2012-23218. Airworthiness Directives; The Boeing Company Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to supersede 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 repetitive inspections of the aft attach lugs of the elevator tab control mechanisms, and replacement of any discrepant elevator tab control mechanism. Since we issued that AD, Boeing has developed a modification of the aft attach lugs of the elevator tab control mechanisms, which will adequately address the unsafe condition. This proposed AD would require replacing the left and right elevator tab control mechanisms with elevator tab control mechanisms that have the modified attach lugs, which would terminate the existing requirements. We are proposing this AD to prevent discrepancies in the aft attach lugs of the elevator tab control mechanism, which could result in severe elevator and tab vibration. Consequent structural failure of the elevator or horizontal stabilizer could result in loss of structural integrity and aircraft control.

DATES:

We must receive comments on this proposed AD by November 5, 2012.

ADDRESSES:

You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: [phone].
• 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 AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone [phone], extension 1; fax [phone]; 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, WA. 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: [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Kelly McGuckin, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification Office (ACO), 1601 Lind Avenue SW., Renton, Washington 98057-3356; phone: [phone]; fax: [phone]; email: [e-mail].

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-2012-0994; Directorate Identifier 2012-NM-119-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because of those comments.

We will post all comments we receive, without change, to http://www.regulations.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD.

Discussion

On August 11, 2010, we issued AD 2010-17-19, Amendment 39-16413 (75 FR 52242, August 25, 2010), for all The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. That AD requires repetitive inspections of the aft attach lugs of the elevator tab control mechanisms, and replacement of any discrepant elevator tab control mechanism. That AD was prompted by reports of failure of the aft attach lugs on the elevator tab control mechanisms, which resulted in severe elevator vibration. That AD also was prompted by reports of gaps in elevator tab control mechanisms and analysis that additional elevator tab control mechanisms might have bearings that will come loose. We issued that AD to detect and correct discrepancies in the aft attach lugs of the elevator tab control mechanism, which could result in elevator and tab vibration. Consequent structural failure of the elevator or horizontal stabilizer could result in loss of structural integrity and aircraft control.

Actions Since Existing AD (AD 2010-17-19, Amendment 39-16413 (75 FR 52242, August 25, 2010)) Was Issued

The preamble to AD 2010-17-19, Amendment 39-16413 (75 FR 52242, August 25, 2010), specifies that we consider the requirements “interim action” and that the manufacturer is developing a modification to address the unsafe condition. That AD explains that we might consider further rulemaking if a modification is developed, approved, and available. The manufacturer now has developed such a modification, and we have determined that further rulemaking is indeed necessary; this proposed AD follows from that determination.

Relevant Service Information

We reviewed Boeing Service Bulletin 737-27-1300, dated April 16, 2012, which describes procedures for replacing elevator tab control mechanisms that have sheet metal aft attach lugs with elevator tab control mechanisms that have new machined aft attach lugs.

Boeing Service Bulletin 737-27-1300, dated April 16, 2012, has been approved as an alternative method of compliance with the requirements of paragraphs (g) through (t) of AD 2010-17-19, Amendment 39-16413 (75 FR 52242, August 25, 2010).

Clarification of Part Name

The elevator tab control mechanism is incorrectly identified as the “elevator control tab mechanism” in certain paragraphs of AD 2010-17-19, Amendment 39-16413 (75 FR 52242, August 25, 2010). We have corrected that part name in this proposed AD.

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 design.

Proposed AD Requirements

This proposed AD would retain all requirements of AD 2010-17-19, Amendment 39-16413 (75 FR 52242, August 25, 2010). This proposed AD would also require replacement of the left and right elevator tab control mechanisms with elevator tab control mechanisms that have new machined aft attach lugs, which would terminate the existing requirements.

Costs of Compliance

We estimate that this proposed AD affects 1,096 airplanes of U.S. registry. We estimate the following costs to comply with this proposed AD:

Estimated Costs

Action	Labor cost	Parts cost	Cost per product
Retained actions	7 work-hours × $85 per hour = $595 per inspection cycle	$0	$595 per inspection cycle.
Mechanism replacement (one option for proposed terminating action)	12 work-hours × $85 per hour = $1,020	$58,579 1 $1,140 (installation kit)	$60,739 per airplane.
Mechanism modification and replacement (one option for proposed terminating action)	24 work-hours × $85 per hour = $2,040	$5,858 (for the modification) $1,140 (installation kit) $2,145 (tooling 2)	$11,183 per airplane.
1 This is the estimated cost for both a left and right mechanism. Boeing is planning a seed/exchange program so operators are not forced to purchase a new mechanism.
2 Per the Boeing service information, tooling is available from Boeing for $90 per day.

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),

(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

[Amended]

2. The FAA amends § 39.13 by removing airworthiness directive (AD) 2010-17-19, Amendment 39-16413 (75 FR 52242, August 25, 2010), and adding the following new AD:

The Boeing Company: Docket No. FAA-2012-0994; Directorate Identifier 2012-NM-119-AD.

(a) Comments Due Date

The FAA must receive comments on this AD action by November 5, 2012.

(b) Affected ADs

This AD supersedes AD 2010-17-19, Amendment 39-16413 (75 FR 52242, August 25, 2010).

(c) Applicability

This AD applies to all The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes, certificated in any category.

(d) Subject

Joint Aircraft System Component (JASC)/Air Transport Association (ATA) of America Code 27, Flight Controls.

(e) Unsafe Condition

This AD was prompted by reports of failure of the aft attach lugs on the elevator tab control mechanisms, which resulted in severe elevator vibration. This AD also results from reports of gaps in elevator tab control mechanisms and analysis that additional elevator tab control mechanisms might have bearings that will come loose. We are issuing this AD to prevent discrepancies in the aft attach lugs of the elevator tab control mechanism, which could result in severe elevator and tab vibration. Consequent structural failure of the elevator or horizontal stabilizer could result in loss of structural integrity and aircraft control.

(f) Compliance

Comply with this AD within the compliance times specified, unless already done.

(g) Retained Repetitive Inspections for Group 1 Airplanes

This paragraph restates the requirements of paragraph (m) of AD 2010-09-05, Amendment 39-16270 (75 FR 21499, April 26, 2010), with revised terminating action. For Group 1 airplanes, as identified in Boeing Alert Service Bulletin 737-27A1297, dated April 16, 2010: Except as required by paragraph (h) of this AD, within 12 days after April 29, 2010 (the effective date of AD 2010-09-05), do a detailed inspection for discrepancies of the inboard and outboard aft attach lugs of the left and right elevator tab control 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. Doing the replacement specified in paragraph (l) of this AD before September 9, 2010 (the effective date of AD 2010-17-19, Amendment 39-16413 (75 FR 52242, August 25, 2010)), terminates the requirements of this paragraph. Doing the inspection required by paragraph (n) of this AD terminates the requirements of this paragraph.

(h) Retained ETOPS Flight Provisions

This paragraph restates the requirements of paragraph (n) of AD 2010-09-05, Amendment 39-16270 (75 FR 21499, April 26, 2010), with a terminating action provision. For Group 1 airplanes as identified in Boeing Alert Service Bulletin 737-27A1297, dated April 16, 2010: Beginning 7 days after April 29, 2010 (the effective date of AD 2010-09-05), no person may operate an airplane on an extended twin operations (ETOPS) flight unless the initial inspection required by paragraph (g) of this AD has been accomplished. Doing the inspection required by paragraph (n) of this AD terminates the requirements of this paragraph.

(i) Retained One-Time Inspection for Group 2, Configuration 1, Airplanes

This paragraph restates the requirements of paragraph (o) of AD 2010-09-05, Amendment 39-16270 (75 FR 21499, April 26, 2010), with revised terminating action provisions. For Group 2, Configuration 1, airplanes as identified in Boeing Alert Service Bulletin 737-27A1297, dated April 16, 2010: Within 30 days after April 29, 2010 (the effective date of AD 2010-09-05), do a one-time detailed inspection for discrepancies of the inboard and outboard aft attach lugs of the left and right elevator tab control mechanisms, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-27A1297, dated April 16, 2010. Doing the inspection required by paragraph (n) of this AD terminates the requirements of this paragraph.

(j) Corrective Actions for Paragraphs (g), (i), and (k) of This AD

This paragraph restates the requirements of paragraph (p) of AD 2010-09-05, Amendment 39-16270 (75 FR 21499, April 26, 2010). If, during any inspection required by paragraph (g), (i), or (k) of this AD, any discrepancy is found, before further flight, replace the elevator tab control mechanism by doing the actions specified in paragraphs (j)(1) and (j)(2) of this AD.

(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.

(2) Re-inspect the installed elevator tab control mechanism using the inspection procedure specified in paragraph (i) of this AD.

(k) Retained Repetitive Inspections for Certain Group 2, Configuration 1, Airplanes

This paragraph restates the requirements of paragraph (q) of AD 2010-09-05, Amendment 39-16270 (75 FR 21499, April 26, 2010), with revised terminating action provisions. For Group 2, Configuration 1, airplanes as identified in Boeing Alert Service Bulletin 737-27A1297, dated April 16, 2010, on which the elevator tab control 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 tab control 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. Doing the replacement specified in paragraph (l) of this AD before September 9, 2010 (the effective date of AD 2010-17-19, Amendment 39-16413 (75 FR 52242, August 25, 2010)), is terminating action for this paragraph. Doing the inspection required by paragraph (n) of this AD terminates the requirements of this paragraph.

(l) Terminating Action Credit for Paragraphs (g), (i), and (k) of This AD

This paragraph restates the requirements of paragraph (r) of AD 2010-09-05, Amendment 39-16270 (75 FR 21499, April 26, 2010), with revised terminating action provisions. Replacing an elevator tab control mechanism with a new, Boeing-built mechanism before September 9, 2010 (the effective date of AD 2010-17-19, Amendment 39-16413 (75 FR 52242, August 25, 2010)), as specified in paragraphs (l)(1) and (l)(2) of this AD, terminates the inspections required by paragraphs (g), (i), and (k) of this AD. Replacement of the elevator tab control mechanism on or after September 9, 2010 (the effective date of AD 2010-17-19), does not terminate the inspections required by paragraphs (g), (i), and (k) of this AD.

Note 1 to paragraph (l) of this AD:

Additional guidance can be found in 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, for establishing whether the mechanism is Boeing-built.

(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.

(2) Re-inspect the installed elevator tab control mechanism using the inspection procedure specified in paragraph (i) of this AD.

(m) Retained Reporting for Paragraphs (g), (i), and (k) of This AD

This paragraph restates the requirements of paragraph (s) of AD 2010-09-05, Amendment 39-16270 (75 FR 21499, April 26, 2010). For airplanes identified in Boeing Alert Service Bulletin 737-27A1297, dated April 16, 2010: At the applicable time specified in paragraph (m)(1) or (m)(2) of this AD, submit a report of any findings (positive and negative) of the first inspection required by paragraphs (g), (i), and (k) of this AD, and any positive findings from the repetitive inspections required by paragraphs (g) and (k) of this AD, to Boeing Commercial Airplanes Group, Attention: Manager, Airline Support, email: [e-mail]. 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.

(1) If the inspection was done on or after April 29, 2010 (the effective date of AD 2010-09-05, Amendment 39-16270 (75 FR 21499, April 26, 2010)): Submit the report within 10 days after the inspection.

(2) If the inspection was done before April 29, 2010 (the effective date of AD 2010-09-05, Amendment 39-16270 (75 FR 21499, April 26, 2010)): Submit the report within 10 days after April 29, 2010 (the effective date of AD 2010-09-05).

(n) Retained Repetitive Inspections

This paragraph restates the requirements of paragraph (n) of AD 2010-17-19, Amendment 39-16413 (75 FR 52242, August 25, 2010). For airplanes having line numbers 1 through 3909 inclusive: At the applicable time specified in paragraph (n)(1), (n)(2), or (n)(3) of this AD, do a detailed inspection for discrepancies of the inboard and outboard aft attach lugs of the left and right elevator tab control mechanisms, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-27A1297, Revision 1, dated August 2, 2010. For Groups 1 and 2 airplanes identified in Boeing Alert Service Bulletin 737-27A1297, Revision 1, dated August 2, 2010, repeat the inspection thereafter at intervals not to exceed 300 flight hours, except as provided by paragraph (t)(2) of this AD. For Group 3 airplanes identified in Boeing Alert Service Bulletin 737-27A1297, Revision 1, dated August 2, 2010, repeat the inspection thereafter at intervals not to exceed 1,800 flight hours, except as required by paragraphs (p) and (t)(2) of this AD. Doing the inspection specified in this paragraph terminates the requirements of paragraphs (g), (h), (i), and (k) of this AD.

(1) For Group 1 airplanes identified in Boeing Alert Service Bulletin 737-27A1297, Revision 1, dated August 2, 2010: Within 300 flight hours after doing an inspection in accordance with Boeing Alert Service Bulletin 737-27A1297, dated April 16, 2010, or within 30 days after September 9, 2010 (the effective date of AD 2010-17-19, Amendment 39-16413 (75 FR 52242, August 25, 2010)), whichever occurs later.

(2) For Group 2 airplanes identified in Boeing Alert Service Bulletin 737-27A1297, Revision 1, dated August 2, 2010: At the later of the times specified in paragraphs (n)(2)(i) and (n)(2)(ii) of this AD.

(i) Before the accumulation of 2,000 total flight cycles or 4,000 total flight hours, whichever occurs first.

(ii) Within 14 days after September 9, 2010 (the effective date of AD 2010-17-19, Amendment 39-16413 (75 FR 52242, August 25, 2010)).

(3) For Group 3 airplanes identified in Boeing Alert Service Bulletin 737-27A1297, Revision 1, dated August 2, 2010: Within 180 days or 1,800 flight hours after September 9, 2010 (the effective date of AD 2010-17-19, Amendment 39-16413 (75 FR 52242, August 25, 2010)), whichever occurs first.

(o) Retained Corrective Actions for Paragraphs (n) and (p) of This AD

This paragraph restates the requirements of paragraph (o) of AD 2010-17-19, Amendment 39-16413 (75 FR 52242, August 25, 2010). If, during any inspection required by paragraph (n) or (p) of this AD, any discrepancy is found, before further flight, replace the elevator tab control mechanism by doing the actions specified in paragraphs (o)(1) and (o)(2) of this AD.

(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, Revision 1, dated August 2, 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.

(2) Re-inspect the installed elevator tab control mechanism using the inspection procedure specified in paragraph (n) of this AD.

(p) Retained Reduced Repetitive Inspection Interval for Group 3 Airplanes

This paragraph restates the requirements of paragraph (p) of AD 2010-17-19, Amendment 39-16413 (75 FR 52242, August 25, 2010). For Group 3 airplanes as identified in Boeing Alert Service Bulletin 737-27A1297, Revision 1, dated August 2, 2010, on which the elevator tab control mechanism is replaced during the actions required by paragraph (o) of this AD: Within 300 flight hours after doing the replacement, do a detailed inspection for discrepancies of the inboard and outboard aft attach lugs of the replaced elevator tab control mechanism, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-27A1297, Revision 1, dated August 2, 2010. Repeat the inspection of the replaced elevator tab control mechanism thereafter at intervals not to exceed 300 flight hours, except as provided by paragraph (t)(2) of this AD.

(q) Retained Credit for Initial Inspection Done in Accordance With the Original Issue of the Service Bulletin

This paragraph restates the requirements of paragraph (q) of AD 2010-17-19, Amendment 39-16413 (75 FR 52242, August 25, 2010). For Group 1 airplanes as identified in Boeing Alert Service Bulletin 737-27A1297, Revision 1, dated August 2, 2010: Inspections done in accordance with Boeing Alert Service Bulletin 737-27A1297, dated April 16, 2010, are acceptable for compliance with only the initial inspection required by paragraph (n) of this AD.

(r) Retained Reporting for Paragraphs (n) and (p) of This AD

This paragraph restates the requirements of paragraph (r) of AD 2010-17-19, Amendment 39-16413 (75 FR 52242, August 25, 2010). For airplanes having line numbers 1 through 3909 inclusive: At the applicable time specified in paragraph (r)(1) or (r)(2) of this AD, submit a report of any findings (positive and negative) of the first inspection required by paragraphs (n) and (p) of this AD, except for airplanes on which a report required by paragraph (m) of this AD has been submitted, only submit positive findings; and submit a report of any positive findings from the repetitive inspections required by paragraphs (n) and (p) of this AD; to Boeing Commercial Airplanes Group, Attention: Manager, Airline Support, email: [e-mail]. 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.

(1) If the inspection was done on or after September 9, 2010 (the effective date of AD 2010-17-19, Amendment 39-16413 (75 FR 52242, August 25, 2010)): Submit the report within 10 days after the inspection.

(2) If the inspection was done before September 9, 2010 (the effective date of AD 2010-17-19, Amendment 39-16413 (75 FR 52242, August 25, 2010)): Submit the report within 10 days after September 9, 2010 (the effective date of AD 2010-17-19).

(s) Retained Provision Regarding Return of Parts

This paragraph restates the provision specified in paragraph (s) of AD 2010-17-19, Amendment 39-16413 (75 FR 52242, August 25, 2010). Although Boeing Alert Service Bulletin 737-27A1297, dated April 16, 2010; and Boeing Alert Service Bulletin 737-27A1297, Revision 1, dated August 2, 2010; specify to return the affected elevator tab control mechanism to the manufacturer, this AD does not require the return of the part to the manufacturer.

(t) Retained Parts Installation Limitations

This paragraph restates the requirements of paragraph (t) of AD 2010-17-19, Amendment 39-16413 (75 FR 52242, August 25, 2010). As of September 9, 2010 (the effective date of AD 2010-17-19), and until the effective date of this new AD, comply with the conditions specified in paragraphs (t)(1) and (t)(2) of this AD.

(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 paragraphs (o)(1) and (o)(2) of this AD, and no discrepancies have been found.

(2) An elevator tab control mechanism, part number 251A2430-( ), may be installed, provided that the inspection specified in paragraph (n) of this AD is done within 300 flight hours after doing the installation, and that the inspection specified in paragraph (n) of this AD is repeated thereafter at intervals not to exceed 300 flight hours.

(u) New Replacement

For airplanes having line numbers 1 through 3909 inclusive: Within 60 months after the effective date of this AD, replace the left and right elevator tab control mechanisms with elevator tab control mechanisms that have new machined aft attach lugs, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 737-27-1300, dated April 16, 2012. This replacement terminates the requirements of paragraphs (g) through (t) of this AD.

(v) New Parts Installation Prohibition

For all airplanes: As of the effective date of this AD, no person may install, on any airplane, an elevator tab control mechanism having P/N 251A2430-13, -14, -15, -16, -17, -18, -101, -102, -103, -104, -105, or -106.

(w) Paperwork Reduction Act Burden Statement

A federal agency may not conduct or sponsor, and a person is not required to respond to, nor shall a person be subject to a penalty for failure to comply with a collection of information subject to the requirements of the Paperwork Reduction Act unless that collection of information displays a current valid OMB Control Number. The OMB Control Number for this information collection is 2120-0056. Public reporting for this collection of information is estimated to be approximately 5 minutes per response, including the time for reviewing instructions, completing and reviewing the collection of information. All responses to this collection of information are mandatory. Comments concerning the accuracy of this burden and suggestions for reducing the burden should be directed to the FAA at: 800 Independence Ave. SW., Washington, DC 20591, Attn: Information Collection Clearance Officer, AES-200.

(x) Alternative Methods of Compliance (AMOCs)

(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. 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. Information may be emailed to [e-mail].

(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) AMOCs approved for AD 2010-17-19, Amendment 39-16413 (75 FR 52242, August 25, 2010), are approved as AMOCs for the corresponding provisions of this AD.

(y) Related Information

(1) For more information about this AD, contact Kelly McGuckin, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification Office (ACO), 1601 Lind Avenue SW., Renton, Washington 98057-3356; phone: [phone]; fax: [phone]; email: [e-mail].

(2) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone [phone], extension 1; fax [phone]; 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, WA. For information on the availability of this material at the FAA, call 425-227-1221.

Issued in Renton, Washington, on September 6, 2012.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.