Airworthiness Directive · Amendment 39-18789 · Fuselage
The Boeing Company Airplanes
(1) This AD applies to The Boeing Company Model 737-600, -700, -700C, -800, and -900 series airplanes, certificated in any category, as identified in Boeing Special Attention Service Bulletin 737-53-1294, Revision 2, dated December 9, 2015 (“SASB 737-53-1294 R2”).
(2) Installation of Supplemental Type Certificate (STC) ST00830SE [ http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/184DE9A71EC3FA5586257EAE00707DA6?OpenDocument&Highlight=st00830se ] does not affect the ability to accomplish the actions required by this AD. Therefore, for airplanes on which STC ST00830SE 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) 2013-19-04 for certain The Boeing Company Model 737-600, -700, -700C, -800, and -900 series airplanes. AD 2013-19-04 required repetitive inspections for cracking of the skin around the fasteners common to the ends of certain bulkhead chords, and related investigative actions and corrective actions if necessary; and provided an optional terminating modification. This new AD reduces the inspection threshold and repetitive inspection intervals. This AD was prompted by a report of cracks found in the skin at fasteners of certain bulkhead chords. We are issuing this AD to address the unsafe condition on these products.
Except as required by paragraphs (i)(1) and (i)(2) of this AD: At the applicable time specified in table 1 of paragraph 1.E., “Compliance,” of SASB 737-53-1294 R2, do detailed and high frequency eddy current (HFEC) inspections for cracking of the skin in the area around the eight fasteners securing the STA 540 bulkhead chords between stringers S-22 and S-23; and do all applicable related investigative and corrective actions; in accordance with Parts 1, 2, 3, 4, and 5 of the Accomplishment Instructions of SASB 737-53-1294 R2, except as required by paragraphs (i)(3), (i)(4), and (i)(5) of this AD. Do all applicable related investigative and corrective actions before further flight. Except as required by paragraph (i)(2) of this AD, repeat the detailed and HFEC inspections thereafter at the intervals specified in table 1 of paragraph 1.E., “Compliance,” of SASB 737-53-1294 R2, until the optional preventive modification specified in paragraph (h) of this AD is done.
Accomplishing the skin repair or preventive modification, including an HFEC inspection for cracking of the skin and STA 540 bulkhead chords, and all applicable repairs, in accordance with paragraph 3.B, Part 2 or Part 4 (left side), or Part 3 or Part 5 (right side), as applicable, of the Accomplishment Instructions of SASB 737-53-1294 R2, except as required by paragraphs (i)(2) and (i)(5) of this AD, terminates the inspection requirements of paragraph (g) of this AD for the side on which the skin repair or preventive modification is done.
(1) Where paragraph 1.E., “Compliance,” of SASB 737-53-1294 R2, 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.
(2) For airplanes on which Boeing Business Jet Lower Cabin Altitude Supplemental Type Certificate (STC) ST01697SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/0812969a86af879b8625766400600105/$FILE/ST01697SE.pdf) (6,500 feet maximum cabin altitude in lieu of 8,000 feet) has been incorporated, the flight-cycle related compliance times for the inspection required by paragraph (g) of this AD are different from those specified in paragraph 1.E., “Compliance,” of SASB 737-53-1294 R2. All initial compliance times specified in total flight cycles or flight cycles must be reduced to half of those specified in SASB 737-53-1294 R2. All repetitive interval compliance times specified in flight cycles must be reduced to one-quarter of those specified in paragraph 1.E., “Compliance,” of SASB 737-53-1294 R2.
(3) If any cracking is found during any inspection required by this AD, and SASB 737-53-1294 R2, specifies to contact Boeing for appropriate action: Before further flight, repair using a method approved in accordance with the procedures specified in paragraph (l) of this AD.
(4) The access and restoration actions identified in the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-53-1294, dated March 31, 2011; Boeing Special Attention Service Bulletin 737-53-1294, Revision 1, dated June 14, 2013; or SASB 737-53-1294 R2; are not required by this AD. Operators may perform those actions in accordance with accepted maintenance procedures.
(5) For doing repairs specified in Part 4 or Part 5 of the Accomplishment Instructions of SASB 737-53-1294 R2: Before further flight, repair using a method approved in accordance with the procedures specified in paragraph (l) of this AD.
Table 2 of paragraph 1.E., “Compliance,” of SASB 737-53-1294 R2, specifies post-modification airworthiness limitation inspections in compliance with 14 CFR 25.571(a)(3) at the modified locations, which support compliance with 14 CFR 121.1109(c)(2) or 129.109(b)(2). As airworthiness limitations, these inspections are required by maintenance and operational rules. It is therefore unnecessary to mandate them in this AD. Deviations from these inspections require FAA approval, but do not require an AMOC.
