EASA AD US-2021-24-12
Fuel / Inert Gas System - Airworthiness Limitations / Critical Design Configuration Control Limitations - Revision
Summary
The Fuel / Inert Gas System - Airworthiness Limitations / Critical Design Configuration Control Limitations - Revision is a final rule airworthiness directive issued by the FAA for certain Boeing Company Model 777 airplanes. It addresses updated and more restrictive airworthiness limitations and critical design configuration control limitations related to fuel tank ignition prevention, the engine fuel suction feed system, and the nitrogen generation system. This directive aims to mitigate risks of fuel tank explosions and engine flameouts.
What Changed
This new airworthiness directive requires revising existing maintenance or inspection programs to incorporate updated and more restrictive airworthiness limitations and critical design configuration control limitations. It introduces requirements based on the latest Boeing 777 Maintenance Planning Data documents, including revisions to Section 9 Airworthiness Limitations and Certification Maintenance Requirements. The directive also terminates the previous AD 2008-11-13.
Why It Matters
This directive is critical for aviation professionals as it addresses unsafe conditions that could lead to fuel tank explosions or dual engine flameouts, which pose significant safety risks. Operators, maintenance, and compliance teams must ensure adherence to the updated limitations to maintain aircraft airworthiness and prevent catastrophic failures. It also clarifies acceptable wire types and maintenance practices, impacting maintenance planning and parts approval.
What To Do
Affected operators must revise their maintenance or inspection programs to incorporate the new or more restrictive airworthiness limitations as specified in the directive. Compliance with these revisions is mandatory by February 1, 2022. Operators unable to comply within the specified times may request approval for alternative methods of compliance from the FAA.
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