EASA AD US-2020-11-01
Flight Controls - Primary Flight Control Actuation System Remote Electronics Unit - Software Update
Summary
The document titled "Flight Controls - Primary Flight Control Actuation System Remote Electronics Unit - Software Update" is a Federal Aviation Administration (FAA) Airworthiness Directive (AD) 2020-11-01. It applies to Gulfstream Aerospace Corporation Model GVI airplanes, also known as G650 and G650ER. The AD addresses a safety issue related to the primary flight control actuation system's linear variable displacement transducer (LVDT) mechanical disconnect monitor, which may fail to disconnect affected control surfaces during a failure event.
What Changed
This new AD requires updating the software of each primary flight control actuation system (PFCAS) remote electronics unit (REU) from Label 34 to Label 35. The software update improves the LVDT disconnect monitor functionality to ensure proper disconnection of control surfaces such as ailerons, elevators, and rudder in the event of a failure. This AD introduces a mandatory software upgrade to mitigate the unsafe condition.
Why It Matters
This AD is critical for aviation professionals because it addresses a potential loss of control risk due to failure of the LVDT disconnect monitor in the flight control system. Operators and maintenance organizations must ensure compliance to prevent spoiler hard-over or structural damage caused by excessive control surface deflection. Compliance enhances flight safety and maintains regulatory airworthiness standards for affected Gulfstream GVI aircraft.
What To Do
Affected operators must update the PFCAS REU software to Label 35 within 24 months from the AD's effective date of July 27, 2020. The update must be performed following the instructions in Gulfstream G650 and G650ER Customer Bulletins and Parker Service Bulletin 469000-27-003, Revision 1. Operators should coordinate with maintenance providers to schedule and complete the software upgrade promptly to maintain compliance.
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