EASA AD 2023-0148R1
Main Rotor Drive – Main Gearbox – Replacement; Placards and Markings – ENG1 Training Idle Switch – Installation / Operational Restriction
Summary
EASA Airworthiness Directive 2023-0148R1 is issued for Airbus Helicopters EC 225 LP models addressing issues with the main rotor drive main gearbox (MGB) and installation of placards related to the ENG1 Training Idle switch. It applies to specific MGB part numbers and configurations that have shown wear and broken roller cages, potentially reducing engine power transfer capability during one engine inoperative (OEI) conditions. The directive mandates inspections, replacements, placard installations, and operational restrictions to ensure continued airworthiness and safe helicopter operation.
What Changed
This revision of EASA AD 2023-0148 reduces the applicability by excluding MGBs with main reduction gear module P/N 332A32-5400-00 in post-mod 07-53069 configuration, which eliminates the unsafe condition. It retains previous requirements for repetitive MGB replacements and operational limitations while expanding affected MGB part numbers. The directive also updates compliance times and allows for alternative methods of compliance for affected parts.
Why It Matters
This directive is critical for operators and maintenance organizations to prevent potential loss of helicopter control due to MGB component wear or failure during OEI scenarios. Compliance ensures the reliability of the main rotor drive system and maintains safe training operations by restricting use of the ENG1 Training Idle switch. It also provides clear instructions for part replacement and placard installation, helping compliance teams meet regulatory requirements and avoid operational disruptions.
What To Do
Operators of EC 225 LP helicopters must determine flight hours on affected MGB parts within specified compliance times, replace MGBs or affected parts before exceeding 1,000 flight hours, and install placards prohibiting ENG1 Training Idle switch use during OEI training. Reporting flight hour determinations to Airbus Helicopters within 30 days of the directive's effective date is required. Installation of serviceable MGBs per the directive is mandatory from 2 August 2023, with placards installed before flight if affected MGBs are fitted.
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