Airworthiness Directive · Amendment 39-19288 · Wings
The Boeing Company Airplanes
This AD applies to all The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes, certificated in any category.
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 requires repetitive high frequency eddy current (HFEC) and detailed inspections, as applicable, for cracking of certain aft vertical stiffeners; repetitive detailed inspections for cracking of time-limited repairs, as applicable; a one-time HFEC inspection for cracking of the keel beam upper chord inboard flanges; a one-time general visual inspection for cracking of a certain angle; and applicable on-condition actions. This AD was prompted by a report of cracks in the left-side and right-side keel beam upper chords and aft vertical stiffeners. We are issuing this AD to address the unsafe condition on these products.
For airplanes identified as Group 1 in Boeing Alert Requirements Bulletin 737-57A1339 RB, dated April 16, 2018: Within 120 days after the effective date of this AD, inspect the airplane and do all applicable corrective actions using a method approved in accordance with the procedures specified in paragraph (k) of this AD.
Except as required by paragraph (i) of this AD: For airplanes identified as Group 2 in Boeing Alert Requirements Bulletin 737-57A1339 RB, dated April 16, 2018, at the applicable times specified in the “Compliance” paragraph of Boeing Alert Requirements Bulletin 737-57A1339 RB, dated April 16, 2018, do all applicable actions identified in, and in accordance with, the Accomplishment Instructions of Boeing Alert Requirements Bulletin 737-57A1339 RB, dated April 16, 2018.
Note 1 to paragraph (h) of this AD: Guidance for accomplishing the actions required by this AD can be found in Boeing Alert Service Bulletin 737-57A1339, dated April 16, 2018, which is referred to in Boeing Alert Requirements Bulletin 737-57A1339 RB, dated April 16, 2018.
(1) For purposes of determining compliance with the requirements of this AD: Where Boeing Alert Requirements Bulletin 737-57A1339 RB, dated April 16, 2018, uses the phrase “the original issue date of Requirements Bulletin 737-57A1339 RB,” this AD requires using the effective date of this AD.
(2) Where Boeing Alert Requirements Bulletin 737-57A1339 RB, dated April 16, 2018, specifies contacting Boeing, this AD requires repair using a method approved in accordance with the procedures specified in paragraph (k) of this AD.
Removal of the time-limited repair and accomplishment of additional actions in accordance with the Accomplishment Instructions of Boeing Alert Requirements Bulletin 737-57A1339 RB, dated April 16, 2018, terminate the repetitive inspections of the aft vertical stiffeners and time-limited repair, as specified in the Accomplishment Instructions of Boeing Alert Requirements Bulletin 737-57A1339 RB, dated April 16, 2018, and required by paragraph (h) of this AD.
