EASA AD CF-2018-23
Engine Turbine/Turboshaft — RPM (N2) Steady-State Operation Avoidance Range Limit
Summary
The Airworthiness Directive CF-2018-23 issued by Transport Canada mandates updated operating limitations for the engine turbine/turboshaft RPM (N2) steady-state operation avoidance range on Bell Helicopter Textron Canada Limited (BHTCL) model 206B and 206L series helicopters. This directive addresses issues related to Rolls Royce 250-C20 Series engine turbine wheel failures by expanding the RPM avoidance range and requiring amendments to the Rotorcraft Flight Manual and installation of a new decal. It applies specifically to certain serial numbers of model 206B and 206L helicopters and excludes those modified by specific Supplemental Type Certificates.
What Changed
This directive supersedes the previous AD CF-2007-13R2 by expanding the RPM (N2) steady-state operation avoidance range limits based on new data from Rolls Royce. It requires operators to update the Rotorcraft Flight Manual with revised power plant operating limitations and engine starting procedures and to install a new decal to inform pilots about the updated avoidance range.
Why It Matters
This AD is critical for aviation professionals because it helps prevent turbine wheel failures caused by detrimental vibrations within certain RPM ranges, enhancing flight safety and engine reliability. Operators and maintenance teams must ensure compliance to avoid regulatory penalties and maintain airworthiness. The updated procedures and decals provide clear guidance to pilots, reducing the risk of engine damage during steady-state operations.
What To Do
Affected operators must amend the Transport Canada approved Rotorcraft Flight Manual within 30 days of the AD's effective date to include the new RPM (N2) operating limitations and engine starting procedures. Additionally, they must install the new decal as specified in the relevant Bell Helicopter Textron Canada Limited Alert Service Bulletins. Pilots should be informed promptly about these changes to ensure compliance during flight operations.
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