EASA AD US-2018-17-01
SUPERSEDED BY FAA AD 2019-09-02
Summary
Airworthiness Directive 2018-17-01 supersedes AD 2017-15-02 and applies to Bell Helicopter Textron, Inc. Model 212, 412, 412CF, and 412EP helicopters. It addresses unsafe conditions related to certain Circor Aerospace engine oil and fuel check valves, part numbers 209-062-520-001 and 209-062-607-001, manufactured between October 2011 and March 2015, excluding those marked with "TQL". The directive requires inspection and replacement of these check valves to prevent potential engine failure or fire.
What Changed
This AD expands the applicability to include Bell Model 412CF and 412EP helicopters, which were previously omitted. It also excludes check valves marked "TQL" from the affected parts list, as these were manufactured using a different process and are not subject to the unsafe condition. The directive retains the replacement and installation prohibition requirements from the previous AD.
Why It Matters
This directive is critical for aviation professionals to prevent engine oil or fuel leakage caused by cracked check valves, which could lead to engine failure or fire and loss of helicopter control. Operators and maintenance teams must ensure compliance to maintain airworthiness and safety. The update clarifies affected models and parts, reducing unnecessary replacements and focusing efforts on truly unsafe components.
What To Do
Operators of affected Bell Model 212, 412, 412CF, and 412EP helicopters must replace the specified engine oil and fuel check valves within 25 hours time-in-service. They must also prohibit installation of the affected check valves unless marked "TQL". Compliance with these actions is mandatory by September 5, 2018.
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