EASA AD 2025-0263
[Correction] Hydraulic Power — Single Generation Hydraulic System Wiring Diode — Cut-Off Test
Summary
EASA Airworthiness Directive 2025-0263 is a corrective directive addressing Airbus Helicopters AS 350 B2 models with specific serial numbers. It mandates a cut-off test of the single generation hydraulic system wiring diode 43D2 to ensure proper hydraulic function and control. The directive aims to prevent loss of yaw load compensator efficiency and hydraulic assistance to key servo-controls.
What Changed
This directive republishes the original AD to correct a typographical error in the title of paragraph (1). It introduces a mandatory cut-off test for the hydraulic system diode 43D2 and requires replacement or installation of the diode if discrepancies are found during the test.
Why It Matters
This AD is critical for maintaining safe helicopter control by ensuring the hydraulic system's integrity. Failure to comply could result in reduced control of the helicopter due to loss of hydraulic assistance, posing safety risks. Operators and maintenance organizations must address this to comply with continuing airworthiness requirements and avoid operational restrictions.
What To Do
Operators of affected AS 350 B2 helicopters must perform the cut-off test within 165 flight hours or 13 months from 10 December 2025, whichever occurs first. If any issues are detected during the test, the diode 43D2 must be replaced or installed before the next flight. Compliance with Airbus Helicopters Alert Service Bulletin AS350-29-10-0001 is required.