EASA AD 25-151
Rotors Flight Control — Tail Rotor Actuator — Inspection
Summary
EASA Airworthiness Directive PAD No. 25-151 is a proposed directive addressing inspection and modification requirements for the tail rotor actuator on Airbus Helicopters SA 365 and AS 365 models, including SA 365 N, N1, and AS 365 N2 and N3 variants. The directive focuses on inspecting and modifying the routing of the tail rotor actuator harness to prevent interference that could block tail rotor pedal control. This affects helicopters with tail rotor actuators having part numbers 704A47135036 or 704A47135059.
What Changed
This proposed directive supersedes EASA AD 2023-0090 and retains its inspection requirements while introducing a mandatory modification to the routing of the yaw harness of the affected tail rotor actuator parts. The modification aims to prevent interference between the cable tie head of the actuator harness and the tail gearbox cowling pin fastener, which was identified as the cause of a tail rotor pedal control blockage during flight.
Why It Matters
This directive is critical for aviation professionals because it addresses a safety issue that could lead to loss of yaw control in affected helicopters, posing a significant flight risk. Operators and maintenance organizations must ensure compliance to maintain airworthiness and prevent potential accidents. The directive also provides clear instructions and timelines to facilitate effective maintenance planning and regulatory adherence.
What To Do
Operators must inspect the position of the cable tie heads on the tail rotor actuator harness within 165 flight hours after 18 May 2023, and perform corrective actions if any looseness is found before the next flight. Additionally, the routing of the yaw harness must be modified within 660 flight hours or 26 months from the effective date of this directive, whichever occurs first. Compliance with the Airbus Helicopters Alert Service Bulletins AS365-22.00.17 and AS365-88-56-0001 is required.