Airworthiness Directive · Amendment 39-19495 · Stabilizers
The Boeing Company Airplanes
(1) This AD applies to all The Boeing Company Model 737-600, -700, -700C, -800, -900, and 900ER series airplanes, certificated in any category.
(2) Installation of Supplemental Type Certificate (STC) 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) 2016-13-16, which applied to all The Boeing Company Model 737-600, -700, -700C, - 800, -900, and -900ER series airplanes. AD 2016-13-16 required an inspection or records check to determine if affected horizontal stabilizers are installed, related investigative actions, and, for affected horizontal stabilizers, repetitive inspections for any crack of the horizontal stabilizer rear spar upper chord, and corrective action if necessary. This AD requires retaining the requirements of AD 2016-13-16, with revised service information that clarifies the inspection areas and serial number information of the horizontal stabilizer. This AD was prompted by reports of a manufacturing oversight, in which a supplier omitted the required protective finish on certain bushings installed in the rear spar upper chord on horizontal stabilizers, which could lead to galvanic corrosion and consequent cracking of the rear spar upper chord. We are issuing this AD to address the unsafe condition on these products.
Except as required by paragraph (h) of this AD: At the applicable times specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-55A1097, Revision 1, dated September 20, 2017, do all applicable actions identified as “RC” (required for compliance) in, and in accordance with, the Accomplishment Instructions of Boeing Alert Service Bulletin 737-55A1097, Revision 1, dated September 20, 2017.
(1) For purposes of determining compliance with the requirements of this AD: Where Boeing Alert Service Bulletin 737-55A1097, Revision 1, dated September 20, 2017, uses the phrase “the Revision 1 date of this service bulletin,” this AD requires using “the effective date of this AD.”
(2) Where Boeing Alert Service Bulletin 737-55A1097, Revision 1, dated September 20, 2017, specifies contacting Boeing, and specifies that action as RC: This AD requires repair using a method approved in accordance with the procedures specified in paragraph (k) of this AD.
As of the effective date of this AD, no person may install a horizontal stabilizer on any airplane, except as specified in paragraphs (i)(1) or (i)(2) of this AD.
(1) A horizontal stabilizer may be installed if the part is inspected in accordance with “Part 2: Horizontal Stabilizer Identification Plate Inspection” of the Accomplishments Instructions of Boeing Alert Service Bulletin 737-55A1097, Revision 1, dated September 20, 2017, and no affected serial number is found.
(2) A horizontal stabilizer may be installed if the part is inspected in accordance with “Part 2: Horizontal Stabilizer Identification Plate Inspection” of the Accomplishments Instructions of Boeing Alert Service Bulletin 737-55A1097, Revision 1, dated September 20, 2017, and an affected serial number is found, provided that the actions specified in paragraphs (i)(2)(i) and (i)(2)(ii) of this AD are done, as applicable.
(i) Initial and repetitive high frequency eddy current (HFEC) inspections, which are part of the required actions specified in paragraph (g) of this AD, are completed within the compliance times specified in paragraph (g) of this AD.
(ii) All applicable corrective actions, which are part of the required actions specified in paragraph (g) of this AD, are done within the compliance times specified in paragraph (g) of this AD.
