Airworthiness Directive · Amendment 39-21157 · Wings
The Boeing Company Airplanes
(1) This AD applies to all The Boeing Company Model 737-300, -400, and -500 series airplanes, certificated in any category.
(2) Installation of Supplemental Type Certificate (STC) ST01219SE 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.
The FAA is adopting a new airworthiness directive (AD) for all The Boeing Company Model 737-300, -400, and -500 series airplanes. This AD was prompted by a report that a crack indication consistent with fatigue cracking was found on the left nacelle support overwing fitting flange fastener hole during teardown of a Model 737-300 series airplane. This AD requires a general visual inspection of the strut to wing diagonal brace at a certain location for cracking. For certain airplanes, this AD also requires an ultrasonic inspection of the nacelle support overwing fitting at certain fastener locations for cracking. For certain other airplanes, this AD requires a magnetic check of the nacelle support overwing fitting at a certain location to determine the material composition. This AD requires applicable on- condition actions. The FAA is issuing this AD to address the unsafe condition on these products.
Except as specified by paragraph (h) of this AD: At the applicable times specified in the “Compliance” paragraph of Boeing Alert Requirements Bulletin 737-57A1345 RB, dated December 17, 2019, do all applicable actions identified in, and in accordance with, the Accomplishment Instructions of Boeing Alert Requirements Bulletin 737-57A1345 RB, dated December 17, 2019. Actions identified as terminating actions in Boeing Alert Requirements Bulletin 737-57A1345 RB, dated December 17, 2019, terminate the applicable required actions of this AD, provided the terminating action is done in accordance with the Accomplishment Instructions of Boeing Alert Requirements Bulletin 737-57A1345 RB, dated December 17, 2019.
Note 1 to paragraph (g): Guidance for accomplishing the actions required by this AD can be found in Boeing Alert Service Bulletin 737-57A1345, dated December 17, 2019, which is referred to in Boeing Alert Requirements Bulletin 737-57A1345 RB, dated December 17, 2019.
(1) Where Boeing Alert Requirements Bulletin 737-57A1345 RB, dated December 17, 2019, uses the phrase “the original issue date of Requirements Bulletin (RB) 737-57A1345 RB,” this AD requires using “the effective date of this AD.”
(2) Where Boeing Alert Requirements Bulletin 737-57A1345 RB, dated December 17, 2019, specifies contacting Boeing for repair instructions, this AD requires doing the repair before further flight using a method approved in accordance with the procedures specified in paragraph (i) of this AD.
