Airworthiness Directive · Amendment 39-17443 · Wings
The Boeing Company Airplanes
(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.
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.
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.
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.”
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
