Airworthiness Directive · Amendment 39-18388 · Wings
the Boeing Company Airplanes
(1) This AD applies to all The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes, certificated in any category.
(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 adopting a new airworthiness directive (AD) for all The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. This AD was prompted by a report of a crack of the forward leg of the left front spar lower chord and cracks on the lower wing skin at three fastener holes common to the nacelle outboard side load fitting. This AD requires repetitive inspections for cracks on the front spar lower chord, inspar skin, and wing skin, and corrective action if necessary. We are issuing this AD to detect and correct fatigue cracking of the forward leg of the front spar lower chord, inspar skin, and wing skin common to the nacelle outboard side load fitting, which could adversely affect the structural integrity of the wing.
For Group 1 airplanes identified in Boeing Alert Service Bulletin 737-57A1323, dated December 5, 2014: Within 120 days after the effective date of this AD, do inspections of the left and right wing front spar lower chord and inspar skin, and the left and right wing nacelle outboard side load fitting fastener holes common to the front spar lower chord and skin, and do all applicable corrective actions, using a method approved in accordance with the procedures specified in paragraph (k) of this AD.
For Group 2 and 3 airplanes identified in Boeing Alert Service Bulletin 737-57A1323, dated December 5, 2014: Except as provided by paragraph (j)(1) of this AD, at the applicable time specified in Table 1 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-57A1323, dated December 5, 2014, do a detailed inspection for cracks on the left and right wing front spar lower chord and inspar skin, and do all applicable corrective actions, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 737-57A1323, dated December 5, 2014, except as specified in paragraph (j)(2) of this AD. Do all applicable corrective actions before further flight. Repeat the inspection thereafter at the applicable interval specified in Table 1 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-57A1323, dated December 5, 2014, except in areas repaired in accordance with the procedures specified in paragraph (k) of this AD.
For Group 3 airplanes identified in Boeing Alert Service Bulletin 737-57A1323, dated December 5, 2014: Except as provided by paragraph (j)(1) of this AD, at the applicable time specified in Table 2 or Table 3 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-57A1323, dated December 5, 2014, do the actions specified in paragraphs (i)(1) or (i)(2) of this AD. Repeat the inspection specified in either paragraph (i)(1) or (i)(2) of this AD thereafter at the applicable interval specified in Table 2 or Table 3 of paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin737-57A1323, dated December 5, 2014. While accomplishing the actions required by this paragraph, ensure that all applicable critical design configuration control limitations are complied with.
(1) Do an HFEC open hole probe inspection for cracks of the left and right wing nacelle outboard side load fitting fastener holes common to the front spar lower chord and skin, and perform all applicable corrective actions, in accordance with Part 2, Option 1 of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-57A1323, dated December 5, 2014, except as provided by paragraph (j)(2) of this AD. Do all applicable corrective actions before further flight.
(2) Do an HFEC surface probe inspection for cracks in the wing inspar skin, and perform all applicable corrective actions, in accordance with Part 2, Option 2 of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-57A1323, dated December 5, 2014, except as provided by paragraph (j)(2) of this AD. Do all applicable corrective actions before further flight.
(1) Where paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-57A1323, dated December 5, 2014, 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) Although Boeing Alert Service Bulletin 737-57A1323, dated December 5, 2014, specifies to contact Boeing for repair instructions, and specifies that action as “RC” (Required for Compliance), this AD requires repair before further flight using a method approved in accordance with the procedures specified in paragraph (k) of this AD.
