Instruments – Warning Unit Emergency Off Switches – Operational Check
- Published
- Effective
AI-generated summary of the official EASA document. Verify against the PDF before acting.
What to do
Operators of affected EC135, EC635, and MBB-BK117 helicopters must perform an operational check of emergency off switches within 55 flight hours or 12 months from 14 October 2026. Additional checks are required before the next flight if any emergency off switch has been activated. If discrepancies are found, the warning unit must be replaced before further flight. Installation of affected parts is allowed only if followed by a successful operational check before next flight.
Summary
EASA Airworthiness Directive 2026-0188 is issued for Airbus Helicopters Deutschland GmbH EC135, EC635, and MBB-BK117 helicopter models. It addresses potential failures of emergency off switches in the warning units that could lead to engine shutdown or loss of fuel shut-off capability. The directive mandates operational checks and possible replacement of affected warning units to ensure continued airworthiness.
What changed
This new Airworthiness Directive introduces requirements for repetitive operational checks of emergency off switches on affected helicopters and mandates replacement if discrepancies are found. It addresses a separate manufacturing non-conformity distinct from a previously issued AD and requires independent compliance without superseding prior directives.
Why it matters
This directive is critical for aviation professionals as it prevents potential in-flight engine shutdowns or loss of fuel shut-off control, which could compromise helicopter safety. Operators and maintenance organizations must ensure compliance to avoid unsafe conditions and regulatory violations. The directive also clarifies acceptable methods of compliance and installation rules for affected parts.
More for Airbus Helicopters EC135
All 49- EASA AD 2026-0131Engine Fuel & Control – Electronic Engine Control Unit – Software Update; Engine Fuel & Control – Preference Injector – Non-extinguishing Test / ReplacementJul 6, 2026
- EASA AD 2026-0032Tail Rotor — Tail Rotor Blades — InspectionFeb 19, 2026
- EASA AD 2026-0031Tail Rotor — Tail Rotor Blades — InspectionFeb 19, 2026
- EASA AD 2026-0024Rotors Flight Control — Ball Bearing Control System — InspectionsFeb 5, 2026
- EASA AD 2025-0260
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