[Federal Register Volume 65, Number 12 (Wednesday, January 19, 2000)]
[Rules and Regulations]
[Pages 2861-2862]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-950]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-209-AD; Amendment 39-11515; AD 2000-01-17]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model MD-90 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 MD-90 series airplanes, 
that requires a one-time detailed visual inspection to detect fatigue 
cracking of certain longerons and the attaching frames of the lower 
left nose; and repair, if necessary. This amendment also requires 
installation of a preventive modification. This amendment is prompted 
by several reports of fatigue cracking of certain longerons and the 
attaching frames. The actions specified by this AD are intended to 
prevent such fatigue cracking, which could result in reduced structural 
integrity of the fuselage, and consequent loss of pressurization of the 
airplane.

DATES: Effective February 23, 2000.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of February 23, 2000.

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Aircraft Group, Long Beach 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: Carl Fountain, Aerospace Engineer, 
Airframe Branch, ANM-120L; FAA, Los Angeles Aircraft Certification 
Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone 
(562) 627-5222; 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 
MD-90 series airplanes was published in the Federal Register on October 
27, 1999 (64 FR 57789). That action proposed to require a one-time 
detailed visual inspection to detect fatigue cracking of certain 
longerons and the attaching frames of the lower left nose; and repair, 
if necessary. That action also proposed to require installation of a 
preventive modification.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
single the comments received.
    The commenter states that it has no objection to the proposed rule.

Conclusion

    After careful review of the available data, including the comment 
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 7 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 6 airplanes of U.S. registry 
will be affected by this AD.
    It will take approximately 1 work hour per airplane to accomplish 
the required inspection, at an average labor rate of $60 per work hour. 
Based on these figures, the cost impact of the inspection required by 
this AD on U.S. operators is estimated to be $360, or $60 per airplane.
    It will take approximately 6 work hours per airplane to accomplish 
the required modification, at an average labor rate of $60 per work 
hour. Parts will cost approximately $312 per airplane. Based on these 
figures, the cost impact of the modification required by this AD on 
U.S. operators is estimated to be $4,032, or $672 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the proposed requirements 
of this AD action, and that no operator would accomplish those actions 
in the future if this AD were not adopted.

Regulatory Impact

    The regulations adopted herein will not have a substantial direct 
effect on the States, on the relationship between the national 
Government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    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.

[[Page 2862]]

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 I111. The authority citation for 
part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec. 39.13  [Amended] I112. Section 39.13 is amended by adding the 
following new airworthiness directive:

2000-01-17  McDonnell Douglas: Amendment 39-11515. Docket 99-NM-209-
AD.

    Applicability: Model MD-90 series airplanes, as listed in 
McDonnell Douglas Service Bulletin MD90-53-004, dated August 20, 
1998, 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 (b) 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 longerons 22 through 26 and the 
attaching frames, which could result in reduced structural integrity 
of the fuselage, and consequent loss of pressurization of the 
airplane, accomplish the following:

Inspection and Modification

    (a) Prior to the accumulation of 40,000 total landings, or 
within 24 months after the effective date of this AD, whichever 
occurs later: Perform a detailed visual inspection to detect 
cracking of longerons 22 through 26 (inclusive) and the respective 
attaching frames at station frames Y=160.000 and Y=200.000 of the 
left lower nose, in accordance with McDonnell Douglas Service 
Bulletin MD90-53-004, dated August 20, 1998.

    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) If no cracking is detected: Prior to further flight, install 
clips and doublers under the longeron flanges and shim the longerons 
in accordance with the service bulletin.
    (2) If any cracking is detected: Prior to further flight, repair 
the cracks and install clips and doublers under the longeron flanges 
and shim the longerons in accordance with the service bulletin.

Alternative Methods of Compliance

    (b) 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 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, Los Angeles ACO.

    Note 3:
     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

    (c) 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

    (d) The actions shall be done in accordance with McDonnell 
Douglas Service
    Bulletin MD90-53-004, dated August 20, 1998. 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 Aircraft Group, Long Beach 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.
    (e) This amendment becomes effective on February 23, 2000.

    Issued in Renton, Washington, on January 10, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-950 Filed 1-18-00; 8:45 am]
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