Airworthiness Directives; General Electric Company Turboshaft Engines

We are superseding airworthiness directives (AD) 2001-18-06 and AD 2008-22-16, for all General Electric Company (GE) CT58 turboshaft engines. AD 2001-18-06 and AD 2008-22-16 required recalculating the lives of life-limited rotating parts using a repetitive heavy-lift (RHL) multiplying factor and removal from service of parts that exceed the recalculated cyclic or hourly life limit. This new AD would consolidate AD 2001-18-06 and AD 2008-22-16, and further reduce the life capability of certain parts. This AD was prompted by recalculation of life for parts installed on engines used in Utility operations, and a reduced life for compressor spools in all operations. We are issuing this AD to prevent failure of life-limited rotating parts, uncontained part release, damage to the engine, and damage to the aircraft.