
[Federal Register: September 9, 2008 (Volume 73, Number 175)]
[Rules and Regulations]               
[Page 52203-52205]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr09se08-6]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0946; Directorate Identifier 2008-NM-147-AD; 
Amendment 39-15667; AD 2008-18-10]
RIN 2120-AA64

 
Airworthiness Directives; McDonnell Douglas Model MD-90-30 
Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: We are adopting a new airworthiness directive (AD) for certain 
McDonnell Douglas Model MD-90-30 airplanes. This AD requires a detailed 
inspection for certain defects of the upper fasteners of the aft mount 
support fitting of the left and right engines and corrective actions if 
necessary. This AD results from reports of loose, cracked, or missing 
fasteners in the aft mount support fitting of the left and right 
engines. We are issuing this AD to detect and correct loose, cracked, 
or missing fasteners in the engine aft support mount fitting, which 
could lead to separation of the support fitting from the pylon, which 
could result in separation of the engine from the airplane.

DATES: This AD is effective September 24, 2008.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of September 
24, 2008.
    We must receive comments on this AD by November 10, 2008.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Portal: Go to http://
www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    For service information identified in this AD, contact Boeing 
Commercial Airplanes, Long Beach Division, 3855 Lakewood Boulevard, 
Long Beach, California 90846, Attention: Data and Service Management, 
Dept. C1-L5A (D800-0024).

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Management Facility 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this AD, the regulatory evaluation, 
any comments received, and other information. The street address for 
the Docket Office (telephone 800-647-5527) is in the ADDRESSES section. 
Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Roger Durbin, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification 
Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; 
telephone (562) 627-5233; fax (562) 627-5210.

SUPPLEMENTARY INFORMATION: 

Discussion

    We have received reports of loose, cracked, or missing fasteners in 
the aft mount support fitting of the left and right engines on several 
McDonnell Douglas Model MD-90-30 airplanes. The airplanes had 
accumulated between 18,767 and 25,400 total flight hours and between 
15,841 and 27,000 total flight cycles. A safety assessment of the 
missing fasteners has concluded that loose or discrepant fasteners in 
the top

[[Page 52204]]

horizontal row, common with the pylon skin, significantly decrease the 
margin of safety of the aft mount support installation at the design 
limit load. Loose, cracked, or missing fasteners in the engine aft 
mount support fitting could lead to separation of the support fitting 
from the pylon. This condition, if not corrected, could result in 
separation of the engine from the airplane.

Relevant Service Information

    We reviewed Boeing Alert Service Bulletin MD90-54A002, dated August 
1, 2008. The service bulletin describes procedures for doing a detailed 
inspection for certain defects of the upper fasteners of the aft mount 
support fitting of the left and right engines, and corrective action as 
applicable. The detailed inspection consists of the following actions: 
(1) A general visual inspection of the upper fasteners for any missing, 
loose, or damaged fasteners, (2) a gap check between the washers and 
structure or between the fastener heads and structure, if applicable, 
and (3) a torque check of the fastener nuts, if applicable. The 
corrective action includes replacing all fasteners if any defect is 
found.

FAA's Determination and Requirements of This AD

    We are issuing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the(se) same type 
design(s). This AD requires accomplishing the actions specified in the 
service information described previously.

Interim Action

    This is considered to be interim action until final action is 
identified, at which time we might consider further rulemaking.

FAA's Justification and Determination of the Effective Date

    Loose, cracked, or missing fasteners in the engine aft mount 
support fitting could lead to separation of the support fitting from 
the pylon, possibly resulting in separation of the engine from the 
airplane. Because of our requirement to promote safe flight of civil 
aircraft and thus, the critical need to assure structural integrity of 
the engine aft mount support fitting and the short compliance time 
involved with this action, this AD must be issued immediately.
    Because an unsafe condition exists that requires the immediate 
adoption of this AD, we find that notice and opportunity for prior 
public comment hereon are impracticable and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety, and we did not provide you with notice and an opportunity to 
provide your comments before it becomes effective. However, we invite 
you to send any written data, views, or arguments about this AD. Send 
your comments to an address listed under the ADDRESSES section. Include 
``Docket No. FAA-2008-0946; Directorate Identifier 2008-NM-147-AD'' at 
the beginning of your comments. We specifically invite comments on the 
overall regulatory, economic, environmental, and energy aspects of this 
AD. We will consider all comments received by the closing date and may 
amend this AD because of those comments.
    We will post all comments we receive, without change, to http://
www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this AD.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. ``Subtitle VII: Aviation 
Programs,'' describes in more detail the scope of the Agency's 
authority.
    We are issuing this rulemaking under the authority described in 
``Subtitle VII, Part A, Subpart III, Section 44701: General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    This AD will not have federalism implications under Executive Order 
13132. This AD 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.
    For the reasons discussed above, I certify that this AD:
    (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.
    You can find our regulatory evaluation and the estimated costs of 
compliance in the AD Docket.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new AD:

2008-18-10 McDonnell Douglas: Amendment 39-15667. Docket No. FAA-
2008-0946; Directorate Identifier 2008-NM-147-AD.

Effective Date

    (a) This airworthiness directive (AD) is effective September 24, 
2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to McDonnell Douglas Model MD-90-30 
airplanes, certificated in any category; as identified in Boeing 
Alert Service Bulletin MD90-54A002, dated August 1, 2008.

Unsafe Condition

    (d) This AD results from reports of loose, cracked, or missing 
fasteners in the aft mount support fitting of the left and right 
engines. We are issuing this AD to detect and correct loose, 
cracked, or missing fasteners in the engine aft support mount 
fitting, which could lead to separation of the support fitting from 
the pylon, which could result in separation of the engine from the 
airplane.

Compliance

    (e) Comply with this AD within the compliance times specified, 
unless already done.

Detailed Inspection

    (f) Within 703 flight cycles after the effective date of this 
AD, do a detailed

[[Page 52205]]

inspection for any defect (missing, loose, or damaged fasteners; 
incorrect gap between washers and structure or between fastener 
heads and structure; or incorrect torque of fastener nuts) of the 
upper fasteners of the aft mount support fitting of the left and 
right engines, and do all the applicable corrective actions before 
further flight, by accomplishing all of the applicable actions 
specified in the Accomplishment Instructions of Boeing Alert Service 
Bulletin MD90-54A002, dated August 1, 2008.

Credit for Actions Done per Multiple Operator Message (MOM)

    (g) Actions done before the effective date of this AD in 
accordance with Boeing MOM 1-893882781-2, dated July 25, 2008, are 
acceptable for compliance with the requirements of paragraph (f) of 
this AD.

Alternative Methods of Compliance (AMOCs)

    (h)(1) The Manager, Los Angeles Certification Office (ACO), FAA, 
ATTN: Roger Durbin, Aerospace Engineer, Airframe Branch, ANM-120L, 
FAA, Los Angeles ACO, 3960 Paramount Boulevard, Lakewood, California 
90712-4137; telephone (562) 627-5233; fax (562) 627-5210; has the 
authority to approve AMOCs for this AD, if requested using the 
procedures found in 14 CFR 39.19.
    (2) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair required by this AD, if it is approved by an 
Authorized Representative for the Boeing Commercial Airplanes 
Delegation Option Authorization Organization who has been authorized 
by the Manager, Los Angeles ACO, to make those findings. For a 
repair method to be approved, the repair must meet the certification 
basis of the airplane, and the approval must specifically refer to 
this AD.

Material Incorporated by Reference

    (i) You must use Boeing Alert Service Bulletin MD90-54A002, 
dated August 1, 2008, to do the actions required by this AD, unless 
the AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) For service information identified in this AD, contact 
Boeing Commercial Airplanes, Long Beach Division, 3855 Lakewood 
Boulevard, Long Beach, California 90846, Attention: Data and Service 
Management, Dept. C1-L5A (D800-0024).
    (3) You may review copies of the service information 
incorporated by reference at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue SW., Renton, Washington; or at the 
National Archives and Records Administration (NARA). For information 
on the availability of this material at NARA, call 202-741-6030, or 
go to: http://www.archives.gov/federal_register/code_of_federal_
regulations/ibr_locations.html.

    Issued in Renton, Washington, on August 25, 2008.
Dionne Palermo,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-20494 Filed 9-8-08; 8:45 am]

BILLING CODE 4910-13-P
