2013-10006. Airworthiness Directives; The Boeing Company Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule.

SUMMARY:

We are superseding two existing airworthiness directives (AD) that apply to certain The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. Those ADs, for certain airplanes, currently require repetitive inspections of the flap track of the wing outboard flap, and corrective actions if necessary; and eventual rework of the flap track assembly and rear spar attachments. For certain airplanes, this new AD adds repetitive inspections, scheduled overhauls, correct alignment during installation, and repetitive maintenance of the flap track, and corrective actions if necessary. This new AD also adds airplanes to the applicability. This AD was prompted by reports that the work sequence and procedures used during installation of replacement tracks could cause loose or cracked tracks. We are issuing this AD to detect and correct cracking and damage in the flap track, which could cause loss of the outboard trailing edge flap and consequent reduced controllability of the airplane.

DATES:

This AD is effective June 13, 2013.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of June 13, 2013.

The Director of the Federal Register approved the incorporation by reference of a certain other publication listed in this AD as of April 22, 2002 (67 FR 11891, March 18, 2002).

The Director of the Federal Register approved the incorporation by reference of a certain other publication listed in this AD as of January 2, 2001 (65 FR 78913, December 18, 2000).

ADDRESSES:

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 AD, the regulatory evaluation, any comments received, and other information. The address for the Docket Office (phone: [phone]) is Document Management Facility, U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT:

Nancy Marsh, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: [phone]; fax [phone]; email: [e-mail].

SUPPLEMENTARY INFORMATION:

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2000-25-07, Amendment 39-12041 (65 FR 78913, December 18, 2000); and AD 2002-05-07, Amendment 39-12675 (67 FR 11891, March 18, 2002). Those ADs apply to the specified products, and require repetitive inspections of the flap track of the wing outboard flap, and corrective actions if necessary; and eventual rework of the flap track assembly and rear spar attachments. The NPRM published in the Federal Register on October 10, 2012 (77 FR 61542). The NPRM proposed to retain all requirements of AD 2000-25-07 and AD 2002-05-07. For certain airplanes, the NPRM proposed to add repetitive inspections, scheduled overhauls, correct alignment during installation, and repetitive maintenance of the flap track, and corrective actions if necessary. This new AD also adds airplanes to the applicability.

Comments

We gave the public the opportunity to participate in developing this AD. The following presents the comments received on the proposal (77 FR 61542, October 10, 2012) and the FAA's response to each comment.

Concurrence

Boeing and United concurred with the content of the NPRM (77 FR 61542, October 10, 2012).

Request To Change Text of Paragraph (p)(3) of the NPRM (77 FR 61542, October 10, 2012)

Alaska Airlines requested that we change the text of paragraph (p)(3) of the NPRM (77 FR 61542, October 10, 2012) to revise the descriptions of the inspection locations to be similar to the instructions included in Boeing 737 Non Destructive Test (NDT) Manual Part 6, 57-50-06. The commenter suggested that the existing wording in paragraph (p)(3) of the NPRM contradicts the instructions specified in Boeing 737 NDT Manual Part 6, 57-50-06.

We disagree with the request to change the text of paragraph (p)(3) of this AD. The inspections specified in paragraph (p)(3) of this AD must be done in accordance with paragraph 3.B.3., “Inspection—Track Webs and Flanges,” of the Accomplishment Instructions of Boeing Service Bulletin 737-57A1271, Revision 3, dated February 13, 2012. The instructions for accomplishing the eddy current inspection required by paragraph (p)(3) of this AD are detailed in Boeing 737 NDT Manual Part 6, 57-50-06, which is an additional source of guidance. There is no contradiction in the instructions. No change has been made to the AD in this regard.

Request for Revised Service Information

Southwest Airlines requested that Boeing Service Bulletin 737-57A1271, Revision 3, dated February 13, 2012, be revised to add missing necessary data to support the rework requirements of paragraphs (s) and (t) of the NPRM (77 FR 61542, October 10, 2012) for flap track part number (P/N) 65C34809-3. The commenter stated that paragraphs (s) and (t) of the NPRM require doing the corrective actions in accordance with Boeing Service Bulletin 737-57A1271, Revision 3, dated February 13, 2012. The commenter also stated that Boeing Service Bulletin 737-57A1271, Revision 3, dated February 13, 2012, provides repair data, but the commenter noted that not all repair data are provided for flap track P/N 65C34809-3. The commenter added that Boeing Overhaul Manual 57-53-15, Figure 614, “Supplemental Track Overhaul Instructions,” should be revised to add minimum allowable dimensions T1 through T4, W, and maximum allowable hole diameters d1, d2, and d3 for flap track P/N 65C34809-3.

We disagree that any revised service information is necessary to comply with the requirements of this AD. While the repair data for flap track P/N 65C34809-3 is less extensive than for other tracks, the information provided in Boeing Service Bulletin 737-57A1271, Revision 3, dated February 13, 2012, is adequate for this part. Since that flap track has improved finishes, it is not expected to wear in the same way as the other parts. If this flap track requires repair or rework that exceeds the data currently provided, then operators may request approval of new repair and rework limits in accordance with paragraph (y) of this AD. No change has been made to the AD in this regard.

Request To Extend Compliance Time

Sky King, Inc. requested that we extend the compliance time from 180 days to 24 months for airplanes with flap tracks that are undocumented or did not previously require inspection by AD 2000-25-07, Amendment 39-12041 (65 FR 78913, December 18, 2000); or AD 2002-05-07, Amendment 39-12675 (67 FR 11891, March 18, 2002). The commenter stated that extending the compliance time as requested will allow the operator to inspect the flap tracks at a more convenient interval, such as a scheduled “C-check” maintenance interval.

We disagree with the request to extend the compliance time. The initial inspection compliance time of 180 days was selected to address potential safety issues on flap tracks that have not been inspected in accordance with AD 2000-25-07, Amendment 39-12041 (65 FR 78913, December 18, 2000); or AD 2002-05-07, Amendment 39-12675 (67 FR 11891, March 18, 2002). The commenter provided no data to support a request to extend the compliance time for these airplanes.

In developing an appropriate compliance time for this AD, we considered not only the safety implications, but the manufacturer's recommendations and the practical aspect of accomplishing the inspection within an interval of time that corresponds to typical scheduled maintenance for affected operators. We consider that U.S. operators have had ample time to consider initiating the actions specified in Boeing Service Bulletin 737-57A1271, Revision 3, dated February 13, 2012, cited in the NPRM (77 FR 61542, October 10, 2012), which this AD ultimately requires. Under the provisions of paragraph (y) of this AD, however, we will consider requests for adjustments to the compliance time if data are submitted to substantiate that such an adjustment would provide an acceptable level of safety. No change has been made to the AD in this regard.

Effect of Supplemental Type Certificate (STC) for Winglet

Aviation Partners Boeing stated that the installation of winglets per STC ST01219SE (http://rgl.faa.gov/​Regulatory_​and_​Guidance_​Library/​rgstc.nsf/​0/​2C6E3DBDDD36F91C862576A4005D64E2?​OpenDocument&​Highlight=​st01219se) does not affect the accomplishment of the manufacturer's service instructions.

We have added paragraph (c)(2) to this AD to state that installation of STC ST01219SE does not affect the ability to accomplish the actions required by this AD. Therefore, for airplanes on which STC ST01219SE is installed, a “change in product” alternative method of compliance (AMOC) approval request is not necessary to comply with the requirements of 14 CFR 39.17. For all other AMOC requests, the operator must request approval in accordance with the procedures specified in paragraph (y) of this AD.

Other Changes to the AD

We have removed table 1 to paragraph (g) from this AD; instead, we have included the subject part numbers in paragraphs (g)(4)(i) through (g)(4)(x) of this AD. This change does not affect the intent of that paragraph.

We have revised the second to last sentence in paragraph (p) of this AD to add references to paragraphs (l) and (m) of this AD. Performing the inspections required by paragraph (p) of this AD terminates the requirements of paragraphs (g), (j), (l), (m), and (n) of this AD.

We have revised paragraph (s) of this AD to clarify the requirements for a damaged or corroded anti-fret strip.

We have revised paragraph (x)(3) of this AD to correct the service bulletin citation to Boeing Service Bulletin 737-57A1271, Revision 2, dated January 17, 2011.

Conclusion

We reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting the AD with the changes described previously and minor editorial changes. We have determined that these minor changes:

• Are consistent with the intent that was proposed in the NPRM (77 FR 61542, October 10, 2012) for correcting the unsafe condition; and
• Do not add any additional burden upon the public than was already proposed in the NPRM (77 FR 61542, October 10, 2012).

We also determined that these changes will not increase the economic burden on any operator or increase the scope of the AD.

Costs of Compliance

We estimate that this AD affects 570 airplanes of U.S. registry. We estimate the following costs to comply with this AD:

Estimated Costs

Action	Labor cost	Parts cost	Cost per product	Number of airplanes	Cost on U.S. operators
Detailed visual inspection [retained actions from existing AD 2000-25-07, Amendment 39-12041 (65 FR 78913, December 18, 2000)]	6 work-hours × $85 per hour = $510	$0	$510	290	$147,900.
Detailed visual, HFEC, and ultrasonic inspections [retained actions from existing AD 2002-05-07, Amendment 39-12675 (67 FR 11891, March 18, 2002)]	4 work-hours × $85 per hour = $340	0	$340	1,100	$374,000.
Detailed and eddy current inspections [new actions]	82 work-hours × $85 per hour = $6,970 per inspection cycle	0	$6,970 per inspection cycle	570	$3,972,900 per inspection cycle.
Overhaul [new action]	70 work-hours × $85 per hour = $5,950 per overhaul cycle	20,000	$25,950 per overhaul cycle	570	$14,791,500 per overhaul cycle.

We have received no definitive data that would enable us to provide cost estimates for labor cost for repair, and parts cost for repair and replacement for the on-condition actions specified in this AD. The labor cost of the replacement is $1,360 (16 work-hours × $85 per hour). We have no way of determining the number of aircraft that might need these repairs/replacements.

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 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.

For the reasons discussed above, I certify that this AD:

(1) Is not a “significant regulatory action” under Executive Order 12866,

(2) Is not a “significant rule” under 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

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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) 2000-25-07, Amendment 39-12041 ( 65 FR 78913, December 18, 2000); and AD 2002-05-07, Amendment 39-12675 (67 FR 11891, March 18, 2002); and adding the following new AD:

2013-09-02 The Boeing Company: Amendment 39-17443; Docket No. FAA-2012-1068; Directorate Identifier 2011-NM-073-AD.

(a) Effective Date

This AD is effective June 13, 2013.

(b) Affected ADs

This AD supersedes ADs 2000-25-07, Amendment 39-12041 (65 FR 78913, December 18, 2000); and 2002-05-07, Amendment 39-12675 (67 FR 11891, March 18, 2002).

(c) Applicability

(1) This AD applies to all The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes, certificated in any category.

(2) Installation of Supplemental Type Certificate (STC) ST01219SE (http://rgl.faa.gov/​Regulatory_​and_​Guidance_​Library/​rgstc.nsf/​0/​2C6E3DBDDD36F91C862576A4005D64E2?​OpenDocument&​Highlight=​st01219se) does not affect the ability to accomplish the actions required by this AD. Therefore, for airplanes on which STC ST01219SE is installed, a “change in product” alternative method of compliance (AMOC) approval request is not necessary to comply with the requirements of 14 CFR 39.17.

(d) Subject

Joint Aircraft System Component (JASC)/Air Transport Association (ATA) of America Code 57, Wings.

(e) Unsafe Condition

This AD was prompted by reports that the work sequence and procedures used during installation of replacement tracks installed in accordance with AD 2000-25-07, Amendment 39-12041 (65 FR 78913, December 18, 2000); or AD 2002-05-07, Amendment 39-12675 (67 FR 11891, March 18, 2002); could cause loose or cracked tracks. We are issuing this AD to detect and correct cracking and damage in the flap track, which could cause loss of the outboard trailing edge flap and consequent reduced controllability of the airplane.

(f) Compliance

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

(g) Retained Repetitive Inspections

This paragraph restates the inspections required by paragraph (a) of AD 2000-25-07, Amendment 39-12041 (65 FR 78913, December 18, 2000), with added references to a terminating action. For Model 737-100, -200, and -200C series airplanes on which the left- or right-hand inboard flap tracks of the wing outboard flap have a part number (P/N) listed in paragraphs (g)(4)(i) through (g)(4)(x) of this AD: Do a detailed visual inspection to detect damage (corrosion, cracking) of the aft end of the left- and right-hand inboard flap tracks of the wing outboard flap, per Boeing All Operator Message (AOM) M-7200-00-01854, dated July 27, 2000, at the latest of the times specified in paragraphs (g)(1), (g)(2), and (g)(3) of this AD. Repeat the inspection thereafter at intervals not to exceed 1,200 flight cycles. Accomplishing the requirements of paragraph (p) of this AD terminates the requirements of this paragraph.

(1) Within 30 days after January 2, 2001 (the effective date of AD 2000-25-07, Amendment 39-12041 (65 FR 78913, December 18, 2000)).

(2) Within 1,200 flight cycles after the last documented inspection or overhaul of the aft end of each flap track.

(3) Before the accumulation of 15,000 total flight cycles.

(4) Boeing flap tracks subject to this AD are identified in paragraphs (g)(4)(i) through (g)(4)(x) of this AD.

(i) P/N 65-46428-9.

(ii) P/N 65-46428-15.

(iii) P/N 65-46428-17.

(iv) P/N 65-46428-19.

(v) P/N 65-46428-21.

(vi) P/N 65-46428-23.

(vii) P/N 65-46428-25.

(viii) P/N 65-46428-27.

(ix) P/N 65-46428-33.

(x) P/N 65-46428-35.

(h) Retained Definition

This paragraph restates the definition specified by Note 2 of AD 2000-25-07, Amendment 39-12041 (65 FR 78913, December 18, 2000). For the purposes of this AD, a detailed visual inspection is defined as: “An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate by the inspector. Inspection aids such as a mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.”

(i) Retained Corrective Actions

This paragraph restates the corrective actions required by paragraph (b) of AD 2000-25-07, Amendment 39-12041 (65 FR 78913, December 18, 2000), with added reference to the Boeing Commercial Airplanes Organization Designation Authorization (ODA). If any damage (corrosion, cracking) is detected during any inspection required by paragraph (g) of this AD, before further flight, repair or rework the flap track per the “Repair and Rework Instructions” specified in Boeing AOM M-7200-00-01854, dated July 27, 2000. Where that AOM specifies that the manufacturer may be contacted for disposition of certain corrective actions (i.e., repair and/or rework of the flaps), this AD requires such repair and/or rework to be done using a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or using data meeting the type certification basis of the airplane approved by a Boeing Company designated engineering representative (DER) or the Boeing Commercial Airplanes ODA that has been authorized by the Manager, Seattle ACO, to make such findings. For a repair method to be approved by the ODA, the repair must meet the certification basis of the airplane, and the approval must specifically refer to this AD. For a repair method to be approved by the Manager, Seattle ACO, as required by this paragraph, the Manager's approval letter must specifically reference this AD.

(j) Retained Initial Inspections

This paragraph restates the initial inspections required by paragraph (a) of AD 2002-05-07, Amendment 39-12675 (67 FR 11891, March 18, 2002), with added references to terminating action. For Model 737-100, -200, and -200C series airplanes with line numbers (L/N) 1 through 869 inclusive, and those airplanes with L/Ns 870 through 1585 inclusive, which either still have their original flap tracks or which have had the original flap tracks replaced with certain tracks as specified in Boeing Service Bulletin 737-57A1249, Revision 1, including Appendix A, dated June 1, 2000; except airplanes on which any replacement flap tracks were installed as specified in Boeing Service Bulletin 737-57-1203, dated November 15, 1990, or production equivalent: Within 6 months after April 22, 2002 (the effective date of AD 2002-05-07, Amendment 39-12675 (67 FR 11891, March 18, 2002)), accomplish the requirements of paragraphs (j)(1) and (j)(2) of this AD, according to Boeing Service Bulletin 737-57A1249, Revision 1, including Appendix A, dated June 1, 2000. Accomplishing the requirements of paragraph (p) of this AD terminates the requirements of this paragraph.

(1) Perform a detailed visual inspection for discrepancies (e.g., corrosion, or missing, damaged, or migrated anti-fret strips and tapered shims) of the rear spar attachments of the flap tracks.

(2) Perform detailed visual, high frequency eddy current (HFEC), and ultrasonic inspections for cracking in the upper flange of the inboard track of each outboard flap at the rear spar attachments.

(k) Retained Credit for Certain Previous Actions

This paragraph restates the credit for certain previously accomplished actions specified by Note 3 of AD 2002-05-07, Amendment 39-12675 (67 FR 11891, March 18, 2002). This paragraph provides credit for the actions specified in paragraphs (j), (l), (m), and (n) of this AD, if those actions were performed before the effective date of this AD using Boeing Alert Service Bulletin 737-57A1249, including Appendix A, dated December 16, 1999, which is not incorporated by reference in this AD.

(l) Retained Repetitive Inspections of the Rear Spar Attachment of the Flap Tracks and Upper Flange of the Inboard Track of Each Outboard Flap at the Rear Spar Attachments

This paragraph restates the repetitive inspections required by paragraph (b) of AD 2002-05-07, Amendment 39-12675 (67 FR 11891, March 18, 2002). For airplanes subject to the requirements of paragraph (j) of this AD: If no discrepancy is found during any inspection required by paragraph (j) of this AD, thereafter, repeat the inspections specified in paragraph (j) of this AD at intervals not to exceed 9 months, until the actions required by paragraph (m) or (p) of this AD have been accomplished.

(m) Retained Rework

This paragraph restates the rework required by paragraph (c) of AD 2002-05-07, Amendment 39-12675 (67 FR 11891, March 18, 2002). For airplanes subject to the requirements of paragraph (j) of this AD: At the applicable time specified in paragraph (m)(1) or (m)(2) of this AD, accomplish rework of the flap track assembly and aft flap track attachments (including removal of the flap track; a detailed visual inspection for a missing, damaged, or migrated anti-fret strip and tapered shim of the rear spar attachments of the flap track; replacement of the anti-fret strip with a new aluminum anti-fret strip (or installation of an aluminum strip if no strip is installed), as applicable; replacement of the tapered shim with a new shim (or installation of a shim if no shim is installed); eddy current and ultrasonic inspections for fatigue cracking of the flap tracks; a detailed visual inspection for corrosion of the flap tracks; and rework of attachment holes), including replacement of the flap tracks, as applicable, by accomplishing all actions specified in Part II of the Accomplishment Instructions of Boeing Service Bulletin 737-57A1249, Revision 1, including Appendix A, dated June 1, 2000. Do these actions according to the Accomplishment Instructions of Boeing Service Bulletin 737-57A1249, Revision 1, including Appendix A, dated June 1, 2000, except as provided by paragraph (o) of this AD. Accomplishment of the actions required by this paragraph terminates the repetitive inspections required by paragraph (l) of this AD. Accomplishing the requirements of paragraph (p) of this AD terminates the requirements of this paragraph.

(1) If no discrepancy is found during any inspection required by paragraph (j) or (l) of this AD: Do the rework within 24 months after April 22, 2002 (the effective date of AD 2002-05-07, Amendment 39-12675 (67 FR 11891, March 18, 2002)).

(2) If any discrepancy is found during any inspection required by paragraph (j) or (l) of this AD: Do the rework prior to further flight.

(n) Retained Repetitive Inspections of the Upper Flange of the Inboard Track of Each Outboard Flap at the Rear Spar Attachments

This paragraph restates the repetitive inspections required by paragraph (d) of AD 2002-05-07, Amendment 39-12675 (67 FR 11891, March 18, 2002). For Model 737-100, -200, -200C, -300, -400, and -500 series airplanes, except airplanes on which any replacement flap tracks were installed as specified in Boeing Service Bulletin 737-57-1203, dated November 15, 1990, or production equivalent: At the applicable time specified in paragraph (n)(1) or (n)(2) of this AD, and thereafter at least every 24 months, perform detailed visual, HFEC, and ultrasonic inspections for cracking in the upper flange of the inboard track of each outboard flap at the rear spar attachments, according to Part I of the Accomplishment Instructions of Boeing Service Bulletin 737-57A1249, Revision 1, including Appendix A, dated June 1, 2000. Accomplishing the requirements of paragraph (p) of this AD terminates the requirements of this paragraph.

(1) For airplanes subject to paragraph (m) of this AD, do the inspections within 10 years after accomplishment of the rework according to paragraph (m) of this AD.

(2) For airplanes other than those identified in paragraph (n)(1) of this AD, do the inspections within 10 years since the airplane's date of manufacture, or within 6 months after April 22, 2002 (the effective date of AD 2002-05-07, Amendment 39-12675 (67 FR 11891, March 18, 2002)), whichever occurs later.

(o) Retained Repair Instructions and Exception to Procedures in Service Information

This paragraph restates the repair instructions and exception to procedures required by paragraph (e) of AD 2002-05-07, Amendment 39-12675 (67 FR 11891, March 18, 2002). If any discrepancy is found during any action required by paragraph (j), (l), or (m) of this AD, and Boeing Service Bulletin 737-57A1249, Revision 1, including Appendix A, dated June 1, 2000, specifies to contact Boeing for appropriate action; or if any discrepancy is found during inspections according to paragraph (n) of this AD: Prior to further flight, repair according to a method approved by the Manager, Seattle ACO, FAA; or according to data meeting the type certification basis of the airplane approved by a Boeing DER or Boeing Company ODA, that has been authorized by the Manager, Seattle ACO, to make such findings. For a repair method to be approved by the ODA, the repair must meet the certification basis of the airplane, and the approval must specifically refer to this AD. For a repair method to be approved by the Manager, Seattle ACO, as required by this paragraph, the approval letter must specifically reference this AD.

(p) New Inspection of Flap Track Web and Flanges

For all airplanes: At the times specified in paragraph (q) of this AD, do the inspections specified in paragraphs (p)(1), (p)(2), (p)(3), and (p)(4) of this AD, and do all applicable corrective actions, in accordance with paragraph 3.B.3., “Inspection—Track Webs and Flanges,” of the Accomplishment Instructions of Boeing Service Bulletin 737-57A1271, Revision 3, dated February 13, 2012, except as required by paragraphs (r) and (v) of this AD. Performing these inspections terminates the requirements of paragraphs (g), (j), (l), (m), and (n) of this AD. Do all applicable corrective actions before further flight.

(1) Detailed inspection for damage (cracks, nicks, corrosion pits, galling, pieces broken off) and stop-drill repairs along the full length of the upper and lower flanges of the flap track.

(2) Detailed inspection for damage, cracking, and stop-drill repairs along the full length of the track webs.

(3) Eddy current inspection for damage (including cracking) of the flap track web and flanges.

(4) Inspection to determine the part number of the flap track assembly.

(q) New Compliance Time

At the latest of the applicable times specified in paragraphs (q)(1), (q)(2), and (q)(3) of this AD, do the actions required by paragraph (p) of this AD.

(1) Within 96 months since the flap track was new or overhauled, or prior to the accumulation of 15,000 flight cycles on the flap track since new or overhauled, whichever occurs first.

(2) Within 180 days after the effective date of this AD.

(3) Within 24 months after the most recent inspection was performed using Part 1 of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-57A1249, including Appendix A, dated December 16, 1999; or Boeing Service Bulletin 737-57A1249, Revision 1, including Appendix A, dated June 1, 2000.

(r) New Replacement

If, during any inspection required by paragraph (p) of this AD, any flap track assembly having P/N 65-46428-31 or 65-46428-33 is found, before further flight, replace the flap track assembly with a new or serviceable flap track assembly, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 737-57A1271, Revision 3, dated February 13, 2012, except as required by paragraph (v) of this AD.

(s) New Inspections of Flap-to-Wing Attachment if Repairs Are Done or if No Damage Is Found in Flap Track Web and Flanges

For airplanes on which no damage is found in the flanges or the web during any inspection required by paragraph (p) of this AD; and for airplanes on which a repair is done during any corrective action required by paragraph (p) of this AD: Before further flight, do the inspections specified in paragraphs (s)(1) through (s)(4) of this AD, and do all applicable related investigative and corrective actions, in accordance with paragraphs 3.B.4., “Inspection—With Track-to-Wing Attachment Assembled,” and 3.B.5., “Inspection—With Track-to-Wing Attachment Disassembled,” of the Accomplishment Instructions of Boeing Service Bulletin 737-57A1271, Revision 3, dated February 13, 2012, except as required by paragraph (v) of this AD. If, during the inspection required by paragraph (s)(1) of this AD, an anti-fret strip is not found installed, before further flight, do the related investigative actions specified in the Accomplishment Instructions of Boeing Service Bulletin 737-57A1271, Revision 3, dated February 13, 2012. If, during the inspection required by paragraph (s)(1) of this AD, an anti-fret strip is found with signs of damage or corrosion, before further flight, do all applicable corrective actions, including making and installing a new anti-fret strip, in accordance with paragraph 3.B.5., “Inspection—With Track-to-Wing Attachment Disassembled,” of the Accomplishment Instructions of Boeing Service Bulletin 737-57A1271, Revision 3, dated February 13, 2012, except as required by paragraph (v) of this AD. Do all applicable related investigative and corrective actions before further flight.

(1) Detailed inspection for signs of movement between the tapered shim and anti-fret strip, installation of the anti-fret strip, and corrosion of the tapered shim and anti-fret strip.

(2) Detailed inspection for signs of movement, cracks and corrosion of the area where the track is attached to the wing rear spar.

(3) High frequency eddy current inspection for cracking of the outboard edge of the track adjacent to the outboard attach bolt.

(4) Ultrasonic inspection for cracking of the inner edge of the track adjacent to the outboard attach bolt.

(t) New Overhaul

Within 10,000 flight cycles on the flap track or 48 months, whichever occurs first, after accomplishing the inspection required by paragraph (p) of this AD: Do an overhaul of the flap track, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 737-57A1271, Revision 3, dated February 13, 2012, except as required by paragraph (v) of this AD. Repeat the overhaul thereafter at intervals not to exceed 20,000 flight cycles on the flap track or 96 months, whichever occurs first.

(u) New Post-Overhaul Inspections

For airplanes on which any overhaul required by paragraph (t) of this AD is done: Do the inspections specified in paragraph (p) of this AD within 10,000 flight cycles on the flap track or 48 months after the most recent overhaul, whichever occurs first. Repeat the inspections specified in paragraph (p) of this AD thereafter at intervals not to exceed 10,000 flight cycles on the flap track or 48 months, whichever occurs first; except that if an overhaul required by paragraph (t) of this AD is done, do the next inspection within 10,000 flight cycles or 48 months, whichever occurs first, after the overhaul.

(v) Service Information Exception

Where Boeing Service Bulletin 737-57A1271, Revision 3, dated February 13, 2012, specifies to contact Boeing for appropriate action: Before further flight, repair using a method approved in accordance with the procedures specified in paragraph (y) of this AD.

(w) New Parts Installation Prohibition

As of the effective date of this AD, no person may install a flap track assembly, P/N 65-46428-31 or 65-46428-33, on any airplane.

(x) New Credit for Previous Actions in Paragraphs (p) Through (t) of This AD

This paragraph provides credit for the actions specified in paragraphs (p) through (t) of this AD, if those actions were performed before the effective date of this AD using the service bulletin specified in paragraph (x)(1), (x)(2), or (x)(3) of this AD.

(1) Boeing Alert Service Bulletin 737-57A1271, dated September 11, 2003, which is not incorporated by reference in this AD.

(2) Boeing Service Bulletin 737-57A1271, Revision 1, dated July 30, 2008, which is not incorporated by reference in this AD.

(3) Boeing Service Bulletin 737-57A1271, Revision 2, dated January 17, 2011, which is not incorporated by reference in this AD.

(y) Alternative Methods of Compliance (AMOCs)

(1) The Manager, Seattle 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) 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 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.

(4) AMOCs approved previously in accordance with ADs 2000-25-07, Amendment 39-12041 (65 FR 78913, December 18, 2000); and 2002-05-07, Amendment 39-12675 (67 FR 11891, March 18, 2002); are approved as AMOCs for the corresponding requirements of this AD.

(z) Related Information

For more information about this AD, contact Nancy Marsh, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: [phone]; fax: [phone]; email: [e-mail].

(aa) Material Incorporated by Reference

(1) The Director of the Federal Register approved the incorporation by reference (IBR) of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) You must use this service information as applicable to do the actions required by this AD, unless the AD specifies otherwise.

(3) The following service information was approved for IBR on June 13, 2013.

(i) Boeing Service Bulletin 737-57A1271, Revision 3, dated February 13, 2012.

(ii) Reserved.

(4) The following service information was approved for IBR on April 22, 2002 (67 FR 11891, March 18, 2002).

(i) Boeing Service Bulletin 737-57A1249, Revision 1, including Appendix A, dated June 1, 2000.

(ii) Reserved.

(5) The following service information was approved for IBR on January 2, 2001 (65 FR 78913, December 18, 2000).

(i) Boeing All Operator Message M-7200-00-01854, dated July 27, 2000.

(ii) Reserved.

(6) 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.

(7) You may view this service information at 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.

(8) You may view this 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/​cfr/​ibr-locations.html.

Issued in Renton, Washington, on April 19, 2013.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.