AIRWORTHINESS DIRECTIVE

CAA-AD-041/2002

Date of issue: April 02, 2002

AIRCRAFT - FLAP TRACKS - INSPECTION

Applicability: Model 737-100, -200, -200C, -300, -400, and -500 series airplanes; certificated in any category; EXCEPT airplanes on which any replacement flap tracks were installed according to Boeing Service Bulletin 737-57-1203, dated November 15, 1990, or production equivalent.

Effective date: May 16, 2002

Compliance: Required as indicated in FAA AD 2002-05-07.

Remarks: The compliance of this AD must be recorded in Aircraft Logbook, where applicable the requirements of this AD must be integrated into Aircraft Technical Documentation. Address inquiries concerning this AD to: Civil Aviation Authority, Airworthiness Division, Ruzyne Airport, 160 08 Prague 6, Czech Republic, tel.: 420 2 33320922, fax: 420 2 20562270.

Ing. Pavel MATOUŠEK

Director of Airworthiness Division

CAA CZ

2002-05-07 Boeing: Amendment 39-12675. Docket 99-NM-21-AD.

Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (f) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

Note 2: Airplanes modified according to Boeing Service Bulletin 737-57-1065 are subject to additional work as described in this AD and in Boeing Service Bulletin 737-57A1249, Revision 1, dated June 1, 2000.

To find and fix discrepancies of the inboard tracks of the outboard flaps, which could result in loss of the outboard trailing edge flaps and consequent reduced controllability of the airplane, accomplish the following:

Initial Inspections

(a) 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: Within 6 months after the effective date of this AD, accomplish the requirements of paragraphs (a)(1) and (a)(2) of this AD, according to Boeing Service Bulletin 737-57A1249, Revision 1, including Appendix A, dated June 1, 2000.

(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.

Note 3: Inspections and rework accomplished according to Boeing Alert Service Bulletin 737-57A1249, including Appendix A, dated December 16, 1999, is considered acceptable for compliance with the applicable action specified in this AD.

Note 4: 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 intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required."

Repetitive Inspections

(b) For airplanes subject to paragraph (a) of this AD: If no discrepancy is found during any inspection required by paragraph (a) of this AD, thereafter, repeat the inspections specified in paragraph (a) of this AD at intervals not to exceed 9 months, until the actions required by paragraph (c) of this AD have been accomplished.

Rework

(c) For airplanes subject to paragraph (a) of this AD: At the applicable time specified in paragraph (c)(1) or (c)(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 that service bulletin, except as provided by paragraph (e) of this AD. Accomplishment of the actions required by this paragraph constitutes terminating action for the repetitive inspections required by paragraph (b) of this AD.

(1) If no discrepancy is found during any inspection required by paragraph (a) or (b) of this AD: Do the rework within 24 months after the effective date of this AD.

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

Repetitive Inspections

(d) For all airplanes: At the applicable time specified in paragraph (d)(1) or (d)(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.

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

(2) For airplanes other than those identified in paragraph (d)(1) of this AD, do the inspections within 10 years since the airplane's date of manufacture, or within 6 months after the effective date of this AD, whichever occurs later.

Repair Instructions and Exception to Procedures in Service Information

(e) If any discrepancy is found during any action required by paragraphs (a), (b), or (c) of this AD, and the service bulletin specifies to contact Boeing for appropriate action; OR if any discrepancy is found during inspections according to paragraph (d) of this AD: Prior to further flight, repair according to a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or according to data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative (DER) who has been authorized by the Manager, Seattle ACO, to make such findings. 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.

Alternative Methods of Compliance

(f) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Seattle ACO. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO.

Note 5: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.

Special Flight Permits

(g) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

Incorporation by Reference

(h) Except as provided by paragraph (e) of this AD, the actions shall be done in accordance with Boeing Service Bulletin 737-57A1249, Revision 1, including Appendix A, dated June 1, 2000. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Effective Date

(i) This amendment becomes effective on April 22, 2002.

Issued in Renton, Washington, on March 8, 2002.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 02-6201 Filed 3-15-02; 8:45 am]

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