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 Department of Transportation Federal Aviation Administration 14 CFR Part 39
[Docket No. FAA-2011-0218; Directorate Identifier 2010-NM-164-AD]
RIN 2120-AA64
 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 would require a detailed inspection to detect distress and existing repairs to the leading edge structure of the vertical stabilizer at the splice at Station Zfs=52.267; repetitive inspections for cracking in the front spar cap forward flanges of the vertical stabilizer, and either the aft flanges or side skins; repetitive inspections for loose and missing fasteners; and related investigative and corrective actions if necessary. This proposed AD was prompted by reports of cracked vertical stabilizer skin, a severed front spar cap, elongated fastener holes at the leading edge of the vertical stabilizer, and a cracked front spar web and front spar cap bolt holes in the vertical stabilizer. We are proposing this AD to detect and correct such cracking damage, which could result in the structure being unable to support limit load, and could lead to the loss of the vertical stabilizer.
 DATES: We must receive comments on this proposed AD by April 28, 2011.
 ADDRESSES: You may send comments by any of the following methods: *Federal Rulemaking 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:*
                         Deliver to Mail address above 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; 
                        *phone:*
                         206-544-5000, extension 2; fax: 206-766-5683; 
                        *e-mail:*( print page 13547)
                        *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 
                    *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 (
                    *phone:*
                     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, Los Angeles ACO, 3960 Paramount Blvd., Lakewood, CA 90712-4137; 
                        *phone:*
                         562-627-5233; fax: 562-627-5210; 
                        *e-mail:**Roger.Durbin@faa.gov.*


SUPPLEMENTARY INFORMATION:  Comments Invited We invite you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under the 
                    **ADDRESSES**
                     section. Include “Docket No. FAA-2011-0218; Directorate Identifier 2010-NM-164-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 We have received a report of elongated fastener holes at the leading edge of the vertical stabilizer at station Zfs=52.267. The affected Model MD-90 airplane had accrued 15,555 total flight hours and 14,310 total landing cycles when the elongated fastener holes were found. Additionally, we have received two reports of Model MD-80 airplanes with cracked vertical stabilizer skin at station Zfs=52.267. Subsequent inspection revealed a severed front spar cap and a cracked front spar web. The affected Model MD-80 airplanes had accrued between 39,749 and 56,212 total flight hours and between 32,176 and 44,001 total landing cycles when the cracks/anomalies were found. Cracks were also found on several other Model MD-80 airplanes in the vertical stabilizer front spar cap bolt holes. The cause of the fastener damage, elongated fastener holes, and skin cracks is high loading occurrences, such as, but not limited to, in-flight turbulence. Cracks in the vertical stabilizer leading edge and front spar cap could result in the structure being unable to support limit load, and could lead to the loss of the vertical stabilizer. Related Rulemaking We are considering similar rulemaking for The Boeing Company Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 airplanes. The Model MD-90 airplane vertical stabilizer is similar in design and loading to that of the Model MD-80 airplane vertical stabilizer. Relevant Service Information We reviewed Boeing Alert Service Bulletin MD90-55A014, dated June 24, 2010. The service information describes procedures for a detailed inspection to detect distress in, and existing repairs to the leading edge structure of the vertical stabilizer at the splice at Station Zfs=52.267, and corrective action if necessary. The corrective action is doing a leading edge repair, if the leading edge is distressed, by repairing or replacing the leading edge splice band of the vertical stabilizer. The service information defines “distress” as deformed holes, elongated holes, oversized holes or cracks in the leading edge skin and splice; and “existing repairs” as bushings, washers or reinforcing repairs to the leading edge. The service information also describes procedures for repetitive inspections for cracking in the front spar cap of the vertical stabilizer using the inspections specified in Option 1 or Option 2 of the service information, and related investigative and corrective actions if necessary. Option 1 involves an open hole eddy current high frequency (ETHF) inspection of the forward flanges and a radiographic testing inspection of the aft flanges; Option 2 involves an open hole ETHF inspection of the forward flanges and an ETHF surface inspection of the side skins of the aft flanges. For airplanes on which any cracking is found, the related investigative action is confirming the cracking through a specified evaluation/verification process. The corrective action is contacting Boeing and doing the repair in accordance with Boeing's instructions. The service information also describes procedures for repetitive detailed inspections for indications of loose and missing fasteners of the leading edge structure of the vertical stabilizer at the splice at Station Zfs=52.267, and corrective actions if necessary. The corrective action, if any loose or missing fasteners are found, is repairing the leading edge by repairing or replacing the leading edge splice band of the vertical stabilizer. FAA's Determination We are proposing 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 same type designs. Proposed AD Requirements This proposed AD would require accomplishing the actions specified in the service information described previously, except as discussed under “Differences Between the Proposed AD and the Service Information.” Differences Between the Proposed AD and the Service Information The service bulletin specifies to contact the manufacturer for instructions on how to repair certain conditions, but this proposed AD would require repairing those conditions in one of the following ways: In accordance with a method that we approve, or
                Using data that meet the certification basis of the airplane, and that have been approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) whom we have authorized to make those findings. Costs of Compliance We estimate that this proposed AD will affect 19 airplanes of U.S. registry. We estimate the following costs to comply with this proposed AD:
                    ( print page 13548) Estimated Costs
Action
Labor cost
Parts cost
Cost per product
Cost on U.S. operatorsInspection for existing repairs, distress
10 work-hours × $85 per hour = $850
$0
$850
$16,150.Repetitive inspections for cracking and loose and missing fasteners
7 work-hours × $85 per hour = $595 per inspection cycle
$0
$595 per inspection cycle
$11,305 per inspection cycle.
 We have received no definitive data that would enable us to provide cost estimates for the on-condition action specified in this proposed 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 We 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 this 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), (3) Will not affect intrastate aviation in Alaska, and (4) 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. 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. § 39.13
  2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD): The Boeing Company: Docket No. FAA-2011-0218; Directorate Identifier 2010-NM-164-AD. Comments Due Date (a) We must receive comments by April 28, 2011. Affected ADs (b) None. Applicability (c) This AD applies to The Boeing Company Model MD-90-30 airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin MD90-55A014, dated June 24, 2010. Subject (d) Joint Aircraft System Component (JASC)/Air Transport Association (ATA) of America Code 55, Stabilizers. Unsafe Condition (e) This AD was prompted by reports of cracked vertical stabilizer skin, a severed front spar cap, elongated fastener holes at the leading edge of the vertical stabilizer, and a cracked front spar web and front spar cap bolt holes in the vertical stabilizer. We are issuing this AD to detect and correct such cracking damage, which could result in the structure being unable to support limit load, and could lead to the loss of the vertical stabilizer. Compliance (f) Comply with this AD within the compliance times specified, unless already done. Inspections for Distress/Repairs (g) Within 4,100 flight cycles after the effective date of this AD, do a detailed inspection for distress in and existing repairs to the leading edge structure of the vertical stabilizer at the splice at Station Zfs=52.267, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD90-55A014, dated June 24, 2010. Repetitive Inspections for Cracks, and Related Investigative and Corrective Actions (h) Before further flight after doing the inspection required by paragraph (g) of this AD, inspect for cracks of the left and right vertical stabilizer front spar cap, in accordance with either Option 1 or Option 2 as specified in the Accomplishment Instructions of Boeing Alert Service Bulletin MD90-55A014, dated June 24, 2010. If any crack is found, before further flight, evaluate and verify to confirm all crack indications, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD90-55A014, dated June 24, 2010. (1) If any cracking is confirmed, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (l) of this AD. (2) If no cracking is confirmed, repeat the inspection thereafter at intervals not to exceed the applicable interval specified in paragraph (h)(2)(i) or (h)(2)(ii) of this AD. (i) If the most recent inspection was done using Option 1, the next inspection must be done within 4,400 flight cycles. (ii) If the most recent inspection was done using Option 2, the next inspection must be done within 3,000 flight cycles. Leading Edge Repair (i) If leading edge distress is found during the detailed inspection required by paragraph (g) of this AD, before further flight and after accomplishing the inspection required by paragraph (h) of this AD, repair the leading edge, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD90-55A014, dated June 24, 2010. Inspection for Loose/Missing Fasteners (j) For airplanes on which no cracking is confirmed during the initial inspection required by paragraph (h) of this AD: At the applicable time specified in paragraph (j)(1) or (j)(2) of this AD, do a detailed inspection for indications of loose and missing fasteners, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD90-55A014, dated June 24, 2010. If any loose or missing fastener is found, before further flight, repair the leading edge, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin MD90-55A014, dated June 24, 2010. (1) If the inspection required by paragraph (h) was done using Option 1, do the inspection required by paragraph (j) of this AD within 4,400 flight cycles after accomplishing the inspection required by paragraph (h) of this AD. 
                                ( print page 13549) (2) If inspection required by paragraph (h) was done using Option 2, do the inspection required by paragraph (j) of this AD within 3,000 flight cycles after accomplishing the inspection required by paragraph (h) of this AD. (k) For airplanes on which no cracking is confirmed during the most recent inspection required by paragraph (h) of this AD: Repeat the inspection for loose and missing fasteners required by paragraph (j) of this AD thereafter at intervals not to exceed the applicable time specified in paragraph (k)(1) or (k)(2) of this AD. (1) If the most recent inspection required by paragraph (h) was done using Option 1, the next inspection required by paragraph (j) of this AD must be done within 4,400 flight cycles after accomplishing the most recent inspection required by paragraph (j) of this AD. (2) If the most recent inspection required by paragraph (h) was done using Option 2, the next inspection required by paragraph (j) of this AD must be done within 3,000 flight cycles after the most recent inspection required by paragraph (j) of this AD. Alternative Methods of Compliance (AMOCs) (l)(1) The Manager, Los Angeles Aircraft Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the ACO, send it to the attention of the person identified in the Related Information section of this AD. (2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office. (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 the approval must specifically refer to this AD. Related Information (m) For more information about this AD, contact Roger Durbin, Aerospace Engineer, Airframe Branch, ANM-120L, Los Angeles ACO, 3960 Paramount Blvd., Lakewood, CA 90712-4137; 
                                *phone:*
                                 562-627-5233; 
                                *fax:*
                                 562-627-5210; 
                                *e-mail:**Roger.Durbin@faa.gov*. (n) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, 3855 Lakewood Boulevard, MC D800-0019, Long Beach, California 90846-0001; 
                                *phone:*
                                 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, the FAA, 1601 Lind Avenue SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221.
 Issued in Renton, Washington, on March 4, 2011. Kalene C. Yanamura, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.


[FR Doc. 2011-5726 Filed 3-11-11; 8:45 am] BILLING CODE 4910-13-P