Airworthiness Directive · Amendment 39-17966 · Fuselage
The Boeing Company Airplanes
(1) This AD applies to The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes, certificated in any category, line numbers (LNs) 1 through 3132 inclusive.
(2) Installation of Supplemental Type Certificate (STC) ST01219SE (http://rgl.faa.govRegulatory_and_Guidance_Libraryrgstc.nsf0be866b732f6cf31086257b9700692796$FILEST01219SE.pdf) 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 Airworthiness Directive (AD) 2014-05-02 for certain The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. AD 2014-05-02 required repetitive inspections for cracking and corrosion of the aft pressure bulkhead, repetitive inspections of the frame chord drain path for debris, and corrective actions if necessary; and, for certain airplanes, enlargement of frame chord drain holes. This AD requires the same actions as AD 2014-05-02, but revises a certain repetitive inspection interval to avoid a misunderstanding of the repetitive inspection interval for the aft pressure bulkhead. This AD was prompted by reports from operators expressing confusion regarding a certain repetitive inspection interval for the aft pressure bulkhead. We are issuing this AD to detect and correct corrosion or cracking of the aft pressure bulkhead, which could result in loss of the aft pressure bulkhead web and stiffeners, and consequent rapid decompression of the airplane.
This paragraph restates the requirements of paragraph (g) of AD 2014-05-02, Amendment 39-17775 (79 FR 12045, March 4, 2014), with no changes. For Model 737 series airplanes having LNs 1 through 929 inclusive, with more than 20,000 hours time-in-service or 7 years since date of manufacture, whichever occurs first: Within 120 days after January 20, 1986 (the effective date of AD 84-20-03 R1, Amendment 39-5183 (50 FR 51235, December 16, 1985)), unless already accomplished within 21 months before January 20, 1986, visually inspect the body station (BS) 1016 pressure bulkhead, including inspecting for cracking and corrosion of the pressure bulkhead, and for debris in the drain path in the chord frame, according to Boeing Alert Service Bulletin 737-53A1075, Revision 1, dated September 2, 1983; Revision 2, dated July 13, 1984; or Revision 3, dated June 8, 2000. Remove any obstruction to the drain hole in the frame chord and replace any deteriorated leveling compound, as noted in Boeing Alert Service Bulletin 737-53A1075, Revision 1, dated September 2, 1983; Revision 2, dated July 13, 1984; or Revision 3, dated June 8, 2000. Treat the area of inspection with corrosion inhibitor Boeing Material Specification (BMS) 3-23, or equivalent. After June 8, 2000 (the effective date of AD 2014-05-02), use only Boeing Alert Service Bulletin 737-53A1075, Revision 3, dated June 8, 2000, to do the actions required by this paragraph.
This paragraph restates the requirements of paragraph (h) of AD 2014-05-02, Amendment 39-17775 (79 FR 12045, March 4, 2014), with no changes. For airplanes identified in paragraph (g) of this AD: Within 1 year after January 20, 1986 (the effective date of AD 84-20-03 R1, Amendment 39-5183 (50 FR 51235, December 16, 1985)), accomplish the drain hole enlargement as shown in Boeing Alert Service Bulletin 737-53A1075, Revision 1, dated September 2, 1983; Revision 2, dated July 13, 1984; or Revision 3, dated June 8, 2000. After April 8, 2014 (the effective date of AD 2014-05-02), use only Boeing Alert Service Bulletin 737-53A1075, Revision 3, dated June 8, 2000, to do the actions required by this paragraph.
This paragraph restates the requirements of paragraph (i) of AD 2014-05-02, Amendment 39-17775 (79 FR 12045, March 4, 2014), with no changes. If cracking or corrosion is found during any inspection required by paragraph (g) or (j) of this AD: Before further flight, repair according to paragraph (i)(1) or (i)(2) of this AD, as applicable.
(1) If the inspection was done before April 8, 2014 (the effective date of AD 2014-05-02, Amendment 39-17775 (79 FR 12045, March 4, 2014)): Repair according to Boeing Alert Service Bulletin 737-53A1075, Revision 1, dated September 2, 1983; Revision 2, dated July 13, 1984; or Revision 3, dated June 8, 2000; or according to a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or per 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 Manager's approval letter must specifically reference this AD.
(2) If the inspection was done on or after April 8, 2014 (the effective date of AD 2014-05-02, Amendment 39-17775 (79 FR 12045, March 4, 2014)): Repair using a method approved in accordance with the procedures specified in paragraph (p) of this AD.
This paragraph restates the requirements of paragraph (j) of AD 2014-05-02, Amendment 39-17775 (79 FR 12045, March 4, 2014), with no changes. For airplanes identified in paragraph (g) of this AD: Repeat the visual inspections and corrosion inhibitor treatment specified in paragraph (g) of this AD at intervals not to exceed 2 years. Accomplishment of the initial aft pressure bulkhead inspection required by paragraph (k) of this AD terminates the inspection required by this paragraph.
This paragraph restates the requirements of paragraph (k) of AD 2014-05-02, Amendment 39-17775 (79 FR 12045, March 4, 2014), with clarification for repaired areas. Do a detailed inspection for cracking or corrosion of the aft pressure bulkhead at BS 1016 (including the forward and aft sides of the pressure web, forward and aft sides of the pressure chord, pressure chord radius, forward and aft sides of the angle stiffener, forward and aft chord, stringer end fitting, system penetration doublers, channel stiffeners and fasteners, “Z” stiffeners and fasteners, and fasteners common to the pressure chord and pressure web), according to Boeing Alert Service Bulletin 737-53A1075, Revision 3, dated June 8, 2000. Do this inspection at the applicable time shown in paragraph (k)(1), (k)(2), or (k)(3) of this AD. For repaired areas, this inspection may be accomplished without removal of the repairs.
(1) For airplanes on which an inspection has previously been done according to the requirements of paragraph (g) of this AD: Do the inspection within 2 years since the most recent inspection according to paragraph (g) or (j) of this AD, as applicable. For the airplanes identified in paragraph (g) of this AD, accomplishment of the inspection required by paragraph (k) of this AD terminates the inspections for cracking and corrosion required by paragraph (j) of this AD.
(2) For airplanes having L/Ns 930 through 1042 inclusive, on which an inspection has not previously been done according to paragraph (g) of this AD: Do the inspection within 2 years after June 27, 2002 (the effective date AD 2002-10-11, Amendment 39-12757 (67 FR 36085, May 23, 2002)).
(3) For airplanes having L/Ns 1043 through 3132 inclusive, on which an inspection has not previously been done according to paragraph (g) of this AD: Do the inspection within 6 years since the airplane's date of manufacture, or within 2 years after June 27, 2002 (the effective date AD 2002-10-11, Amendment 39-12757 (67 FR 36085, May 23, 2002)), whichever occurs later.
This paragraph restates the requirements of paragraph (l) of AD 2014-05-02, Amendment 39-17775 (79 FR 12045, March 4, 2014), with revised compliance times in paragraph (l)(2) of this AD. Repeat the inspection in paragraph (k) of this AD at the applicable time shown in paragraph (l)(1) or (l)(2) of this AD.
(1) For airplanes having L/Ns 1 through 1042 inclusive: Repeat the inspection thereafter at intervals not to exceed 2 years.
(2) For airplanes having L/Ns 1043 through 3132 inclusive: Repeat the inspection within 2 years since the last inspection or within 120 days after April 8, 2014 (the effective date of AD 2014-05-02, Amendment 39-17775 (79 FR 12045, March 4, 2014)), whichever occurs later. Repeat the inspection thereafter at intervals not to exceed 2 years.
This paragraph restates the requirements of paragraph (m) of AD 2014-05-02, Amendment 39-17775 (79 FR 12045, March 4, 2014), with no changes. If any corrosion or cracking is found during any inspection according to paragraph (k) or (l) of this AD: Do the applicable action specified in paragraph (m)(1) or (m)(2) of this AD.
(1) If the inspection was done prior to April 8, 2014 (the effective date of AD 2014-05-02, Amendment 39-17775 (79 FR 12045, March 4, 2014)): Before further flight, repair according to Boeing Alert Service Bulletin 737-53A1075, Revision 3, dated June 8, 2000. Exception: If corrosion or cracking of the web and stiffeners is outside the limits specified in Boeing Alert Service Bulletin 737-53A1075, Revision 3, dated June 8, 2000, or if corrosion or cracking is found in any structure not covered by the repair instructions in Boeing Alert Service Bulletin 737-53A1075, Revision 3, dated June 8, 2000, before further flight, repair according to a method approved by the Manager, Seattle ACO; or per data meeting the type certification basis of the airplane approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) 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 Manager's approval letter must specifically reference this AD.
(2) On or after April 8, 2014 (the effective date of AD 2014-05-02, Amendment 39-17775 (79 FR 12045, March 4, 2014)), if any corrosion or cracking is found during any inspection required by this AD: Before further flight, repair the corrosion or cracking using a method approved in accordance with the procedures specified in paragraph (p) of this AD.
This paragraph restates the requirements of paragraph (n) of AD 2014-05-02, Amendment 39-17775 (79 FR 12045, March 4, 2014), with no changes. For airplanes having L/N 1 through 3132 inclusive: Within 2 years since the last inspection in accordance with paragraph (k) of this AD or within 2 years after April 8, 2014 (the effective date of AD 2014-05-02), whichever occurs later: Do a general visual inspection of the drain path in the chord frame for debris, in accordance with Figure 2, Steps 1 through 6, of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-53A1075, Revision 3, dated June 8, 2000. Remove any obstruction to the drain hole in the frame chord and replace any deteriorated leveling compound. Treat the area of inspection with corrosion inhibitor BMS 3-23, or equivalent, as specified in the Accomplishment Instructions of Boeing Alert Service Bulletin 737-53A1075, Revision 3, dated June 8, 2000. Repeat the actions required by this paragraph at intervals not to exceed 2 years. Do all actions required by this paragraph in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-53A1075, Revision 3, dated June 8, 2000. For the purposes of this AD, a general visual inspection is a visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to ensure visual access to all surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.
This paragraph restates the requirements of paragraph (o) of AD 2014-05-02, Amendment 39-17775 (79 FR 12045, March 4, 2014), with clarification for repaired areas. For airplanes having L/Ns 1043 through 3132 inclusive: In lieu of performing the first inspection after April 8, 2014 (the effective date of AD 2014-05-02), required by paragraph (l)(2) of this AD, operators may do the actions specified in this paragraph. Within 2 years from the most recent aft pressure bulkhead inspection done as specified in the service information identified in paragraph (o)(1), (o)(2), or (o)(3) of this AD, or within 120 days after April 8, 2014, whichever occurs later: Do a detailed inspection for cracking or corrosion of the aft side of the aft pressure bulkhead at BS 1016 (including the aft sides of the pressure web, aft sides of the pressure chord, pressure chord radius, aft chord, stringer end fitting, system penetration doublers, and fasteners common to the pressure chord and pressure web), in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-53A1075, Revision 3, dated June 8, 2000. For repaired areas, this inspection may be accomplished without removal of the repairs. If any corrosion or cracking is found: Before further flight, repair the corrosion or cracking using a method approved in accordance with the procedures specified in paragraph (p) of this AD. Repeat the inspection thereafter at intervals not to exceed 90 days for a period not to exceed 2 years, until the actions required by paragraph (l)(2) of this AD are accomplished.
(1) Boeing Alert Service Bulletin 737-53A1075, Revision 1, dated September 2, 1983.
(2) Boeing Alert Service Bulletin 737-53A1075, Revision 2, dated July 13, 1984.
(3) Boeing Alert Service Bulletin 737-53A1075, Revision 3, dated June 8, 2000.
