EASA AD US-2018-17-23
Fuselage - Number 3 Windshield Assembly Aft Sill Web - Inspection
Summary
Federal Aviation Administration Airworthiness Directive 2018-17-23 is a final rule addressing all Boeing 737-100, -200, -200C, -300, -400, and -500 series airplanes. It mandates repetitive high frequency eddy current inspections of the number 3 windshield assembly aft sill web to detect cracking and requires applicable on-condition corrective actions. This directive aims to maintain structural integrity and safety of the affected windshield assembly components.
What Changed
This new airworthiness directive introduces mandatory repetitive inspections using high frequency eddy current techniques on the number 3 windshield assembly aft sill web of specified Boeing 737 models. It clarifies inspection locations and conditions, and confirms that installation of Supplemental Type Certificate STC ST01219SE does not affect compliance. The directive also refines language regarding repair instructions and applicability to all affected airplane line numbers.
Why It Matters
This directive is critical for aviation professionals to prevent structural failures caused by cracking in the windshield assembly aft sill web, which could compromise aircraft safety. Operators and maintenance organizations must incorporate these inspections into their maintenance programs to ensure continued airworthiness. Compliance helps avoid potential in-service failures and regulatory penalties.
What To Do
Operators of Boeing 737-100 through -500 series airplanes must perform repetitive high frequency eddy current inspections of the number 3 windshield assembly aft sill web at specified locations. Any detected cracking must be addressed with on-condition corrective actions as outlined in Boeing Alert Requirements Bulletin 737-53A1377 RB. Compliance with this directive is required starting October 4, 2018.
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