AD 2010-09-05

The FAA is superseding an existing airworthiness directive (AD) that applies to all The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. The existing AD currently requires doing a detailed inspection of the inboard and outboard aft attach lugs of the left and right elevator control tab mechanisms for gaps between the swage ring and the aft attach lug, and between the spacer and the aft attach lug; trying to move or rotate the spacer using hand pressure; and replacing any discrepant elevator tab control mechanism, including performing the detailed inspection on the replacement part before and after installation. For certain airplanes, this new AD adds improved repetitive inspections for discrepancies of the inboard and outboard aft attach lugs of the left and right elevator control tab mechanisms, and replacement if necessary. For certain other airplanes, this new AD adds a one-time inspection for discrepancies of the inboard and outboard aftattach lugs of the left and right elevator control tab mechanisms, and replacement if necessary. For airplanes on which the elevator control tab mechanism is replaced with a certain mechanism, this AD requires repetitive inspections for discrepancies of the elevator control tab mechanism and replacement if necessary. Replacing the elevator control tab mechanism with a new, Boeing-built mechanism terminates the repetitive inspections. This AD results from a report of failure of the aft attach lugs on the left elevator tab control mechanism, which resulted in severe elevator vibration; this event occurred on an airplane on which the existing AD had been done. We are issuing this AD to detect and correct a loose bearing in the aft lug of the elevator tab control mechanism, which could result in unwanted elevator and tab vibration. Consequent structural failure of the elevator or horizontal stabilizer could result in loss of structural integrity and aircraft control.

Final rule; request for comments.

2010-09-05 The Boeing Company: Amendment 39-16270. Docket No. FAA- 2010-0430; Directorate Identifier 2010-NM-098-AD. \n\nEffective Date \n\n\t(a) This AD becomes effective April 29, 2010. \n\nAffected ADs \n\n\t(b) This AD supersedes AD 2010-06-51, Amendment 39-16250. \n\nApplicability \n\n\t(c) This AD applies to all The Boeing Company Model 737-600, - 700, -700C, -800, -900, and -900ER series airplanes; certificated in any category. \n\nSubject \n\n\t(d) Air Transport Association (ATA) of America Code 27: Flight controls. \n\nUnsafe Condition \n\n\t(e) This AD results from a report of failure of the aft attach lugs on the left elevator tab control mechanism, which resulted in severe elevator vibration; this event occurred on an airplane on which the existing AD had been done. The Federal Aviation Administration is issuing this AD to detect and correct a loose bearing in the aft lug of the elevator tab control mechanism, which could result in unwanted elevator and tab vibration. Consequent structural failure of the elevator or horizontal stabilizer could result in loss of structural integrity and aircraft control. \n\nCompliance \n\n\t(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. \n\nRestatement of Requirements of AD 2010-06-51 \n\nInspection and Corrective Action \n\n\t(g) For Groups 1, 2, and 3; and Group 4, Configuration 2; as identified in Boeing Alert Service Bulletin 737-27A1296, dated March 12, 2010: At the applicable time specified in paragraph 1.E. Compliance of Boeing Alert Service Bulletin 737-27A1296, dated March 12, 2010, except as required by paragraph (i) of this AD, do a detailed inspection of the inboard and outboard aft attach lugs of the left and right elevator control tab mechanisms for gaps between the swage ring and the aft attach lug, and between the spacer and the aft attach lug; and try to move or rotate the spacer using hand pressure; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-27A1296, dated March 12, 2010. Doing the inspection required by paragraph (m) or (o) of this AD, as applicable, terminates the requirements of this paragraph. \n\t(h) If, during accomplishment of the actions required by paragraph (g) of this AD, any gap is found between the swage ring and the aft attach lug, or between the spacer and the aft attach lug; or if the spacer moves or rotates: Before further flight, do the actions required by paragraphs (h)(1) and (h)(2) of this AD, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-27A1296, dated March 12, 2010. \n\t(1) Inspect the replacement elevator tab control mechanism for discrepancies, as specified in paragraph (g) of this AD; and, if no discrepancy is found, install the replacement elevator tab control mechanism. \n\t(2) Re-inspect the installed elevator tab control mechanism, as required by paragraph (g) of this AD. \n\nException to Service Bulletin Specifications \n\n\t(i) Where Boeing Alert Service Bulletin 737-27A1296, dated March 12, 2010, specifies a compliance time after the date of the original issue of the service bulletin, this AD requires compliance within the specified compliance time after April 7, 2010 (the effective date of AD 2010-06-51). \n\nInspection Done According to Multi Operator Message (MOM) \n\n\t(j) An inspection done before April 7, 2010, according to Boeing Multi Operator Message Number MOM-MOM-10-0159-01B, dated March 10, 2010, is considered acceptable for compliance with the corresponding inspection specified in paragraph (g) of this AD. \n\nReporting \n\n\t(k) At the applicable time specified in paragraph (k)(1) or (k)(2) of this AD: Submit a report of the findings (both positive and negative) of the inspections required by paragraph (g) of this AD to Boeing Commercial Airplanes Group, Attention: Manager, Airline Support, e-mail: rse.boecom@boeing.com. The reportmust include the inspection results including a description of any discrepancies found, the airplane line number, and the number of flight cycles and flight hours accumulated on the airplane. Under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.), the Office of Management and Budget (OMB) has approved the information collection requirements contained in this AD and has assigned OMB Control Number 2120-0056. \n\t(1) If the inspection was done on or after April 7, 2010: Submit the report within 10 days after the inspection. \n\t(2) If the inspection was done before April 7, 2010: Submit the report within 10 days after April 7, 2010. \n\nParts Installation Specified in AD 2010-06-51 \n\n\t(l) For all airplanes: As of April 7, 2010, and until the effective date of this AD, no person may install an elevator tab control mechanism, part number 251A2430-( ), on any airplane, unless the mechanism has been inspected before and after installation, in accordance with the requirements of paragraph (g) of this AD, and no discrepancies have been found. As of the effective date of this AD, comply with paragraph (u) of this AD. \n\nNew Requirements of This AD \n\nRepetitive Inspections for Group 1 Airplanes, as Identified in Boeing Alert Service Bulletin 737-27A1297, Dated April 16, 2010 \n\n(m) For Group 1 airplanes, as identified in Boeing Alert Service Bulletin 737-27A1297, dated April 16, 2010: Except as required by paragraph (n) of this AD, within 12 days after the effective date of this AD, do a detailed inspection for discrepancies of the inboard and outboard aft attach lugs of the left and right elevator control tab mechanisms, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-27A1297, dated April 16, 2010. Repeat the inspection thereafter at intervals not to exceed 300 flight hours until the replacement specified in paragraph (r) of this AD is done. Doing the initial inspection required by this paragraph terminates the requirements of paragraph (g) of this AD. \n\t(n) For Group 1 airplanes as identified in Boeing Alert Service Bulletin 737-27A1297, dated April 16, 2010: Beginning 7 days after the effective date of this AD, no person may operate an airplane on an extended twin operations (ETOPS) flight unless the initial inspection required by paragraph (m) of this AD has been accomplished. \n\nOne-Time Inspection for Group 2, Configuration 1 Airplanes, as Identified in Boeing Alert Service Bulletin 737-27A1297, Dated April 16, 2010 \n\n\t(o) For Group 2, Configuration 1 airplanes as identified in Boeing Alert Service Bulletin 737-27A1297, dated April 16, 2010: Within 30 days after the effective date of this AD, do a one-time detailed inspection for discrepancies of the inboard and outboard aft attach lugs of the left and right elevator control tab mechanisms, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-27A1297, dated April 16, 2010. Doing the inspection required by this paragraph terminates the requirements of paragraph (g) of this AD. \n\nCorrective Actions \n\n\t(p) If, during any inspection required by paragraph (m), (o), or (q) of this AD, any discrepancy is found, before further flight, replace the elevator tab control mechanism by doing the actions specified in paragraphs (p)(1) and (p)(2) of this AD. \n\t(1) Do a detailed inspection for discrepancies of the replacement elevator tab control mechanism; and, if no discrepancy is found, install the replacement elevator tab control mechanism; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-27A1297, dated April 16, 2010. If any discrepancy is found, then that elevator tab control mechanism cannot be installed and the actions specified in this paragraph must be done before further flight on another replacement elevator tab control mechanism. \n\t(2) Re-inspect the installed elevator tab control mechanism using the inspection procedure specified in paragraph (o) of this AD. \n\nRepetitive Inspections for Certain Group 2, Configuration 1 Airplanes, as Identified in Boeing Alert Service Bulletin 737-27A1297, Dated April 16, 2010 \n\n\t(q) For Group 2, Configuration 1 airplanes as identified in Boeing Alert Service Bulletin 737-27A1297, dated April 16, 2010, on which the elevator control tab mechanism is replaced with a mechanism other than a new, Boeing-built mechanism: Within 300 flight hours after doing the replacement, do a detailed inspection for discrepancies of the inboard and outboard aft attach lugs of the left and right elevator control tab mechanisms, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-27A1297, dated April 16, 2010. Repeat the inspection thereafter at intervals not to exceed 300 flight hours until the replacement specified in paragraph (r) of this AD is done. \n\nTerminating Action \n\n\t(r) Replacing an elevator tab mechanism with a new, Boeing-built mechanism, as specifiedin paragraphs (r)(1) and (r)(2) of this AD, terminates the inspections required by paragraphs (m), (o), and (q) of this AD. \n\n\tNote 1: Refer to paragraphs 3.B.7.b.(1)(a)1) and 3.B.7.b.(1)(a)2) of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-27A1297, dated April 16, 2010, to establish whether the mechanism is Boeing-built. \n\n\t(1) Do a detailed inspection for discrepancies of the new, Boeing-built replacement elevator tab control mechanism; and, if no discrepancy is found, install the replacement elevator tab control mechanism; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-27A1297, dated April 16, 2010. If any discrepancy is found, then that elevator tab control mechanism cannot be installed and the actions specified in this paragraph must be done on another new, Boeing-built replacement elevator tab control mechanism. \n\t(2) Re-inspect the installed elevator tab control mechanism using the inspection procedure specified in paragraph (o) of this AD. \n\nReporting \n\n\t(s) At the applicable time specified in paragraph (s)(1) or (s)(2) of this AD: Submit a report of any findings (positive and negative) of the first inspection required by paragraphs (m), (o), and (q) of this AD, and any positive findings from the repetitive inspections required by this AD, to Boeing Commercial Airplanes Group, Attention: Manager, Airline Support, e-mail: rse.boecom@boeing.com. The report must include the inspection results including a description of any discrepancies found, the airplane line number, and the total number of flight cycles and flight hours accumulated on the airplane. Under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.), the Office of Management and Budget (OMB) has approved the information collection requirements contained in this AD and has assigned OMB Control Number 2120-0056. \n\t(1) If the inspection was done on or after the effective date of this AD: Submit the report within 10 days after the inspection. \n\t(2) If the inspection was done before the effective date of this AD: Submit the report within 10 days after the effective date of this AD. \n\nReturn of Discrepant Parts \n\n\t(t) If, during any inspection required by paragraph (m), (o), or (q) of this AD, any discrepancy is found, and if the inspection was done on or after the effective date of this AD: Within 30 days after the inspection, return the discrepant elevator tab control mechanism, and include a copy of the inspection report sent to Boeing, as specified in paragraph (s) of this AD, to: Spares Distribution Center, Attention: Manager, Airline Support, Repair Overhaul and Exchange Services, SSA 111, Boeing Commercial Airplane Group, 2201 South 142nd Street, Door W10, Seatac, Washington, USA, 98168. \n\nParts Installation \n\n\t(u) For all airplanes identified in paragraph (c) of this AD: As of the effective date of this AD, comply with the conditions specified in paragraphs (u)(1) and (u)(2) ofthis AD. \n\t(1) No person may install an elevator tab control mechanism, part number 251A2430-(), on any airplane, unless the mechanism has been inspected before and after installation using the inspection procedures specified in either paragraphs (p)(1) and (p)(2) of this AD, or in paragraphs (r)(1) and (r)(2) of this AD; and no discrepancies have been found. \n\t(2) An elevator tab control mechanism, part number 251A2430-(), that is not a new, Boeing-built elevator tab control mechanism may be installed, provided that the mechanism is inspected using the inspection procedures specified in paragraph (m) of this AD within 300 flight hours after doing the installation, and that the inspection is repeated thereafter at the interval specified in paragraph (m) of this AD. \n\nAlternative Methods of Compliance (AMOCs) \n\n\t(v)(1) The Manager, Seattle 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: Kelly McGuckin, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle ACO, 1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone 425-917-6490; fax 425-917-6590. Information may be e-mailed to 9-ANM-Seattle-ACO-AMOC- Requests@faa.gov. \n\t(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 refer to this AD. \n\t(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, Seattle 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. \n\t(4) AMOCs approved previously in accordance with AD 2010-06-51 are approved as AMOCs for the corresponding provisions of paragraph (g) or (l) of this AD. \n\nMaterial Incorporated by Reference \n\n\t(w) You must use Boeing Alert Service Bulletin 737-27A1296, dated March 12, 2010; or Boeing Alert Service Bulletin 737-27A1297, dated April 16, 2010; as applicable, to do the actions required by this AD, unless the AD specifies otherwise. \n\t(1) The Director of the Federal Register approved the incorporation by reference of Boeing Alert Service Bulletin 737- 27A1297, dated April 16, 2010, under 5 U.S.C. 552(a) and 1 CFR part 51. \n\t(2) The Director of the Federal Register previously approved the incorporation by reference of Boeing Alert Service Bulletin 737- 27A1296, dated March 12, 2010, on April 7, 2010 (75 FR16648, April 2, 2010). \n\t(3) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P. O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-544-5000, extension 1; fax 206-766-5680; e-mail me.boecom@boeing.com; Internet https://www.myboeingfleet.com. \n\t(4) You may review copies of the 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. \n\t(5) You may also review copies of the service information that is incorporated by reference 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.

Discussion \n\n\tOn March 18, 2010, we issued AD 2010-06-51, amendment 39-16250 (75 FR 16648, April 2, 2010). That AD applies to all The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. That AD requires doing a detailed inspection of the inboard and outboard aft attach lugs of the left and right elevator control tab mechanisms for gaps between the swage ring and the aft attach lug, and between the spacer and the aft attach lug; trying to move or rotate the spacer using hand pressure; and replacing any discrepant elevator tab control mechanism, including performing the detailed inspection on the replacement part before and after installation. That AD resulted from a report of failure of the aft attach lugs on the left elevator tab control mechanism, which resulted in severe elevator vibration. The actions specified in that AD are intended to detect and correct a loose bearing in the aft lug of the elevator tab control mechanism, which could result in unwanted elevator and tab vibration. Consequent structural failure of the elevator or horizontal stabilizer could result in loss of structural integrity and aircraft control. \n\nActions Since AD Was Issued \n\n\tSince we issued that AD, we received an additional report of failure of the aft attach lugs on the left elevator tab control mechanism. This event occurred on an airplane that had been inspected in accordance with AD 2010-06-51. We have determined that an improved inspection is necessary to address the identified unsafe condition. We verified the inspection procedure with an operator prior to approval of Boeing Alert Service Bulletin 737-27A1297, dated April 16, 2010. \n\nRelevant Service Information \n\n\tWe have reviewed Boeing Alert Service Bulletin 737-27A1297, dated April 16, 2010. The service bulletin describes procedures for Model 737-700, -700C, -800, and -900ER series airplanes, line numbers 2508 through 3250 inclusive. The service bulletinspecifies a one-time detailed inspection (for all airplanes having line numbers 2708 through 3250 inclusive that are approved for operation under ETOPS), and repetitive detailed inspections (for all airplanes having line numbers 2508 through 2707 inclusive) for discrepancies of the inboard and outboard aft attach lugs of the left and right elevator control tab mechanisms, and replacing any discrepant mechanisms. The detailed inspection includes the use of a feeler gage and finger pressure and instructs to apply hand pressure during the inspection for gaps and looseness. Discrepancies include the following conditions: \n\tThe spacer moves or rotates. \n\tGap exists between the swage ring and the outer face of the aft attach lug such that a 0.005 inch feeler gage can be inserted more than 0.025 inch. \n\tGap exists between two nested lugs such that a 0.005 inch feeler gage can be inserted more than 0.050 inch. \n\tGap exists between the inner face of the aft attach lug and the spacer such that a 0.005 inch feeler gage can be inserted more than 0.050 inch. \n\tThe service bulletin also specifies that for airplanes on which the elevator control tab mechanism is replaced with an elevator control tab mechanism that is not a Boeing-built mechanism, the repetitive detailed inspections described above are necessary. \n\tThe service bulletin also specifies that replacing discrepant elevator control tab mechanisms with Boeing-built elevator control tab mechanisms eliminates the need for the repetitive inspections. \n\nFAA's Determination and Requirements of This AD \n\n\tThe unsafe condition described previously is likely to exist or develop on other airplanes of these same type designs. For this reason, we are issuing this AD to supersede AD 2010-06-51. This new AD retains the inspection requirements of AD 2010-06-51, and also requires, for certain airplanes, accomplishing the actions specified in Boeing Alert Service Bulletin 737-27A1297, dated April 16, 2010, described previously,except as discussed under "Differences Between the AD and Boeing Alert Service Bulletin 737-27A1297.'' This new AD also requires sending the inspection results to the manufacturer and sending discrepant elevator control tab mechanisms to the manufacturer. \n\nDifferences Between the AD and Boeing Alert Service Bulletin 737- 27A1297 \n\n\tBoeing Alert Service Bulletin 737-27A1297, dated April 16, 2010, specifies that replacing discrepant elevator control tab mechanisms with Boeing-built elevator control tab mechanisms eliminates the need for the repetitive inspections. This AD specifies that installing only a new, Boeing-built elevator control tab mechanism terminates the repetitive inspections. We have not received sufficient data to demonstrate that repaired elevator control tab mechanisms were repaired using procedures that will adequately address the identified unsafe condition. We find that only allowing new Boeing elevator control tab mechanisms as terminating action, as specifiedby this AD, will adequately address the unsafe condition. We have coordinated this issue with Boeing. \n\tWhile Boeing Alert Service Bulletin 737-27A1297, dated April 16, 2010, does not identify Model 737-600 and -900 series airplanes, this AD applies to those airplanes because they are subject to the Parts Installation paragraph of this AD. \n\nInterim Action \n\n\tThis AD is considered to be interim action. The inspection reports and the returned discrepant parts that are required by this AD will enable the airframe manufacturer and the FAA to obtain better insight into the nature, cause, and extent of the issue, and eventually to develop final action to address the unsafe condition. Once final action has been identified, we might consider further rulemaking. \n\nFAA's Justification and Determination of the Effective Date \n\n\tA loose bearing in the aft lug of the elevator tab control mechanism could result in unwanted elevator and tab vibration. Consequent structural failure of the elevator or horizontal stabilizer could result in loss of structural integrity and aircraft control. Because of our requirement to promote safe flight of civil aircraft and thus the critical need to ensure the structural integrity of the airplane, and the short compliance time involved with this action, this AD must be issued immediately. \n\tBecause 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. \n\nComments Invited \n\n\tThis 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-2010-0430;Directorate Identifier 2010-NM-098-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. \n\tWe 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. \n\nAuthority for This Rulemaking \n\n\tTitle 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. \n\tWe 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. \n\nRegulatory Findings \n\n\tWe have determined that 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. \n\nFor the reasons discussed above, I certify that the regulation: \n\n\t1. Is not a "significant regulatory action'' under Executive Order 12866; \n\t2. Is not a "significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and \n\t3. 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. \n\tWe prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation. \n\nList of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \n\nAccordingly, under the authority delegated to me by the Administrator, the FAA amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: \n\nPART 39--AIRWORTHINESS DIRECTIVES \n\n1. The authority citation for part 39 continues to read as follows: \n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\nSec. 39.13 (Amended) \n\n2. The Federal Aviation Administration (FAA) amends Sec. 39.13 by removing amendment 39-16250 (75 FR 16648, April 2, 2010) and by adding the following new airworthiness directive (AD):