EASA AD US-2021-10-11
Wings - Bulkhead Splice Angles - Inspection
Summary
The Federal Aviation Administration Airworthiness Directive 2021-10-11 addresses all Boeing 737-100, -200, -200C, -300, -400, and -500 series airplanes. It mandates repetitive surface high frequency eddy current inspections of the STA 540 bulkhead splice angles to detect cracks and requires corrective actions if cracks are found. This directive aims to maintain structural integrity and prevent potential fuel leaks and fires.
What Changed
This new airworthiness directive introduces mandatory repetitive inspections of the left and right STA 540 bulkhead splice angles for cracking using high frequency eddy current methods. It also requires on-condition repairs or replacements if cracks are detected. Additionally, it clarifies that installation of Supplemental Type Certificate ST01219SE does not affect compliance requirements.
Why It Matters
This directive is critical for aviation professionals to ensure the structural safety of affected Boeing 737 models by preventing cracks that could compromise principal structural elements. Operators and maintenance organizations must monitor and address potential cracking to avoid structural failure and associated risks such as fuel leaks and fire. Compliance ensures continued airworthiness and regulatory adherence.
What To Do
Operators of affected Boeing 737 series airplanes must perform the initial inspection within 120 days of July 29, 2021, and continue with repetitive inspections as specified. Any detected cracks must be repaired or the affected parts replaced using FAA-approved methods. Stakeholders should consult Boeing Alert Requirements Bulletin 737-57A1347 RB dated July 29, 2020, for detailed procedures.
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