EASA AD US-2023-03-20
Time Limits / Maintenance Checks — Airworthiness Limitations Section — Amendment
Summary
The FAA Airworthiness Directive 2023-03-20 is a final rule addressing all Boeing Model 747-400, -400D, and -400F series airplanes. It mandates revisions to the maintenance or inspection programs to incorporate new or more restrictive airworthiness limitations related to the fuel system. This directive aims to enhance safety by reducing the risk of fuel tank ignition sources.
What Changed
This directive requires operators to update their maintenance or inspection programs to include the latest airworthiness limitations specified in the April 2022 revision of Boeing 747-400 Maintenance Planning Data Document D621U400-9. It supersedes the previously proposed September 2021 revision and adds credit for prior incorporation of that earlier revision. The AD introduces new compliance requirements to mitigate unsafe conditions identified in the fuel system.
Why It Matters
This AD is critical for aviation professionals because it addresses potential ignition sources inside fuel tanks, which could lead to explosions and loss of the airplane. Operators and maintenance organizations must ensure their programs reflect the latest safety standards to maintain regulatory compliance and aircraft airworthiness. Failure to comply could result in unsafe operating conditions and regulatory penalties.
What To Do
Affected operators must revise their existing maintenance or inspection programs within 60 days after the AD's effective date to incorporate the specified airworthiness limitations from the April 2022 Boeing 747-400 MPD document. They should also verify compliance with all initial airworthiness limitation instruction tasks as detailed in the directive. Operators who have already incorporated the September 2021 revision receive credit and must ensure their programs align with the latest requirements.
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