Airworthiness Directives; McDonnell Douglas Corporation Model MD-90-30 Airplanes, 38056-38058 [2010-15988]

Download as PDF 38056 Federal Register / Vol. 75, No. 126 / Thursday, July 1, 2010 / Proposed Rules 01803; e-mail: kevin.dickert@faa.gov; telephone (781) 238–7117; fax (781) 238– 7199, for more information about this AD. (x) Contact Pratt & Whitney, 400 Main St., East Hartford, CT 06108; telephone (860) 565–8770, fax (860) 565–4503, for a copy of the service information referenced in this AD. Issued in Burlington, Massachusetts, on June 22, 2010. Peter A. White, Assistant Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. 2010–16010 Filed 6–30–10; 8:45 am] BILLING CODE 4910–13–P 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 WReier-Aviles on DSKGBLS3C1PROD with PROPOSALS AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Notice of proposed rulemaking (NPRM). 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. VerDate Mar<15>2010 15:20 Jun 30, 2010 Jkt 220001 You may send comments by any of the following methods: • Federal eRulemaking Portal: Go to https://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 dse.boecom@boeing.com; 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. ADDRESSES: Examining the AD Docket You may examine the AD docket on the Internet at https:// 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 PO 00000 Frm 00015 Fmt 4702 Sfmt 4702 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 https:// 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 E:\FR\FM\01JYP1.SGM 01JYP1 38057 Federal Register / Vol. 75, No. 126 / Thursday, July 1, 2010 / Proposed Rules 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 Action Average labor rate per hour Work hours Replacement ............ 14 $85 Inspections ............... 4 85 WReier-Aviles on DSKGBLS3C1PROD with PROPOSALS 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 VerDate Mar<15>2010 15:20 Jun 30, 2010 Jkt 220001 Parts $152 per replacement. $0 ............................. $1,342 per replacement cycle. $340 per inspection cycle. 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: PO 00000 Frm 00016 Fmt 4702 Number of U.S.-registered airplanes Cost per airplane Sfmt 4702 13 13 Fleet cost $17,446 per replacement cycle. $4,420 per inspection cycle. 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. § 39.13 [Amended] 2. The FAA amends § 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. E:\FR\FM\01JYP1.SGM 01JYP1 38058 Federal Register / Vol. 75, No. 126 / Thursday, July 1, 2010 / Proposed Rules 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. 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. WReier-Aviles on DSKGBLS3C1PROD with PROPOSALS 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. Exception to Service Bulletin Compliance Times 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 VerDate Mar<15>2010 15:20 Jun 30, 2010 Jkt 220001 (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] BILLING CODE 4910–13–P PO 00000 Frm 00017 Fmt 4702 Sfmt 4702 DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2010–0642; Directorate Identifier 2007–NM–332–AD] RIN 2120–AA64 Airworthiness Directives; BAE Systems (Operations) Limited Model BAe 146 and Avro 146–RJ Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). SUMMARY: We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: * * * [F]uel leaks and failed fasteners [have been reported] in the region of the rear spar root joint attachment fitting at wing rib 2. * * * * * * * * The unsafe condition is stress corrosion failures in the region of the rear spar root joint attachment fitting at wing rib 2, which could lead to reduced structural integrity of the wing, and consequent reduced controllability of the airplane. The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI. 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 https://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 W12–40, 1200 New Jersey Avenue, SE., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. For service information identified in this proposed AD, contact BAE Systems (Operations) Limited, Customer Information Department, Prestwick E:\FR\FM\01JYP1.SGM 01JYP1

Agencies

[Federal Register Volume 75, Number 126 (Thursday, July 1, 2010)]
[Proposed Rules]
[Pages 38056-38058]
From the Federal Register Online via the Government Printing 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).

-----------------------------------------------------------------------

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 https://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 
dse.boecom@boeing.com; 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 https://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 https://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
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                   Number of U.S.-
               Action                  Work hours     Average labor          Parts            Cost per airplane      registered          Fleet cost
                                                      rate per hour                                                   airplanes
--------------------------------------------------------------------------------------------------------------------------------------------------------
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.
--------------------------------------------------------------------------------------------------------------------------------------------------------

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]
BILLING CODE 4910-13-P
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