EASA AD 2025-0141
Rotorcraft Flight Manual — Limitations and Normal Procedures Section — Amendment
Summary
EASA Airworthiness Directive 2025-0141 is an amendment concerning Airbus Helicopters EC 175 B models equipped with integrated avionics Helionix version 11 or later. The directive addresses a critical issue where the rotor speed sensor failure is not correctly indicated during flight, potentially leading to undetected damage to rotor and drive system components. This AD mandates updates to the Rotorcraft Flight Manual to include new limitations and procedures.
What Changed
This amendment requires the incorporation of a temporary revision to the Rotorcraft Flight Manual that instructs pilots not to de-synchronize the main rotor speed and free turbine speed during flight and restricts rotor brake use on the ground unless rotor speed information is confirmed. It introduces interim operational limitations pending an avionics software update to correct the sensor indication issue.
Why It Matters
This directive is critical for aviation professionals as it prevents undetected rotor and engine speed discrepancies that could cause catastrophic mechanical failures. Operators and maintenance teams must ensure compliance to maintain aircraft airworthiness and safety. The amendment ensures flight crews are properly informed of sensor failures during operations, reducing risk of damage and accidents.
What To Do
Operators of Airbus Helicopters EC 175 B with Helionix v11 or later must amend their Rotorcraft Flight Manual within 7 days of 14 July 2025 by incorporating the specified temporary revision. Flight crews must be informed of the new procedures and limitations and operate the helicopter accordingly. Compliance with these instructions is mandatory until further updates are issued.