[Federal Register Volume 75, Number 126 (Thursday, July 1, 2010)]
[Proposed Rules]
[Pages 38056-38058]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-15988]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2010-0645; Directorate Identifier 2009-NM-200-AD]
RIN 2120-AA64
Airworthiness Directives; McDonnell Douglas Corporation Model MD-
90-30 Airplanes
AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to supersede an existing airworthiness
directive (AD) that applies to certain Model MD-90-30 airplanes. The
existing AD currently requires a detailed inspection for certain
defects of the upper fasteners of the aft mount support fittings of the
left and right engines, and corrective actions if necessary. This
proposed AD would instead require repetitive replacement of the upper
row of fasteners of the support fittings of the engine aft mount with
new fasteners; and perform repetitive general visual inspections for
defects of the lower row fasteners (Row B) of the support fittings of
the left and right engine aft mounts, and replacement of all clearance
fit fasteners in the lower row if necessary. This proposed AD results
from reports of loose, cracked, or missing fasteners in the aft mount
support fitting of the left and right engines. We are proposing this AD
to prevent loose, cracked, or missing fasteners in the engine aft mount
support fittings, which could lead to separation of the support
fittings from the pylon, and could result in separation of the engine
from the airplane.
DATES: We must receive comments on this proposed AD by August 16, 2010.
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 proposed AD, contact
Boeing Commercial Airplanes, Attention: Data & Services Management,
3855 Lakewood Boulevard, MC D800 0019, Long Beach, California 90846-
0001; telephone 206-544-5000, extension 2; fax 206 766-5683; e-mail
[email protected]; Internet https://www.myboeingfleet.com. You may
review copies of the referenced service information at the FAA,
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington. For information on the availability of this material at the
FAA, call 425-227-1221.
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 proposed 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:
Comments Invited
We invite you to send any written relevant data, views, or
arguments about this proposed AD. Send your comments to an address
listed under the ADDRESSES section. Include ``Docket No. FAA-2010-0645;
Directorate Identifier 2009-NM-200-AD'' at the beginning of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy aspects of this proposed AD. We
will consider all comments received by the closing date and may amend
this proposed 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 proposed AD.
Discussion
On August 25, 2008, we issued AD 2008-18-10, Amendment 39-15667 (73
FR 52203, September 9, 2008), for certain McDonnell Douglas Corporation
Model MD-90-30 airplanes. That AD requires a detailed inspection for
certain defects of the upper fasteners of the aft mount support
fittings of the left and right engines, and corrective actions if
necessary. That AD resulted from reports of loose, cracked, or missing
fasteners in the aft mount support fittings of the left and right
engines. We issued that AD to detect and correct loose, cracked, or
missing fasteners in the engine aft support mount fittings, which could
lead to separation of the support fittings from the pylon, and could
result in separation of the engine from the airplane.
Actions Since Existing AD Was Issued
The preamble to AD 2008-18-10 explains that we considered the
requirements ``interim action'' and were considering further
rulemaking. We now have determined that further rulemaking is indeed
necessary, and this proposed AD follows from that determination.
We also have received additional reports of loose, cracked, or
missing fasteners in the aft mount support fitting of the left and
right engines on 29 McDonnell Douglas Corporation Model MD-90-30
airplanes. The airplanes had accumulated between 15,560 and 37,298
total flight hours, and between 13,995 and 31,294 total flight cycles.
Results of a safety assessment of the missing fasteners indicate
that loose or otherwise discrepant fasteners in the top horizontal row,
common with the pylon skin, significantly decrease the margin of safety
of the aft mount support installation at the design limit load.
Replacement of the upper row of fasteners at new specified intervals
will help minimize the possibility of these fasteners becoming an
unsafe condition while in service. Inspection of the lower
[[Page 38057]]
row of fasteners will help ensure design integrity.
Relevant Service Information
We have reviewed Boeing Alert Service Bulletin MD90-54A003,
Revision 2, dated February 12, 2010. The service bulletin describes
procedures for repetitive replacement of the upper row of fasteners
(Row A) of the support fittings of the left and right engine aft mount
with new fasteners.
The service bulletin also describes procedures for repetitive
general visual inspections for defects of the lower row fasteners (Row
B) of the support fittings of the left and right engine aft mounts
(that includes a gap check under the head or nut, and a torque check),
as necessary for defects of the lower row of fasteners (Row B) of the
support fittings of the left and right engine aft mounts, and replacing
all clearance fit fasteners in the lower row (Row B) with new fasteners
if any defect is found. Defects include missing, loose, and damaged
fasteners.
The service bulletin specifies the compliance times for the initial
replacement and inspections as follows:
For Configurations 1 and 3 airplanes, as identified in the
service bulletin: Within 10,000 flight cycles after fastener
replacement in accordance with Boeing Service Bulletin MD90-54A002 or
Boeing Multiple Operator Message 1-893882781-2, dated July 25, 2008.
For Configurations 2 and 4 airplanes, as identified in the
service bulletin: Within 2,457 flight cycles after the original issue
date on the service bulletin (August 10, 2009).
The repetitive interval for replacement and inspections is not to
exceed 10,000 flight cycles.
FAA's Determination and Requirements of the Proposed AD
We have evaluated all pertinent information and identified an
unsafe condition that is likely to develop on other airplanes of the
same type design. For this reason, we are proposing this AD, which
would supersede AD 2008-18-10. This proposed AD would not retain the
requirements of AD 2008-18-10. This proposed AD would require
accomplishing the actions specified in the service information
described previously.
Costs of Compliance
There are about 107 airplanes of the affected design in the
worldwide fleet. The following table provides the estimated costs for
U.S. operators to comply with this proposed AD.
Estimated Costs
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Number of U.S.-
Action Work hours Average labor Parts Cost per airplane registered Fleet cost
rate per hour airplanes
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Replacement........................ 14 $85 $152 per replacement. $1,342 per 13 $17,446 per
replacement cycle. replacement cycle.
Inspections........................ 4 85 $0................... $340 per inspection 13 $4,420 per inspection
cycle. cycle.
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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
We have determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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 the proposed
regulation:
1. Is not a ``significant regulatory action'' under Executive Order
12866;
2. Is not a ``significant rule'' under the 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.
We prepared a regulatory evaluation of the estimated costs to
comply with this proposed AD and placed it in the AD docket. See the
ADDRESSES section for a location to examine the regulatory evaluation.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
The Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 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. The FAA amends Sec. 39.13 by removing Amendment 39-15667 (73 FR
52203, September 9, 2008) and adding the following new AD:
McDonnell Douglas Corporation: Docket No. FAA-2010-0645; Directorate
Identifier 2009-NM-200-AD.
Comments Due Date
(a) The FAA must receive comments on this AD action by August
16, 2010.
Affected ADs
(b) This AD supersedes AD 2008-18-10, Amendment 39-15667.
Applicability
(c) This AD applies to McDonnell Douglas Corporation Model MD-
90-30 airplanes, certificated in any category, as identified in
Boeing Alert Service Bulletin MD90-54A003, Revision 2, dated
February 12, 2010.
Subject
(d) Air Transport Association (ATA) of America Code 54:
Nacelles/Pylons.
[[Page 38058]]
Unsafe Condition
(e) This AD results from reports of loose, cracked, or missing
fasteners in the aft mount support fitting of the left and right
engines. The Federal Aviation Administration is issuing this AD to
prevent loose, cracked, or missing fasteners in the engine aft
support mount fitting, which could lead to separation of the support
fitting from the pylon, and could result in separation of the engine
from the airplane.
Compliance
(f) You are responsible for having the actions required by this
AD performed within the compliance times specified, unless the
actions have already been done.
Replacement and Inspection
(g) Except as required by paragraph (i) of this AD, at the
applicable time specified in paragraph 1.E. ``Compliance'' of Boeing
Alert Service Bulletin MD90-54A003, Revision 2, dated February 12,
2010: Replace the upper row of fasteners (Row A) of the support
fittings of the left and right engine aft mounts with new fasteners,
in accordance with the Accomplishment Instructions of Boeing Alert
Service Bulletin MD90-54A003, Revision 2, dated February 12, 2010.
Repeat the replacement thereafter at intervals not to exceed 10,000
flight cycles.
(h) Concurrently with any replacement required by paragraph (g)
of this AD: Perform a general visual inspection for defects of the
lower row fasteners (Row B) of the support fittings of the left and
right engine aft mounts, in accordance with the Accomplishment
Instructions of Boeing Alert Service Bulletin MD90-54A003, Revision
2, dated February 12, 2010. Defects include missing, loose, and
damaged fasteners.
(1) If no defect is found during any general visual inspection
required by paragraph (h) of this AD, before further flight, insert
a 0.0015-inch feeler gauge between the washer and the structure, or
between the fastener head and structure, as applicable, to detect a
gap condition, in accordance with the Accomplishment Instructions of
Boeing Alert Service Bulletin MD90-54A003, Revision 2, dated
February 12, 2010. A gap condition is a defect identified in any
location where the feeler gauge can slip completely between a washer
or a fastener head and the structure.
(i) If no defect is found during any gap check required by
paragraph (h)(1) of this AD, before further flight, apply torque to
the fasteners of the lower row (Row B) to determine if there is a
defect, in accordance with the Accomplishment Instructions of Boeing
Alert Service Bulletin MD90-54A003, Revision 2, dated February 12,
2010. A defect is any fastener that turns with the application of
the specified torque. If any defect is found, before further flight,
replace all clearance fit fasteners in the lower row (Row B), in
accordance with the Accomplishment Instructions of Boeing Alert
Service Bulletin MD90-54A003, Revision 2, dated February 12, 2010.
(ii) If any defect is found during any gap check required by
paragraph (h)(1) of this AD, before further flight, replace all
clearance fit fasteners in the lower row (Row B), in accordance with
the Accomplishment Instructions of Boeing Alert Service Bulletin
MD90-54A003, Revision 2, dated February 12, 2010.
(2) If any defect is found during any general visual inspection
required by paragraph (h) of this AD, before further flight, replace
all clearance fit fasteners in the lower row (Row B), in accordance
with the Accomplishment Instructions of Boeing Alert Service
Bulletin MD90-54A003, Revision 2, dated February 12, 2010.
Exception to Service Bulletin Compliance Times
(i) Where Boeing Alert Service Bulletin MD90-54A003, Revision 2,
dated February 12, 2010, specifies a compliance time after the
original issue date on the service bulletin, this AD requires
compliance within the specified compliance time after the effective
date of this AD.
Credit for Actions Accomplished in Accordance With Previous Service
Information
(j) Replacements and inspections accomplished before the
effective date of this AD in accordance with Boeing Alert Service
Bulletin MD90-54A003, Revision 1, dated November 17, 2009, are
considered acceptable for compliance with the corresponding actions
required by this AD.
Alternative Methods of Compliance (AMOCs)
(k)(1) The Manager, Los Angeles Aircraft Certification Office
(ACO), FAA, has the authority to approve AMOCs for this AD, if
requested using the procedures found in 14 CFR 39.19. Send
information to 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.
(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 principal maintenance inspector (PMI) or
principal avionics inspector (PAI), as appropriate, or lacking a
principal inspector, your local Flight Standards District Office.
The AMOC approval letter must specifically reference this AD.
(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 the
Boeing Commercial Airplanes Organization Designation Authorization
(ODA) that 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 14 CFR 25.571,
Amendment 45, and the approval must specifically refer to this AD.
Issued in Renton, Washington, on June 23, 2010.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2010-15988 Filed 6-30-10; 8:45 am]
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