EASA AD US-2025-07-10
Engine Controls - Engine Indicating and Crew Alerting System - Dispatch Prohibition; Full Authority Digital Engine Control (FADEC) Integrated Circuit Microprocessor - Replacement; Electronic Engine Control FADEC - Software Upgrade
Summary
The document titled "Engine Controls - Engine Indicating and Crew Alerting System - Dispatch Prohibition; Full Authority Digital Engine Control (FADEC) Integrated Circuit Microprocessor - Replacement; Electronic Engine Control FADEC - Software Upgrade" is a final rule Airworthiness Directive issued by the FAA affecting General Electric Company Model GE90-110B1 and GE90-115B engines. It addresses unsafe conditions related to engine thrust control and FADEC microprocessor degradation by mandating operational restrictions, hardware replacements, and software upgrades.
What Changed
This AD supersedes AD 2020-20-17 and AD 2021-15-05, retaining their requirements while adding a new mandate to upgrade the EEC FADEC software to a version eligible for installation as a terminating action. It also updates incorporated service bulletins and clarifies compliance methods, including allowance for previously approved alternative methods of compliance.
Why It Matters
This directive is critical for aviation professionals as it mitigates the risk of uncommanded high engine thrust due to FADEC microprocessor degradation, enhancing flight safety. Operators and maintenance teams must ensure compliance to avoid dispatch prohibitions and maintain regulatory adherence, thereby preventing potential in-flight engine control failures.
What To Do
Affected operators must revise their FAA-approved minimum equipment lists to include dispatch restrictions, perform initial and repetitive replacements of the FADEC MN4 microprocessor, and upgrade the EEC FADEC software by May 21, 2025. Compliance includes following updated GE service bulletins and coordinating with FAA-approved methods for any alternative compliance requests.