Engine Controls – Microswitches – Inspection / Modification
Superseded. Comply with 2023-0187R1, which replaces this document.
- Published
- Effective
- Deadline
- Replaces
- 2017-0059
AI-generated summary of the official EASA document. Verify against the PDF before acting.
What to do
Operators of affected helicopters must modify the twist grip operational logic and install MOD 074699 within specified flight hours or calendar days, depending on the helicopter model and engine type. Repetitive inspections and tests of the 'IDLE' and 'FLIGHT' controls must be conducted at intervals defined by operating conditions, with immediate corrective actions required if discrepancies are found. The effective date for compliance is 2023-07-19.
Summary
EASA Airworthiness Directive 2023-0133 is an airworthiness directive issued by the European Union Aviation Safety Agency affecting Airbus Helicopters AS 350 B3, EC 130 B4, and EC 130 T2 models. It addresses issues related to engine control microswitches and pilot twist grips, specifically targeting part numbers associated with these components to ensure safe engine power control operation. The directive mandates inspections, modifications, and corrective actions to prevent failure of engine power control during critical flight phases.
What changed
EASA AD 2023-0133 supersedes the previous AD 2017-0059 and introduces the requirement to install a serviceable engine power control assembly (MOD 074782) with updated microswitches. It prohibits the installation or reinstallation of affected microswitches and retains prior modification and inspection requirements while adding new compliance measures to address corrosion and operational failures in salt-laden environments.
Why it matters
This directive is critical for aviation professionals because it ensures the reliability of engine power control systems on affected Airbus Helicopters, preventing potential engine power loss during flight. Operators and maintenance organizations must comply to avoid unsafe conditions that could compromise flight safety, particularly during autorotation training and offshore operations. Compliance helps maintain regulatory conformity and reduces the risk of in-flight engine control failures.
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