Airworthiness Directive · Amendment 39-18575 · Wings
The Boeing Company Airplanes
(1) This AD applies to The Boeing Company Model 737-100, -200, -300, -400, and -500 series airplanes; certificated in any category; as identified in Boeing Alert Service Bulletin 737-57A1296, Revision 2, dated April 1, 2015.
(2) Installation of Supplemental Type Certificate (STC) ST01219SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/ebd1cec7b301293e86257cb30045557a/$FILE/ST01219SE.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) 2008-05-06 for certain The Boeing Company Model 737-100, -200, -300, -400, and -500 series airplanes. AD 2008-05-06 required repetitive inspections for fatigue cracking in the longitudinal floor beam web, upper chord, and lower chord located at certain body stations, and repair if necessary. This new AD requires, for certain airplanes, an inspection to determine if tapered fillers are installed, and related investigative and corrective actions if necessary. This AD was prompted by reports of cracks in the center wing box longitudinal floor beams, upper chord, and lower chord. We are issuing this AD to detect and correct fatigue cracking of the upper and lower chords and web of the longitudinal floor beams, which could result in rapid loss of cabin pressure.
This paragraph restates the requirements of paragraph (f) of AD 2008-05-06, with revised service information and revised affected airplanes. For Groups 1 through 4 airplanes identified in Boeing Alert Service Bulletin 737-57A1296, Revision 2, dated April 1, 2015, do the various inspections for fatigue cracks in the longitudinal floor beam web, upper chord, and lower chord, located at the applicable body stations specified in the Accomplishment Instructions of Boeing Service Bulletin 737-57-1296, dated June 13, 2007; or Boeing Alert Service Bulletin 737-57A1296, Revision 2, dated April 1, 2015; by doing all the actions in accordance with the Accomplishment Instructions of Boeing Service Bulletin 737-57A1296, dated June 13, 2007; or Boeing Alert Service Bulletin 737-57A1296, Revision 2, dated April 1, 2015; except as provided by paragraph (h) of this AD. Do the inspections at the time specified in paragraph (g)(1) or (g)(2) of this AD, as applicable. As of the effective date of this AD, only use Boeing Alert Service Bulletin 737-57A1296, Revision 2, dated April 1, 2015, for accomplishing the actions required by this paragraph.
Note 1 to paragraphs (g) and (h) of this AD: The airplane groups identified in Boeing Service Bulletin 737-57-1296, dated June 13, 2007, do not, in all cases, match the airplane groups identified in Boeing Alert Service Bulletin 737-57A1296, Revision 2, dated April 1, 2015 (Group 4 airplanes in Boeing Alert Service Bulletin 737-57A1296, Revision 2, dated April 1, 2015, coincide with certain Group 2 airplanes in Boeing Service Bulletin 737-57-1296, dated June 13, 2007).
(1) For Groups 1 and 2 airplanes, except for line numbers 1 through 291, identified in Boeing Service Bulletin 737-57-1296, dated June 13, 2007: Do the inspections at the applicable initial compliance time listed in paragraph 1.E., “Compliance,” of Boeing Service Bulletin 737-57-1296, dated June 13, 2007, except where Boeing Service Bulletin 737-57-1296, dated June 13, 2007, specifies a compliance time after the date on the service bulletin, this AD requires compliance within the specified compliance time after April 8, 2008 (the effective date of AD 2008-05-06). Repeat the inspections thereafter at the intervals specified in paragraph 1.E., “Compliance,” of Boeing Service Bulletin 737-57-1296, dated June 13, 2007.
(2) For Group 3 airplanes identified in Boeing Service Bulletin 737-57-1296, dated June 13, 2007: Do the inspections at the applicable initial compliance time listed in paragraph 1.E., “Compliance,” of Boeing Service Bulletin 737-57-1296, dated June 13, 2007, except where Boeing Service Bulletin 737-57-1296, dated June 13, 2007, specifies a compliance time after the date on the service bulletin, this AD requires compliance within the specified compliance time after April 8, 2008 (the effective date of AD 2008-05-06). Repeat the inspections thereafter at the intervals specified in paragraph 1.E., “Compliance,” of Boeing Service Bulletin 737-57-1296, dated June 13, 2007.
This paragraph restates the requirements of paragraph (g) of AD 2008-05-06, with revised service information that contains new repair actions. If any crack is found during any inspection required by paragraph (g) of this AD, do the applicable actions specified in paragraph (h)(1) or (h)(2) of this AD.
(1) For inspections done using Boeing Service Bulletin 737-57-1296, dated June 13, 2007: If any crack is found during any inspection required by paragraph (g) of this AD, and Boeing Service Bulletin 737-57-1296, dated June 13, 2007, specifies contacting Boeing for repair instructions, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (n) of this AD.
(2) For inspections done using Boeing Alert Service Bulletin 737-57A1296, Revision 2, dated April 1, 2015: If any crack is found during any inspection required by paragraph (g) of this AD, before further flight, repair, including doing all applicable related investigative actions and corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-57A1296, Revision 2, dated April 1, 2015; except where Boeing Alert Service Bulletin 737-57A1296, Revision 2, dated April 1, 2015, specifies contacting Boeing for repair instructions, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (n) of this AD. Accomplishing a repair specified in Boeing Alert Service Bulletin 737-57A1296, Revision 2, dated April 1, 2015, terminates the repetitive inspections required by paragraph (g) of this AD for the repaired area only.
For Groups 1 through 4, Configuration 1 airplanes identified in Boeing Alert Service Bulletin 737-57A1296, Revision 2, dated April 1, 2015: Except as provided by paragraph (k) of this AD, at the applicable time specified in table 5 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-57A1296, Revision 2, dated April 1, 2015, do an inspection to determine if tapered fillers are installed; and do all applicable related investigative and corrective actions; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-57A1296, Revision 2, dated April 1, 2015; except where Boeing Alert Service Bulletin 737-57A1296, Revision 2, dated April 1, 2015, specifies contacting Boeing for repair instructions, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (n) of this AD. Do all applicable related investigative and corrective actions before further flight. A review of the maintenance records is acceptable in lieu of this inspection if the installation of tapered fillers can be conclusively determined from that review.
For Group 5 airplanes identified in Boeing Alert Service Bulletin 737-57A1296, Revision 2, dated April 1, 2015: Except as provided by paragraph (k) of this AD, at the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-57A1296, Revision 2, dated April 1, 2015; accomplish inspections and applicable corrective actions using a method approved in accordance with the procedures specified in paragraph (n) of this AD.
Where paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-57A1296, Revision 2, dated April 1, 2015, specifies a compliance time “after the Revision 2 date of this service bulletin,” this AD requires compliance within the specified compliance time “after the effective date of this AD.”
Accomplishing the applicable preventative modification specified in paragraph 3.B.4., “Preventive Modification” of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-57A1296, Revision 2, dated April 1, 2015, terminates the applicable repetitive inspection required by paragraph (g) of this AD. The preventative modification, including related investigative and corrective actions, must be done in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-57A1296, Revision 2, dated April 1, 2015; except where Boeing Alert Service Bulletin 737-57A1296, Revision 2, dated April 1, 2015, specifies contacting Boeing for repair instructions, before further flight, repair using a method approved in accordance with the procedures specified in paragraph (n) of this AD.
