98-30049. Airworthiness Directives; McDonnell Douglas Model DC-9-31 Series Airplanes  

  • [Federal Register Volume 63, Number 218 (Thursday, November 12, 1998)]
    [Rules and Regulations]
    [Pages 63134-63137]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 98-30049]
    
    
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    DEPARTMENT OF TRANSPORTATION
    
    Federal Aviation Administration
    
    14 CFR Part 39
    
    [Docket No. 97-NM-99-AD; Amendment 39-10877; AD 98-23-11]
    RIN 2120-AA64
    
    
    Airworthiness Directives; McDonnell Douglas Model DC-9-31 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 certain McDonnell Douglas Model DC-9-31 series airplanes, 
    that requires a one-time visual inspection to determine if all corners 
    of the forward service door doorjamb have been modified previously, 
    various follow-on repetitive inspections, and modification, if 
    necessary. This amendment is prompted by reports of fatigue cracks 
    found in the fuselage skin and doubler at the corners of the forward 
    service door doorjamb. 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, 1998.
        The incorporation by reference of certain publications listed in 
    the regulations is approved by the Director of the Federal Register as 
    of December 17, 1998.
    
    ADDRESSES: The service information referenced in this AD may be 
    obtained from McDonnell Douglas Corporation, 3855 Lakewood Boulevard, 
    Long Beach, California 90846, Attention: Technical Publications 
    Business Administration, Department C1-L51 (2-60). 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 FAA, Transport Airplane Directorate, Los Angeles 
    Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, 
    California; or at the Office of the Federal Register, 800 North Capitol 
    Street, NW., suite 700, Washington, DC.
    
    FOR FURTHER INFORMATION CONTACT: Wahib Mina, Aerospace Engineer, 
    Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification 
    Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone 
    (562) 627-5324; fax (562) 627-5210.
    
    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 certain McDonnell Douglas Model 
    DC-9-31 series airplanes was published in the Federal Register on 
    January 27, 1998 (63 FR 3852). That action proposed to require a one-
    time visual inspection to determine if all corners of the forward 
    service door doorjamb have been modified previously, various follow-on 
    repetitive inspections, and modification, if necessary.
        Interested persons have been afforded an opportunity to participate 
    in the making of this amendment. Due consideration has been given to 
    the comments received.
    
    Request to Allow Designated Engineering Representative (DER) 
    Approval of Certain Repairs
    
        One commenter requests that the FAA revise the proposed AD to 
    permit repairs of cracked structure to be accomplished in accordance 
    with the DER of The Boeing Company, Douglas Products Division, on a 
    temporary basis, rather than in accordance with the Manager of the Los 
    Angeles Aircraft Certification Office (ACO). The commenter states that 
    such an approval would expedite the process for repair approval for a 
    crack condition beyond the allowable repair limits (i.e., greater than 
    2 inches in length) and for existing repairs that are not accomplished 
    in accordance with the DC-9 Structural Repair Manual (SRM) or Service 
    Rework Drawing.
        The FAA does not concur. While DER's are authorized to determine 
    whether a design or repair method complies with a specific requirement, 
    they are not currently authorized to make the discretionary 
    determination as to what the applicable requirement is. However, the 
    FAA has issued a notice (N 8110.72, dated March 30, 1998), which 
    provides guidance for delegating authority to certain type certificate 
    holder structural DER's to approve alternative methods of compliance 
    for AD-required repairs and modifications of individual airplanes. The 
    FAA is currently working with The Boeing Company, Douglas Products 
    Division, to develop the implementation process for delegation of 
    approval of alternative methods of compliance in accordance with that 
    notice. Once this process is implemented, approval authority for 
    alternative methods of compliance can be delegated without revising the 
    AD.
    
    [[Page 63135]]
    
    Request To Revise Paragraph (e) of the Proposed AD
    
        One commenter requests that paragraph (e) of the proposed AD be 
    revised to read as follows:
        ``(e) If the visual inspection required by paragraph (a) of this AD 
    reveals that the corners of the forward doorjamb of the service door 
    have been modified by FAA approved repairs other than the DC-9 SRM or 
    Service Rework Drawing, prior to further flight, accomplish an initial 
    Low Frequency Eddy Current inspection of the fuselage skin adjacent to 
    the repair.
        (e)(i) If no cracks are detected, within (6) months after the 
    initial LFEC inspection, accomplish a repair approved by the Manager, 
    Los Angeles ACO.
        (e)(ii) If cracks are detected, prior to further flight, repair in 
    accordance with a method approved by the Manager, Los Angeles ACO.''
        This commenter states that, as paragraph (e) of the proposed AD is 
    currently worded, it will cause an unnecessary operational impact since 
    FAA-approved non-standard SRM or Service Rework Drawing repairs are 
    known to exist for this area of the doorjamb. The commenter contends 
    that obtaining approval for such repairs from the Los Angeles ACO, 
    prior to further flight, will be time consuming and will result in an 
    unwarranted extended ground time for the airplane.
        The FAA does not concur with the commenter's request to revise 
    paragraph (e) of the AD. The FAA, in conjunction with McDonnell 
    Douglas, has conducted further analysis of this issue. The FAA has 
    determined that, for doorjambs of the forward service door that are 
    found to be modified previously, but not in accordance with the DC-9 
    SRM, an initial low frequency eddy current inspection of the fuselage 
    skin adjacent to those existing repairs will not detect any cracking 
    under the repairs. In light of this determination, no change to this 
    final rule is necessary.
    
    Request To Revise DC-9 Supplemental Inspection Document (SID)
    
        One commenter requests that, prior to issuance of the final rule, 
    the DC-9 SID be revised to incorporate the actions required by this 
    proposed AD. The commenter states that such a revision will eliminate 
    confusion between the DC-9 SID and the proposed AD. The FAA does not 
    concur. The actions required by this AD are necessary to ensure 
    inspection continuity for the affected Principal Structural Element 
    (PSE). After issuance of the final rule, the manufacturer may revise 
    the DC-9 SID.
    
    Request To Revise Compliance Time for Low Frequency Eddy Current 
    (LFEC) or X-ray Inspection
    
        One commenter requests that the compliance time for the initial 
    inspection (LFEC or x-ray) in paragraph (b) of the proposal be revised 
    to correspond with those presently in the SID program--within three 
    years after the effective date of the AD, or prior to 53,140 landings, 
    whichever occurs later. The commenter points out that such a revision 
    would permit its fleet to be inspected during major scheduled 
    maintenance checks, which would reduce the burden of line maintenance 
    and the number of line airplanes out of service as a result of any 
    findings. The commenter agrees that the repetitive inspection interval 
    should remain at 3,225 landings, as specified in the proposed rule.
        The FAA does not concur with the commenter's request to revise the 
    compliance time for the initial inspection specified in paragraph (b) 
    of the AD. The commenter provided no technical justification for 
    revising this interval. Fatigue cracking of the fuselage skin and 
    doubler at the corners of the forward service door doorjamb is a 
    significant safety issue, and the FAA has determined that the 
    inspection threshold, as proposed, is warranted, based on the 
    effectiveness of the inspection procedure to detect fatigue cracking. 
    The FAA considered not only those safety issues in developing an 
    appropriate compliance time for this action, but the recommendations of 
    the manufacturer, and the practical aspect of accomplishing the 
    required inspection within an interval of time that parallels normal 
    scheduled maintenance for the majority of affected operators. In light 
    of these factors, the FAA has determined that the initial compliance 
    time, as proposed, is appropriate.
    
    Other Relevant Rulemaking
    
        The FAA has revised the final rule to include a new paragraph (f). 
    This new paragraph states that accomplishment of the inspection 
    requirements of this AD constitutes terminating action for inspections 
    of Principal Structural Element (PSE) 53.09.033 (reference McDonnell 
    Douglas Model DC-9 Supplemental Inspection Document) required by AD 96-
    13-03, amendment 39-9671 (61 FR 31009, June 19, 1996). Since this new 
    paragraph is being added, the FAA has removed ``NOTE 4,'' which is no 
    longer necessary.
    
    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 change previously 
    described. The FAA has determined that this change will neither 
    increase the economic burden on any operator nor increase the scope of 
    the AD.
    
    Cost Impact
    
        There are approximately 64 McDonnell Douglas Model DC-9-31 series 
    airplanes of the affected design in the worldwide fleet. The FAA 
    estimates that 51 airplanes of U.S. registry will be affected by this 
    AD, that it will take approximately 1 work hour per airplane to 
    accomplish the required one-time visual inspection, and that the 
    average labor rate is $60 per work hour. Based on these figures, the 
    cost impact of the one-time visual inspection required by this AD on 
    U.S. operators is estimated to be $3,060, or $60 per airplane.
        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.
        Should an operator be required to accomplish the LFEC or x-ray 
    inspection, it would take approximately 1 work hour per airplane to 
    accomplish, at an average labor rate of $60 per work hour. Based on 
    these figures, the cost impact of any necessary LFEC or x-ray 
    inspection is estimated to be $60 per airplane, per inspection cycle.
        Should an operator be required to accomplish the HFEC inspection, 
    it would take approximately 1 work hour per airplane to accomplish, at 
    an average labor rate of $60 per work hour. Based on these figures, the 
    cost impact of any necessary HFEC inspection is estimated to be $60 per 
    airplane, per inspection cycle.
        Should an operator be required to accomplish the modification, it 
    would take approximately 30 work hours per airplane to accomplish, at 
    an average labor rate of $60 per work hour. Required parts would cost 
    approximately $4,800 per airplane. Based on these figures, the cost 
    impact of any necessary modification is estimated to be $6,600 per 
    airplane.
    
    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
    
    [[Page 63136]]
    
    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:
    
    98-23-11  McDonnell Douglas: Amendment 39-10877. Docket 97-NM-99-AD.
    
        Applicability: Model DC-9-31 series airplanes, as listed in 
    McDonnell Douglas Service Bulletin DC9-53-288, dated February 10, 
    1997, 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 (g) 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 in the fuselage skin or 
    doubler at the corners of the forward service door doorjamb, which 
    could result in rapid decompression of the fuselage and consequent 
    reduced structural integrity of the airplane, accomplish the 
    following:
    
        Note 2: Where there are differences between the service bulletin 
    and the AD, the AD prevails.
        Note 3: The words ``repair'' and ``modify/modification'' in this 
    AD and the referenced service bulletin are used interchangeably.
    
        (a) Prior to the accumulation of 50,000 total landings, or 
    within 3,225 landings after the effective date of this AD, whichever 
    occurs later, perform a one-time visual inspection to determine if 
    the corners of the forward service door doorjamb have been modified. 
    Perform the inspection in accordance with McDonnell Douglas Service 
    Bulletin DC9-53-288, dated February 10, 1997.
        (b) For airplanes identified as Group 1 in McDonnell Douglas 
    Service Bulletin DC9-53-288, dated February 10, 1997: If the visual 
    inspection required by paragraph (a) of this AD reveals that the 
    corners of the forward service door doorjamb have not been modified, 
    prior to further flight, perform a low frequency eddy current (LFEC) 
    or x-ray inspection to detect cracks of the fuselage skin and 
    doubler at all corners of the forward service door doorjamb, in 
    accordance with McDonnell Douglas Service Bulletin DC9-53-288, dated 
    February 10, 1997.
        (1) Group 1, Condition 1. If no crack is detected during any 
    LFEC or x-ray inspection required by paragraph (b) of this AD, 
    accomplish the requirements of either paragraph (b)(1)(i) or 
    (b)(1)(ii) of this AD, in accordance with the service bulletin.
        (i) Option 1. Repeat the LFEC inspection required by this 
    paragraph thereafter at intervals not to exceed 3,225 landings, or 
    the x-ray inspection required by this paragraph thereafter at 
    intervals not to exceed 3,075 landings; or
        (ii) Option 2. Prior to further flight, modify the corner skin 
    of the forward service door doorjamb in accordance with the service 
    bulletin. Prior to the accumulation of 28,000 landings after 
    accomplishment of the modification, perform a high frequency eddy 
    current (HFEC) inspection to detect cracks on the skin adjacent to 
    the modification, in accordance with the service bulletin.
        (A) If no crack is detected on the skin adjacent to the 
    modification during the HFEC required by this paragraph, repeat the 
    HFEC inspection thereafter at intervals not to exceed 20,000 
    landings.
        (B) If any crack is detected on the skin adjacent to the 
    modification during any HFEC inspection required by this paragraph, 
    prior to further flight, repair it in accordance with a method 
    approved by the Manager, Los Angeles Aircraft Certification Office 
    (ACO), FAA, Transport Airplane Directorate.
        (2) Group 1, Condition 2. If any crack is found during any LFEC 
    or x-ray inspection required by paragraph (b) of this AD, and the 
    crack is 2 inches or less in length: Prior to further flight, 
    modify/repair the corners of the doorjamb of the forward service 
    door in accordance with the service bulletin. Prior to the 
    accumulation of 28,000 landings after accomplishment of the 
    modification, perform a HFEC inspection to detect cracks on the skin 
    adjacent to the modification, in accordance with the service 
    bulletin.
        (i) If no crack is detected during the HFEC inspection required 
    by this paragraph, repeat the HFEC inspection thereafter at 
    intervals not to exceed 20,000 landings.
        (ii) If any crack is detected during any HFEC inspection 
    required by this paragraph, prior to further flight, repair it in 
    accordance with a method approved by the Manager, Los Angeles ACO.
        (3) Group 1, Condition 3. If any crack is found during any LFEC 
    or x-ray inspection required by paragraph (b) of this AD, and the 
    crack is greater than 2 inches in length: Prior to further flight, 
    repair it in accordance with a method approved by the Manager, Los 
    Angeles ACO.
        (c) Group 2, Condition 1. For airplanes identified as Group 2 in 
    McDonnell Douglas Service Bulletin DC9-53-288, dated February 10, 
    1997: If the visual inspection required by paragraph (a) of this AD 
    reveals that the corners of the forward service door doorjamb have 
    been modified previously in accordance with the McDonnell Douglas 
    DC-9 Structural Repair Manual, using a steel doubler, accomplish 
    either paragraph (c)(1) or (c)(2) of this AD in accordance with 
    McDonnell Douglas Service Bulletin DC9-53-288, dated February 10, 
    1997.
        (1) Option 1. Prior to the accumulation of 6,000 landings after 
    accomplishment of that modification, or within 3,225 landings after 
    the effective date of this AD, whichever occurs later, perform an 
    HFEC inspection to detect cracks on the skin adjacent to the 
    modification, in accordance with the service bulletin.
        (i) If no crack is detected during the HFEC inspection required 
    by paragraph (c)(1) of this AD, repeat the HFEC inspection 
    thereafter at intervals not to exceed 3,000 landings.
        (ii) If any crack is detected during any HFEC inspection 
    required by paragraph (c)(1) of this AD, prior to further flight, 
    repair it in accordance with a method approved by the Manager, Los 
    Angeles ACO.
        (2) Option 2. Prior to further flight, modify the corner skin of 
    the forward service door doorjamb in accordance with the service 
    bulletin. Prior to the accumulation of 28,000 landings after 
    accomplishment of the modification, perform an HFEC inspection to 
    detect cracks on the skin adjacent to the modification, in 
    accordance with the service bulletin.
        (i) If no crack is detected on the skin adjacent to the 
    modification during the HFEC required by this paragraph, repeat the 
    HFEC inspection thereafter at intervals not to exceed 20,000 
    landings.
        (ii) If any crack is detected on the skin adjacent to the 
    modification during any HFEC inspection required by this paragraph, 
    prior to further flight, repair it in accordance with a method 
    approved by the Manager, Los Angeles ACO.
    
    [[Page 63137]]
    
        (d) Group 2, Condition 2. For airplanes identified as Group 2 in 
    McDonnell Douglas Service Bulletin DC9-53-288, dated February 10, 
    1997: If the visual inspection required by paragraph (a) of this AD 
    reveals that the corners of the forward service door doorjamb have 
    been modified previously in accordance with McDonnell Douglas DC-9 
    Structural Repair Manual, using an aluminum doubler, prior to the 
    accumulation of 28,000 landings after accomplishment of that 
    modification, or within 3,225 landings after the effective date of 
    this AD, whichever occurs later, perform an HFEC inspection to 
    detect cracks on the skin adjacent to the modification, in 
    accordance with McDonnell Douglas Service Bulletin DC9-53-288, dated 
    February 10, 1997.
        (1) If no crack is detected on the skin adjacent to the 
    modification during the HFEC required by this paragraph, repeat the 
    HFEC inspection thereafter at intervals not to exceed 20,000 
    landings.
        (2) If any crack is detected on the skin adjacent to the 
    modification during any HFEC inspection required by this paragraph, 
    prior to further flight, repair it in accordance with a method 
    approved by the Manager, Los Angeles ACO.
        (e) Group 2, Condition 3. For airplanes identified as Group 2 in 
    McDonnell Douglas Service Bulletin DC9-53-288, dated February 10, 
    1997: If the visual inspection required by paragraph (a) of this AD 
    reveals that the corners of the forward service door doorjamb have 
    been modified previously, but not in accordance with McDonnell 
    Douglas Structural Repair Manual, prior to further flight, repair 
    the corners in accordance with a method approved by the Manager, Los 
    Angeles ACO.
        (f) Accomplishment of the actions required by this AD 
    constitutes terminating action for inspections of Principal 
    Structural Element (PSE) 53.09.033 (reference McDonnell Douglas 
    Model DC-9 Supplemental Inspection Document) required by AD 96-13-
    03, amendment 39-9671.
        (g) 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, Los Angeles ACO. Operators shall 
    submit their requests through an appropriate FAA Principal 
    Maintenance Inspector, who may add comments and then send it to the 
    Manager, Los Angeles ACO.
    
        Note 4: Information concerning the existence of approved 
    alternative methods of compliance with this AD, if any, may be 
    obtained from the Los Angeles ACO.
    
        (h) 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.
        (i) Except as provided by paragraphs (b)(1)(ii)(B), (b)(2)(ii), 
    (b)(3), (c)(1)(ii), (c)(2)(ii), (d)(2), and (e) of this AD, the 
    actions shall be done in accordance with McDonnell Douglas Service 
    Bulletin DC9-53-288, dated February 10, 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 McDonnell Douglas Corporation, 3855 Lakewood 
    Boulevard, Long Beach, California 90846, Attention: Technical 
    Publications Business Administration, Department C1-L51 (2-60). 
    Copies may be inspected at the FAA, Transport Airplane Directorate, 
    1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Transport 
    Airplane Directorate, Los Angeles Aircraft Certification Office, 
    3960 Paramount Boulevard, Lakewood, California; or at the Office of 
    the Federal Register, 800 North Capitol Street, NW., suite 700, 
    Washington, DC.
        (j) This amendment becomes effective on December 17, 1998.
    
        Issued in Renton, Washington, on November 3, 1998.
    Darrell M. Pederson,
    Acting Manager, Transport Airplane Directorate, Aircraft Certification 
    Service.
    [FR Doc. 98-30049 Filed 11-10-98; 8:45 am]
    BILLING CODE 4910-13-U
    
    
    

Document Information

Effective Date:
12/17/1998
Published:
11/12/1998
Department:
Federal Aviation Administration
Entry Type:
Rule
Action:
Final rule.
Document Number:
98-30049
Dates:
Effective December 17, 1998.
Pages:
63134-63137 (4 pages)
Docket Numbers:
Docket No. 97-NM-99-AD, Amendment 39-10877, AD 98-23-11
RINs:
2120-AA64: Airworthiness Directives
RIN Links:
https://www.federalregister.gov/regulations/2120-AA64/airworthiness-directives
PDF File:
98-30049.pdf
CFR: (1)
14 CFR 39.13