EASA AD 2024-0139
Stabilizers — Vertical Fin — Inspection / Modification / Placards and Markings — Interior Placards — Installation / Aircraft Flight Manual / Airspeed Limitations — Amendment
Summary
EASA Airworthiness Directive 2024-0139 is an amendment addressing inspection, modification, and placard installation requirements for the vertical fin stabilizers of Airbus Helicopters AS 350 and AS 355 models. It applies to all serial numbers of AS 355 E, F, F1, F2, N, NP helicopters and AS 350 B3 helicopters except those with modification 073148 embodied in production. The directive mandates inspections, cleaning, flight manual amendments, placard installations, and introduces a reinforced upper fin assembly modification.
What Changed
EASA AD 2024-0139 supersedes the previous AD 2023-0089 and retains its requirements while adding a mandatory modification of the AS 355 helicopters' upper fin assembly as a terminating action to repetitive inspections. It also allows removal of the temporary reduced never-exceed speed (Vne) limitations and related placards after modification. Additionally, it clarifies inspection intervals and compliance times for affected helicopters.
Why It Matters
This directive is critical for aviation professionals to prevent potential in-flight separation of the vertical fin upper part, which could lead to loss of control. Operators and maintenance organizations must ensure compliance to maintain airworthiness and safety. The modification provides a permanent solution, reducing the need for frequent inspections and operational limitations, thus impacting maintenance planning and flight operations.
What To Do
Operators of affected AS 350 and AS 355 helicopters must amend the Rotorcraft Flight Manual and install placards within specified flight hour limits, conduct repetitive inspections and cleaning of the vertical fin spar and attachments, and ultimately perform the reinforced upper fin assembly modification by the effective date. Compliance deadlines include amending manuals and placards before exceeding 660 flight hours or within 7 days after 14 April 2023, and completing inspections and modifications as detailed in the directive.