GE CT58 civil turboshaft derivative family of the T58, with FAA certification for civil helicopter use and distinct CT58-100/-110/-140 manual and maintenance boundaries. GE identifies CT58 applications in the civil Sikorsky S-61, Boeing 107-II, and Sikorsky S-62 families; current GE technical-manual indexes preserve the CT58 product-support boundary. Lifecycle is left unknown because current fleet service and production status are not established by the cited evidence.