EASA AD 2021-0240
Rotors Flight Control — Main / Tail Servo Control Systems — Replacement
Summary
EASA Airworthiness Directive 2021-0240 is an airworthiness directive affecting all serial numbers of Airbus Helicopters EC 175 B helicopters. It addresses the main and tail rotor servo control systems, specifically the Main Servo Control System (P/N M673A80A1005) and Tail Servo Control System (P/N M673A80A1006). The directive mandates replacement of certain affected servo control parts to ensure continued airworthiness.
What Changed
This new airworthiness directive introduces mandatory replacement requirements for affected main and tail servo control systems that have exceeded their recalculated life limits due to incorrect log card updates. It also defines serviceable parts eligibility and establishes installation restrictions for these components. The directive is based on Airbus Helicopters Alert Service Bulletin EC175-67A012.
Why It Matters
This directive is critical for aviation professionals as it prevents potential failure of rotor servo control systems caused by life limit exceedance, which could lead to reduced helicopter control. Operators and maintenance organizations must ensure compliance to maintain safety and regulatory approval. Failure to comply could result in unsafe flight conditions and regulatory penalties.
What To Do
Operators of EC 175 B helicopters must replace affected main and tail servo control parts before their recalculated life exceeds the applicable limit or within 60 days after 19 November 2021, whichever is later. Only serviceable parts may be installed from the effective date onward. Compliance with Airbus Helicopters Alert Service Bulletin EC175-67A012 is required to perform these actions.
AI-generated summary from official EASA source document. Always verify against the original.