Airworthiness Directive · Amendment 39-18145 · Fuselage
The Boeing Company Airplanes
(1) This AD applies to The Boeing Company Model 737-600 and -700 series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin 737-53A1325, dated December 3, 2013.
(2) Installation of Supplemental Type Certificate (STC) ST00830SE (http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/932b6080caa1856e86257d6c005c5a37/$FILE/ST00830SE.pdf) 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 adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737-600 and -700 series airplanes. This AD was prompted by reports of cracking in the body station (STA) 727 bulkhead lower frame. This AD requires a detailed and open hole high frequency eddy current (HFEC) inspection of the left- and right-side lower frame webs and inner chords for cracking, and corrective actions and preventative modifications if necessary. This AD also provides for optional terminating action of the repetitive inspections, under certain conditions. We are issuing this AD to detect and correct cracking in a bulkhead lower frame web and inner chord, which could result in a severed frame and induced skin cracks, and could lead to rapid decompression of the fuselage.
At the applicable times specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-53A1325, dated December 3, 2013, except as provided by paragraph (i)(1) of this AD: Do a detailed and open hole high frequency eddy current (HFEC) inspection of the left- and right-side lower frame webs and inner chords for cracking, as applicable, and do all applicable corrective actions and preventative modifications, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-53A1325, dated December 3, 2013, except as required by paragraph (i)(2) of this AD. Repeat the applicable inspections required by this paragraph thereafter at the applicable intervals specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-53A1325, dated December 3, 2013. Do all applicable corrective actions and preventative modifications before further flight.
Accomplishment of a modification or a repair, in accordance with Boeing Alert Service Bulletin 737-53A1325, dated December 3, 2013, terminates the repetitive inspections required by this AD.
(1) Where Boeing Alert Service Bulletin 737-53A1325, dated December 3, 2013, specifies a compliance time “after the original issue date of this service bulletin,” this AD requires compliance within the specified compliance time after the effective date of this AD.
(2) Where Boeing Alert Service Bulletin 737-53A1325, dated December 3, 2013, specifies to contact Boeing for appropriate action: Before further flight, accomplish the corresponding action using a method approved in accordance with the procedures specified in paragraph (k) of this AD.
The post-repair inspections specified in tables 4, 5, and 6 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-53A1325, dated December 3, 2013, are not required by this AD.
Note 1 to paragraph (j) of this AD: The damage tolerance inspections specified in tables 4, 5, and 6 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-53A1325, dated December 3, 2013, may be used in support of compliance with Section 121.1109(c)(2) or 129.109(b)(2) of the Federal Aviation Regulations (14 CFR 121.1109(c)(2) or 14 CFR 129.109(b)(2)). The corresponding actions specified in the Accomplishment Instructions of Boeing Alert Service Bulletin 737-53A1325, dated December 3, 2013, are not required by this AD.
