EASA AD 2024-0195R1
Engine Fuel & Control — Electronic Engine Control Unit — Software Update; Preference Injector — Non-extinguishing Test / Replacement
Summary
EASA Airworthiness Directive 2024-0195R1 addresses safety concerns related to SAFRAN Helicopter Engines ARRIUS 2B2 engines, commonly installed on Airbus Helicopters Deutschland EC135 models. The directive mandates software updates to the Electronic Engine Control Unit and introduces requirements for non-extinguishing tests and replacement of the preference injector to prevent engine flame out. This AD applies to all serial numbers of the ARRIUS 2B2 engine.
What Changed
This revision updates the grouping of affected engines, clarifying that modification TU 173 applies only to engines installed on specific Airbus Helicopters Deutschland EC135 variants. It requires operators to perform non-extinguishing tests and replace preference injectors at reduced intervals and mandates an Electronic Engine Control Unit software upgrade for Group 1 engines within 24 months. The AD also prohibits installation of pre-mod TU 173 EECUs on Group 1 and Group 2 engines after modification or from the effective date, respectively.
Why It Matters
The directive addresses a critical safety issue where fuel coking can clog the preference injector, potentially causing engine flame out and uncommanded in-flight shutdown. For operators and maintenance organizations, compliance ensures continued airworthiness and reduces the risk of engine failure during flight. The software upgrade automates testing, improving reliability and maintenance efficiency while aligning with regulatory requirements.
What To Do
Operators must perform non-extinguishing tests on affected engines within 100 flight hours after the effective date and at specified intervals thereafter, replace preference injectors within 100 flight hours or before 500 flight hours accumulation, and upgrade the Electronic Engine Control Unit software on Group 1 engines within 24 months. Installation of serviceable preference injectors is permitted only if they meet defined criteria, and installation of pre-mod TU 173 EECUs is restricted as specified. Alternative compliance methods via overhaul are acceptable if done per SAFRAN manuals.