Stabilizers — Vertical Upper Fin Assembly — Inspections
- Published
- Effective
- Deadline
- Replaces
- 2023-0154
AI-generated summary of the official EASA document. Verify against the PDF before acting.
What to do
Operators of AS 355 E, F, F1, F2, N, and NP helicopters must perform an initial cleaning and inspection of the right-hand upper fin spar within 15 flight hours after 3 August 2023, followed by repetitive inspections every 15 flight hours. If cracks are found, the upper fin assembly must be replaced before further flight. Installation of the reinforced upper fin assembly part number 355A14-0522-1751 is required to terminate repetitive inspections. No affected parts may be installed on Group 2 helicopters from 3 August 2023 onward.
Summary
EASA Airworthiness Directive 2023-0154R1 is an updated safety directive addressing inspections of the vertical upper fin assembly on Airbus Helicopters AS 355 series (E, F, F1, F2, N, NP). It mandates cleaning and repetitive inspections of the right-hand upper fin spar to detect structural cracks that could lead to in-flight separation of the fin and potential loss of control. The directive also references installation of a reinforced upper fin assembly as a terminating action for inspections.
What changed
This revision of EASA AD 2023-0154 adds reference to the reinforced upper fin assembly modification introduced by EASA AD 2024-0139, which serves as a terminating action for the repetitive inspections. It updates the inspection requirements and compliance procedures to align with the new modification and clarifies conditions under which temporary exceedance of reduced Vne is allowed during maintenance flights.
Why it matters
This directive is critical for operators and maintenance personnel to prevent structural failure of the vertical fin spar, which could cause catastrophic loss of helicopter control. Compliance ensures continued airworthiness and safety of AS 355 helicopters by detecting cracks early and applying corrective actions. The modification option reduces the inspection burden by eliminating the need for repetitive checks once installed.
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