proposed AD. Whereas the proposal 
    specified a close visual inspection, as recommended in Boeing Service 
    Bulletin 727-53A0219, Revision 1, dated May 8, 1997, the FAA has 
    revised this final rule to clarify that its intent is to require a 
    detailed visual inspection. Additionally, a note has been added to the 
    final rule to define that inspection.
        In addition, in the notice of proposed rulemaking (NPRM), the FAA 
    stated that this AD is considered interim action until final action is 
    identified, at which time the FAA may consider further rulemaking. 
    Since the issuance of the NPRM, the FAA has determined that no further 
    action is required at this time. No modification to address the unsafe 
    condition is currently available, and the FAA finds that the 
    inspections required by this AD are adequate for continued safe 
    operation.
        Also, throughout the proposed rule, the FAA referred to Boeing 
    Service Bulletin 727-53A0219, Revision 1, as an ``alert'' service 
    bulletin. The reference to this service bulletin as an alert is 
    erroneous. The original issue of the service bulletin is considered an 
    alert service bulletin; however, the FAA does not consider Revision 1 
    an alert. Therefore, this final rule refers to Boeing Service Bulletin 
    727-53A0219, Revision 1, as ``the service bulletin.''
    
    Comments
    
        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 rule.
    
    Request to Allow Inspection of Each Frame Separately
    
        One commenter states that it does not agree that a high frequency 
    eddy current (HFEC) inspection of both forward and aft frames should be 
    required within 3,000 flight cycles if a repair has only been 
    accomplished on one frame or the other. The commenter makes no specific 
    request; however, the FAA infers that the commenter is requesting to be 
    allowed to inspect forward and aft frames at separate intervals, if 
    only one of the frames has been repaired.
        The FAA concurs with the commenter's request. There is no technical 
    reason to require inspections of repaired and non-repaired frames at 
    the same time. Therefore, the FAA has determined that it would be more 
    appropriate to allow inspection of the forward or aft frame at the 
    threshold corresponding to its configuration repaired or non-repaired 
    rather than requiring that forward and aft frames both be inspected at 
    the threshold for repaired structure if repair has been accomplished on 
    one or the other. As proposed, paragraph (c) of this AD already allows 
    for repeat inspections of repaired structure to be accomplished 
    separately, at a different interval than non-repaired structure. 
    Therefore, only paragraphs (a)(1), (a)(2), and (a)(3) of the final rule 
    have been revised accordingly.
    
    Request to Include Instructions for Inspection
    
        One commenter requests that either the service bulletin or the 
    proposed AD be revised to include instructions for the inspections to 
    be performed at 3,000 flight cycles. The commenter states that
    
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    the service bulletin includes accomplishment instructions only for the 
    inspections to be performed at 15,000 flight cycles.
        The FAA partially concurs with the commenter's request. The FAA 
    notes that the access requirements and instructions for the repetitive 
    detailed visual inspections of the frame web are the same at both 3,000 
    and 15,000 flight cycles. (However, at the repetitive interval of 
    15,000 flight cycles, an HFEC inspection is also required.) The 
    instructions for the detailed visual inspection (which, as stated 
    previously, is identified in the service bulletin as a close visual 
    inspection) and HFEC inspections are defined in the Accomplishment 
    Instructions of the service bulletin, which references Figures 1, 2, 
    and 3 for additional instructions. The FAA finds that clarification of 
    the source of the access requirements and instructions for the detailed 
    visual inspection is necessary. Therefore, paragraph (a) of this final 
    rule has been revised to specify that the inspections are to be 
    accomplished in accordance with the Accomplishment Instructions of the 
    service bulletin.
    
    Request to Revise Threshold for Initial Inspection of Repaired 
    Airplanes
    
        One commenter requests that paragraphs (a)(2) and (a)(3) of the 
    proposed rule be revised to increase the threshold, for the initial 
    inspection of airplanes on which repairs have been accomplished 
    previously, from 3,000 to 30,000 flight cycles. The commenter 
    substantiates its request by stating that cracking has not been 
    detected on repaired structure on any airplane in its fleet.
        The FAA does not concur with the commenter's request. The FAA has 
    determined that repairs accomplished previously on the affected 
    airplanes may not be adequate to ensure the safety of the airplane 
    fleet. As explained in the Discussion section of the notice of proposed 
    rulemaking (NPRM), cracking of repaired structure has been detected on 
    several airplanes. In one case, cracking of repaired structure was 
    detected prior to the accumulation of 3,000 flight cycles after the 
    repair. Based on these data, the FAA has determined that 3,000 flight 
    cycles represents an appropriate interval for affected airplanes to 
    continue to operate safely. No change to the final rule is necessary in 
    this regard.
    
    Request for Justification of Inspection Threshold
    
        One commenter requests that the FAA provide justification for the 
    inspection threshold stated in paragraph (a)(2) of the proposed rule. 
    The commenter states that paragraph (a)(2) requires an inspection 
    within 3,000 flight cycles after repair, and remarks that, ``It does 
    not seem logical to require HFEC within 3,000 cycles from repair and 
    then repeat at 15,000 cycle intervals.'' The commenter requests that 
    paragraph (a)(2) be revised to require repetitive inspections at 3,000 
    flight cycle intervals and HFEC inspections at 15,000 flight cycles.
        The FAA does not concur. The FAA finds that the commenter 
    misunderstands the inspection threshold stated in paragraph (a)(2) of 
    the proposed rule. That paragraph requires that airplanes on which a 
    repair in accordance with the service bulletin has been accomplished be 
    inspected within 3,000 flight cycles after the effective date of this 
    AD, not after the installation of the repair, as the commenter 
    suggests. As discussed previously, the FAA has determined that repairs 
    accomplished previously on the affected airplanes may not be adequate 
    to ensure the safety of the airplane fleet. The FAA finds that a 
    compliance time of 3,000 flight cycles after the effective date of this 
    AD will provide operators with enough time to inspect repaired 
    structure while still ensuring that any cracks are detected in a timely 
    manner. No change to the final rule is necessary in this regard.
    
    Request to Remove Requirements for FAA Approval of Repairs and 
    Inspections
    
        Two commenters request that the inspection methods and intervals 
    for repaired airplanes be the same as those specified in the service 
    bulletin for non-repaired airplanes. Along with this, the commenters 
    request the removal of the requirement to obtain FAA-approval of 
    certain repairs and repetitive inspections from paragraphs (a)(3), 
    (b)(2), and (c)(2) of the proposed AD. The commenters contend that it 
    would be cost prohibitive to survey and evaluate their entire fleets 
    for previous repairs, and to coordinate repair and inspection methods 
    and intervals with Boeing and the FAA. One of the commenters further 
    states that it is impractical to require operators to develop special 
    inspection methods for each repair, and that inspection criteria for 
    any repair should be defined in the service bulletin or proposed AD, 
    and should be generic enough to apply to any repair that might exist in 
    the area. One of the commenters also states that the requirements for 
    approval of inspections and methods proposed in the NPRM were not 
    mentioned in the service bulletin.
        The FAA does not concur with the commenters' request. As discussed 
    previously, the FAA has determined that repairs accomplished previously 
    on the affected airplanes may not be adequate to ensure the safety of 
    the fleet of airplanes. As stated in the Discussion section of the 
    NPRM, at least one incident has been reported in which a previously 
    repaired aft frame web and frame inner chord were found completely 
    severed. Therefore, the FAA finds that the affected airplanes, 
    including those on which repairs have been accomplished previously, 
    must be inspected as proposed in the NPRM.
        The FAA also notes that the proposed method and inspection 
    intervals are the same as those specified in paragraph IV 
    (``Appendix'') of the service bulletin, except when the repair was 
    accomplished in accordance with a method approved by Boeing. (As stated 
    in the ``Differences Between Proposed Rule and Relevant Alert Service 
    Bulletin'' section of the proposal, although the service bulletin 
    specifies that the manufacturer be contacted for disposition of certain 
    repair conditions, this AD requires repair of those conditions to be 
    accomplished in accordance with a method approved by the FAA.) Because 
    a method of repair obtained from Boeing is not defined in the service 
    bulletin, it is unknown if the inspection procedures specified in the 
    service bulletin are sufficient to adequately ensure the safety of the 
    affected airplanes.
        With regard to the commenters' contentions that developing special 
    inspection methods for each repair will be cost prohibitive, the FAA 
    finds that the commenters' concerns are based on repairs for large 
    areas of damage. The FAA has determined that it is not possible to 
    specify generic repair and inspection methods in the service bulletin 
    or in the AD for large areas of damage. Such repairs would be unique 
    because of the amount of damage that could occur. However, the FAA 
    anticipates that there should be few initial cases of extensive damage 
    for which FAA approval will be required, and after the initial 
    inspections, the repetitive inspections are intended to detect any 
    damage (i.e., cracking), before it becomes extensive. No change to the 
    final rule is necessary in this regard.
    
    Request to Increase Repetitive Inspection Interval
    
        One commenter requests that the proposed rule be revised to delete 
    the requirement in paragraph (c)(1) to perform an HFEC inspection of 
    repaired structure within 3,000 flight cycles. The commenter states 
    that it does not expect
    
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    that cracking would occur within 3,000 flight cycles after the 
    installation of that repair, and remarks, as stated previously, that, 
    ``It does not seem logical to require HFEC within 3,000 cycles from 
    repair and then repeat at 15,000 cycle intervals.''
        The FAA does not concur with the commenter's request. As discussed 
    in the NPRM, there is concern that repairs accomplished previously on 
    the affected airplanes may not be adequate to ensure the safety of the 
    airplane fleet. The FAA finds that a threshold of 3,000 flight cycles 
    after accomplishment of the repair provides operators adequate time to 
    inspect repaired structure and ensures that any cracking will be 
    detected in a timely manner. No change to the final rule is necessary 
    in this regard.
    
    Request to Revise Accomplishment Instructions
    
        Two commenters request that the proposed rule be revised to explain 
    that removal of certain parts (including attachment hardware and seal 
    retainer) is not necessary for accomplishment of the close visual 
    inspection. One commenter requests that the proposed AD be revised to 
    include a NOTE to this effect. That commenter justifies its request by 
    stating that removal of certain parts is not necessary to visually 
    inspect the frame. The other commenter expresses concern that 
    accomplishing the procedures associated with removing the seal 
    retainer--e.g., drilling fasteners through the frame, scraping sealant 
    and paint finishes from the frame--every 3,000 flight cycles would 
    increase the probability of manmade damage to the structure. The 
    commenter states that an inspection program in which the seal retainer 
    and cargo liner are not required to be removed should have about the 
    same damage tolerance rating as the inspection program proposed in the 
    NPRM, at about half the cost. The same commenter also suggests that the 
    repetitive inspection interval for the HFEC inspection could be reduced 
    from 15,000 to 6,000 flight cycles to account for not removing such 
    parts during the visual inspections.
        The FAA does not concur with the commenters' requests. The FAA has 
    determined that cracking may initiate under the seal retainer and 
    around the number 6 door stop. The FAA finds that to gain access to the 
    web area to perform the detailed visual inspections, it is necessary to 
    remove the same parts that are removed for the detailed and HFEC 
    inspections of the doorway cutout frame webs, inner and outer chords, 
    bear strap, and skin panel.
        With regard to the commenter's concern about increasing the risk of 
    structural damage, the FAA acknowledges that such removal of parts does 
    increase the risk of manmade damage. However, the risk of such manmade 
    damage must be balanced with the necessity to detect and correct 
    operational damage such as that the inspections associated with this AD 
    is intended to detect. In this case, the manufacturer's recommendation, 
    as contained in the service bulletin, is for the removal of the seal 
    retainer and the cargo liner. In consideration of the manufacturer's 
    recommendation, as well as the nature and location of known cracking, 
    the FAA has determined that it is necessary to remove such parts for 
    the detailed visual and HFEC inspections.
        With regard to the commenter's assertion that an inspection program 
    that doesn't require removal of the seal retainer and cargo liner 
    ``should'' have the same damage tolerance rating as the inspection 
    program proposed in the NPRM, the FAA finds that the commenter provides 
    no technical justification for such a claim. However, should the 
    commenter develop an inspection procedure that can be shown to provide 
    an adequate level of safety, the commenter may apply for approval of an 
    alternative method of compliance in accordance with paragraph (d) of 
    this AD.
        No change to the final rule is necessary in this regard.
    
    Request to Allow Credit for Inspections Accomplished Previously
    
        Two commenters request that credit be given for inspections 
    performed previously. The commenters state that the actions specified 
    in the proposed AD have been accomplished prior to the effective date 
    of this AD. One of the commenters specifically requests that the 
    compliance time for the initial inspection be extended from 3,000 
    flight cycles after the effective date of this AD to 4,000 flight 
    cycles after the effective date of this AD, if inspections have been 
    accomplished in accordance with Boeing Service Bulletin 727-53A0219, 
    Revision 1, dated May 8, 1997. The commenter justifies its request by 
    stating that it has found no crack on any affected airplane in its 
    fleet. The commenter's rationale is that accomplishing the inspection 
    at the threshold proposed in the NPRM would be very costly because it 
    would impact the operator's normal maintenance schedules.
        The FAA does not concur that a change to the final rule is 
    necessary to give credit for work accomplished previously. With regard 
    to inspections accomplished prior to the effective date of this AD, 
    operators are always given credit for work accomplished previously, by 
    means of the phrase in the compliance section of the AD that reads 
    ``required as indicated, unless accomplished previously.''
        The FAA does not concur with the commenter's request for an 
    extension of the compliance time from 3,000 to 4,000 flight cycles 
    after the effective date of this AD. The FAA has determined that an 
    interval of 4,000 flight cycles would not address the identified unsafe 
    condition in a timely manner. Though the commenter has not found 
    cracking on any airplanes in its fleet, other operators have. The FAA 
    finds the proposed compliance time of 3,000 flight cycles for 
    initiating the required actions to be warranted, in that it represents 
    an appropriate interval of time allowable for affected airplanes to 
    continue to operate without compromising safety. No change to the final 
    rule is necessary in this regard.
    
    Request to Revise Supplemental Structural Inspection Document 
    (SSID)
    
        One commenter, who otherwise supports the proposed rule, notes that 
    the area subject to the proposed inspections is already subject to 
    inspections in accordance with AD 98-11-03, amendment 39-10530 (63 FR 
    27455, May 19, 1998), which is the Supplemental Structural Inspection 
    Program (SSIP) AD. The commenter therefore requests that the inspection 
    be deleted from the SSIP.
        The FAA finds that no change to the final rule is necessary in this 
    regard. Boeing, not the FAA, is responsible for revisions to the SSID. 
    However, the FAA will suggest to Boeing that, in the next revision to 
    the SSID, the inspections required by this AD should be deleted from 
    the SSID, and the service bulletin referenced by this AD should be 
    added to Section 9 of the SSID, as provided for by the SSIP.
    
    Request to Simplify the Format of the AD
    
        One commenter requests that the proposed rule be revised to 
    simplify the format. The commenter provided an example of how the 
    proposed AD could be simplified; however, no justification is given for 
    the commenter's request.
        The FAA does not concur with the commenter's request. The FAA 
    infers from the comment that the commenter finds the format of the 
    proposed AD difficult to follow. The FAA acknowledges that there are 
    certain complexities to the AD. However, as described in the preamble 
    of the NPRM,
    
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    this AD differs from the service bulletin only in the fact that repair 
    of certain conditions would be required to be accomplished in 
    accordance with the method approved by the FAA rather than the 
    manufacturer. This AD is intended to ensure that cracking is detected 
    in a timely manner on both repaired and unrepaired airplanes. Based on 
    the reports of cracking that the FAA has received, which were described 
    in the preamble of the proposed rule, the FAA finds that the 
    commenter's proposed format would not ensure that any cracking would be 
    detected in a timely manner. No change to the final rule is necessary 
    in this regard.
    
    Request to Revise Cost Impact
    
        One commenter, who otherwise supports the proposed rule, requests 
    that the cost of necessary repairs be included in the cost impact of 
    the proposed AD. The commenter states that the cost impact does not 
    include the time required to install repairs if cracking is found 
    during an inspection.
        The FAA does not concur with the commenter's request. The cost 
    impact of the AD is limited only to the cost of actions actually 
    required by the rule. It does not consider the costs of ``on 
    condition'' actions (that is, actions taken to correct an unsafe 
    condition if found), because those actions would be required to be 
    accomplished, regardless of AD direction, in order to correct an unsafe 
    condition identified in an airplane and to ensure operation of that 
    airplane in an airworthy condition, as required by the Federal Aviation 
    Regulations. No change to the final rule is necessary in this regard.
    
    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 described 
    previously. 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 1,100 airplanes of the affected design in 
    the worldwide fleet. The FAA estimates that 770 airplanes of U.S. 
    registry will be affected by this AD, that it will take approximately 
    60 work hours per airplane to accomplish the required inspections, and 
    that the average labor rate is $60 per work hour. Based on these 
    figures, the cost impact of the inspections required by this AD on U.S. 
    operators is estimated to be $2,772,000, or $3,600 per airplane, per 
    inspection cycle.
        The cost impact figure discussed above is 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:
    
    99-23-13  Boeing: Amendment 39-11409. Docket 97-NM-227-AD.
    
        Applicability: All Model 727-200 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 (d) 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 fatigue cracking between the upper and 
    lower sills of the number 1 cargo door, which could result in rapid 
    decompression of the fuselage and consequent reduced structural 
    integrity of the airplane, accomplish the following:
    
    Initial Inspection
    
        (a) Perform a detailed visual inspection or a high frequency 
    eddy current (HFEC) inspection (as applicable) to detect cracks in 
    the forward and aft frames (web, inner chord, and outer chord), bear 
    strap, and fuselage skin between the upper and lower sills of the 
    number 1 cargo door at BS 560 and BS 620. Accomplish the inspection 
    at the time specified in paragraph (a)(1), (a)(2), or (a)(3) of this 
    AD, as applicable.
    
        Note 2: For the purposes of this AD, a detailed visual 
    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.''
    
        (1) For any forward or aft frame (web, inner chord, and outer 
    chord), bear strap, or fuselage skin that has not been repaired in 
    accordance with Boeing Service Bulletin 727-53A0219, Revision 1, 
    dated May 8, 1997: Inspect prior to the accumulation of 30,000 total 
    flight cycles, or within 3,000 flight cycles after the effective 
    date of this AD, whichever occurs later, in accordance with the 
    Accomplishment Instructions of the service bulletin.
        (2) For any forward or aft frame (web, inner chord, and outer 
    chord) that has been repaired in accordance with Boeing Service 
    Bulletin 727-53A0219, Revision 1, dated May 8, 1997: Inspect within 
    3,000 flight cycles after the effective date of this AD, in 
    accordance with the Accomplishment Instructions of the service 
    bulletin.
        (3) For any bear strap, fuselage skin, or a combination of the 
    frame web and chord (inner or outer) on either the forward or aft 
    frame that has been repaired in accordance with Boeing Service 
    Bulletin 727-53A0219, Revision 1, dated May 8, 1997: Inspect within 
    3,000 flight cycles after the effective date of this AD, in 
    accordance with a method
    
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    approved by the Manager, Seattle Aircraft Certification Office 
    (ACO), FAA, Transport Airplane Directorate.
    
        Note 3: Where there are differences between this AD and the 
    referenced service bulletin, the AD prevails.
    
        Note 4: The inspections specified in paragraph (a)(3) of this AD 
    are not defined in the service bulletin.
    
    Repetitive Inspections
    
        (b) If no crack is detected during any inspection required by 
    paragraph (a) of this AD, accomplish paragraph (b)(1) or (b)(2) of 
    this AD, as applicable.
        (1) For any forward or aft frame (web, inner chord, and outer 
    chord), bear strap, or fuselage skin identified in paragraphs (a)(1) 
    and (a)(2) of this AD: Repeat the detailed visual and HFEC 
    inspections required by paragraph (a) of this AD thereafter at the 
    times specified in paragraphs (b)(1)(i) and (b)(1)(ii) of this AD.
        (i) Repeat the detailed visual inspection of the frame web at 
    intervals not to exceed 3,000 flight cycles.
        (ii) Repeat the detailed visual and HFEC inspections (as 
    applicable) of the frame web, frame inner and outer chords, bear 
    strap, and fuselage skin thereafter at intervals not to exceed 
    15,000 flight cycles.
        (2) For any bear strap, fuselage skin, or a combination of the 
    frame web and chord (inner or outer) on either the forward or aft 
    frame identified in paragraph (a)(3) of this AD: Repeat the 
    inspections of the repaired bear strap, fuselage skin, or 
    combination of a repaired frame web and chord (inner or outer) 
    thereafter at intervals not to exceed those approved by the Manager, 
    Seattle ACO.
    
    Repair
    
        (c) If any crack is detected during any inspection required by 
    paragraph (a) of this AD, prior to further flight, accomplish 
    paragraph (c)(1) or (c)(2) of this AD, as applicable.
        (1) For any crack detected in the frame web, inner chord, or 
    outer chord: Repair in accordance with Boeing Service Bulletin 727-
    53A0219, Revision 1, dated May 8, 1997. Prior to the accumulation of 
    3,000 flight cycles after accomplishment of the repair, accomplish 
    the detailed visual and HFEC inspections specified in paragraph (a) 
    of this AD. Repeat the detailed visual inspection of the frame web 
    thereafter at intervals not to exceed 3,000 flight cycles. Repeat 
    the detailed visual and HFEC inspections (as applicable) of the 
    frame web, inner chord, and outer chord thereafter at intervals not 
    to exceed 15,000 flight cycles.
        (2) For any crack detected in the fuselage skin, bear strap, or 
    a combination of the frame web and chord (inner or outer): Repair 
    and perform repetitive inspections in accordance with both a method 
    and repetitive inspection interval approved by the Manager, Seattle 
    ACO.
    
        Note 5: The repairs and inspections specified in paragraph 
    (c)(2) of this AD are not defined in the service bulletin.
    
    Alternative Methods of Compliance
    
        (d) 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.
    
        Note 6: 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
    
        (e) 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.
    
    Incorporation by Reference
    
        (f) Except as provided by paragraphs (a)(3), (b)(2), and (c)(2) 
    of this AD, the actions shall be done in accordance with Boeing 
    Service Bulletin 727-53A0219, Revision 1, dated May 8, 1997. 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.
        (g) This amendment becomes effective on December 17, 1999.
    
        Issued in Renton, Washington, on November 3, 1999.
    D.L. Riggin,
    Acting Manager, Transport Airplane Directorate, Aircraft Certification 
    Service.
    [FR Doc. 99-29329 Filed 11-10-99; 8:45 am]
    BILLING CODE 4910-13-P
    
    
    

Document Information

Effective Date:
12/17/1999
Published:
11/12/1999
Department:
Federal Aviation Administration
Entry Type:
Rule
Action:
Final rule.
Document Number:
99-29329
Dates:
Effective December 17, 1999.
Pages:
61487-61491 (5 pages)
Docket Numbers:
Docket No. 97-NM-227-AD, Amendment 39-11409, AD 99-23-13
RINs:
2120-AA64: Airworthiness Directives
RIN Links:
https://www.federalregister.gov/regulations/2120-AA64/airworthiness-directives
PDF File:
99-29329.pdf
CFR: (1)
14 CFR 39.13