EASA AD 2017-0129R1
Integrated Modular Avionics — Internal Timer — Power Cycle (Reset)
Summary
EASA Airworthiness Directive 2017-0129R1 is an updated regulatory document addressing a potential unsafe condition in Airbus A350-941 aeroplanes related to the Integrated Modular Avionics internal timer. It applies to all Airbus A350-941 aircraft except those with Airbus modifications 112312 and 112313 incorporated during production. The directive mandates repetitive power cycle resets to prevent loss of communication between avionics systems and network, which could lead to partial or total loss of avionics functions.
What Changed
This revision reduces the applicability by excluding Airbus A350-941 aeroplanes that have incorporated modifications 112312 and 112313 in production. It also introduces reference to Airbus Service Bulletin A350-42-P010 as an optional terminating action for the repetitive power cycle resets previously required. The update reflects the availability of software updates for the Core Processing Input/Output Module and Common Remote Data Concentrator.
Why It Matters
This directive is critical for operators and maintenance teams to prevent avionics system failures caused by an internal timer issue after extended continuous power-up. Compliance ensures continued airworthiness and safety by avoiding potential loss of avionics functions that could compromise flight operations. It also provides a clear path to terminate repetitive resets through software updates, reducing operational disruptions.
What To Do
Operators of affected Airbus A350-941 aeroplanes must perform an on-ground power cycle reset within 30 days after 1 August 2017 and repeat it every 149 hours of continuous power-up thereafter. Alternatively, operators can update the avionics software following Airbus Service Bulletin A350-42-P010 to terminate the need for repetitive resets. Compliance with these actions is mandatory unless the aircraft has the specified Airbus modifications incorporated in production.
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