Transport Canada 2019-30

Affects CMSX-6 compressor turbine vanes repaired in accordance with repair specification number STI 72-50-254 held by Southwest Turbine Inc. (STI). Requires any STI-repaired compressor turbine vane and their associated CMSX-6 blades be replaced within nine months or 250 flight hours, whichever occurs first, from the AD’s effective date with non-STI-repaired parts. Prompted by eight reported events of low-time compressor turbine blade fractures resulting in power loss and/or in-flight shutdown. In-service data shows that all low time CMSX-6 compressor turbine blade failures occurred below 620 flight hours and were reported on engines that had vanes repaired by STI.