## EMERGENCY AIRWORTHINESS DIRECTIVE

Aircraft Certification Service Washington, DC
We post Emergency ADs on the internet at "www.faa.gov" U.S. Department of Transportation Federal Aviation Administration

ISSUE DATE: March 12,2010 AD 2010-06-51; Docket No. FAA-201 0-0230; Directorate Identifier 201O-NM-071-AD Emergency airworthiness directive (AD) 2010-06-51 is sent to all owners and operators ofThe Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. Background The FAA received areport offailure ofthe aft attach lugs on the left elevator tab control mechanism, which resulted in severe elevator vibration. The flightcrew diverted 

### from the intended route and made an 

### uneventful landing. Subsequent investigation revealed extensive damage tothe elevator tab control system. Severe vibration in this attach point is suspected ofallowing rapid wear of thejoint, and resulted in failure ofthe attach lugs. This condition, ifnot corrected, could result in a loss ofaircraft control and structural integrity. Explanation ofRelevant Service lnformation We have reviewed Boeing Alert Service Bulletin 737-27A1296, dated March 12,2010. The service bulletin describes procedures foradetailed inspection to detect discrepancies ofthe inboard and outboard aft attach lugs ofthe elevator tab control mechanism. Discrepancies include movement or rotation ofthe spacer, and gaps between the swage ring and the aft attach lug orbetween the spacer and the aft attach lug. The service bulletin describes procedures for replacing any discrepant elevator tab control mechanism, including perfonning the detailed inspection on the replacement part before and after installation. For certain airplanes, the compliance time forthe inspeCtion is 12or 30days, depending on airplane line number, total accumulated flight cycles, and approval for operation under extended twin operations (ETOPS). FAA's Determination and Requirements ofthis AD Wehave evaluated all pertinent infomlation and identified an unsafe condition that is likely to exist or develop on other airplanes ofthis same type design. Therefore, we are issuing this AD to detect and correct aloose bearing in the aft lug oftbe eJevator tab control mechanism, which could result in unwanted elevator and tab vibration. The consequent structural failure ofthe elevator or horizontal stabilizer could result in loss ofaircrall control and structural integrity. This AD requires accomplishing the actions specified inthe service information described previously, except as discussed under "Differences Between this AD and the Service Bulletin." This AD also requires reporting the JI1spectionresults toBoeing.Differences Between this AD and the Service Bulletin

The effectivity ofBoeing Alert Service Bulletin 737-27A1296, dated March 12,20I0, includes allModel 737-600, -700, -700e, -800, -900, and -900ER series airplanes. The inspection requirements ofthis AD, however, affect only those airplanes subject to ashort compliance time (within 12or 30 days). Because the suspect components may be installed as replacements on all airplanes subject to this AD, paragraph (I)ofthis AD requires that the part be inspected before and after installation. We may consider superseding this AD to apply the inspection requirements to the remaining airplanes, which would be subject to alonger compliance time that would allow enough time toprovide notice and opportunity forprior public comment on the merits ofthe inspection for these airplanes. Interim Action This AD isconsidered tobe interim action. The inspection reports that are required by this AD will enable the manufacturer to obtain better insight into the nature, cause, and extent ofthe issue, and eventually to develop final action to address the unsafe condition. Once final action has been identified, we might consider further rulemaking. Examining the Docket You may examine the contents ofthis AD docket on the Internet athttp://www.rcQulations.\!ov; (on the next business day after we have issued the AD), orin person al U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200New Jersey Avenue SE., Washington, DC, between 9 a,m. and 5 p.m., Monday through Friday, except Federal holidays. This docket number isFAA-2010-0230; the directorate identifier for this docket is 2010-NM-071-AD. Authority for this Rulemaking Title 49 ofthe United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority ofthe FAA Administrator. Subtitle VIl, Aviation Programs, describes inmore detail the scope ofthe Agency's authority.
We are issuing this rulemaking under the authority described in Subtitle 

## vn, Part A, Subpart Ill, Section 44701, "General requirements," Under that section, Congress charges the FAA with promoting safe night ofcivil aircraft in air commerce by prescribing regulations forpractices, methods, and procedures the Administrator fmds necessary forsafety in air commerce. This regulation iswithin the scope ofthat authority because itaddresses an unsafe condition thal is likely to exist or develop on products identified inthis rulemaking action. Regulatory Findings We have determined that this AD will not have federalism implications under Executive Order 13132. This AD will not have asubstantial direct effect on the States, on the relationship between the national government and the States, or on the distribution ofpower and responsibilities among the various levels of government. The FAA has determined that this regulation is anemergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that itis not a "significant regulatory action" under Executive Order 12866. Ithas been determined further that this action involves anemergency regulation under DOT Regulatory Policies and Procedures (44 FR I1034, February 26, 1979). Ifthis 2emergency regulation is later deemed significant under DOT Regulatory Policies and Procedures, "ve

will prepare a final regulatory evaluation and place itin the AD Docket. See the "Examining the Docket" section foralocation to examine the regulatory evaluation, iffiled. Determination ofRule's Effective Date This emergency AD is issued under 49 D.S.C. Section 44701 according to the authority delegated tome by the Administrator, and is effective immediately upon receipt.
Because an unsafe condition exists that requires the immediate adoption ofthis emergency AD, we find that notice and opportunity for prior public comment hereon are impracticable and that good cause exists formaking this emergency AD effective inless than 30days. 2010-06-51 The Boeing Company: Docket No. FAA-2010-0230; Directorate Identifier NO.2010-NM-071-AD. Effective Date (a) Emergency airworthiness directive (AD) 2010-06-51, issued on March 12,2010, is effective immediately upon receipt. Affected ADs (b) None. Applicability (e) This AD applies to all The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes; certificated in any category. Subject(d) Air Transport Association (ATA) ofAmerica Code 27: Flight controls. Unsafe Condition (e) This AD results from areport offailure ofthe aft attach lugs on the left elevator tab control mechanism, which resulted in severe elevator vibration. The Federal Aviation Administration is issuing this AD to detect and conect aloose bearing inthe aft lug ofthe elevator tab control mechanism, which could result inunwanted elevator and tab vibration. The consequent structural failure ofthe elevator orhorizontal stabilizer could result in loss ofaircraft control and structural integrity. Compliance (f) You are responsible forhaving the actions required bythis AD performed within the compliance times specified, unless lhe actions have already been done. Inspection and Corrective Action (g) For Groups 1,2, and 3; and Group 4, ConfiguraLion 2; as identified inBoeing Alert Service Bulletin 737-27A1296, dated March 12,2010: At the applicable time specified inparagraph l.E. 3Compliance ofBoeing Alert Service Bulletin 737-27A1296, dated March 12,2010, except as required

byparagraph (i) ofthis AD, do adetailed inspection oftileinboard and outboard aft attach lugs ofthe left and right elevator control tab mechanisms forgaps between the swage ring and tbe aft attach lug, and between the spacer and the aft attach lug; and try to move orrotate the spacer using hand pressure, in accordance with the Accomplishment Instructions ofBoeing Alert Service Bulletin 737-27A1296, dated March 12,2010. (h) Lf,during accomplishment ofthe actions required by paragraph (g) oftbjs AD, any gap is found between the swage ring and the aft attach lug, orbehveen the spacer and the aft attach lug; orif the spacer moves orrotates: Before further flight, do the actions required by paragraphs (h)(l) and (h)(2) ofthis AD, in accordance with the Accomplishment Instructions ofBoeing Alert Service Bulletin 737-27AI296, dated Mareh 12,2010. (1) Inspect the replacement elevator tab control mechanism for discrepancies, as specified in paragraph (g) ofthis AD; and, ifno discrepancy is found, install the replacement elevator tab control mechanism. (2) Re-inspect the installed elevator tab control mechanism, as required byparagraph (g) ofthis AD. Exception to Service Bulletin Specifications (i) Where Boeing Alert Service Bulletin 737-27A1296, dated March 12,2010, specifies a compliance time after the date ofthe original issue ofthe service bulletin, this AD requires compliance within the specified compliance time after receipt ofthis AD. Inspection Done According to Multi Operator Message (MOM) (j) An inspection done before receipt ofthis AD according to Boeing Multi Operator Message Number MOM-MOM-l 0-0 159-01B, dated March 10,2010, isconsidered acceptable forcompliance with the corresponding inspection specified inparagraph (g) ofthis AD. Reporting (k) At the applicable time specified inparagraph (k)(l) or (k)(2) ofthis AD: Submit areport of the findings (both positive and negative) ofthe inspections required by paragraph (g) ofthis AD to Boeing Commercial Airplanes Group, Attention: Manager. Airline Support, email: rse.boec.om@boeing.com. The report must include the inspection results including adescription ofany discrepancies found, the airplane line number, and the number offlight cycles and flight hours accumulated on the airplane. Under theprovisions oftilePaperwork Reduction Act (44 U.S.c. 3501 et seg.), the Office ofManagement and Budget (OMB) has approved the infomlalion collection requirements contained inthis AD and has assigned OMB Control Number 2120-0056. (1) Ifthe inspection was done on or after receipt ofthis AD: Submit the report within 10days after lhe inspection. (2) Lfthe inspection was done before receipt ofthis AD: Submit the report within 10days after receipt ofthis AD.

4Parts Installation

(1) For all airplanes: As ofreceipt ofthis AD, no person may install anelevator tab control mechanism, part number 251A2430-(), on any airplane, unless the mechanism has been inspected before and after Installation, in accordance with the requirements ofparagraph (g) ofthis AD, and no discrepancies have been found. Special Flight Permit (m) Special flight permits, as described in Section 21.197 and Section 21.199 orthe Federal Aviation Regulations (14 CFR 21.197 and 21.199), are not allowed. Alternative Methods ofCompliance (AMOCs) (n)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, lfrequested using the procedures found in 14eFR 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-AMOCReguests({iihla.gov. (2) To request adifferent method ofcompliance or adifferent compliance time for this AD, follow the procedures in 14CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PJ\1I) orprincipal avionics inspector (PAT), as appropriate, orlacking aprincipal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically refer tothis AD. (3) An AMOC that provides an acceptable level ofsafety may be used for any repair required bythis AD ifitis approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) that has been authorized by the Manager, Seattle ACO, to make those findings. For arepair method tobe approved, the repair must meet the certification basis ofthe airplane. and the approval must specifically referto this AD.

5Contact Information

(0) For technical information about this AD, contact 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. For service infomlation identified inthis AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P. O. Box 3707, 

### Me 2H-65, Seattle, Washington 98124-2207; telephone 206-544-5000, extension I; fax206-766-5680; c-maiIme.boecom@boeing.com; Internet https:l/www.ll1vboeilH.,rfleeLcom. 

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March 12,2010.

Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service.

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