Airworthiness Directive · Amendment 39-18298 · Fuselage
The Boeing Company Airplanes
This AD applies to The Boeing Company Model 737-200, -200C, -300, -400, and -500 series airplanes, certificated in any category, line numbers 292 through 2565 inclusive.
We are superseding Airworthiness Directive (AD) 2002-07-08 for certain The Boeing Company Model 737 airplanes. AD 2002-07-08 required repetitive inspections for cracking of the lower skin at the lower row of fasteners in the lap joints of the fuselage; repair of any cracking found; modification of the fuselage lap joints at certain locations, which terminated the repetitive inspections of the modified areas; and replacement of a certain preventive modification with an improved modification. This new AD adds repetitive inspections for cracking at certain window corner fastener holes, a preventive modification, and repair if necessary. This AD was prompted by the FAA's determination that certain modifications of the fuselage lap joints do not provide an adequate level of safety, and the subsequent discovery of cracks in additional fastener locations in the window belt skin panels, adjacent stringers, and window frames in locations outside the previous inspection area. We are issuing this AD to detect and correct fatigue cracking of the fuselage lap joints and window belt skin panels, which could result in reduced structural integrity and sudden decompression of the airplane.
This paragraph restates the actions required by paragraph (g) of AD 2002-07-08, Amendment 39-12702 (67 FR 17917, April 12, 2002), with revised service information. Except as provided by paragraphs (h) and (q)(2) of this AD: Install the lap joint repair as specified in Part 1.E.1. (“Compliance”) of Boeing Service Bulletin 737-53A1177, Revision 4, dated September 2, 1999; Boeing Service Bulletin 737-53A1177, Revision 5, dated February 15, 2001; or Boeing Service Bulletin 737-53A1177, Revision 6, dated May 31, 2001; per PART III or IV (“Lap Joint Repair”), as applicable; or Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013; per PART III, IV, VI, or VII (“Lap Joint Modification (Repair)”), as applicable, of the Accomplishment Instructions of the applicable service bulletin; at the time specified in paragraph (g)(1), (g)(2), (g)(3), (g)(4), or (g)(5) of this AD, as applicable. Accomplishment of this repair terminates the repetitive inspections required by paragraph (j) of this AD. As of the effective date of this AD, only Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013, may be used to do the actions required by this paragraph. A lap splice modification (repair) done in accordance with the Accomplishment Instructions of Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013, terminates the inspections required by paragraphs (g) and (i) of AD 2013-09-01, Amendment 39-17442 (78 FR 27001, May 9, 2013), for the modified (repaired) area only.
(1) For airplanes that have accumulated 70,000 total flight cycles or more as of May 17, 2002 (the effective date of AD 2002-07-08, Amendment 39-12702 (67 FR 17917, April 12, 2002)): Within 600 flight cycles after May 17, 2002, do the lap joint repair.
(2) For airplanes that have accumulated 65,000 total flight cycles or more, but fewer than 70,000 total flight cycles as of May 17, 2002 (the effective date of AD 2002-07-08, Amendment 39-12702 (67 FR 17917, April 12, 2002)): Do the repair at the later of the times specified in paragraphs (g)(2)(i) and (g)(2)(ii) of this AD.
(i) Before the accumulation of 70,000 total flight cycles.
(ii) Within 600 flight cycles after May 17, 2002 (the effective date of AD 2002-07-08, Amendment 39-12702 (67 FR 17917, April 12, 2002)).
(3) For airplanes that have accumulated 45,000 total flight cycles or more, but fewer than 65,000 total flight cycles as of May 17, 2002 (the effective date of AD 2002-07-08, Amendment 39-12702 (67 FR 17917, April 12, 2002)): Within 5,000 flight cycles after May 17, 2002.
(4) For airplanes that have accumulated less than 45,000 total flight cycles as of May 17, 2002 (the effective date of AD 2002-07-08, Amendment 39-12702 (67 FR 17917, April 12, 2002)): Before the accumulation of 50,000 total flight cycles.
(5) Notwithstanding the times specified in paragraphs (g)(1), (g)(2), (g)(3), and (g)(4) of this AD, for airplanes on which the “Preventive Change” (NACA modification) has been accomplished per PART III of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-53A1177, Revision 1, dated September 19, 1996; Revision 2, dated July 24, 1997; or Revision 3, dated September 18, 1997: Within 18,000 flight cycles after accomplishment of the NACA modification.
This paragraph restates the requirements of paragraph (h) of AD 2002-07-08, Amendment 39-12702 (67 FR 17917, April 12, 2002), with revised service information and revised airplane groups.
(1) For airplanes identified as Groups 3 and 5 in Boeing Service Bulletin 737-53A1177, Revision 6, dated May 31, 2001: Install the lap joint repair at stringers 4R and 10R, as specified in Part 1.E.1. (“Compliance”) of Boeing Service Bulletin 737-53A1177, Revision 6, dated May 31, 2001, at the time specified in paragraph (g)(1), (g)(2), (g)(3), (g)(4), or (g)(5) of this AD, as applicable, using a method approved in accordance with the procedures specified in paragraph (t) of this AD.
(2) For airplanes identified in Groups 6, 7, and 8 in Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013: Install the lap joint repair at stringers 4R and 10R, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013, at the time specified in paragraph (g)(1), (g)(2), (g)(3), (g)(4), or (g)(5) of this AD, as applicable, unless previously accomplished as specified in paragraph (h)(1) of this AD.
This paragraph restates the actions required by paragraph (i) of AD 2002-07-08, Amendment 39-12702 (67 FR 17917, April 12, 2002), with revised service information. Before the accumulation of 70,000 total flight cycles, or within 2,500 flight cycles after May 17, 2002 (the effective date of AD 2002-07-08), whichever comes later: Do an LFEC inspection to find cracking of the lap joints of the fuselage, as specified in Part 1.E.2. (“Compliance”) of Boeing Service Bulletin 737-53A1177, Revision 6, dated May 31, 2001; or Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013; and as identified in Figures 2 through 6 of the Accomplishment Instructions of Boeing Service Bulletin 737-53A1177, Revision 6, dated May 31, 2001; or as identified in Figures 50 through 64 of the Accomplishment Instructions of Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013. Do the inspection per Boeing Service Bulletin 737-53A1177, Revision 6, dated May 31, 2001; or Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013. As of the effective date of this AD, only Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013, may be used to do the actions required by this paragraph. Repeat the inspection after that at intervals not to exceed 5,000 flight cycles.
This paragraph restates the actions required by paragraph (j) of AD 2002-07-08, Amendment 39-12702 (67 FR 17917, April 12, 2002), with revised service information. For airplanes that have the “Preventive Change” (NACA modification) of the crown lap joint stringers (“Crown Laps”) done per PART III of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-53A1177, Revision 1, dated September 19, 1996; Boeing Service Bulletin 737-53A1177, Revision 2, dated July 24, 1997; or Boeing Service Bulletin 737-53A1177, Revision 3, dated September 18, 1997: Within 12,000 flight cycles after accomplishment of the NACA modification, or within 750 flight cycles after May 17, 2002 (the effective date of AD 2002-07-08), whichever is later, do either an external or internal LFEC inspection to find cracking and corrosion as specified in Part 1.E.4.a. (“Compliance”) of Boeing Service Bulletin 737-53A1177, Revision 6, dated May 31, 2001; or Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013; per PART I (“Inspection”) of the Accomplishment Instructions of Boeing Service Bulletin 737-53A1177, Revision 6, dated May 31, 2001; or Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013. The external and internal LFEC inspections are specified in Figures 8 and 9, respectively, of Boeing Service Bulletin 737-53A1177, Revision 6, dated May 31, 2001; and Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013. As of the effective date of this AD, only Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013, may be used to do the actions required by this paragraph.
(1) If the external inspection is done: Repeat the inspection after that at intervals not to exceed 1,500 flight cycles until accomplishment of the lap joint repair required by paragraph (g) of this AD.
(2) If the internal inspection is done: Repeat the inspection after that at intervals not to exceed 4,500 flight cycles until accomplishment of the lap joint repair required by paragraph (g) of this AD.
This paragraph restates the actions required by paragraph (k) of AD 2002-07-08, Amendment 39-12702 (67 FR 17917, April 12, 2002), with revised service information. For airplanes that have the “Preventive Change” (NACA modification) outside the crown areas done per PART III of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-53A1177, Revision 1, dated September 19, 1996; Boeing Service Bulletin 737-53A1177, Revision 2, dated July 24, 1997; or Boeing Service Bulletin 737-53A1177, Revision 3, dated September 18, 1997: Before the accumulation of 20,000 flight cycles after accomplishment of the NACA modification, or within 750 flight cycles after May 17, 2002 (the effective date of AD 2002-07-08), whichever is later, do either an external or internal LFEC inspection to find cracking and corrosion as specified in Part 1.E.4.b. (“Compliance”) of Boeing Service Bulletin 737-53A1177, Revision 6, dated May 31, 2001; or Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013; per PART I (“Inspection”) of the Accomplishment Instructions of Boeing Service Bulletin 737-53A1177, Revision 6, dated May 31, 2001; or Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013. The external and internal LFEC inspections are specified in Figures 8 and 9, respectively, of Boeing Service Bulletin 737-53A1177, Revision 6, dated May 31, 2001; and Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013. As of the effective date of this AD, only Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013, may be used to do the actions required by this paragraph.
(1) If the external inspection is done: Repeat the external inspection after that at intervals not to exceed 1,500 flight cycles.
(2) If the internal inspection is done: Repeat the internal inspection after that at intervals not to exceed 4,500 flight cycles.
This paragraph restates the actions required by paragraph (l) of AD 2002-07-08, Amendment 39-12702 (67 FR 17917, April 12, 2002), with revised service information. For airplanes that have the “lap joint repair,” as specified in Part IV of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-53A1177, Revision 2, dated July 24, 1997; or Revision 3, dated September 18, 1997: Within 45,000 flight cycles after accomplishment of this lap joint repair, modify the splice straps per Figures 10, 11, and 12 of the Accomplishment Instructions of Boeing Service Bulletin 737-53A1177, Revision 6, dated May 31, 2001; or Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013. As of the effective date of this AD, only Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013, may be used to do the actions required by this paragraph.
This paragraph restates the actions required by paragraph (m) of AD 2002-07-08, Amendment 39-12702 (67 FR 17917, April 12, 2002), with revised service information. Within 45,000 flight cycles after accomplishment of the lap joint repair required by paragraph (g) or (h) of this AD, as applicable: Do either an external or internal LFEC inspection as specified in Part 1.E.7. (“Compliance”) of Boeing Service Bulletin 737-53A1177, Revision 6, dated May 31, 2001; or Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013; to find cracking of the lap joint repair, per PART I (“Inspection”) of the Accomplishment Instructions of Boeing Service Bulletin 737-53A1177, Revision 6, dated May 31, 2001; or Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013. Repair any crack found before further flight using a method approved in accordance with the procedures specified in paragraph (t) of this AD. The internal LFEC inspection is specified in Figure 9 of Boeing Service Bulletin 737-53A1177, Revision 6, dated May 31, 2001; and Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013. As of the effective date of this AD, only Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013, may be used to do the actions required by this paragraph. Repeat the inspection after that at intervals not to exceed 2,800 flight cycles.
This paragraph restates the actions required by paragraph (n) of AD 2002-07-08, Amendment 39-12702 (67 FR 17917, April 12, 2002), with revised service information. For airplanes having line numbers 520 through 2565 inclusive: Before the accumulation of 50,000 total flight cycles, or within 2,250 flight cycles after May 17, 2002 (the effective date of AD 2002-07-08), whichever comes later, do an HFEC inspection to find cracking as specified in Part 1.E.10 (“Compliance”) of Boeing Service Bulletin 737-53A1177, Revision 6, dated May 31, 2001, or Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013; per PART V (“Window Corner Fastener Hole Cracking, Inspection and Repair”) of the Accomplishment Instructions of Boeing Service Bulletin 737-53A1177, Revision 6, dated May 31, 2001; or Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013. Repeat the inspection after that at intervals not to exceed 4,500 flight cycles, until the initial actions required by paragraph (p) of this AD have been done. Accomplishment of the modification (which includes removing and discarding fasteners, oversizing fastener holes, and installing rivets or Hi-Lok fasteners, as applicable), per PART V of the Accomplishment Instructions of Boeing Service Bulletin 737-53A1177, Revision 5, dated February 15, 2001; or Boeing Service Bulletin 737-53A1177, Revision 6, dated May 31, 2001; or Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013; constitutes terminating action for the inspections required by this paragraph.
This paragraph restates the actions required by paragraph (d) of AD 2002-07-08, Amendment 39-12702 (67 FR 17917, April 12, 2002), with revised service information. If any crack is found during any inspection required by paragraph (i), (j), or (k) of this AD: Before further flight, repair per PART II (“Crack Repair”) of the Accomplishment Instructions of Boeing Service Bulletin 737-53A1177, Revision 6, dated May 31, 2001; or Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013; except as required by paragraph (r)(2) of this AD. As of the effective date of this AD, only Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013, may be used to do the actions required by this paragraph.
For airplanes identified as Groups 2 through 28 in Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013: At the applicable times specified in tables 8, 9, 10, and 11 of paragraph 1.E.10, “Compliance,” of Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013, except as required by paragraph (r)(1) of this AD, do a surface HFEC inspection for cracking at the applicable window corner fastener holes, and do a preventive modification, as applicable, in accordance with Part V of the Accomplishment Instructions of Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013, except as required by paragraph (r)(2) of this AD. Repair any crack found before further flight, in accordance with Part V of the Accomplishment Instructions of Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013, except as required by paragraph (r)(2) of this AD. Repeat the applicable inspection thereafter at the applicable times specified in tables 8, 9, 10, and 11 of paragraph 1.E.10, “Compliance,” of Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013. Accomplishment of the initial inspection specified in this paragraph terminates the repetitive inspection requirements of paragraph (n) of this AD. Accomplishment of the preventive modification specified in this paragraph terminates the repetitive inspection requirements of this paragraph for the applicable corner fastener locations specified in Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013.
(1) Replacement of the skin panel as specified in Part VIII or Part IX, as applicable, of the Accomplishment Instructions of Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013, terminates the repetitive inspections at the window corners specified in paragraph (p) of this AD for the windows common to the replaced panel only.
(2) Replacement of the skin panel as specified in Part VIII or Part IX, as applicable, of the Accomplishment Instructions of Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013, terminates the lap joint modification required by paragraph (g) of this AD for the S-10 and S-14 lap joints common to the replaced panel only.
(3) Replacement of the skin panels as specified in Part VIII or Part IX, as applicable, of the Accomplishment Instructions of Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013, terminates the inspections required by paragraphs (g) and (i) of AD 2013-09-01, Amendment 39-17442 (78 FR 27001, May 9, 2013), for the replaced skin panel only.
(1) Where Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013, specifies a compliance time “after the Revision 7 date of this service bulletin,” this AD requires compliance within the specified compliance time after the effective date of this AD.
(2) Where Boeing Service Bulletin 737-53A1177, Revision 6, dated May 31, 2001; and Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013; specify to contact Boeing for certain procedures: Do the specified actions before further flight using a method approved in accordance with the procedures specified in paragraph (t) of this AD.
(3) Where Boeing Service Bulletin 737-53A1177, Revision 6, dated May 31, 2001; and Boeing Service Bulletin 737-53A1177, Revision 7, dated June 14, 2013; include the phrase “or is Boeing or FAA approved,” this AD requires the “Boeing Approval” to be requested in accordance with the procedures specified in paragraph (t) of this AD.
