EASA AD US-2023-23-14
Fuel - Engine Fuel Feed System - Inspection / Measurement
Summary
Federal Aviation Administration Airworthiness Directive 2023-23-14 is a final rule addressing all Boeing Company Model 747 airplanes. It mandates inspections and electrical bonding resistance measurements of the engine fuel feed system's out-tank fuel feed tube bonding jumper and front spar bulkhead fitting adapter to mitigate latent failures in lightning protection features. The directive aims to prevent potential ignition sources inside fuel tanks during lightning strikes.
What Changed
This new airworthiness directive introduces mandatory inspections for damage and electrical bonding resistance measurements on specific fuel feed system components for all Boeing 747 models. It also requires related investigative and corrective actions, including adjustments, replacements, and sealant applications as needed. Additionally, operators must report inspection findings to Boeing.
Why It Matters
This directive is critical for aviation professionals because it addresses a significant safety risk involving compromised lightning protection in the engine fuel feed system, which could lead to fuel tank explosions. Operators and maintenance teams must ensure compliance to maintain aircraft airworthiness and prevent catastrophic failures. The inspections provide essential data to develop final corrective actions and enhance fleet safety.
What To Do
Operators of Boeing 747 airplanes must perform detailed inspections and electrical bonding resistance measurements on the engine fuel feed system components for each of the four engines by December 15, 2023. They must carry out any necessary corrective actions identified during inspections and report all findings to Boeing. Comments on the directive can be submitted to the FAA until January 16, 2024.
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