[Federal Register Volume 64, Number 171 (Friday, September 3, 1999)]
[Rules and Regulations]
[Pages 48284-48286]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-22922]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-69-AD; Amendment 39-11289; AD 99-18-23]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model MD-90-30 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 McDonnell Douglas MD-90-30 series airplanes, that 
requires revising the Airworthiness Limitations Section of the 
Instructions for Continued Airworthiness [MD-90-30 Airworthiness 
Limitations Instructions (ALI)] to incorporate certain replacement 
times for safe-life limited parts. This amendment is prompted by 
analysis of data that identified reduced replacement times for certain 
safe-life limited parts. The actions specified by this AD are intended 
to prevent fatigue cracking of various safe-life limited parts; such 
fatigue cracking could adversely affect the structural integrity of 
these airplanes.

DATES: Effective October 8, 1999.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of October 8, 1999.

ADDRESSES: The service information referenced in this AD may be 
obtained from The Boeing Company, Douglas Products Division, 3855 
Lakewood Boulevard, Long Beach, California 90846, Attention: Technical 
Publications Business Administration, Dept. 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: Brent Bandley, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA, Transport Airplane Directorate, Los 
Angeles Aircraft Certification Office, 3960 Paramount Boulevard, 
Lakewood, California 90712-4137; telephone (562) 627-5237; 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 all McDonnell Douglas MD-90-30 
series airplanes was published in the Federal Register on March 2, 1999 
(64 FR 10113). That action proposed to require revising the 
Airworthiness Limitations Section of the Instructions for Continued 
Airworthiness [MD-90-30 Airworthiness Limitations Instructions (ALI)] 
to incorporate certain replacement times for safe-life limited parts.

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 Withdraw Proposed AD

    One commenter states that timely incorporation of revisions to the 
ALI may be secured by processes other than the issuance of an AD. The 
commenter contends that the proposed AD places an unnecessary burden on 
engineering and maintenance personnel and defeats the regulatory 
mandates that are currently in place by standing Federal Aviation 
Regulations (FAR). The ALI is currently monitored and revised as new 
revisions are issued and made available by the manufacturer. This 
practice is duplicated with other similar maintenance and operational 
documents, including, but not limited to, aircraft maintenance manuals, 
flight manuals, pilot's operating handbooks, and aircraft service 
bulletins. The commenter also states that Model MD-90 series airplanes 
are operated in accordance with the Type Certificate (TC) of the 
aircraft. In order to adhere to operation of the aircraft in accordance 
with the TC, the commenter asserts that it is clear to operators that 
the ALI and its subsequent revisions must be considered and 
accomplished concurrent with any other requirement specified within the 
parameters of the TC.
    From this comment, the FAA infers that the commenter is requesting 
that the proposed AD be withdrawn. The FAA does not concur. In 
accordance with the airworthiness standards requiring ``damage 
tolerance assessments'' (current Section 1529 of 14 CFR parts 23, 25, 
27, and 29; Section 4 of 14 CFR parts 33 and 35; Section 82 of 14 CFR 
part 31; and the Appendices referenced in those sections), all products 
certificated to comply with those sections must have Instructions for 
Continued Airworthiness (or, for some products, maintenance manuals), 
that include an Airworthiness Limitations Section (ALS).
    Based on in-service data or post certification testing and 
evaluation, the manufacturer may revise the ALS to include new or more 
restrictive life limits and inspections, or it may become necessary for 
the FAA to impose new or more restrictive life limits and structural 
inspections, in order to ensure continued structural integrity and 
continued compliance with damage tolerance requirements. However, in 
order to require compliance with these new inspection requirements and 
life limits for previously certificated airplanes, the FAA must engage 
in rulemaking. Because loss of structural integrity would constitute an 
unsafe condition, it is appropriate to impose these requirements 
through the AD process. Although prudent operators may already have 
incorporated the latest revisions of the ALI, issuance of this AD 
ensures that all operators take appropriate action to correct the 
identified unsafe condition. It should be noted that, simultaneously 
with the issuance of the AD, the responsible Aircraft Certification 
Office (ACO) will revise the TC data sheet for the product to indicate 
the change in the airworthiness limitations.
    The practice of mandating ALS revisions has been used for several 
years and is not a novel or unique procedure. The FAA finds that 
requiring ALS revisions has the advantage of keeping all airworthiness 
limitations, whether imposed by original certification or by AD, in one 
place within the operator's maintenance program, thereby reducing the 
risk of non-compliance because of oversight or confusion. In some cases 
where there is a large fleet of airplanes with several small operators, 
it is possible that operators may not receive

[[Page 48285]]

revisions to the ALS documents. The AD process ensures that these 
operators are aware of the revisions to the ALS.

Request To Delete Paragraph (b) of the Proposed AD

    One commenter states that the restriction imposed by paragraph (b) 
of the proposed AD does not take into consideration: (1) Any individual 
part with safe-life limits imposed by special analysis and approved by 
the manufacturer on an individual basis; or (2) future revision of the 
safe-life limits section of the ALI. The commenter also states that the 
proposed AD would ultimately requires that each part be analyzed by the 
manufacturer (and subsequently approved with a safe-life limit 
deviation from the ALI) and submitted to the FAA for approval as an 
alternative method of compliance (AMOC).
    From this comment, the FAA infers that the commenter is requesting 
that paragraph (b) of the proposed AD be deleted. The FAA does not 
concur. Paragraph (b) is necessary because section 91.403 of the FAR 
would otherwise permit operation in accordance with alternative 
inspection intervals set forth in approved operations specifications or 
inspection programs, which might conflict with the intervals referenced 
in this AD. However, under the provisions of paragraph (c) of the final 
rule, the FAA may approve requests for AMOC's or adjustments to the 
compliance time if data are submitted to substantiate that such a 
method or adjustment would provide an acceptable level of safety.
    In addition, the FAA agrees with the commenter that any reduction 
or expansion to the safe-life limits has to be coordinated between the 
operator, manufacturer, and the FAA. However, the FAA finds that this 
will not impose a significant burden because such changes must already 
be FAA-approved.

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 as proposed.

Cost Impact

    There are approximately 150 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 100 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 actions, and that the 
average labor rate is $60 per work hour. Based on these figures, the 
cost impact of the AD on U.S. operators is estimated to be $6,000, 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.

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:

99-18-23  McDonnell Douglas: Amendment 39-11289. Docket 98-NM-69-AD.

    Applicability: All Model MD-90-30 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 fatigue cracking of various safe-life limited parts, 
which could adversely affect the structural integrity of these 
airplanes, accomplish the following:
    (a) Within 180 days after the effective date of this AD, revise 
the Airworthiness Limitations Section of the Instructions for 
Continued Airworthiness [Airworthiness Limitations Instructions 
(ALI), McDonnell Douglas Report No. MDC-94K9000, dated November 
1994] to incorporate the Part Number, Item, and Mandatory 
Replacement Time of certain safe-life limited parts by inserting a 
copy of Revision 3, dated November 1997, into the ALI.
    (b) Except as provided by paragraph (c) of this AD: After the 
actions specified in paragraph (a) of this AD have been 
accomplished, no alternative replacement times may be approved for 
the safe-life limited parts specified in McDonnell Douglas ALI 
Report No. MDC-94K9000, Revision 3, dated November 1997.

Alternative Methods of Compliance

    (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, the FAA, Transport Airplane 
Directorate, Los Angeles Aircraft Certification Office. 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 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.

Special Flight Permits

    (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.

Incorporation by Reference

    (e) The ALI revision shall be done in accordance with McDonnell 
Douglas Airworthiness Limitations Instructions Report No. MDC-
94K9000, Revision 3, dated November 1997, which contains the 
following list of effective pages:

[[Page 48286]]



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                                  Revision level
           Page No.               shown on page      Date shown on page
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List of Effective Pages.......  Not Shown........  November 1997.
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(Note: The revision level is indicated only on the Title page; no 
other page contains this information.) 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 The Boeing Company, Douglas Products Division, 3855 
Lakewood Boulevard, Long Beach, California 90846, Attention: 
Technical Publications Business Administration, Dept. 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.

    (f) This amendment becomes effective on October 8, 1999.

    Issued in Renton, Washington, on August 27, 1999.
Vi L. Lipski,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-22922 Filed 9-2-99; 8:45 am]
BILLING CODE 4910-13-P