EASA AD US-2021-26-03
Fuselage - Frame Splice - Inspection
Summary
The Federal Register Volume 87, Number 11 Airworthiness Directive 2021-26-03 is a final rule issued by the FAA that applies to certain Boeing 737-300, -400, and -500 series airplanes. It addresses widespread fatigue damage in the fuselage frame splice between stringers S-13 and S-14, requiring inspections and corrective actions to ensure structural integrity. This directive mandates inspections for existing repairs and repetitive high frequency eddy current inspections for cracking in the affected fuselage frame splices.
What Changed
This new airworthiness directive introduces mandatory inspections of the fuselage frame splice between stringers S-13 and S-14 on specified Boeing 737 models. It requires general visual inspections for existing repairs, repetitive high frequency eddy current inspections for cracking, and applicable on-condition repair or replacement actions. The directive clarifies that installation of Supplemental Type Certificate STC ST01219SE does not affect compliance requirements.
Why It Matters
This directive is critical for aviation professionals as it addresses a potential unsafe condition that could lead to uncontrolled decompression and loss of structural integrity in affected Boeing 737 aircraft. Operators and maintenance organizations must implement the inspection and repair requirements to maintain airworthiness and comply with FAA regulations. Failure to comply could result in safety risks and regulatory penalties.
What To Do
Operators of Boeing 737-300, -400, and -500 series airplanes must perform the required inspections and on-condition actions as specified in Boeing Alert Requirements Bulletin 737-53A1388 RB dated October 27, 2020. Compliance with this directive is mandatory by February 22, 2022, the effective date of the AD. Maintenance teams should also note that installation of STC ST01219SE does not require an alternative method of compliance approval.
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